For making such unbelievable statements, you should probably prove this with some information. The 125 and the 250 have different gear ratios. For all I know the top of 5th gear on a 250 ends at a higher top speed than the top of 6th gear on the 125.

 

yeah.please prove this....id like to see

 

honestly who gives a s/hit about it sure topping out is fun as hell but name one form of dirtbike racing that has anything to do with toppin out. acceleration is the besty part about dbikes

 

super motard.and motocross if you have long straights

 

Ok, well gear numbers (5 vs. 6)don’t matter, it’s the ratio of them. My 6th gear on my 125 is 1 wile the 2002 kx250 5th gear is .869. And why does your bike go faster when you rev it up more? Is it making more power making you go faster? Absolutely not, it is because the motor is spinning faster making the tires spin faster also. Once you hit a dead point where the bike won't rev up any more (usually around 10,500-11000 rpm on a 125 and 8500-9000 on a 250) all the power you make wont help because the bike can't rev any higher and can spin the tire fast enough. It all depends bike, rider, tire size/width and what mods and how well the bike is maintained (some mods allow bike to rev higher). I used a speed calculator and my 2002 kx125 at 10500 rpm vs. a 2002 kx250 at 8,500 rpm. Mine had a top speed of 68.7 and the 250 had one of 70.1. Now the 250 won there, but it still isn't by much. Now the old CR125s (with 6 gears) were good for over 75 mph I've herd. But top speed doesn’t really matter, its acceleration, and there’s where 250s really win.

 

you dont go over 60 on a mx track

 

At a supercross they start was 300 ft and they wrere hitting 5th gear. Also doesn't Reed sometimes hit whoops in 5th? So its very possible people hit 5th gear.

 

its all about excelleration

 

Yea, but when if there are alot of open straights you wan top speed too.

 

whatever.........ive personally hit top of 6th gear on a stock rm 125 on a supercross track

 

WTF, 125's will only run 65ish?

my old xr100 went 55 with my fat *** on it and it was geared for bottom end and had a 14 inch back wheel........only performance mods were a Big Gun pipe and a twin air filter........

 

Haha, my ***. My 03 xr100 pulls 45 stock. Pipe and filter won't add speed, and if you down geared it i doubt it hit 40. Xr100s are slow.

 

believe it if u want.....was pulled up beside friend in his car, he was going 55.....