How much extra horsepower would a rider get for each kilo of weight shed?

[Doc]

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

[HVA61]

It's not the size of the dog in the fight, it's the size of the fight in the dog. by Mark Twain.

[09.0]

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  whats the secret ? i wanna drop about 5 kgs , wont make me any quicker but more ahsteticly pleasing 

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 

[jerry]

Where's Ji when we need him? J

[TM BILL]

Where's Ji when we need him? J

At the Gym installing titainium equipment 

[VMX247]

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 
http://www.bodyblitz.net.au/calculators/body-mass-index/
cheers A

[the stig]

     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..

[Colin Jay]

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

[Taka 100]

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 

power to weight ratio, when all else fails buy a drum of methanol go up to a 530X18

lets form a  club

Club 100K

[Lozza]

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  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 

[Colin Jay]

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 

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

[IT490K1983]

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 

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 

[Kenneth S (222)]

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!

[Curly3]

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.
 

[Taka 100]

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