HF 99cc Engine. Recommend a Friction Drive Kit

Discussion in 'Friction Drive' started by Nehmo, Sep 7, 2012.

  1. Nehmo

    Nehmo New Member

    I want to use this HF 90cc engine . What are the recommendations for drive kits? I seethe bikemotorparts appears to be a dead site, but I understand there are competitors​

  2. Richard H.

    Richard H. Member

    There are FD kits from Staton, reputable and made in the USA, others are available made offshore from Dax and eBay sellers as well. These kits are usually associated with 33cc to 50cc engines that weigh between 8 and 12 lbs. I cannot imagine hanging a 26 lb engine like the HF off the side of a bicycle. In fact, I can't feature mounting something that big anywhere on a bicycle frame, but that's just me. Is that size displacement legal on a MAB where you live?
  3. grinningremlin

    grinningremlin Active Member

    As "Richard" said 33 to 50cc's.From first hand experience, my first engine was a HF 52cc and a BMP kit, instead of slipping in the clutch where you want it to slip, it would slip the tire AKA rubber dust.Because of tire slip it constantly broke clutch springs, and the compression was so high I would lift up the back of my bike starting the beast.Have since moved to a 33cc 4stroke, and it's more like being superman on a bike, you have to pedal, but you go so much further/faster.
    If you are bent on the 90cc consider frame mount chain drive ( I saw a Husky 72cc frame mount and the dude was SO bow legged), or if you're going friction your drive spindle will have to be bigger than any makers housing I know of, anything lower than say a 2.5" spindle would just grind a hole in your tire pronto.
  4. Nehmo

    Nehmo New Member

    Which one? Actually, I was hoping somebody already had experience with this engine and could point to some kit in particular.
    If I were to make the drive arrangement from scratch, I would mount the engine above the rear tire. But that's my inexperienced guess. I see most engines are mounted to the side.
    I'm in Kansas City, which straddles the Kansas-Missouri state line. The limit it 3 hp in MO, and the law is ambiguous in KS but 3.5 hp probably safe. The 99 cc HP engine is rated at 3 hp, and there's also a 79 cc version, but the weight is the same.
    One more point. I'm settled on using a 4-stroke.
  5. Nehmo

    Nehmo New Member

    I finished motorizing the bike some time ago. I posted about it in the other mbike forum. But now that I know the admin is a fascist, I'll no longer post there.
    The first pic is current. The second has more detail, but I moved the gas tank since I took the pic. snapshot2013022734.jpg
  6. darwin

    darwin Well-Known Member

    How does it work, how fast? Eating up your tires? Good job putting it all together.......let us know. How does the weight affect balance/ride?
  7. Nehmo

    Nehmo New Member

    (I"m OP, and the engine is actually the 79cc version of the Predator) It will never be a finished project as there will always be improvements possible.
    The current state of build is different form the big pic in that I moved the gas tank to in front of the bike (secured to the frame; not the handlebars).
    The bike does OK on the flats, but the roller-tire contact doesn't provide enough friction to transfer enough torque for a good hill. Also, the roller, made from wood, wears down after a while. This lowers the gear ratio and eventually causes the engine-support frame to rub the tire.
    Yes, it's certainly better than a plain bike, but there's plenty of room for improvement.
    On the next one, I won't have the motor & roller bearings both fixed to the same mounting-frame. The clutch needs to operate without the weight of the engine.
    Every day, people compliment me on it , but I can't take much credit because it wasn't complicated to put together. I believe a man (girls are excused) *should* at least have this much mechanical skill. I also don't deserve being told "good job" because I don't see it as such. If my father were alive, he would be critical, and I model him in my mind for judgement sometimes. (I'm using public WiFi and I have to go , so I'll post now.)