That sounds fair enough to me, I've done 100mph (indicated) on a restriced (to 12hp) Aprilia RS125 and an RM125 has probably got about 30hp+. If you stick the right sprockets on it I would imagine that should be easily possible. I had a Suzuki 250X a few years back (road going lame impression of an RM250) two stroke single and that only had a weedy 30hp and would do 90mph+ (indicated).

 

WAY BACK when I had my YZ-125 (completely stock), I had my GF ride along with me in her jeep down a dry river bed. She said I clocked in at 66 MPH, wide open. I would doubt very seriously that a stock RM125 will do 85, but I've been a lot more wrong about much more important things [/emoticons/emotion-5.gif]...

 

It should have the power to do 85 if the front sprocket is big and thre rear is small. You wouldn't want to gear it that way all of the time or your bottom end would be a dog for climbing hills. I doubt that it will do more than 65-70 with a stock sprocket setup.

 

My point or points exactly, this bike is pretty much stock. I know he hasn't put on taller gearing for top speed runs. I do know that one of the big dirt bike magazines did a top speed test looking for the fastest dirt bike. They ran some big 400+ 4 strokes, a 500cc oil burner, and other assorted big dirt bikes. They could barely crack 100 with these monsters, and they were modded with exhaust/jetting/stripped for weight loss, etc. The fastest bike was around 109mph...and that was a huge 4 stroke! I just amuses me to hear people talking about how fast their dirt bikes are. I've never seen a 125cc that'll do 85mph. Not even close. I'd be willing to bet it tops at at no more than 60mph.

 

It could run 75 to 80 my 2000 rm 250 runs 85 to 90.