Has anyone tried a 16t front with the stock 42t rear or a 40t rear with a 15t front? Is there enough clearance to run a 16t front?

Dunno man... gunna be tight at the very least. Why not just run 15/42 or 15/41 and get very similar results?

Oh! Stock rear is 45t.

I myself run a 15/42 for street and for 1 track. If you search, you will find many riders that run similar gearing while still using the stock chain or a stock length chain.

Oh! Stock rear is 45t.

It is? I read that it dropped teeth from the 250 and was stock 42. Someone please confirm :P

stock is 14/42. Im running 15/42 now which is much nicer and want to try 16/42. It may hurt accelleration but Im running 50 miles of interstate each way to work so the lower rpm will help there. I just am not sure if there is room for a 16 tooth. They sell up to 17 tooth for the 250 so If the cases are the same it should fit. If not I can drop two teeth or more on the rear.

I should have noticed what forum this is in. :( Fail

To fit a 16t in the 250, you have to shave off material to fit the sprocket.

I'm not sure if a 16t will fit in the 300 or not. Search for a rear with fewer teeth if you really want lower rpm's. How many rpm's are you turning at 65 with 15/42?

from memory around 7k rpm.

I ordered a 39t rear today. I could not find a 16t front for anything after 07. Should be about the same though.

Put on the 39 tooth rear today (42 stock), (previously installed 15t front, 14 stock) and it is much nicer now. Can actually complete a left turn and accellerate some before shifting. I was able to roll on from 25 mph in 5th into my neiborhood which is uphill about 15 degree grade and go from 25 to 35 in short order so the bike has the torque to pull the taller gearing no problem. Starting from a stopsign uphill no problem. This is how it should have been geared stock.

Put on the 39 tooth rear today (42 stock), (previously installed 15t front, 14 stock) and it is much nicer now. Can actually complete a left turn and accellerate some before shifting. I was able to roll on from 25 mph in 5th into my neiborhood which is uphill about 15 degree grade and go from 25 to 35 in short order so the bike has the torque to pull the taller gearing no problem. Starting from a stopsign uphill no problem. This is how it should have been geared stock.

I ride with the same gearing 15/39 i agree with you it shoud be geasring like that stock

I went to 15/39 for a few hundred miles.

For me, it was hitting the "too tall" end of useable gearing. I could ride it, but it was just a little much at my 200 lbs. and I'd not have enjoyed a passenger added to that in that gear ratio.

I'd run it again if I was going across country on interstate (I hope that never happens!). I dropped it back to 14/39 and it is pretty much the same as 15/42 now.