OzVMX Forum
Clubroom => General Discussion => Topic started by: Kenneth S (222) on January 24, 2012, 09:05:27 pm
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OK, I know this is coming from left field but I would seriously like to know the answer to this question just for the hell of it and I think it would be an interesting exercise to find out how to work it out. Since the beginning of time I have seen how the Factory teams drill holes in just about anything, brake activator levers, sprockets, sub frames etc and swap out standard parts for exotic light weight parts, just to save a few kilos of weight.
What I have wondered and I am hoping there are some on this forum capable of working it out is if a rider drops his weight from 90kg to 85kg or 90Kg to 80Kg how much extra horsepower does that free up? An average VMX bike weighs what, 100kg fueled with a 90kg rider on top totaling 190Kg. If the rider drops his weight from 90 to 85kg, a drop in total bike/rider weight from 190kg to 185kg is 2.6%. Does that mean in effect the rider has 2.6% more power? or from 190 Kg to 180Kg, 5.2% more power?
What are the physics behind this question? Is there someone on here who can offer a formula?
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This will be good ;D I've thought about this as well. Most of the top riders are lightweight short arses. Bit like jockeys ;D
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Joel Robert was pretty solid but then again the RH 250 was pretty light.Interesting! J
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Given the bike weighs the same and therefore is a constant any weght drop by the rider would have to influence the power to weight ratio favourably would it not. Off to Jenny Craig fella's. J
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Racing dirt bikes isn't drag racing - even in the trip to the first corner, a good 100kg rider will be able to out-drag a 60kg gumby, even if they're on the same bikes.
When you add real obstacles in, the rider skill matters even more.
Bike weight matters more than rider weight because it has to be manhandled by the rider. The MTB guys always put extra weight (spares, etc) on their body, rather than the bike.
That said, lower rider weight generally goes hand-in-hand with better fitness, and that's what really makes the difference.
More generally speaking, I reckon we massively overestimate the value of light bikes. Sure, you'd be mad to leave a 20kg lead weight bolted to your bike, but people often spend lots of money saving grams here and there, when the same money would be better spent on riding lessons, new tyres, or even just riding more often...
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I agree Nathan your correct to factor in the variables but I think were only talking about strictly power to weight here. As an aside have you noticed some guys fill their tank prior to a 3 lap race. That one always makes me laugh! J
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What Nathan said....light bikes handle, stop, go and are easier for the rider to manipulate.
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As an aside have you noticed some guys fill their tank prior to a 3 lap race. That one always makes me laugh! J
If you took as long as me to finish 3 laps you'd understand why I fill my tank! Probably lose more to evaporation than I burn..... :-[
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I have gone from 96kg to 80kg so far. It's got to equate to being faster due to less weight. It will be a great advantage for me now on my rm125 and cr125 . Dropping weight from your person would be much better than off the bike as ones fitness is better as well so you can push for longer which makes you quicker over the whole race.Doesn't hurt to be healthier for it either.
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Of course you are correct Brad..and a healthier rider is a plus...I believe it is more about having to slow down a heavier bike..make it accelerate out of a corner..lean it over in a corner...landing off a jump...."man handle"...it's tough when the bike weighs more..try an old pommy 4 banger..ask John Selva...
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Racing dirt bikes isn't drag racing - even in the trip to the first corner, a good 100kg rider will be able to out-drag a 60kg gumby, even if they're on the same bikes.
When you add real obstacles in, the rider skill matters even more.
Bike weight matters more than rider weight because it has to be manhandled by the rider. The MTB guys always put extra weight (spares, etc) on their body, rather than the bike.
That said, lower rider weight generally goes hand-in-hand with better fitness, and that's what really makes the difference.
More generally speaking, I reckon we massively overestimate the value of light bikes. Sure, you'd be mad to leave a 20kg lead weight bolted to your bike, but people often spend lots of money saving grams here and there, when the same money would be better spent on riding lessons, new tyres, or even just riding more often...
You know what Nathan, I hear you and to a certain point I agree. The comments you and others have made that the lighter bike is easier to handle etc makes a lot of sense and is no doubt correct. I also think fitness is such a crucial key for fast racing not only as a fit person can ride harder for longer but if a racer feels fresher they will make better decisions of which we are making 1000s per lap.
In my view, racing motocross 'is' drag racing though, from corner to corner, and it is also brake testing, as you leave your braking as late as you can at the end of each drag race to the next corner. In a typical lap effectively we are racing 11 to 20 drag races, some more horse power critical than others like up hills and those out of slow corners.
If 090 has gone from 96Kg to 80Kg (BTW, great effort. That takes some serious discipline at our age. I have gone from 101 to 87, I'm shooting for a Pre85Kg body for this season) That is 16Kg he is not having to carry as he takes off on each of those drag races and not having to carry as he tries to pull up at the end of those drag races, even more critical on a 125. That has to make a HUGE difference as an extra advantage to his new level of fitness.
What I would like to know is what is the actual measurable advantage of the weight loss if you had two riders of identical skill and fitness.
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I have gone from 96kg to 80kg so far. It's got to equate to being faster due to less weight. It will be a great advantage for me now on my rm125 and cr125 . Dropping weight from your person would be much better than off the bike as ones fitness is better as well so you can push for longer which makes you quicker over the whole race.Doesn't hurt to be healthier for it either.
Brad thats a great effort mate well done :) shit you were quick enough at 96 kgs :o whats the secret ? i wanna drop about 5 kgs , wont make me any quicker but more ahsteticly pleasing ;D
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so what are all you guys saying, because I get passed by fat bastards all the time?
so 1, am I fatter than the fat bastards?
2, so slow that even fat bastards beat me?
3, their just better riders?
4, their bikes are so lite it dosnt matter what i do?
I think its 3, no matter what you do, if their good riders, weight is not an equation
Cheers Worms
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I guess a big part of my thinking comes from my experience with rally cars.
I've watched plenty of people spend lots of time and money trying to save weight, and have it make zero difference to their stage times - and often make the car fragile and difficult to live with.
Personally, I owned a car that was 1160kgs, and then a rule change meant it had to be ballasted up to 1280kgs - and I swapped from a 70kg to a 110kg navigator at the same time. The ONLY time the extra weight was an issue was braking in the wet. Acceleration was not changed by any noticable amount - in particular, there was one regularly used stage start where I never knew whether or not I should change into 4th just before the first significant corner - I'd run out of 3rd gear in exactly the same spot, regardless of what the car weighed.
The heavier version of the car sat better on the road, over the rough stuff - basic sprung:unsprung weight stuff. In the case of a heavier rider on a dirt bike, most of the rider's weight is 'double sprung' (ie: the bike's suspension and the rider's arms & legs), so its gotta be even more helpful, right?
I think this is a big part of the "manhandling" issue - a big/fat rider has less need to manhandle the bike, because the rider's weight automatically dampens out a lot of the bike's nervousness.
The ability to move your weight around is a big influence to how much traction a bike gets on dirt. Obviously, more weight is harder to accelerate but I reckon that in lots of circumstances, if that extra weight is put over the rear wheel, the increase in traction cancels out the extra total mass.
Ah, shit, I'm sounding like I'm saying that being a fatty is a good thing... :P Really, the point I'm trying to make is that extra rider weight doesn't kill off engine performance all that much, and may improve handling and traction in some circumstances.
Going back to the original post, even on a drag car, losing 2.6% of non-rotating mass has LESS effect than increasing HP by 2.6%. Every part that rotates has both a static mass and a rotational mass - and to accelerate the bike/car, both of those masses must be overcome.
Imagine you had a 200kg bike/rider, and a 200kg lump of steel and you had to push both of them to 10kph.
If they were both on ice, it would require the same amount of energy for both.
But once you let the bike's wheels rotate, you'd find that the bike requires quite a bit more energy to get to 10kph because you have to get the wheels/chain/engine internals rotating as well.
For the record: 90kgs, down from a peak of 98. Aiming for 85.
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Your always going to be astheticly pleasing Bill ;D
Drilling holes in everything does SFA for the mass of a component. Moving to light weight materials Mg etc etc to strip mass is the only way to go. Light weight wheels help suspension, dropping unsprung mass is always a good thing.
However it is by far the most expensive way to gain performance. eg Stock cast road bike wheel new off a dealer will be say $500 a marchesini magnesium wheel will be $2000. Light weight components don't like gravel traps and get offs.
More HP is by far the best way to increase power to weight ratio
190kg bike/rider with 30HP= 0.15 kg/hp
190kg with 35HP =0.18 kg/hp
180 kg with 30HP = 0.16 kg/hp
You have to drop almost 3 times the weight to make up a modest increase in HP
At a national/international level mass makes a difference as the bar is so high.
More generally speaking, I reckon we massively overestimate the value of light bikes. Sure, you'd be mad to leave a 20kg lead weight bolted to your bike, but people often spend lots of money saving grams here and there, when the same money would be better spent on riding lessons, new tyres, or even just riding more often...
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as a lightweight rider (56kg) I've always found the biggest gain wasn't from outright acceleration but how quick I can wipe the speed off..late braking and holding corner speed always gave better results than straight line acceleration or HP ;)
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It's not the size of the dog in the fight, it's the size of the fight in the dog. by Mark Twain.
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The comparison here is one bike, one rider with more and then less weight. Not comparing risers or bikes. So for me, shaving off a kilo(can that even be done on an rm125b?) as opposed (in my case) dropping 16 kg plus the extra fitness. Me losing weight wins by a mile. Now on my 490 Maico, same thing, can I even shave off a whole kilo off it with titanium this and drill the crap out of that? My sixteen kilo loss and better fitness will win by a mile again. Even 5 kilos and you are ahead.
I have gone from 96kg to 80kg so far. It's got to equate to being faster due to less weight. It will be a great advantage for me now on my rm125 and cr125 . Dropping weight from your person would be much better than off the bike as ones fitness is better as well so you can push for longer which makes you quicker over the whole race.Doesn't hurt to be healthier for it either.
Brad thats a great effort mate well done :) shit you were quick enough at 96 kgs :o whats the secret ? i wanna drop about 5 kgs , wont make me any quicker but more ahsteticly pleasing ;D
it is easy for me as I have the right body type. I have been abusing it for twenty years. I try not to over eat (John has seen that first hand), don't eat anywhere near as much crap and I am going to the gym. Best way to burn calories is on a bike. I do cycle class 45 min to an hour. It uses your biggest muscle group. With the bonus of a cardio workout so I can ride harder for longer so look out! I think I will be entering ten bikes in the Aussie titles this year :D
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Where's Ji when we need him? J
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Where's Ji when we need him? J
At the Gym installing titainium equipment ;D
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so what are all you guys saying, because I get passed by fat bastards all the time?
so 1, am I fatter than the fat bastards?
2, so slow that even fat bastards beat me?
3, their just better riders?
4, their bikes are so lite it dosnt matter what i do?
I think its 3, no matter what you do, if their good riders, weight is not an equation
Cheers Worms
Worms --you put on weight before you lose weight, due to muscle build up...then you just become Buff ;D
http://www.bodyblitz.net.au/calculators/body-mass-index/
cheers A
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I read an Article in a dirt bike Mag last year they had an interview with
Chad Read about all the trick Bits on his Super cross bike and he said it
is no different than a stock bike in Handling or performance it is only the
rider that makes a Difference ...
The Stig..
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I am a member of the DLRA (Dry Lake Racer Australia) and in general nobody goes overboard trying to make either bikes or any of the various four wheelers untra light weight. The general opinion is that to a certain degree, weight is good at it equated to traction. It is not uncommon for bikes (and I presume cars) to still be suffering chronic wheel spin in top gear as they go through the timing lights at top speed. In fact many of the 4 wheel fraterinty actually use steel rollcages instead of Chromemoly as they prefer the extra weigh of the steel.
I think that this would also be applicable to dirt bikes, where a very light rider on a very light high power bike would have trouble actually getting the bike to hookup and put the power to the ground.
As I weight about 125kg ready to ride and none of the dinosuars that I ride are remotely light weight or power full it is all irrelevant to me. But, it give me a bit of an excuse not to loose the few(!) extra kg that I am carrying as I would cause me to have less traction when racing.
CJ
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depends ask marty tripes he just f#"**n blew em all away between burgers , get some more pies inya tommorow for australia day and back it up with pavalova , burp wateya think they make 500 2 strokes for ;D
power to weight ratio, when all else fails buy a drum of methanol go up to a 530X18
lets form a club
Club 100K
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I like that summary , yes that has much to do with it . I think Lozza is also right on road racing side , where all horses are needed . But in offroad racing I believe only a portion of max power is ever used , especially with the narrow windy tracks we have to today . Well sorted suspension , good working brakes and smooth power delivery is the key today . ( + a little talent and balls that can make the additional difference)
Was talking about 5HP across the range ;D There was also the time when in 500cc they jacked the min weight up from 115 to 130kgs, after a season or so most maunfacturers went mauch faster as they had learned to put the mass where it would be of benefit.
HIJACK ALERT............
Hey Col you off to the salt this year? Hopefuly won't get rained out.
Someone told me I squeeze the water out from under neath the tyre good in the wet ;D
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HIJACK ALERT............
Hey Col you off to the salt this year? Hopefuly won't get rained out.
Someone told me I squeeze the water out from under neath the tyre good in the wet ;D
Yes, but unfortunately not to run.
I will be heading over to the East for the TRAILZONE Tenere Tragic ride earlier in the month and won’t get back home until just a few days before Speedweek. I do plan to head up to the lake for a couple of days over the weekend of tech inspection to checkout whats new and to catch up with some of the others I know who will be running. Hopefully the Tenere will be up to a few more miles on top of the Tragic ride.
So, my salt racer will remain in the shed for another year, which will make it 6 years without hitting the salt; rained out, rained out, working, working, working and this year’s excuse is that I just haven’t had enough time to get my shit together.
CJ
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depends ask marty tripes he just f#"**n blew em all away between burgers , get some more pies inya tommorow for australia day and back it up with pavalova , burp wateya think they make 500 2 strokes for ;D
power to weight ratio, when all else fails buy a drum of methanol go up to a 530X18
lets form a club
Club 100K
Exackery ;D
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as a lightweight rider (56kg) I've always found the biggest gain wasn't from outright acceleration but how quick I can wipe the speed off..late braking and holding corner speed always gave better results than straight line acceleration or HP ;)
A few of us went out riding on the weekend to Barleigh Ranch for a much needed ride and thanks to the organisers, the track was in top shape and the day professionally run. Doc, I think you could be onto something. Perhaps it's my imagination but it seemed it was a little easier for me to brake later, not sure why, perhaps it is because I am feeling lighter on my legs but I felt less disturbed by the breaking bumps and I felt more comfortable when I pushed it through corners. I don't know whether that equated to being faster but it felt faster. I couldn't notice any difference in acceleration but I found it easier to stand up. Maybe the weight loss is an aid to helping the old hub brakes to work better!
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Newton's 3rd law.
For each and every action is an equal and opposite reaction.
It's not really rocket science but everything works that little bit easier per every little bit of weight reduced, mechanical & physical.
Interesting topic.
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Newton's 3rd law.
For each and every action is an equal and opposite reaction.
It's not really rocket science but everything works that little bit easier per every little bit of weight reduced, mechanical & physical.
Interesting topic.
is that bert newtons 3rd law dont walk out side with a stiff noreaster blowin ya hair piece will end up in the parramatta river
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I thought that wieght was not revilant to a motors horsepower, ie a 47hp motor produces 47 bhp, just because a fat bastard tries to ride it dosnt mean it has any less hp?
cheers worms ;D
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I think he is meaning power to weight ratio. I would say the gain is heaps as all the top riders in both MX and road racing tend to be Hobbit size dudes who weigh 60-70kg ringing wet.
We had this theory it also effects what injuries you get and your career end with big guys going out with backs and knees from the downward force and leverage of their bulk and little guys finishing because of breaking their bird like bones. ;)
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Take the bike to a dyno and start adding weight,take note of the difference per kilo.Or get your gps and take the bike somewhere that has a long straight and check top speed,then start adding weight and take note.ps.Gps set to speed reading.p
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o have missed the point.{as usual] Horse power is horse power no matter what weight it is asked to carry.p
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Isn't a horsepower moving 550lbs one foot, in one second?
I'm not a math wiz, but if add weight or increase horsepower you change the equation. Bottom line is it takes more horsepower to drag our fat asses around a track. Horsepower costs money and lowers reliability, better to lose 10-15Kg.
;D
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power to weight mmmmm ??? might affect a 125 and maybe 250 in certain conditions but not a big bore power ,(i tested this theary once in my board shorts and thongs on a gravel road aboard a machh 111 kwaka forward thrust (ooohh thats sounds good) , more like whiplash ,there was an old say that you dont punch a railway spike with a panel hammer :o no extra horsepower anywhere except in motor design and modification , maybe it should read how much extra performance for each kilo shed. i am willing to undertake the mission under strictly controlled monitered conditions maybe at the witsundays in a beachside bungalow with controlled diet and riding manicured tracks , but only for 6 months any longer you know what they say " its mango season" quick hide here he comes now
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I think he is meaning power to weight ratio. I would say the gain is heaps as all the top riders in both MX and road racing tend to be Hobbit size dudes who weigh 60-70kg ringing wet.
Yep.
Mostly, they're fit short-arses - I reckon their weight is a by-product of being both short and fit, rather than the main goal.
Look at the start line of any pro dirt bike race, and the average height is noticably lower than the average of the general public.
Yes, there's guys like Toby Price, David Knight and Joel Smets out there, but they're the exception among pro dirt bike riders.
I'm pretty sure that being short has a weight distribution advantage, that's way more important than the weight itself... Matt Phillips is short, fit and surprisingly not-skinny - and is way faster than anyone on these forums...
The taller blokes are always strapping young lads who (have to) manhandle the bikes, because their height screws up the balance - a tall, skinny pro-level rider is virtually unheard of.
Glen Bell was reported to be comfortably in the 80kg weight range when he was winning lots of 125 races... You'd reckon that if weight really mattered for dirt bikes, that his extra weight at the very top of the national level would have made the difference.
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Glen Bell was reported to be comfortably in the 80kg weight range when he was winning lots of 125 races... You'd reckon that if weight really mattered for dirt bikes, that his extra weight at the very top of the national level would have made the difference.
But what if Glen had come up against a lighter guy of the same ability, if a 125 weighs say 100kgs plus Glen is 180, say a rider is 60 kilos drops the weight the bike has to haul by what little over 10%. On a 125 thats like gaining 4-5hp. Not sure what Ricky Carmichael weighed but he was a very short dude.
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Then in some situations the xtra wieght would mean more traction= more go forward and speed
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I think he is meaning power to weight ratio. I would say the gain is heaps as all the top riders in both MX and road racing tend to be Hobbit size dudes who weigh 60-70kg ringing wet.
Yep.
Mostly, they're fit short-arses - I reckon their weight is a by-product of being both short and fit, rather than the main goal.
Look at the start line of any pro dirt bike race, and the average height is noticably lower than the average of the general public.
Yes, there's guys like Toby Price, David Knight and Joel Smets out there, but they're the exception among pro dirt bike riders.
I'm pretty sure that being short has a weight distribution advantage, that's way more important than the weight itself... Matt Phillips is short, fit and surprisingly not-skinny - and is way faster than anyone on these forums...
The taller blokes are always strapping young lads who (have to) manhandle the bikes, because their height screws up the balance - a tall, skinny pro-level rider is virtually unheard of.
Glen Bell was reported to be comfortably in the 80kg weight range when he was winning lots of 125 races... You'd reckon that if weight really mattered for dirt bikes, that his extra weight at the very top of the national level would have made the difference.
All very well... but the question is about how a reduction in mass affects the performance of a theoretical bike and rider. You can point out anomalies, with riders of all sizes and shapes, till the cows come home, but none of those actually address the original question.
The simple fact is that, in isolation, less mass makes it easier for an engine of a given power output to accelerate that mass [with all other variables being constant]. The question is by how much? And the second inferred part of the question is: do you chase horsepower or mass reduction, or both?
Then in some situations the xtra wieght would mean more traction= more go forward and speed
In the real world that is of course true, but at what point do you reach diminishing returns... an extra 5kg or 10, what about 100?
That is the great thing about dirt bikes, with the enormous number of variables, there is no perfect answer. Which gives all competitors a chance...
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All very well... but the question is about how a reduction in mass affects the performance of a theoretical bike and rider.
On tar, or even smooth, hard-packed dirt [ie: Dirt Track], then the usual rules apply.
But on an MX track, the original question is a LOOOOONNNG way down the list of things that affect performance - if the rider if fit and competent, then his/her weight is only a bit more important than the colour of the chain joining link.
Even if they're on a 125.
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ahhh well back to being a numbskull im sick of being a professor, it hurts my head too much i hope to get a bigger helmet soon so i can fit more in, i will make it a full face with a visor next time it keeps me from eating so many snacks whilst on the computer on rainy days , its sorta like calorie control , you can only consume so much through a straw 8)
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A interesting note is gymnastics, at an olympic level all the competitors are all Doc's size and weight, they are incredibly strong for their weight, there would not be a competitor over 70kgs in that level. Now if you take Dani Pedrosa or Toni Ellias (or Kevin Schwantz)for instance whom are tiny jockey size blokes but have the strength to punt a heavy and very powerful motorcycle around for 45mins flat out. Then the late Super Sic was over 6ft and fairly average build (though very fit) that didn't seem to matter much in overall performance. When Dani first went to MotoGP many said he was too small and not strong enough to ride one and last year he was 'to light and should have to carry ballast'.
If in doubt , always go flat out and go to the front and stay there , Thats two most important rules in racing . Wait, wait there is another one ( mainly for the chrome trolleys ) . If the front wheel fits through , the rest will follow .
;D
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GP bikes and F1 cars favor short blokes because the feeder series favor short blokes.
And - like I said before - the rules of power-to-weight actually apply on tar.
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GP bikes and F1 cars favor short blokes because the feeder series favor short blokes.
I guess if a factory has spent billions on the carbon fibre and titanium weight reduction program it is nonsense for them to put an old fatty behind the wheel or on the seat. Its a bit like basketball where it favors a certain body type and you only have fraction of a second spreads between racers so every tiny edge counts.
I am not sure power to weight has such a big influence off road, to support this idea there have been plenty of times at MXd Nations and other events where 125s have shut down the 500s with top level riders on both. Shane Watts was a good example he could alternate between 125s, 200, 250, 450 on consecutive weekends in the States and still win.
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I guess if a factory has spent billions on the carbon fibre and titanium weight reduction program it is nonsense for them to put an old fatty behind the wheel or on the seat.
If the old fatty can get the lap times, the team won't care that they're fat.
The issue is that 125 GP bikes, and Formula Fords are built for short-arses.
Maybe a tall rider/driver would screw up their power-to-weight ratio and/or aerodynamics - but they'll never get the chance to find out because they simply don't fit...
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I reckon Stefan Dorflinger would disagree, he was a tall lanky German racing against jockey size Spaniards and e was still a 4 time world champion on 50 and 80cc GP bikes.That was in a class where riders eschewed sew on lettering on the back of their leathers just in case it slowed them down. He was very careful to never be photographed standing next to the bike.
(http://www.kreidler.nl/artikelen/stefandorflinger/stefan-dorflinger-2.jpg)
(http://www.elsberg-tuning.dk/images/81germangpdoerflinger.jpg)
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Just to confirm: the best example you can find is a bloke who won his last championship a quarter of a century ago? ;D
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Acknowledging that weight saving doesn’t increase actual horsepower so then if we look at actual power to weight ratios then according to…
Geoff’s second law of Virtual physics
H divided by (R + B) = PWR
H = Horsepower
R = Rider weight in kilograms
B = Bike weight in kilograms
PWR = Power to weight ratio
Examples…
If horsepower is 40, rider weighs 95Kg and bike weighs 105Kg therefore…
40/ (95+105) = 40/200 = 0.2 PWR (0.2 horsepower per Kilogram)
If horsepower is 41, rider weighs 95Kg and bike weighs 105Kg therefore…
41/ (95+105) = 41/200 = 0.205 PWR
Therefore to gain a PWR of 0.205 from a 40 Hp engine then…
If horsepower is 40, rider weighs 95Kg and bike weighs 105Kg therefore…
40/ (95+100) = 40/195 = 0.2051 PWR
Thus, in this example a weight saving of 5Kg has a benefit of 1 Hp to create the same power to weight ratio.
It was stated earlier that there are greater benefits to be had from the rider losing weight in the form of general fitness and wellbeing but this isn’t altogether true.
If a rider loses 5Kg then he will probably be walking around the pits hungry. If he happens to walk past someone else who has a bucket of hot chips he will develop a craving for them. If the track happens to go past the food stand and he smells hamburgers cooking then this could easily destroy his state of mind giving the opposition a psychological advantage.
It is much wiser to lose weight from the bike, for example if you can save ¼ Kg in weight by the use of $500.00 in Titanium fasteners then this will give you a psychological advantage knowing that your bike is closer to being ‘state of the art’
This smug feeling though can easily disappear when you realize that you lap times haven’t increased one iota.
To fully gain the advantage of Titanium fasteners you must tell all and sundry that you have them. Others will then realize how cool and determined you are to win and will probably pull over for you and wave you by as they won’t consider themselves worthy.
Also to be considered is the equation…
(H/2) / (R + B) = PWR
H/2 = Horsepower as stated in the manufacturers brochure.
R = Rider weight in kilograms
B = Bike weight in kilograms
PWR = Power to weight ratio
And to keep in line with Walter the wise…
When the start gate drops the bullshit stops.
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ha i am with brad i have dropped from
94 kg down to 84kg
and my kx 500 still feels fast ;D
must admit i feel fitter on bike and can stand a lot more ;)
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Geoff - I hope $500 worth of titanium doesn't increase my lap times????
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Geoff - I hope $500 worth of titanium doesn't increase my lap times????
Bloody…
Trust the Louse from Laos to pick up on a typo in my well thought out Thesis
:-[
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Just to confirm: the best example you can find is a bloke who won his last championship a quarter of a century ago? ;D
yep, but still a 4 time champion.Would have continued but FIM cut the 80cc championship. When Cathcart tested a 80cc GP he couldn't even tuck under the screen, he was told to brake when you feel the tyre rolling off the rim.
50/80cc was where a lot of technical innovation came from, cassette gearboxes, dual curve ignitions etc etc. Apparently the smaller the capacity the later at night you had to be up revving them ;D
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Gavin McLeod could beat KTM EXC 250's on his XR200 in enduro's ,winning the Australian 4 day in the 250 class.
He also won the Weipa croc run on an XL500 . :o
Horsepower to weight was not a factor.
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Weight is a factor in Dirt Track (Flat Track)Racing. Approx. Ten pounds equals one HP.in real life. That's why there are no huge Flattrackers. They do kinda good on Short Tracks and smaller TTs but lose on the 1/2 mile and Miles. One,they are giving away HP. Two,They are not Aerodynamic enough (Wind Resistance) Three ,that being said,There were several National Number Riders'here in the states that won on Short Tracks and TTs a lot. Enough to keep their points up to Nat.Standards. Randy Cartell from Amarillo,Texas and Eddie Wirth From California being two most notable.both weighing over 200 Lb (100 KG ?) and were over 6 feet tall. On the longer tracks and Road Racing is where the difference really shows. Anyway enough blathering. See Ya TCL
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