Sbp shift kit changing gears

[Luis M Ortiz]

Hello I have a sbp shift kit for my mountain motorbike. The 7 gears on the back wheel are very big so the bike only does good uphill. Is it possible to add more gears to the front of the shift kit where the pedals are and do more shifting there? (Any feedback helps)

P.s. sorry for bad explanation I don't know much about bikes

 

[ej132]

Limited knowledge here, but I believe sbp sells different size gears for the jackshaft itself, standard is 10t and they make a 9t and 11t. That would help some changing it out I believe

 

[Jonda500]

It is pretty difficult to set up with a front derailleur, it is possible but always involves compromises that I don't like such as mounting the engine higher, having the pedals wider apart, etc... You could just simply swap the chain wheels (put the 36T on the outside and the 44T on the inside), or get the 11T jackshaft gear and maybe also a mega-range gear cluster, e.g. 13-34. (I run 14-38 5 speed gear clusters on all mine.)

 

[Luis M Ortiz]

Thank you for the replies. I don't want to change out the chain gears because I need to keep the strength also. The megarange gears are exactly what I need but I just couldn't find what they were called. I will do that and get the 11t and megarange cassette. Does the 11t make a significant difference or will I still be able to go up hill

 

[Jonda500]

the 11T will give you 10% higher gearing, but if you change the cassette as well and first gear is bigger, your hill climbing ability should be the same - e.g. say if 1st changed from 30T to 33T, then it would be 10% bigger and combined with the 10% bigger 11T jackshaft gear, first gear would be exactly the same as before 'n top gear would be 10% higher...

 

[Luis M Ortiz]

ok this is exactly what i need. the highest range i could find online for 7 speed is 11-34 so i will just get that and an 11t jack-shaft gear. the one i have right now is i think 14-28 so i will be getting more speed and power. Thanks again for help

 

[Luis M Ortiz]

One last thing, I don't think the 11 tooth will be enough for my top speeds. If I wanted to get HIGHER SPEED would i change the LEFT side jackshaft GEAR Higher or Lower?

 

[Jonda500]

For higher speed you would need a smaller left side jackshaft gear - but they only have stock(17T) or a larger(23T) one available. You could replace the 36T drive chainwheel with a 40T chainwheel or alternately use the 40T in place of the 44T driven chainwheel - either way it will give you higher gearing for faster downhill speeds.

I messed around with many gear combinations - mostly giving me higher overall gearing (more speed), but after much testing have fitted all six of my bikes with 23T left side jackshaft gears, standard 10T right side jackshaft gears and changed BOTH chainwheels to 30T items. This gives me an overall gear ratio the same as the stock SBP kits' overall gear ratio. Higher gearing is great when you're going downhill, but for general riding around I found the final drive ratio that sbp's settled on is just right - unless you have a hotted up engine, I think they really nailed it.
I acheive the stock final ratio in a different way so that my bikes are geared low enough to pedal up even a steep hill without using the engine, and use the 23T left side so I can run equal size chainwheels whilst still keeping the stock final ratio..