1. breath_easy13

    Torque Converter Not Lining up

    The build hit a major halt last night. After mounting the engine, I started to install the torque converter from COMET only to find that the backside of the plate was butting up against the seat post. After an hour of moving the engine around, trying out different placements for the converter...
  2. G

    420cc Motorcycle Build Ideas

    First time on this site as a member, but I've built one of these 66cc bikes before, now i'm addicted and want to go further. I want to use a 420 predator to make an actual 50mph motorcycle. My question is this: Where can I find a small (minimum 3 speed) transmission that can take up to 20 hp...
  3. T

    Looking for replacement sprocket for HuaSheng 49cc transmission

    Need a replacement sprocket, but am having difficulty finding one that fits this type of shaft. Please let me know of anyone who sells this sprocket or this transmission . Thanks.
  4. waynesdata

    79cc gear ratio?

    Most kits I have seen have the same default gear setup. Motor Sprocket 11 tooth Jackshaft Input Sprocket 22 tooth Jackshaft Output Sprocket 9 tooth Wheel Sprocket 44 tooth Tire Height 26“ Is this gear ratio ok?
  5. TheNecromancer13

    Help with 2 speed auto for 79cc

    A while back I tried to build a 2 speed manual trans for my 79cc bike, I have since scrapped the idea. I want to build a 2 speed auto instead, but I really have no idea how to go about doing it. I have seen pictures of them made using 2 centrifugal clutches, but don't know how to do this. Can...
  6. TheNecromancer13

    2 speed 79cc predator build

    After building a few 79cc predator bikes for friends of mine and having them turn out far better than the first one I built for myself, I want to have the best bike again, so I'm starting a new build on an old trek 820 with a 21" frame that I got off craigslist for $150. I figure I'll keep my...
  7. TheNecromancer13

    Dog clutch question

    So I was looking around the other day and I came across this DIY 2 speed dog clutch: Here's a closeup: It looks like a useful (and cool) thing to add to my...
  8. A

    Arrow 9.5HP 66cc Grubee

    A bunch of us are upgrading from the 4.5 to the 9.5HP Arrow engines. We like the power and performance of the 4.5 with a 36 tooth direct drive. With a motor with twice the HP how can I add multiple gears or automatic derailleurs to the "transmission" of power from the engine to the rear...
  9. D

    Used Qmatic Wanted

    My stock wet chain transmission is slowly coming apart in its teardrop casing of death. I need me some real American made quality! .flg. Anyone looking to get rid of their used Qmatic? Condition doesn't matter to me as long as its functional. All the hardware the transmission comes with would be...