Are any of you BB351 types using a 15 tooth front? Can yo tell me what you think of top end speed and bottom end?

Thanks

 

yes Iam and i like it a lot.
I am thinking of dropping a few from the back as well.
First gear is so low that in the woods on single track it is still low with 15t.
The 351 has ample torque to make up the difference.

 

Thanks, and I already know that you can easily loft the front wheel in second just giving her throttle. Sounds like the 351 is my next project. I would love it if the bike would do 130 km/hr at around 5 thousand RPM and still be able to lift the front end at will in second gear.

 

Just to give you some sort of reference, I'm running a 15T front and stock rear sprocket. Engine speed at only 100KPH with this set-up is already 5400RPM. I think you would have to change the gearing drastically to be in the 5's at 130kph. Good luck though, and please share the results.

The CS sprocket I'm using now is for the Eliminator 250V...it's a perfect fit. I believe you can go all the way to 17T on the Eliminator, but I'm not sure how much case clearance would be left on the KLX at the size. I think the stock CS guard/cover would likely need to be removed, regardless.

 

yeah I was sort of dreaming about that one. Are you using 17" rims on your bike? I wonder what your overall rear wheel diameter is.

 

I'd have to measure, but the D-tracker's 39T stock rear sprocket and 17" wheel - tire combo brings the effective ratio to pretty much the same as the KLX 42T on the dirt rim and tire.

 

ive been thinking about running a 15 tooth lately, i think a klx with pipe and jetting can run it atleast on the street. if i do ill post up, but it might be me being cocky from running a really worn out 110/80-18. well see once i switch to a stock xr650l rear tire, think its 110/100-18.

 

I use a 15 tooth countershaft sprocket with a 50 tooth rear sprocket on my BB 331 KLX. The engine has ample low down torque to drive this higher gearing and will top out at around 120-130 km/h. I only ride off road and this gearing is OK to take off in second with a touch of clutch and will lift the front in 1st, 2nd and 3rd with a twist of the wrist.

 

Not really higher gearing, just bigger numbers. Pretty well the same as 14 - 47. Which is lower than stock. You've added weight; larger sprockets and longer chain. Higher gearing would be 15 front with stock rear.

 

What model is your KLX? I run 14/47 on my '06, and the rear sprocket gets darned close to the lower chainguide with the adjusters at the "1" position. In fact, I have to loosen the lower chainguide to remove the wheel. It's easy to do that, but I'm not sure a 50 would clear my chainguide without the rear wheel/chain adjustment being back pretty far. I like the wheel somewhat forward for the off road handling influence that it gives this bike. On the other hand, most people probably wouldn't notice it, so no big deal.