Another Friction Drive, Last One I Swear!!

GoldenMotor.com

OC_Hugh

Member
Jul 18, 2017
40
2
8
NE Washington
Another very interesting build CB, if I may call you CB.

I'm thinking of combining your centered rack mount with this scissor lift mechanism. Clearly the offset install works fine but I prefer the look of the motor centered.

The HF engine would chain drive a jack shafted roller. I really like the idea of being able to shut off the motor if I'm peddling or feel the need to be quiet and then bump start it and ride it up the hills.

Does that seem a reasonable idea? Maybe I should stop reading and start building, too many good ideas actually hinders my ability to get started. Anyone else have that problem?
Hugh
 
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Dan

Staff
May 25, 2008
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LoL Hugh. Yes, that is common. To many ideas and to little time.

Like when an engine won't start. I try the simple and easy first. Ya can build on it later.

Really cool part about this. Parts and tools never go to waste.
 
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xseler

Well-Known Member
Apr 14, 2013
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OKC, OK
LoL Hugh. Yes, that is common. To many ideas and to little time.

Like when an engine won't start. I try the simple and easy first. Ya can build on it later.

Really cool part about this. Parts and tools never go to waste.

I'm beginning to think that half the reason I built my bike is so I could stop feeling guilty for having a 'junk pile'..........there's a reason for everything!

scratg
 
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Dan

Staff
May 25, 2008
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No kidding. I have boxes and draws full of old washing machine springs, old actuator arms and just plain junk. But at the oldest times, they can be used, made to fit or in rare occasions, the perfect part and the only thing that will work.
 
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cannonball2

Well-Known Member
Oct 28, 2010
3,682
221
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Colonial Coast USA.
Another very interesting build CB, if I may call you CB.

I'm thinking of combining your centered rack mount with this scissor lift mechanism. Clearly the offset install works fine but I prefer the look of the motor centered.

The HF engine would chain drive a jack shafted roller. I really like the idea of being able to shut off the motor if I'm peddling or feel the need to be quiet and then bump start it and ride it up the hills.

Does that seem a reasonable idea? Maybe I should stop reading and start building, too many good ideas actually hinders my ability to get started. Anyone else have that problem?
Hugh
Yep CB is fine.
I built two offset Lifan bikes. This one and a full suspension Mongoose that I still have. The reasoning was to get the engine as low as possible. Also running a bigger bore engine(the Lifans are torque monsters) eliminated the need for any form of transmission save the roller. The rollers could be changed in about a minute making ratio changes a snap. I carried several sizes on the Mongoose for various terrain/ weather conditions(I had a rain roller). They were all wooden with oak being my favorite. Quick to make with a hole saw. I rode the Mongoose over 8k miles before the speedo checked out, and again about that much more. It was/is the most pleasant usable bike I have built.
Adding complexity to an FD sort of defeats the advantage of its simplicity. I have certainly done just that. If you are wanting to build a jackshafted roller, I would suggest belt over chain Its quieter and has no backlash(irritating!). It is easier to get ratios with a chain especially the smaller T8F sizes but depending on engine size large reductions arent really necessary on an FD.
Also bump starting a larger engine is a trick with direct drive and even more so through a reduction. The HF will drive directly just fine but only(easily) offset .I have seen and thought about using a vertical engine(cheap and plentiful) driving the side wall, that would be above the tire and basically centered.
Figure out what you like and want and build it the way you want it. Im a real fan of friction drive, and just about every other kind of MB also!

If I can help you in any way let me know!
 
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OC_Hugh

Member
Jul 18, 2017
40
2
8
NE Washington
Yep CB is fine.
I built two offset Lifan bikes. This one and a full suspension Mongoose that I still have. The reasoning was to get the engine as low as possible. Also running a bigger bore engine(the Lifans are torque monsters) eliminated the need for any form of transmission save the roller. The rollers could be changed in about a minute making ratio changes a snap. I carried several sizes on the Mongoose for various terrain/ weather conditions(I had a rain roller). They were all wooden with oak being my favorite. Quick to make with a hole saw. I rode the Mongoose over 8k miles before the speedo checked out, and again about that much more. It was/is the most pleasant usable bike I have built.
Adding complexity to an FD sort of defeats the advantage of its simplicity. I have certainly done just that. If you are wanting to build a jackshafted roller, I would suggest belt over chain Its quieter and has no backlash(irritating!). It is easier to get ratios with a chain especially the smaller T8F sizes but depending on engine size large reductions arent really necessary on an FD.
Also bump starting a larger engine is a trick with direct drive and even more so through a reduction. The HF will drive directly just fine but only(easily) offset .I have seen and thought about using a vertical engine(cheap and plentiful) driving the side wall, that would be above the tire and basically centered.
Figure out what you like and want and build it the way you want it. Im a real fan of friction drive, and just about every other kind of MB also!

If I can help you in any way let me know!
Thank you CB.
I started a build thread here
https://motorbicycling.com/threads/my-1st-build-cb2-inspired-rack-mounted-scissor-lift-fd.63226/