Had a little epiphany at the track today.....

[Dirt Addict]

I was doing some bike maintenance and needed a new rear sprocket. I found a few on the shelf in the shed I got from RMMC on sale last year. The down side was that they are 47's and I've been running the stock 50's on my rm. I threw one on just because I'm not racing lately and wasn't concerned about all out acceleration.
At the track this morning I was surprised at how well it hooked up! Acceleration like a beefy 250f. I could hold a gear longer and twist the throttle harder without any loss of control. And the suspension felt more forgiving over accel bumps coming out of turns. I found myself launching further over jumps too. I had been concerned about a loss of torque but I actually felt more due to the increased grip.
I have a very fast buddy, rides and often wins the expert vet classes, that regularly runs -3 teeth in the rear and for gp's will even go up one tooth in the front on his yz250. I had been a doubter of his setup, but now .....?
I probably won't go to his extreme gearing, but I'm gonna stick with the -3 on the rear, at least for the 3 RMA sprockets I have left..

[twosmoke595]

most people don't realize that gearing and a flywheel can make all the difference in a smoker.

Imagine your gearing but with a heavier flywheel? even less hop/wheelspin/out of control and just cruising right along? talk about unfair against 250f's lol

[Stusmoke]

most people don't realize that gearing and a flywheel can make all the difference in a smoker.

Imagine your gearing but with a heavier flywheel? even less hop/wheelspin/out of control and just cruising right along? talk about unfair against 250f's lol

Too true on the first part. I think my 2013 250sx would benefit just as much from 2 LESS teeth on the rear as it would two MORE. Reason being is that with 2 less I could hold second gear on some jumps that I have to quickly grab third on the exits of. With two more, I could probably hold third through those same corners. I see too many people going all out on engine mods before they even look at a rear sprocket. Then they go and buy one because of the blingage, not performance... Sigh.

[ridered125]

I recently went up a tooth on the  rear sprocket and like you, Addict, I noticed the suspension got much harsher in the chop. The motor also lost some of its smooth harmonics and got punchier. The only place where the bigger sprocket was an advantage was on steep climbs when riding trails.

[eprovenzano]

Don't know but just wondering if the rear wheel being farther back (assuming you didn't shorten yout chain ) has an effect in the handling?  I think with the wheel back farther you can get more drive and the bike is less prone to wheelie. I know it really helps in the single track I ride with some of the steeper hills.

[citabjockey]

I am orienting my dual sport KTM250 a bit more towards street with a 42 tooth rear sprocket (replacing the 48 that is on there now). THAT ought to test the limits of this theory!

[factoryX]

Imo, I personally like my back end loose, not on the straights obivously but in the chops and berm, right. Look at Carmichael's riding style.   

[Dirt Addict]

Don't know but just wondering if the rear wheel being farther back (assuming you didn't shorten yout chain ) has an effect in the handling?  I think with the wheel back farther you can get more drive and the bike is less prone to wheelie. I know it really helps in the single track I ride with some of the steeper hills.

Rear wheel is forward. I put a new chain on at the same time. It was short. The axle is almost all the way forward. I have found over the years that I like the rear axle forward. It seems to improve my turning  and I like the feel. I think it's an individual thing.