Tires Anyone Using Moped Wheels and Tires?

Discussion in 'Bicycle Repair' started by 5-7HEAVEN, Apr 22, 2012.

  1. 5-7HEAVEN

    5-7HEAVEN Active Member

    I posted this on the other forum too, but want to know how you members feel:

    How about something like these?

    I've read that quite a few builders use moped hubs and lace them onto bicycle wheels.

    They might not look cool (short 21.5" wheels in 24" fork/26" tall frame). However, they come assembled with short tough spokes.

    They can work with $15 Michelin 2.25 x 17 motorcycle/moped tubeless tires rated @ 93mph.


  2. professor

    professor Active Member

    I bought a moped for the paperwork, to turn my bike into a legal NY usable "Moped".

    Later, realizing I had a viable front end, hd.wheels with real brakes. So I made bike #2 using these components. great stuff. Still using the 1977 tires.
    Had to stretch the rear triangle a little and make tabs for the brake arm and mod the front fork to fit the bike frame. Does look different though.
    Was disappointed with the brakes until a few hundred miles elapsed (probably got rid of left- over rust). Am using a dual brake lever and life is good.
  3. BigBlue

    BigBlue Active Member

    5-7 Heaven,

    FYI, all your links are bad in the above post.
    They do work on the other forum :)
    AKA: BigBlue
  4. 5-7HEAVEN

    5-7HEAVEN Active Member

    Thanks for the headsup, Chris.
    Last edited: Apr 22, 2012
  5. birdmannn101

    birdmannn101 Member

    Professor, any chance of seeing some pictures of your moped conversion? I have a wrecked moped that I need something to do with it....Dan
  6. professor

    professor Active Member

    Dan- please do a search for "huffy puch" and my posts about that bike will come up.
    I don't know how to bring it to this reply. It does look a bit weird, I stretched it out a tad too far in the rear frame. But the long wheelbase handles and rides like a dream.
  7. 5-7HEAVEN

    5-7HEAVEN Active Member

    Awesome creation, Professor!

    I'm trying to make mine as simple as possible. The drive system will be a 10-tooth centrifugal clutch. The single jackshaft will be supported by a Torque-Convertor jackplate, with other end suspended by pillow-block bearing mounted onto the seat tube. Two jack sprockets and rear sprocket will produce 8.1:1 gearing as a starting point.
  8. professor

    professor Active Member

    5-7, thank you.
    I wanted to alert anyone about long chains.
    I have gone round and round with the long drive chain- added idlers to keep the thing on. The legnth was necessary because of the rear suspension- you need to keep the sprockets in line with the pivot point of the rear end.

    Initally I wanted to use a derailer on the bike hub (under the motor area) and select gears for the engine. Lots of issues, so I abandoned the derailer and used one of the sprockets for a straight drive. This is my long distance bike and has been working well now.

    Your gearing sequence looks good. Chains are noisy though, especially on the motor,a ten tooth is the smallest available, I think, and a 12 might last longer and be slightly quieter.
    I used McMaster Carr (credit card) to buy pillow blocks, keyed shaft, sprocket and pulleys/ belts. The blocks were not expensive and had set screws to retain position.
  9. 5-7HEAVEN

    5-7HEAVEN Active Member

    Hey Professor,

    What final gear are you using? Since both of us are using short tires, we can get away with numerically smaller gear ratios.

    FWIW, I'll be using 8-tooth or 9-tooth #40/41 jackshaft sprockets to connect to the 54-tooth wheel sprocket. A 10t clutch sprocket will chain up to the 12t jackshaft sprocket.

    I have had much better success with one-piece locking collars than setscrew collars. They're cheaper, and seem to work better:
  10. professor

    professor Active Member

    Hi 5-7, I was looking at my old post on the huffy puch, and noticed I had measured the gearing at 7.5. , now I do remember the 7.5 being correct.
    This gives about 34 mph- wound against the tweaked governor (4000 rpm).

    I really like using the gov. for 3 reasons- it aids in take-off with my hand operated clutch, acts a bit like cruise control at hills, and if a drive component should fail- the engine will not sky in rpm- flywheel can not explode.

    Somehow, I had in my mind a 12 ratio number- good I looked at that post.

    I say measured, because I hoisted the rear and counted revs. I think I removed the drive pulley key off the motor so it would spin easily.
    My engine sits with the spark plug right next to the right side or the frame and the engine pulley is still a ways off of being straight to the rear wheel where a sprocket would be- so I think you will need a jack shaft to get the chain straight. You WILL love this motor.

    My usage is quite different than your though, mostly I putt-putt at less than 20 mph on the side of the road like a bicycle.
    Crusing at 30+ would be too anoying rpm wise - would have to use some kind of CV or 2 speed set-up.