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HP to speed ratio

Posted: Fri Jun 09, 2006 2:12 pm
by Shrimphead
I'm looking into building a mini bike, and the plans I found said that with a 2.5 HP engine it could go 10 mph. I was wondering if it putting a 5 hp engine on it would make it go twice as fast. Maybe even more? I was thinking that say the bike needs anything greater than 1 hp to move. So a 2.5 hp engine would effectively be giving it 1.5 hp of speed. Then a 5.5 hp engine (for good number's sake) would be giving it 4.5 hp of speed which is 3 times as much as the 2.5. Is this right?

TOPIC MOVED BY PIMPMANN22- This obviously isnt spud related so it belongs in off-topic.

Posted: Fri Jun 09, 2006 3:04 pm
by alex bennett
no such thing as X amount of hp to speed. many, many other factors to speed. But yes, a bigger motor has more potential to give you more speed than a smaller motor, mainly on a bike you want to look at transmission gears/clutch to rear tire sproket ratios. but im assuming your going with centrifugal clutch. So a small sproket at the clutch and a big sproket on the rear tire will give you torque, such as my mini that has a 7 or 8 tooth sproket at the clutch, and a 32 tooth at the tire with a huge fat sand/mud tire w/ a 5 hp motor allows me to wheelie like nothing, and get up to ~ 35-40 mph. You willl have to do some research for sproket ratios, smaller sproket in back = more speed.

Posted: Fri Jun 09, 2006 8:07 pm
by Shrimphead
Ya I'm sorry about that pimpmann, I just realized that I put it in the wrong section. Anyways, I was originally thinking centrifugal clutch, but if I can afford it, I might go with a torque converter instead. What do you guys think of that? Expensive, but I think that it would be simpler overall. Is that right? And that will help me to get torque when I need it, and speed when I don't.