49cc on a 10 speeder

Discussion in 'Performance Mods' started by -CON-, Mar 3, 2009.

  1. -CON-

    -CON- New Member

    Hi! Just bragging about my bike. Hope you don't mind and will check my videos!

    Some specs> 49cc, custom expansion chamber exhaust, took me 6 hrs and approximately $150, engine internals somewhat ported and polished, increased compression, accel spark plug wire, rotary engine (trailing) spark plug NGK, don't try this plug it needs to be modded! Bicycle standard chain, chain self tension mod, 40 teeth rear sprocket, maximum speed reached 72km/h or 45 miles/h with 38 teeth, and a 150lbs rider, bike weight 55lbs, aluminum frame, 28 inch wheels, puncture less tires.

    Thanks !



    Attached Files:

    Last edited: Mar 4, 2009

  2. DetonatorTuning

    DetonatorTuning Active Member


    real nice derailer based chain guide/ tensioner.

    the vid of you burning that corner apex is excellent. pure Isle of Man technique.

  3. nadroj

    nadroj Member

    cool chain tensioner. I would swap your handle bars, dont the ones you have on there get annoying..
  4. -CON-

    -CON- New Member

    Yeah I kind of went through that corner like 50 times before I shot that video!!

    Handle bars yeah the back after long riding gets stiff a bit but I kind of got used to it, actually it's not that bad I like it because I could lean against the bars, it supports my body.

    Thanks guys !!
    Last edited: Mar 4, 2009
  5. The Seamus

    The Seamus Member

    I didn't not know you could motorize a road bike. Any special mods to the bike itself to run the engine on that?
  6. -CON-

    -CON- New Member

    No really! All I did just put longer studs 11mm, stainless steel actually, even for the cylinder it is better to replace because the ones it comes with (10mm) is no good it's like it's made out of paper, easily breaks!
    Last edited: Mar 4, 2009
  7. Mountainman

    Mountainman Active Member

    nice job -- looks like fun on that MB ride

    ride the motor bike

    TINKERER Member

    Cool Ride!
  9. fastboy9

    fastboy9 Member

    Love your bike mate, We've both got a pretty similiar set up, Just waiting for my new carb and I can finally see what it can do lol. After seeing how good yours is I cant wait!!

  10. Esteban

    Esteban Active Member

    Some , but not all, of the older road bikes can do pretty well with an added engine. The lightweight bikes, skinny tires, etc., can make for a fast ride. BUT, around here, the roads are just too rough for it !
  11. -CON-

    -CON- New Member

    Thanks guys !!

    Yeah the only thing that is annoying on my bike is that there is no suspension, it needs a front suspension, it gets very bumpy some times, one time it shook my hands off the handle bars I almost flew over but I did flew over but it wasn't at that time and not because it was a bumpy road, anyway I think it just needs a front suspension, that would be nice. They sell a suspension for the road bike with only one shock on the center of the fork, pretty cool one actually, I forgot the name.

    I think I am going to park my MB for a while, I just got my self a new 50cc DERBI GPR, so I'll be riding that, which is OK because my MB needs a repair work.

    I was riding it one day and the engine just staled and seized, I thought "oho I melted a piston!" Then I opened it up it was all OK, turned out I need a crankshaft bearings. Probably going to get NSK, hope they make bearings that size!

    With high compression and high RPM it was probably detonating a bit which in result crushed those Chinese bearings, or maybe wasn't enough lubrication, I didn't opened the engine that far yet, so I don't know. I knew something was going on but no mercy, I was pushing it anyway until it died. Oh well now I have a risen for taking it a part, maybe I"ll do more porting, I'll go max on it see what it could do!
    Last edited: Mar 8, 2009