Typical Easily made motor bike

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MisterSteve124

Guest
Hi I'm Steve and me and my friend are going to be making motored bikes this summer. I thought I'd run some ideas and questions by you guys for some help. We just plan on making a simple, cheap and easy motor bike. We're just gonna get some cheap bikes and a rear mount and hook the engine up directly onto the gears on the bike with a clutch of course. His dad can weld so we were gonna reinforce the mounts to make sure they are sturdy. My first question is how powerful of an engine should we aim for. We both weigh about 130 lbs and want to go pretty fast hopefully 25-30mph. Is there anything we should know before we start buying the materials and building? Thanks for all your help in advance. Oh I forgot to ask is it easier to use a one speed bike or a multi speed bike? Or does it not really matter?
 
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MisterSteve124

Guest
why? I introduced myself in the introduce yourself thread and I posted this in the section for rack motor bikes because thats what it's about? It's not like its not in the right section can't someone just help me out here?
 

azbill

Active Member
Joined
Dec 15, 2006
Messages
3,721
sorry dude...I read this post before your intro...again sorry
I should have looked there first before my post
:eek::eek::eek:
 
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Alaskavan

Guest
My TREK does 30 - 35 easy with a 2.2 hp friction drive. I'd think you'd get better speed with chain drive.
 

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MisterSteve124

Guest
No proble azkronic it's all cool. Ok thanks for that information Alaskavan. I was looking at 3 hp 4 stroke engines and I think that's my best bet so far. Yeah I thought that going with chain driven would just be easier and hopefully more power. And what do you think about using a multi gear or just single gear bike. I know I wouldn't be able to switch gears without getting a shorter/longer chain but would it be better to go for one or the other or would it not reallly matter. I guess that would give easy adjustment for torque and speed but I will see what I can find.
 
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Alaskavan

Guest
I'm interested in any answers you get. I suspect that a bike chain isn't strong enough.
 
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MisterSteve124

Guest
I don't necesarily need to use a bike chain I just need to use a chain that will fit a bike sprocket. But why would you think it isn't strong enough? It should be fine.
 
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custom_tecumseh

Guest
I don't know if its the chain I would be worried about...

The center pedal crank sprocket on my 24" mountain bike has almost 3 teeth completely sheared off.:eek:

Probably from shifting while pedaling hard, and I'm sure 3hp is more than I can muster.
 
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MisterSteve124

Guest
What do you mean from shifting? I'm not going to be shifting at all. If worse comes to worse then the sprocket wears down and I replace it with a stronger one.
 

azbill

Active Member
Joined
Dec 15, 2006
Messages
3,721
I don't necesarily need to use a bike chain I just need to use a chain that will fit a bike sprocket. But why would you think it isn't strong enough? It should be fine.
you can use a bike chain, I use a heavy-duty bmx chain (KMC Z510H) on my bike, it is made for stunt bmx's (jumping), and is designed to take a lot of torque
I have been using it since building my chopper, and it hasn't ever stetched (between the 2 bikes must be 7-800 miles at least)
 
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