Is the hub strong enough?

Discussion in 'General Questions' started by Rapidrob, Jul 19, 2012.

  1. Rapidrob

    Rapidrob Member

    I have a early 60's Schwinn Knucklehead Boulevard Cruiser that I'm thinking about putting an engine on . A few years back I put in a Shimano 7 speed hub as I live in the mountains and every direction seems to be uphill.
    If I was to install a 2 or 4 stroke engine of 1.5-2 HP,would this hub be strong enough to take the speed and torque of the engine? I understand the force a human leg can place on the crank shaft of the peddles but would hate to trash this outstanding hub.
    I'm also open to any ideas as to what engine to use on this bike. It's a tank to be sure.
    Thank you.

  2. Greg58

    Greg58 Member

    Some will say I'm wrong but if you don't abuse it just about any hub will work. I have two bikes, one has 12ga spokes the other has 14ga . I haven't had any problems with either, the op cruiser has about 800 miles on it.
  3. Rapidrob

    Rapidrob Member

    Thank you for the reply.
  4. Purple Haze

    Purple Haze Active Member

    I agree. Unless you have a heavily modified engine, shouldn't be any problem. One option would be an aftermarket sprocket mount that avoids mounting to the spokes, but I've never had any trouble using the stock rag joint. Be sure it is centered and true'd, that's where most hub and chain problems occur.
  5. Rapidrob

    Rapidrob Member

  6. It all depends on what sort of kit you will use. If you go with a cheap China Girl/happy time kit, the power is applied to the spokes through a rag joint sprocket. The only power going through the hub will be you pedaling, just like now. A friction drive applies power to the outside of the tire, so again, no power goes through the hub that isn't going through now. If you use a shift kit or one of the kits that puts the power through the standard chain drive already transmitting power to the hub, then you MIGHT be able to over torque the hub.

    To get information from us, don't make us guess what you are doing. Be very specific as to what sort of drive/engine you will be using so we can answer your questions.

    I always had good luck with a Subaru Robin EHO35, but I'm certain the Honda 35 is as good. If you decide to go 2 cycle engines, consider a Tanaka. They are much louder than 4 strokes, but put out a bit more power with a bit worse fuel mileage.
    Last edited: Jul 21, 2012