Roller OD to speed?


New Member
Sep 21, 2008
Los Angeles,CA
Looks like my top speed is going to be 32mph on the 33cc Saw. Im running a 1.5" peg with some tack welds so im figuring its at 1.75". Would it be too much on the engine to run a 2" roller which would come out to about 2.25" with tacks?

The 3/4 pipe nipple roller with tacks got me up too about 25mph. Im looking to get to a good 36mph. cruising. I can always swap rollers when i get to the big hill on the way home.

The tires im running are 26x1.95. What would be a good tire pressure to run with a friction drive? Right now they are at 40psi which feels good but i wondering if i fill them up more then the roller will have less contact area ans it will be too much tension on the spring.
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minor bike philosopher
Jan 15, 2008
north carolina
Bigger the roller the longer it take to get up to speed but it will go faster. on my 42 bike I have to pedal like mad to get it moving then it picks up okay, but if I dont give it a serious boost it chokes off.

When I had the smaller wheel on it, the thing got up to speed easier but it was much slower. I would settle for 25mph no problem. I rode the 42 today with the wheel at about 1.75 And it picks up speed pretty well when it is moving which is good since it needs to bleed it off on the hills.

I have a 3/4 inch with epoxy or about an inch one to try next. I think I might have to wait a couple of days the nasty weather is moving in.