[karvinkarl]

Fellas,

I'm converting an old WR426 to SM. I will be mostly on the street/twisties and want to do 70/75 without blowing up. Any suggestions on what size front and rear sprockets I should use?

...and should I get a 4.25" or 4.5" rear wheel? A buddy has a 5" but it gets way too much chain-slap on both the rim and tire, so I want to go with something smaller.

Thanks!
Karl

 

[Kx250FRider651]

I don't have an older WR, just a new one. But I'm running 15/43 and it's pretty good for street riding/commutes, I can cruise 65/70mph and it's just purring along not too high in the revs at all.

4.25 is pretty standard size rear SM wheel, no real benefit that I see to go wider, just more fitment issues. My 4.25 with 150 rear is just barley touching the chain there's just a verrrrry faint chain mark in the very edge. May get the toxic Moto chain block just for peace of mind.

 

[elroy121]

im running 13-43 on the go cart track, with a 5 in wheel, the smaller sprockets and keeping the chain tension right keeps the chain off the rim, most pre built wheels are 4.25 , I don't see the 4.5 size much, and the 5 in rim is a tight fit but it works,