Huffy Puch update

Discussion in 'Antique Motorized Bicycles' started by professor, Sep 15, 2011.

  1. professor

    professor Active Member

    The vibration issue was really bugging me. I went so far as to order a different style "Clone" engine, thinking that the vibes were unique to the HF 212. Got a nice go kart motor put away now- both shake the same.
    Brainstorm- isolate the engine with rubber isolators (not just rubber pads).
    Pic one is a sample (smaller but same style). Came from McMaster Carr.

    These babys work, I was able to raise the engine up to fit them in.
    But they are a bit squiggly so I added rubber bump pads to the engine topside - to compensate for drive belt loading.

    I get some shake at idle like before, but everything goes away on rpm.
    I mean REALLY goes away. It's like a new motor.

    This bike reminds me of the big block vette I had long ago. The engine dominates the bike.
    Still using the governor and I love it, knowing it is rpm limited to around 4 grand (peak power according to a dyno report I saw) @ 35mph.

    I changed the exhaust to go backward into the Puch muffler that I opened up the baffle holes (big-time) sounds very quiet with a cycle-like note. The exhaust has 3 slip joints in it with a smear of orange silicone, and doesn't make any weird noises- also allows for engine movement.

    The only questionable areas are some belt slippage at full throttle- not real bad, but is there- I can live with it as the bike is accelerating at a fair clip even with a bit of slip.
    And the drive chain is 10 speed stuff- seems to be holding up OK.

    Full suspension is wonderful- I am not getting pounded going down a road that is a bit rough. Really, this thing rides like a motorcycle.

    Gas milage seems real good - motor is loafing most of the time. I typically ride between 15 and 25 mph.

    I have a CVT coming and may experiment with it, but this has no trouble getting going as it is. And it is simple.

    Attached Files:

  2. MikeJ

    MikeJ Member

    Hi Professor -

    Thanks for posting your pics. You really placed a 212 cc engine in that frame? That's amazing. Good for you. I like the overall design, especially placement of the rear wheel relative to the seat post.

    Recall that I put together a really long yellow bike. At speeds above 27 mph or so, the frame would oscillate, like a shudder. That was a bad discovery. I suspect it was because the frame had too much play in one joint. My bike's frame is now in the phase of being welded into a shorter, more stout, one-piece frame. My bike's rear wheel axle will be about the same distance as yours from the seat post.

    After I get my bike back together, I hope it rides as well as yours. As far as belt slip goes... I experience about 3.5% slip when compared to no-slip Excel spreadsheet calculations. I dismiss the slip as a tradeoff: no high-speed chain noise and no lubricant slinging onto my clothes.
  3. professor

    professor Active Member

    That shudder might have ben generated by wheel balance. Sure, you could have a loose joint, but it would just sit there if other forces are not present. My 2 cents.

    My legnth came about mainly because I didn't want to cut-up the rear triangle and I needed to fit that engine to clear my feet. A bit shorter would look better. The plus side is long bikes handle super once you get going, as you know.
    I well remember your set-up. A couple of you guys pioneered the long bike!

    I love belt drives.
  4. Happy Valley

    Happy Valley Active Member

    Hi professor. Do I recall correctly reading you used a moped frame which yielded a VIN so your bike is registered as a moped?