How many rear sprocket teeth for wide tire

[BobbedSled]

Stock motor no big bore or long rod super cammed race fuel deal. Just a plan old stock motor.

Gearing multiplies torque so going up in the rear should work well at the expense of cruising speed, but as a bar hopper/fun bike that is an acceptable tradeoff. I can go down in the front too I know but I prefer to go up in the rear for aesthetic reasons.

Will be running a 240 Avon tire. I am speculating that I will need to jump from a 34 rear tooth count to a 38 tooth count. That sound right size wise given the tire load compared to stock? 240 is a pretty big girl.

Thanks!

 

[jd750ace]

That's a LOT of rotating mass to pull with a stock motor. If I were trying that out, I'd probably get the largest rear sprocket available and a suitably long chain with several spare master links. Might take a good bit of tinkering to get it happy.

 

[BobbedSled]

Right, I have 2 chains actually as I am running a jack shaft. I am starting with a 38 tooth sprocket.
Sprockets have to be custom made, thus largest rear sprocket available is somewhere around 75 or so. No way it need to be that large.

 

[I am Carbon]

I had a 38t rear 17 front no real top end but lots of get up and go!
around town okay
wide open spaces not the way to go

 

[BobbedSled]

what size rear tire? Guessing 200?

 

[I am Carbon]

I will have to go a look.
not wide it is a 18" wheel probably around 4" wide
the bike was a tracker when I got it.
so top end was not what the PO was looking for