OzVMX Forum
Clubroom => Tech Talk => Topic started by: Ji Gantor on April 02, 2009, 06:12:24 pm
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This topic is for information only and the detail is not to be used without checking with manufacturers recommendations.
There may be some error in some of the data and it can be considered that this is not a technically correct document.
The heart and soul of a motocross bike may be the engine but the chassis determines how the power from the engine can be used. It also effects the steering and the absorption of impact loads due to uneven ground or jumps. The chassis also holds everything in place so all the components can work as a team.
The frame is the skeleton of a bike and goes mostly unnoticed until it flexes or cracks.
The tube frames of the early bikes were mild steel that had a tensile strength of 450mpa and weighed 7850kilos/m3.
My research is limited but in the mid 60s the Rickman brothers designed and built the first designated motocross frame out of chrome moly. I am not sure what grade it would have been but lets say it was 4130 which is the most common. 4130 Has a tensile strength of 650mpa and weighs 7850kilos/m3. I am not sure how the brothers fused the tubes together but I would assume they oxy welded the joints. Oxy welding is still used today to weld chrome moly along with Tig and Mig. Oxy and Tig heat the members up evenly while Mig is a very quick heat that cools very fast. This quick up and down heat in a small area produces brittle joints in thick walled pipes. If the tube wall thickness is less than 3mm thick then there is no need to preheat the members and Mig should work fine but some old welders still preheat the tubes before and after welding. The proper filler rod also plays a big part in joint strength. ER 80S-D2 gives the best result, ER70-S6 is still used but there is a little strength loss and 310, 312 stainless steel filler rod seems to be an old favourite.
As can be seen chrome moly is the same weight as mild steel but it is 70% stronger so the weight reduction is gained due to less material being used to do the same job. Flex or what is know as deflection in engineering speak is not really governed by strength but by depth of beam. The flex in a motocross chassis is very small because the length of the members or tubes between supports are very short. Thus flex or deflection is not the main factor when designing a chassis. Bending moment and shear would be more concerning and these forces are helped by extra strength and tube wall thickness. The next biggest problem is fatigue failure. If you have ever bent a piece of wire back and forth you will know that eventually it will break, this is fatigue failure. Remember, because the tubes are only short they don't have to flex much in both directions and say 40 000 cycles later the tube exhibits a crack. Chrome moly is more tensile than mild steel so it is more brittle thus if the frame received a direct impact, mild steel would yield or bend while chrome moly will if the force is great enough break.
Chrome moly is a great material to use for motorcycle frames and I think KTM still employ the metal in their chassis. Alloy is the new metal due to welding procedures and the loss of even more weight if used correctly.
Ji
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From my limited research CZ used chrome moly for their chassis metal starting at around 1968. This produced weight savings and a stiffer frame. I can not find anything about Maico's but it would appear from the few brochures I have that they were using chrome moly for their frames in the early 70s.
These early MX bikes only had 4 inches of rear wheel travel and the chassis's must have taken a pounding over jumps designed for new models, but 30 years later those frames are still going strong. Vindication that 4130 was the right material for the job.
Ji
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Chrome moly or CrMo is also used as axle, dampener rod and foot peg material. Titanium is the next big thing but it is very brittle. The fire arms industry used it for all sorts of applications that did not suite its true calling like handgun slides and firing pins. The firing pins shattered after only a few uses. They have been using titanium valves in four stroke engines for some time know especially in the V8 Super Car engines. To compensate for the brittleness of the valves the seats are made from beryllium a soft and deadly material that after a certain amount of use will no longer hold its shape and have to be replaced. Beryllium has high temperature stability, and low coefficient of expansion with temperature.
Titanium can not be used much at this stage if my memory serves me right as FIM only allow a limited use of the material.
Ji
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Thanks Ji, very interesting 8).
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The tube frames of the early bikes were mild steel that had a tensile strength of 450mpa and weighed 7850kilos/m3.
That 450MPa figure seems high. The FIA approved CDS roll-cage material (which was such a bitch to get hold of in Australia, that CAMS changed the rules to allow CDW) is only rated to 350MPa.
Schedule X (aka "dash") tubing is ~250MPa, so a "mild" steel that's 450MPa wouldn't be very mild at all???
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The standard BHP CHS Dura Gal C350 Grade C350LO has a min Tensile strength of 430mpa here in Australia. The tube I referred to is the US standard.
The reason that the roll cage has to be only 350mpa is so it will bend instead of a catastrophic failure when impact occurs.
Ji
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As a slight addition to Ji's nice piece, Rickman frames are in fact made from Reynold 531 tubing which varies only slightly from 4130 chrome-moly. The tubes are butt brazed using special bronze alloy rods made specifically for the Rickmans by Sifbronze and liquid flux. Anyone who's ever done work on a Rickman, Cheney or most other 531 constructed frames will vouch that the quality and strength is beyond reprooach. You don't see too many broken 531 brazed frames.
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Hi Oggy Doggy,
That is a great add to my topic.
Thanks mate
Ji
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and I'd like to add that Titanium is the best material for frying pans made so far to date ;D
Alison
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Steel comes in many grades, the hard part is to find the shape of tube you want in a specific grade. (same problems in alloy)
Structural steel (large RHS & I beams) will have a higher tensile stength for structural purposes but most of the small tubes I don't think are very high.
Black flat is very low in tensile strength but bright flat (usually 1020) is much better.
4130 Cro-Mo is rated at 650 mpa.
Grade 1018-1026 is 350 mpa. I know this is brought in in tube & is used in roll cages. It's a bit cheaper than Cro-Mo & doesn't become brittle next to the welds.
From my experiance all Cro-Mo becomes brittle next to the welds (the heat affected zone) no matter what it's welded with. I always heat treat my frames to "normalise" the Cro-Mo
The Poms usually build their frames from Reynolds tube. The tensile strength is slightly higher than Cro-Mo & they usually use nickel bronze to weld it thus avoiding any brittle zones.
From what I have heard it is hard to obtain, only made in afew sizes & usually only in the UK.
Despite its higher tensile strength I haven't heard of it being used in planes, only 4130?
CZ may have claimed to use Cro-Mo as did Maico & many other brands but from my experiance of repairing frames they are just not in the same league as 4130.
They may well be Cro-Mo but of a lesser grade.
I think the current alloy frame fad is more about casting sections & CNC maching.
A modern frame may only have a dozen pieces to it.
My HL frames for instance has about 90 different pieces to be prepared before welding.
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BSA B44 GP is also made from Reynolds 531 brazed together.
someone was telling me the other day about a new bike being made (i think CCM) that has the frame made from a carbon fibre or plastic material, it was something strange and out of the norm for a bike. It was somthing that involved the different frame parts being glued togther, it might of been alloy tubes gued together with a resin or something. I wish i could remember the exact details.
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Interesting point Geoff.
The yZ125E was suppsoed to have a chromoly frame, over the 'non-chromoly' of the earlier ones.
Having one D frame and one E frame in my hands at the same time, showed no sign of them being different materials - the weight difference was imperceptable and the wall thicknesses are the same.
Based on a sample of three each, YZ125D and E frames are both just as prone to corrosion as each other (ie: Nothing dramatic in either frame, but the E frames showed none of the additional corrosion resistance that Chromoly should have).
Plus... the only badly cracked YZ125 frame I've seen was an E....
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BHP grade C350LO 430mpa CHS tubes come in 26.9mm and 21.3mm diameters.
CrMo still rusts.
Razor blades rust, chrome vanadium tools rust.
I don't think there is an easy way to tell mild steel from CrMo except via a hardness test.
Every year the frames have been getting smaller because our knowledge on how the loads are applied to the frame is getting better. Take GMC's CZ swingarm it weighs 2.3kilos. This means that Geoff has made the swingarm with a thinner wall thickness tube than stock and stiffened it up via a gusset plate, thus reducing the weight by 400 grams.
If two frames have the same shape and the same diameter tube with the same wall thickness but one is CrMo and the other is mild steel than they would weigh the same. If the frame that was CrMo had a crack in it this kinda proves that it was CrMo because it is more brittle.
Ji
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Hey JI,
Enjoying your chassis rave, but you need to do a bit more research on Titanium. It is certainly not known for being brittle and its applications are far more varied than just being used in V8 Supercar valves.
Most passenger and military aircraft use enormous quantities of the stuff in their airframes and engines. In fact the new Airbus A380 uses 26 tonnes of titanium in the 4 engines alone. Not really the place to put a brittle material.
Lots of production MXers use a small amount in engines, specifically their valves as you say, but Yamaha has used it recently for the rear shock spring on the YZs. Again not really an application for a brittle material.
Re the CCM: it uses a machined/fabricated aluminum frame that is bonded with aerospace epoxies and not welded. It uses a bit of carbon fibre [fuel tank and possibly airbox/subframe] but it is essentially just a production Yamaha YZ engine in the alloy frame [as described] that uses KTM suspension [including stock swingarm and geometry] and plastic. It is an interesting bike, but not earth shattering except for the bonded frame - the Poms always talk up their latest marque resurrection as being a 'world beater' when in fact over the last quarter century on Triumph as suceeded.
And even bonded aluminium isn't that unique. The old Suzuki DR250/350 used a bonded aluminium swingarm 20 years ago. I hope they [CCM] enjoy a bit of success, both on and off the track, but they are not pushing the envelope as they seem to be claiming.
Back to you.
VMX42
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VMX42, just on the subject of CCM i have just read where 2 CCM factory riders finished in the top 11 at the first MX1 GP. Pretty good for a small company.
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Hi vmx42,
I am so glad you are enjoying my topic about "Chassis Evolution".
Your reply to my topic has very little to do with chassis evolution.
I was going to post aluminium in bike frames to day but 1 step forward 3 steps back I have spent all my time defending what level of tensile strength is mild steel and now Titanium is not brittle because they use it in aircraft engines.
They use a lot of glass in car manufacturing too but it is brittle under impact load and is not suited as a bumper or an engine valve because when there is an impact load it will shatter. I don't know much about aircraft engines but there would be several tones of titanium bolts per engine alone. Titanium used in the right situation is the right product as it is strong and light.
May be you should do a materials property course so you understand that brittleness is only a problem under impact load and long term fatigue. Apart from valves in an engine are there any other components that receive impact load, metal hitting metal?
As I said titanium has been used for all sorts of parts in handguns. The parts that receive impact load have not been successful but other components like sear springs have.
Ji
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Whoa slow down Ji,
Nobody says you have to DEFEND anything. Foolishly I thought that this was a simple discussion and not just a series holy 'pronoucements from on high'.
I don't remember seeing a rule on this site stating that we have to supply a detailed resume stating our qualifications to make comments on various subjects in a post - if it exists then I must have missed yours.
As for my crime that my reply doesn't have anything to do with chassis evolution, then you should go back and reread your posts, they don't address chassis evolution, as such, but discuss the progression of various material improvements involved in motocross frames over the last 30 years.
My comments were made in good faith and only to attempt to add to the discussion not to add to your DEFENCE time.
You really need to lighten up.
VMX42
P.S. and JohnnyO, yeah I saw the GP results. It was a good start for the CCM boys. It will be interesting to see how they progress over the course of the season. It is always good to see an underdog make good.
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If you feel the need to defend yourself Ji its because you have generalized all mild steel as being 430 MPA..
The 26.9mm and 21.3mm diameters are odd sizes & would be useless when trying to fit into tube bending formers which are all still based on imperial sizes such as 7/8” – 1” – 1 1/8” etc.
I think you will find that the common mild steels such as ERW tube would have a much lower tensile strength.
Cro-Mo rusts a bit slower than mild steel but not significantly to be able to tell what type of material your looking at.
Your right Ji, my swingarm is of thinner wall compared to stock but the long gusset down the top is more to support the extra stresses of having the shock mounts forward mounted. When mounting the shocks at the rear in the normal 74 CZ position then the long gusset is unnecessary & therefore not used.
Frame design has come a long way with perimeter frames etc. Also with single shock bikes the frame needs it’s strength at the shock mount & the sub-frame is only needed to support the seat & rear guard, unlike a twin shock that has the shock mounts at the rear of the sub-frame.
I don’t know that I would consider Cro-Mo as a brittle material, maybe compared to mild steel but that is far outweighed by the extra strength.
The fact that a frame has cracked doesn’t really mean anything due to the diverse conditions that any one frame can be subjected to.
Drakies original CMS frame which was made in the 70’s form heat treated 4130 has survived well to this day. I did some repairs to it maybe 15 years ago & that was only some cracks in the headstem gussets which weren’t braced all that well & the exhaust mount which hangs out in the breeze a bit on the CZ’s.
I believe it is a credit to the original builders.
I think we may be generalizing Titanium a bit too.
None of the elements are of much use to us in their pure form ( except maybe gold & silver) & Ti. is no exception. There are many different grades of Ti. alloys. Beryllium is one that comes to mind that is mixed in with Ti.
I have found modern Ti. exhaust systems to be a bit on the brittle side, especially the “Y” piece in the twin muffler CRF 250 as I have had to weld up a few of these, some of which weren’t very old.
The grade of Ti. & the manufacturing process would not be the same in a after market exhaust system & a jet engine.
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When did Australia become the centre of the universe for making motocross bike chassis's or materials?
The largest producers of bike frames is Japan, followed by European countries.
Why are some members trying to relate vintage motocross frame making techniques and materials to what we have here.
Please enlighten me, When did Australia make a CZ, Maico..... frame for their respected companies?
It has been established that the Rickman frames are in fact made from Reynold 531 which is a metal that is very difficult to obtain here, ergo their metals are different from what we get. The tensile strength of mild steel in America is 450mpa so may be we can say that the tensile strength of different metals in Europe and Japan are similar after all they are true manufacturing countries.
Japan and Europe are metric and have been since the VMX bikes were made. The tubes they use are metric sizes. Apart from the good old USA that did not make Maico's, Cz's.... are one of the last countries that use the imperial system. Stahlwille tools in Germany no longer make imperial tools as they believe the world is now metric. During the week I received some tool catalogues with pipe benders for sale and they do sell the dies for imperial, but they also sell dies that are for metric tubes. If Australian's were making high volume frames I would think the company involved would have a die made to measure the tubes they commonly used.
Geoff you say "From my experience all Cro-Mo becomes brittle next to the welds (the heat affected zone) no matter what it's welded with. I always heat treat my frames to "normalise" the Cro-Mo" and then you say "I don’t know that I would consider Cro-Mo as a brittle material" I am now confused, which is it?
I will have to do some more research to discover that CZ and MAICO lied about using CrMo in their frames or used a very watered down material as stated. If they did use a watered down CrMo then this too supports the premise that different countries have different metal standards from our own.
Ji
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Ji, As much as we all enjoy reading your posts, you could learn to be no so defensive and to lighten up a bit. You don't have to jump in, arms swinging every time someone disagrees with your opinion. This is a discussion forum, not the 'Gospel According to Ji Gantor'. Open up and accept differing and further opinion and you'll find the seed you've grown with your posts will grow into information oak trees!
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thanks VMX42 for clarifying the CCM frame construction. i knew it was something like that but i couldnt quite remember.
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Sorry to see you get so toey Ji, you opened the discussuion, added a disclaimer & I am just adding my 2c worth as I know it.
Despite some rumours in other threads I don't consider myself the "God of frames" :o
Not sure about your first rant, I can only imagine that you have confused GMC with CMS?
CMS was an American Co. that produced after market frames in the early 70's.
I make replica's of these frames.
(http://i15.photobucket.com/albums/a393/gmcloa/CMSadd-1.jpg)
they also made them for Bultaco's
(http://i15.photobucket.com/albums/a393/gmcloa/CMSframe-1.jpg)
So in effect I make in Aust. a replica of a US frame made for a Czech bike, I make them from Imperial size Cro-Mo imported from the US of which I then send to the UK & back to the US ???
I have no doubt that some mild steel is rated at 450 Mpa, my point was is mild steel comes in so many shapes & sizes for so many various purposes & that it won't all meet that standard.
Water pipe for instance I doubt would be made to that standard yet it is still considered mild steel. (The Chinese seem to think it's good enough for frames :D)
Bright round & flat bar probably meets that standard
I don't have any specs to quote, and are going off my gut feeling that ERW tubes which are reasonably common and size wise would be suitable for frame repairs are a bit weaker.
Cro-Mo is a strong & tough material, it becomes brittle in the heat affected zone which is next to the weld. This brittleness can be removed by heat treating to "normalise" the Cro-Mo. It's common state is normalised.
It may be considered more brittle than mild steel but I believe it is misleading to claim that a Cro-mo frame would be brittle. Because it flexes less ( which makes them better handling frames) it is less likely to fatigue.
Chrome-Moly is the name of the material, it is basically normal steel with the addition of Chromium & Molybdenum. With certain amounts of each added it gains optimum strength & is defined by a number, being 4130.
Not sure if Cro-Mo is available in other grades but with different amounts added it would still be Cro-Mo just not 4130.
Standards are similar worldwide allthough most countries have different standard code names.
It's not the first time I have stated that I doubt that Maico's & others used 4130 in their frames & it's previously brought up some interesting debates.
At the end of the day it is just my opinion, gained from working with 4130 (80 frames now) & repairing many different frames.
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heres somethingi would like to know. I read all the old bike tests and sales brochures for example on the old suzuki RM/PE's and they have offten said 'chromoly frame's' but ive always thought this not to be true and theres no way a PE400 frame is chromoly
what japanese frames were chromoly?
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very interesting discussion ,it doesn't matter if people get a bit excited it can and should lead to more and better info. i can't add much except to recite Phil irvings comment from way-back when he did say among other things that the only reliable way to join reynolds 531 tubing was to bronze weld [commonly &incorrectly called brazing], the material while heating only to a dull red so as to not heat the material above the critical temp. point. i think the other point about titanium being brittle is interesting&agree that it must depend on different alloying content for differing applications, i think you would not want brittle valves on an engine that is likely to suffer severe valve bounce in the heat of the moment. a question will a magnet stick to chrome moly?
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Hi Wally Cox,
Yes, a magnet will be attracted to CrMo.
Great add about the reynolds 531.
Ji
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This is an extract from the FIM rule book.
As I said Titanium can not be used much on modern motocross bikes but I don't think this applies to VMX bikes.
25.01
The use of titanium in the construction of the frame, the front forks, the
handlebars, the swinging arms, the swinging arm spindles and the wheel
spindles is forbidden.
The use of light alloys for wheel spindles is also forbidden (except for Trial
motorcycles).
The use of titanium alloy nuts and bolts is allowed.
Titanium test to be performed at trackside:
25.01.1 Magnetic test (titanium is not magnetic).
25.01.2 3% nitric acid test (Titanium does not react. If metal is steel, the
drop will leave a black spot).
25.01.3 Specific mass of titanium alloys 4,5-5, of steel 7,5-8,7 can be
ascertained by weighing the part and measuring its volume in a calibrated glass
vessel filled by water (intake valve, rocker, connecting rod, etc.)
Ji
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This is another extract from the FIM rule book.
Again I can not see in MA rules where this applies to VMX bikes.
I guess we can lighten our bikes to what ever we want to achive the power to weight ratio we think we require.
01.19 MOTORCYCLE WEIGHTS
Weights of motorcycles without fuel
19.01
The minimum weights are:
for the 85 cc class 85 cc - 2T 65 kg
150 cc - 4T 73 kg
for the 125 cc class 88 kg
for the 250 cc class 98 kg
for the 500 cc class 102 kg
A 1% tolerance in the weight of the machine after the race is accepted.
Ji
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It would be interesting to see how light you could get a vintage bike. No one has really bothered about weight too much before. I guess it gets expensive to make a lighter frame or take weight out of a heavy engine.
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It would be interesting to see how light you could get a vintage bike. No one has really bothered about weight too much before. I guess it gets expensive to make a lighter frame or take weight out of a heavy engine.
What do you reckon would be cheaper, lose weight (titanium et al) or gain Uber (useable) horsepower or quality handling (within the VMX reg restrictions). Which would be most beneficial (lap/race times) 8).
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I think that weight reduction is more beneficial in regard to dollars spent per seconds off lap times, our bikes already have more power than most of us can use. Suspension certainly helps track time, over jumps and braking bumps before corners.
I have taken my stock CZ400 1973 that has a manufacture weight of 105kilos down to 98kilos with just bolt on modern material parts. I think I can remove another 3 to 4 kilos without drilling stuff.
The more reduction in unsprung weight the faster and better handling the bike will be.
Ji
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This is a typical late 60s to mid 70s frame geomtery.
This is not meant to cover all frames of that period it is just so we are talking about the same thing.
Ji
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This this a typical load path that the frame is designed to.
Ji
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The attached drawing is of a modern aluminium frame.
Notice the differences and the similiarities.
Ji
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This is a typical load path that a modern frame is designed to.
Ji
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I think good suspension and handling is the most beneficial for motocross but probably not the cheapest. I'd like to ride a bike 10 kilos lighter, i'm sure that would bring the lap times down as well.
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I would go for usable power and good suspension first then weight. A friend of mine works on the MXGP circuit, He used to have an XR600 with good suspension which He would sometimes have in the truck when he went testing. I can’t remember who the rider was, but they were testing on a 250 and 500 2T’s after they had finished he pulled out the 600 and did a few laps, the rider then jumped on it so my mate timed the laps. When he come in my mate thought the 600 was going to melt and the rider said he hated it, they then looked at the times, He was fastest on the 500 then 1sec back was the 250 and 600 was only 1sec behind that.
Noel
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The following frame has three truss sections.
The first is the steering head/spine,
The second is the air filter section and
the third incorporates the air filter section and the rear shock.
The members in a truss are subjected to tension and compression and not bending moment.
Small diameter steel tube is excellent at carrying tension and compression loads but not so good at resisting bending moment.
That is why the original tube swing arms had the rear shocks fixed very close to the rear axle. The load from the shocks transferred just about directly into the axle. When the shock was moved away from the rear axle the swingarm members were subjected to bending moment and the tube alone was not adequate. To reinforce the load carrying capacity of the tube swingarm a gusset plate was welded to the top of the tube stiffening the swingarm from pivot to axle.
Ji
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I am not sure this is correct but from very limited research I believe that the 1997 Honda CR250 R was the first motocross bike to have an all aluminium frame.
I will keep checking to see if I can find out the type of aluminium used and how it was welded.
If any one knows this info please post it.
Ji
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If the Mid 1960s to mid 1970s chassis is our starting point we can see the evolution and what influences made the changes.
As we have seen the swingarm was horizontal and the rear shock was almost vertical and fixed to the swingarm near the rear wheel axle. This produced only about 4 inches of rear wheel travel. Riders were getting faster and the tracks were getting more technical so the next round of requirements were more wheel travel, better cornering and less weight. So the bottom shock fixture was moved up the swingarm towards the pivot point or the top shock fixture was moved down the frame to increase the shock angle. Both of these shock orientations positioned the swingarm with a negative angle and produced more rear wheel travel. It also raised the back end of the bike up placing more rider/bike weight onto the front forks. This added advantage gave more ground clearance and made the bike corner better. The first thing the top riding coaches in the States do is drop the forks down in the triple clamps up to 1 inch and then set the ride height. This way the bike will corner like it should.
Ji
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I am not sure this is correct but from very limited research I believe that the 1997 Honda CR250 R was the first motocross bike to have an all aluminium frame.
what about the Hagons as featured in VMX mag, do they count?
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Hi LWC3077,
I don't have that issue of VMX mag.
This is great, what year was it made and did it have a full aluminum frame including swingarm?
Ji
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The Hagon is a monocoque. Not really a 'production' bike though.
Magoo thinks its ugly, but he's wrong.
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Beauty's in the eye of the beholder. The Hagon's owned by Klub Kevlars own Alan Jones and even he thinks it's been hit by the ugly stick. I myself think it's cool but we all reckon there are a lot of things on the bike that could have done better with a bit more thought. For instance the integrated welded in tank isn't the smartest idea, especially seeing that the tank now needs some repairs. The main reason Alan bought the bike is to complete a personal trifecta. He's now got speedway, long track/short circuit and now motocross monocoque Hagons. A side bonus of course is that he's now got a good pre '78 or Evo racer to add to the pre 65 and pre 70 stuff he's more noted for. The bike will be getting a superficial rebuild in the near future to rid the bike of the previous owners bodges and rough touches and to refit the OEM 38mm Maico forks.
(http://img.villagephotos.com/p/2005-8/1062154/Hagon%20001.jpg)
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As much as i'd like to join this topic, i got scared off by page 2, just maybe ross was onto somthing here :O)
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Here's another monocoque. The frame was made by CRDC in San Francisco around 1972.
(http://img.villagephotos.com/p/2005-8/1062154/momocoque%20DT1.jpg)
(http://img.villagephotos.com/p/2005-8/1062154/mono%20cyclerider.jpg)
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Freaky, At least Ji's contributing to our knowledge. I don't recall Ross ever doing anything other than taking the piss.
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British EMC/EMX frames are all Reynolds 531. An absolute work of art. All brazed. I'll put up some pics of the welds when I get the chance.
The new CCMs are bonded aluminium frames, featuring KTM plastics & Yamaha motors. I'll be stumping up the cash if they ever land here. ;D
http://www.ccm-racing.com (http://www.ccm-racing.com)
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im skeptical of the bonded alluminium frames. They tryed it on bicycles, it didnt work/didnt last long
ive gt some good pics of some Hagon alloy framed bikes that i dont think anyone here would have seen as they are from old french magazines. i will look for them tonight and scan over easter.
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There is a lot of old talk on ozvmx of Hagons in days gone by,wish I knew where the boss stored the Morgan SA sidecar photos. :( Tim may have some pics 8)
Got to say there are very impressive bikes. :P good to see something different. 8)
http://www.cybermotorcycle.com/gallery/hagon/index.htm
http://ozvmx.com/community/index.php?topic=648.0
Alison
Hagon shocks are 18 years old.
http://cgi.ebay.com.au/Hagon-swingarm_W0QQitemZ140311329470QQcmdZViewItemQQptZAU_Motorcycle_Parts_Accessories?hash=item140311329470&_trksid=p3286.c0.m14&_trkparms=66%3A2|65%3A1|39%3A1|240%3A1318
http://cgi.ebay.com.au/Hagon-fuel-tank-slider-longtrack-speedway_W0QQitemZ140311334627QQcmdZViewItemQQptZAU_Motorcycle_Parts_Accessories?hash=item140311334627&_trksid=p3286.c0.m14&_trkparms=66%3A2|65%3A1|39%3A1|240%3A1318
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Hi Nathan S and Old Phil,
When, where and by whom were these Hagons manufactured.
monocoque usually means one piece, how is that possible with the swingarm?
They certainly look really cool but they sort of look like a Frantinbike, bits from different manufacturers.
A very cool add to my topic.
Ji
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entrant 999 at the bonaza has a Hagon outfit
http://www.ma.org.au/AM/Template.cfm?Section=Forms&Template=/CM/ContentDisplay.cfm&ContentFileID=44682
The Hagons were made in England. i think they are the same company who make Hagon shocks
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Hi NR555,
That sounds great I look forward to seeing the images of these past craftsman.
Ji
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What's the advantages of a perimeter frame over the older style "backbone" ?
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i just found the Hagon article
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This is great.
This is the spirit I was looking for when I started this topic.
I have never heard of a Hagons before nor did I know about Reynolds 531.
Lets all share what we know about frames.
There will be some dead ends and some paths that lead the manufacturers to the modern chassis.
Ji
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Okay I see the monocoque definition in this case means that the bike does not have a tube frame but instead all the number plates tank and so on are the chassis.
Very Cool.
I think the Hagons is a very attractive bike.
How many were made?
Where does one get parts?
Were they made of Aluminium?
What did they weigh?
Ji
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Frame weight loss using similar materials can only be achieved by reducing the amount of metal used. In the case of CrMo tube frames this means that the wall thickness has to be reduced. If the original frame was over designed then reducing the wall thickness is no problem. Take my CZ400 1973 bare frame, it weighs 9.7kilos. CZ state that it should be CrMo but I am still checking to see if it is actually some kind of mild steel. Geoff of GMC makes a CZ / CMS replica frame from CrMo 4130 and it weighs 7.8kilos. Thanks Geoff for graciously supplying this data. That is a reduction of 1.9kilos which is great for the power to weight ratio. The only other way to reduce weight is but removing sections of the frame that by testing to see how the loads are applied are no longer needed. This moving the frame sections around in an attempt to design the frame to just carry the loads is evolution as is using lighter metals.
Ji
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Hagon frames have been around forever in speedway and long track racing.
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Hi JohnnyO,
How about motocross?
How well did they do in MX?
Ji
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Didn't see too many in motocross especially in OZ. May have been successfull in England where they were made.
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If the monocoque framed bikes were not really MX bikes may we assume that they did not contribute to the chassis evolution?
That said than the 1997 Honda CR250 R is still the first MX bike with a aluminium frame.
Shame I liked the Hagons.
Ji
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The speedway and grasstrack frames that i have seen were just regular frames. The motocross frame is the only hagon monocoque i've seen.
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http://www.trakbytes.co.uk/hofaha.html
http://adrenalintrip.net/ve-hagon-suzukis-where/forum/viewtopic/60/287087?siteid=1
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Hi TM Bill and Wasp,
Great additions to the topic.
History is how we move forward.
Ji
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If the monocoque framed bikes were not really MX bikes may we assume that they did not contribute to the chassis evolution?
Ji, the Hagon was indeed a production motocross bike and quite a respectable number were made. The great Vic Eastwood of CCM, BSA and Maico fame rode the monocoques in GPs and UK National motocross hence the 'VE Hagon" name. They were light but failed on many fronts, most notably the difficulty and cost of manufacture.
Because the monocoque failed to inspire further development by other manufacturers doesn't omit it from the evolution of the motocross chassis. It was an experiment easily as important in frame development as the titanium BSA and Husky GP bikes of the 60s. Each had its plusses that contributed to engineering progress and knowledge but at the same time were let down by weaknesses, both structurally and conceptually. Jonesys Hagon is a great relic from an era when motocross engineering dared to delve into different and sometimes daring innovation.
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Hi Oggy Doggy,
Thanks for clearing that up.
So the Hagon was the first all aluminium framed motocross bike, and it was built in 1972 ?
Do we know what type of aluminium was used?
What was the first titanium framed bike?
Ji
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Sorry for sidelining , Bill did you ever race sidecars against Martin ? Or did he come in after your sidecar career? He raced about 88-96 on a lefthander EML .
Martin Hagon was well after my time 1979 1981 :) do you remember who his swinger was ?
The first Ti framed bike would that be the ill fated works BSA that Jeff smith campaigned ?
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The Hagon frame featured in VMX was built as an MXer & must have been built around late 70’s as it was designed around the TT 500 motor.
I don’t think it had much success but this is normal for small companies as they can’t afford the big dollars to buy the fastest riders of the day.
Yamaha built a works alloy framed bike I think in the early eighties?
I think it was dubbed the YZM & may have been for Carlqivst ? ( I know the spellings wrong)
It was rumored to be very fragile & I heard they only used a frame for 2 or 3 GP’s before replacing it with a new one. Not sure how true that was but I think it was because of the constant grief that they dropped the alloy frame.
I think the first production alloy frame may go to the Beta “zero” trials bike of around 91.
It was a bit like the Hagon as it had the fuel tank as part of the frame. It was a good idea to incorporate it as part of the structure in order to save weight but becomes a drama once problems occur.
I think it was the Beta that also had a alloy expansion chamber.
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Okay so the first all alloy monocoque framed MX bike was the Hagon in 1979?
The first works all aluminium framed MX bike was a Yamaha YZM in 1982? (can anyone post a photo of this bike)
The first all aluminium framed production bike was the Honda CR250 R 1997.
The Beta does not count because it is trials and not MX.
The first works all titanium framed MX bike was the BSA in (what year)? (can anyone post a photo of this bike)
I guess the titanium framed works bikes were hazardous due to the fact that FIM banned the material in frames?
Ji
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i have found several interesting articles with good pictures o the Hagon yamaha and suzuki 4 strokes and a couple more on CCM and JBR specials and one on the Cheney Yamaha 2 stroke. i saw Reynolds 531 mentioned as frame material somewhere too. i will try and scan all these articles on the weekend. They are all in French so translation is up to you.
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Ji, The Hagon mono came out around 1977. The first ti frame that I know of was the works BSA Victor 1966. Lars Larsson rode a ti Husky in the 1971 season. Below is Ed Youngbloods description of the bike.
In 1971, Torsten Hallman commissioned Pro-Fab to build a small number of titanium frames. One was built to house Husqvarna's tried and true four-speed “egg engine,” and the others were built for the new five-speed engine. Using a 400cc version of the four-speed engine, Lars Larsson barnstormed the support class of the Inter-Am that year, winning four of the six rounds. Modern Cycle (January 1972) reported the project under the headline, “Titanium, the Racer's Latest Secret Weapon.” The machine struck fear into the American racing community, resulting in the 1972 AMA rule book declaring, "Titanium frames will not be allowed in AMA comptition (page 45)." It was believed that titanium would radically increase the cost of racing. This was a fair concern since, during the Cold War era, titanium was considerably more expensive than it is today. Because Larsson has restored this motorcycle with a 250cc engine, it weighs a few pounds less than it did when raced in 1971.
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Okay so the first all alloy monocoque framed MX bike was the Hagon in 1977
The first works all aluminium framed MX bike was a Yamaha YZM in 1982? (can anyone post a photo of this bike)
The first all aluminium framed production bike was the Honda CR250 R 1997.
The first works all titanium framed MX bike was the BSA in 1966 (can anyone post a photo of this bike)
Thanks Oggy Doggy we are getting there.
Ji
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What about the funky monocoque Bultaco powered bike that was pictured in the VMX article on Bultaco history (sorry, I'm away from home ATM so cannot reference it). Had a composite name - Something-taco, and was apparently ridden by Pomeroy at some stage. Early 1970s, IIRC.
That was an ugly bike.
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The alloy frame yzm500 that Carlquist rode was more like '85/'86. I think husky500evo has a photo of it, beautiful looking bike.
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The first all alloy monocoque framed MX bike was the Hagon in 1977 (pending the Bultaco)
The first works all aluminium framed MX bike was a Yamaha YZM500 in 1985 (can anyone post a photo of this bike)
The first all aluminium framed production bike was the Honda CR250 R 1997.
The first works all titanium framed MX bike was the BSA in 1966 (can anyone post a photo of this bike)
Thanks JohnnyO.
Ji
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1990....perimeter frame in dirt.....although earlier on road.
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Another Alf Hagon monocoque machine,. Past half way down this set of gorgeous photos ,you cannot miss it ;) http://twinshock-chairs.tripod.com/id2.html Yes there is a least one Hagon S/car in Australia.
The Wasp universal sidecar frames I have are bronze welded Reynolds 531 Tube , Wasp still to this day uses 531 tube as required. http://wasp-motorcycles.tripod.com/
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Hi evo555,
Check out the perimeter frame CZ/Jawa 1963/4 (Banana frame) MXer, "czechpoint" web site will show you the photos , very collectable,very cool, I have never seen one in the flesh though,
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Not an mxer, but interesting none the less.
1969 works Ossa monocoque .
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not mx, but did anyone else get the latest Classic Dirtbike with the 1970 alloy/aluminium Mclaren Trials bike in it?
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i would have a photo oiff jeff smith TI framed B44 somewhere. i have a feeling it was in 65 though. im afraid i wont get to looking for the photo for a while though as i gotta sift through a stack of BSA books to find it.
i think the yamaha you want to see is on here somewhere
http://mxtrax.co.uk/official-factoryworksbike-pic-thread/forum/viewtopic/60/286430?siteid=6
whats the one with pink seat here?
http://mxtrax.co.uk/official-factoryworksbike-pic-thread/forum/viewtopic/60/286430?siteid=6&start=30
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Thanks LWC3077,
Here is the works Yamaha YZM500 which we think was built in 1985.
Ji
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Here is the mystery Yamaha that LWC3077 found. Does anyone know when this bike was made? It is a YZM but seems to have a frame almost like a modern bike.
Ji
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This is the Honda CR250 R 1997. The first production all aluminium framed MX bike.
Ji
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The pink seat, perimeter framed YZM is around a 91 model. The colours and the Deltabox styled swing arm fit with the production YZs of that era.
Trusting my very rubbery memory, but I don't think that bike was used in the World Championships - all the photos I've seen, show it being used in Japan.
Pretty sure that the older YZM500 is more like 1987/88 than 85 - at least in that (watercooled) spec. There was a similar, earlier air-cooled, power-valved YZM500 which is more like 85/86. It was definitely used in Europe, in the World Champs and stuff like the Le Torquet (sp?) beach race.
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Thanks Nathan S,
So the YZM alloy frame no matter what type of cooling system they used was somewhere between 85 to 88.
Ji
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Yep, the yzm 250 was only used in the Japan national championships(where all the factories bring out the juicy stuff) in the early 90's. Although not on that particular bike, Yamaha was also experimenting with a single leaf rear suspension setup. I think they own the patent on it.
See if I can google something.
The 500 pictured came out about '88/'89, me thinks the original alloy framed ones where aircooled/powervalved in '85/'86
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Here's an interesting piece by Frank Melling on the development of the Ti BSA. There were some pretty trick works bikes built in the 70s but this bike would have to be considered for the trickest of the trick.
http://www.motorcycle-usa.com/290/1686/Motorcycle-Article/Memorable-Motorcyles-BSA-Titanium.aspx (http://www.motorcycle-usa.com/290/1686/Motorcycle-Article/Memorable-Motorcyles-BSA-Titanium.aspx)
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Oggy Doggy that is a great history piece, well found.
Ji
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The BSA with a titanium chassis.
Ji
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Here's the less well known Ti Husky from '71.
http://www.motorcyclemuseum.org/classics/bike.asp?id=109 (http://www.motorcyclemuseum.org/classics/bike.asp?id=109)
http://vintagemxvideo.com/profabtitaniumhusky73400.html (http://vintagemxvideo.com/profabtitaniumhusky73400.html)
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1971 Husqvarna 400cc titanium framed AMA winning bike.
I wonder if Steve McQueen got a ride?
Thanks Oggy Doggy
Ji
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This is the Honda CR250 R 1997. The first production all aluminium framed MX bike.
Ji
And what a heap of sh*t that was.. rigid as all hell. Remember the single radiator? I rode one at the old Hallam MX track back to back with my trusty '93 model (just like Jeremy :)) and I couldn't get off the thing fast enough. I was sorely disappointed. I recall seeing it on the cover of ADB and being totally blown away.
You could probably blame that bike for Kim Askenazi's jail term, McGrath getting straight on the phone to Roger, curtailing Steve Lamson's career, and Everts' works version being nothing like it.
It only reinforced my mantra; never, ever buy version 1.0 of anything!
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Yes she sure was a pig to ride.
The lesson to learn here is that the frame needs to flex even if the bike has 300mm of wheel travel front and back.
Ji
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http://www.vmxmag.com.au/02_Home%20page/homepage_photos/optaco.jpg
Started looking through my VMX mags for the pic of the monocoque Bultaco. Got sidetracked with every issue, so I went to the website.
Couldn't find the info I was looking for, but found the pic...
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Noted motorcycle designer/stylist John Keogh has agood article in the current AMCN on this subject, but it can really be sumed up with 1 sentence.
Before/after the McCandless brothers and before/after Antonio "JJ" Cobas.
Before Cromie and Rex McCandless designed and built the first featherbed frame. They were just variations of push bike frames. Before JJ Cobas made the first twin spar aluminium frames for a Honda RS 125(the one a very young Alex Creville won the 125 championship first year at Phillip Island) frames were just variations of the McCandless brothers featherbed frames.
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Speaking of push bikes and Reynolds tubing, alot of racing bikes use 531 and more expensive bikes use 631 and more expensive again is 753. Reynolds do make a tubing for tig welding called 525 and 725.
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the articles i promised to scan are located here
http://ozvmx.com/community/index.php?topic=7274.msg70388;topicseen#msg70388
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Noted motorcycle designer/stylist John Keogh has agood article in the current AMCN on this subject, but it can really be sumed up with 1 sentence.
Before/after the McCandless brothers and before/after Antonio "JJ" Cobas
There's no doubting that the McCandless Bros and their Featherbed definitely revolutionised chassis design but we're discussing the progress of the motocross chassis here and it was proved pretty impressively in the mid to late fifties that the basic featherbed design had some major shortcomings when it came to motocross. Les Archer was a millionaire semi supported by the factory to develop the Manx Norton for GPs. From the mid fifties through to 1962 Les eventually chopped and channeled the initial featherbed design until he ended up with something barely recognisable from the McCandless concept. The main problems to overcome were ground clearance and more importantly chassis flex, or more accurately a lack of it. As the '97 alloy spar Honda proved, you can't have a frame that's too rigid, you need a certain amount of flexibility. While there was nothing better than a featherbed on tarmac, on the dirt it was way too rigid. Because Archers contract with Norton called for him to use Norton frames exclusively he spent the next 10 years developing the featherbed into something usable on the dirt. As photos show, the finished Reynolds 531 "featherbed" frame bore little resemblence to the original design. It was a featherbed in name only. Les won the 1956 European Motocross Championship which became the World Championship the following year.
http://www.motorcyclemuseum.org/exhibits/mx/bike.asp?id=92]]http://www.motorcyclemuseum.org/exhibits/mx/bike.asp?id=92 (http://)
http://books.google.com.au/books?id=uAzl8ICKMXcC&pg=PA11&lpg=PA11&dq=les+archer+norton&source=bl&ots=3lg5mLDQHR&sig=cxJt6t6VxBs_Naeio-LKQwFkO4w&hl=en&ei=q0jgSZr1C4zW6gOLr52ADA&sa=X&oi=book_result&ct=result&resnum=1 (http://books.google.com.au/books?id=uAzl8ICKMXcC&pg=PA11&lpg=PA11&dq=les+archer+norton&source=bl&ots=3lg5mLDQHR&sig=cxJt6t6VxBs_Naeio-LKQwFkO4w&hl=en&ei=q0jgSZr1C4zW6gOLr52ADA&sa=X&oi=book_result&ct=result&resnum=1)
In my opinion the Rickman Brothers Metisse design is the chassis that set the standards for future motocross design. Previous to the advent of the Metisse in 1962/3 most frames were based on road going frames. The Rickmans took basic BSA Gold Star geometry and designed a much lighter and stronger frame using lightweight 531 tubing and quality bronze welding using new flux and brazing material designed specifically for the Rickmans. The Rickman Metisse was the first chassis designed specifically for motocross and deserves its place in history.
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How to bend Reynolds 531.
Step 1
Take an old plumbers pipe bender.
Step 2
Weld it to some steel rsj stolen from a WW2 air raid shelter in the army camp next door.
Step 3
Eat loads of spinach and your away ;D
The tube my coleague is holding is the seat rail for a Beamish Suzuki trials bike. We did loads of tube bending for many diferent people in the 70's. This also included the top and down tubes for Bengt Abergs 4 stroke Yamahas. He tried loads of diferent companies but none were able to do the job. The thin wall chromoly tube would crack when bent on modern tube bending machines. We did it using a pile of scap and muscle power ! Charged him a fortune too :D
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This also included the top and down tubes for Bengt Abergs 4 stroke Yamahas. He tried loads of diferent companies but none were able to do the job. The thin wall chromoly tube would crack when bent on modern tube bending machines. :D
I went through the same dilemma myself when I started building my replica's.
At first I thought I would just send the large tube out to be bent but they cracked as you said.
Then I bought some formers for my own tube bender ($700.00), did a practice run with m/s to test angles & lengths, beudy, now put in the cro-mo & the fuggin shit wouldn't budge. Obviously I don't eat enough spinach :o
Eventually found a Co. that was able to do it & was happy to leave the headache to someone else.
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The attached image is of a part that is not from a motorcycle but from a drag car. It has a similar diameter to a bike frame and is subjected to similar loading. It was hand made in the States from Cr Mo 4130. It has been TIG welded and the welds are some of the most beautiful I have ever seen.
When the component was over loaded the main load carrying member ruptured near the welds. This is a typical Cr Mo failure when the load is greater than the load carrying member or when the metal has not been normalised post welding.
Ji
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Talking of aluminium frames, this would have to be one of the earliest. Lito built this aluminium framed 500 in 1966 but the bike didn't prove to be very competitive. The frame is made from aluminium tubing bonded together using Araldite and cast alloy joining sections.
(http://img.villagephotos.com/p/2005-8/1062154/lito11.jpg)
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The new Benelli's and Lotus Elise sports cars chassis/frames are made the same way, except the join is pegged.
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Hi Mark,
That looks like a PVC tube pool chair frame.
The front hub and fork looks like CZ stuff.
Very cool looking.
How many of them were ever built?
Ji
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Just a bad engineered design, nothing to do with the welds or material