Hey y'all, I'm working on planing out a diy build from an Old Briggs 80202 3hp I got running thanks to this forum. I have a pretty odd italjet bambino mini dirtbike frame I plan on cutting up to build a more traditional looking minibike. Probably just going to reuse the swing arm and fork. I also have a good deal of 420 chain from the king o lawn mower the engine came off of.
I've seen some ratio calculators but frankly I am a little confused about calculating. My rear tire measures roughly 15 inches in diameter and about 3 wide. I'd like to ride on dirt if possible, weigh about 145 lb, and prefer a bike that can climb a lil hill to one with an extra couple mph top speed. I'd like to avoid running a jackshaft if possible and plan on building the frame around that once I get a clutch and rear sprocket.
over here on this go kart ratio speed calculator i'm seeing that a 12/60 would give me a top speed of 32 mph which seems like a lot but I imagine the low end would be terrible?
I'm wondering if anyone has a similar wheel size and engine and could drop some knowledge my way?
ps. frame was free but the fella kept the original engine hence modding it to run my 3hp briggs
I've seen some ratio calculators but frankly I am a little confused about calculating. My rear tire measures roughly 15 inches in diameter and about 3 wide. I'd like to ride on dirt if possible, weigh about 145 lb, and prefer a bike that can climb a lil hill to one with an extra couple mph top speed. I'd like to avoid running a jackshaft if possible and plan on building the frame around that once I get a clutch and rear sprocket.
over here on this go kart ratio speed calculator i'm seeing that a 12/60 would give me a top speed of 32 mph which seems like a lot but I imagine the low end would be terrible?
I'm wondering if anyone has a similar wheel size and engine and could drop some knowledge my way?
ps. frame was free but the fella kept the original engine hence modding it to run my 3hp briggs
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