Custom Billet triple clamps

[mx250]

I love those clamps that Lozza shows but in my opinion, they're not legal unless they are exact copies of period items. Just because the technology was available to build them was available back then doesn't make them kosher. I know I harp on this but I passionately believe that our sport is about preserving the technology and visual image of particular eras of motocross history. Fitting modern styled billet clamps takes away a large chunk of the period integrity of the bike. I get people saying that works bikes had billet clamps back in the day so why can't their bike? My answer is that you most certainly can but the clamps you use must be based off works parts or commercially available parts. In my case I wanted to fit billet clamps to my Cheney project and noticed that ProCircuit made billet triples for Huskys back in '73/'74 and that somebody was making exact replicas of them. I bought a set because of that pre '75 provenance. Fitting clamps (or any other majot parts) with no historic precedence is the stepping stone to our bikes losing their period look and turning into vintage/modern hybrids. Look at the shitfight post classic road racing became because of the "she'll be right" attitude to allowing non period parts.

It's all by degrees Firko, it all by degrees. How many chambers, replica frame or suspensions are "exact copies of period items".

[LWC82PE]

i dont know why rear shocks are not classed as major components? they are the main items that make most of the difference on old bikes and many look way more out of place than a set of billet clamps but thats just my opinion.

anyway im not thinking of trying to make/get made real modern looking clamps and thats also what i do not want, i am more looking at making billet versions of stock cast alloy ones that are very close to how the originals look but maybe with a bit less rounded edges and scolloped out areas which might make it cheaper and easy to machine.

i also want to keep period looks and that is important to me aswell and a set of basic machined clamps, nothing too fancy or modern looking would be ok for me. it would be nice to find some billet KYB or White Brothers clamps to copy but i cant see that happening.

i have also seen replica Profab triple clamps for Husqvarnas on ebay.

so although i agree with Firko, i think you should be able to make your own clamps just as any one else could have done in their back shed back then or got a machine shop down the road to make some back in 70/80's but i guess it would be hard to deifine what sort of designs ar too modern looking thats the problem. its a bit like water cooling, anyone could have done it in the 70's-early 80's and some people did but its still no legal in EVO class.

it sort of seems like aftermarket brand name parts or replicas of those parts are allowed in vintage, but any home made/do it yourself stuff isnt allowed

[Lozza]

Most of the 'what could have been made in the day' stuff has died off with the inception of log books in road racing.Show me pics of the back in the day aftermarket ones and you'll have copies. 
Wasp even people who are good at Solidworks still have a lot to learn, I'm in awe of what that program can do and the power you have at your finger tips,just wish I had the time to learn how to drive it properly. ProE is a bit more intuitive give that a go, SW makes prettier pictures though
 

[Lozza]

Torrens has it at a massively reduced price

[firko]

It's all by degrees Firko, it all by degrees. How many chambers, replica frame or suspensions are "exact copies of period items".

Exact copy is perhaps a little harsh but I think 'reasonable facimile' would be easier to enforce. Nearly all of the aftermarket frames I've seen are pretty corect. I've seen two Metisse frames sitting on a mates floor that were absolutely identical. One was made by the Rickmans in 1964, the other by Pat French in 1999. Geoff Morrises frames are pretty correct to my eye(I'm sure he can verify that himself) and even the locally made Redline and Trackmaster copies are damn good copies, the only differences being the welds. I'm certain the guys who make aftermarket frames could make little geometry changes to 'modernise' the design a little but they largely don't. Why? To maintain that period integrity. Eric Cheney made 'modernised' versions of his period frames and all it bought him was grief. The organisations wouldn't allow them to race in pre '65 and the racers wanted authenticity, so he quickly went back to the original jigs!
I also have the same thoughts on pipes. I don't think that modern style pipes should be allowed. It's a hard one to enforce but it should come down to not allowing 'fatty' pipes in pre '75. Both my DT1 and Maico squarie have modern, computer designed pipes that work a treat so I'm as guilty as the next bloke of pushing the envelope but if I was to ever race the DT1 again, I'd refit the GYT pipe. If I have to change the Maico pipe, I'd also do it without argument. Shock absorbers are a tricky one but they're considered 'consumables' by the rulebook and not covered by the period rule with the exception of remote reseviour shocks not being allowed in pre '75.

firko so those replica pro circuit pre75 triples are ok

Holeshot, I'ts been a long time since I had any say in what's in the rulebook so I can't say with authority but to my way of thinking they're legal as the originals were around in '73. A friend had an original set on his '71 Husky back in the early days of vintage and I always liked them. When the replicas started appearing I got a set and the'yre pretty damn close. The originals were cast and then machined, the new ones are CNC billet and you can tell the difference in the materials used if you know what you're looking at but they're otherwise identical.

[LWC82PE]

i might start on some hand drawn sketches with sizes and then get them done in CAD. ultimatley it will be the price quote that dictates if i will proceed any further and also if i can offload some other gear for funding, but if i can get some under $600 AUD that would be good.

[LWC82PE]

just found out who billet YZ is, i thought it was a USA place, but i cant get to their website yet......no now its working as soon as i find out the fork spacing on some RM/PE's i can get started on this.

[Lozza]

Problem with taking a hardline with this period correct caper is when evidence is presented of items being raced in the period and there is a rule to prohbit the use of the said item.Freaky has already posted a period pic of a fairly fat pipe on a dirt tracker, I have a scan of an old Kawasaki manual that gives pipe specs both of which are over 100mm in the belly and a tapered header.This was not some works only top secret bulletin but the manual that came with the bike,Info freely available at the time.
Mark Boddy might be able to provide more details on the hoo ha around the full floating disc rotor for P5 road racing. Which IIRC were barred then unbarred and you can now get copies of.

[LWC82PE]

http://cgi.ebay.com/ebaymotors/HUSQVARNA-PROFAB-REPLICA-ALUMINUM-TRIPLE-CLAMP-ASSEMBLY_W0QQcmdZViewItemQQ_trksidZp3286Q2em20Q2el1116QQitemZ280294414964QQptZMotorcyclesQ5fPartsQ5fAccessories

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=280293843575&ssPageName=MERC_VI_RCRX_Pr4_PcY_BIN_Stores_IT&refitem=280294414964&itemcount=4&refwidgetloc=active_view_item&usedrule1=CrossSell_LogicX&refwidgettype=cross_promot_widget&_trksid=p284.m184&_trkparms=algo%3DCRX%26its%3DS%252BI%252BSS%26itu%3DISS%252BUCI%252BSI%26otn%3D4

seems like everyone is using 6061 but we cant get in in Australia? even Franks Racing imports it i wonder how much it costs/where to buy it?

[YSS]

Ask Frank 

[LWC82PE]

he was going to be my first choice as he has been making parts for vintage bikes since they were new, but then i saw the price and i cant afford to spend $1000 on these and as freaky said, hes not set up for CNC. i should be able to get the CAD done by a friend so then that should reduce costs and then just send it to a CNC place or Lozza?

but yes maybe i could buy some alloy off Frank if he just sells it to people, he might not do that though and uses it only for himself to machine if its that hard to get.

i like to listen what everyone says. Lozza says the 5000 series marine grade is fine, but then most manufacuturers are using 6061, so surely that says something?

[YSS]

Torrens has it at a massively reduced price

How much ?

[YSS]

he was going to be my first choice as he has been making parts for vintage bikes since they were new, but then i saw the price and i cant afford to spend $1000 on these and as freaky said, hes not set up for CNC. i should be able to get the CAD done by a friend so then that should reduce costs and then just send it to a CNC place or Lozza?

but yes maybe i could buy some of the alloy off him

I dont think a one of will save that much . Many , many yes .

[LWC82PE]

there would be a fair bit of labour doing the drawings/measuring etc, ive done it before and its very time consuming, so surely that will save fair chunk of costs if i do that myself rather than paying someone to do it? and that way all i need is to pay for material and CNC machining.

[LWC82PE]

yeah that too!