my official build thread. pro street bike

Discussion in 'Frame Mounted Engines' started by runslikeapenguin, Jan 20, 2009.

  1. hello all.

    a while back i decided to stop driving a car while i went to school and start riding a bike, and i discovered that my dad had an old moped stashed among the bikes i had stored in a shed we had. so i basically rebuilt the thing in one afternoon and hit the streets for close to a year loving every crazy adventure of a ride. well i moved out of the state and i dident take it with me so instead of paying a hefty price for another moped i figured i could build a pretty sweet motorized bike for less money and get something cooler.

    originally i was going to build this thing completley custom from the frame up but i realized that i wasn't sure exactly what i wanted, its hard to make decisions like rake, trail, wheel base, post height, pedal placement, gearing vs wheel size etc. etc.
    so im going to do a preliminary build with a 26" beach cruiser frame and go from there. when its all done i will sell it and start over from scratch and build exactly what i want.

    my moped would top out at 32, had decent pep with a centripetal clutch paired up to a 50cc engine. i was fairy happy with the cruising speeds, the dead stop pull power and the top end that was limited by the gearing and the clutch. so with a 70cc engine, an expansion chamber, some port work, a balanced bottom end with better bearings, a tuned bigger carb with a custom manifold a boost bottle and possibly a reed cage (not sure if im going to go there yet) boosted compression and the right gearing, all bolted up to a lighter frame, im hoping i can get this thing to haul some ***. im thinking cruising speeds of around 30-35 and a max out around 45+. yes im nuts.

    so here's what im starting with.
    its a shame the paints actually super high quality metal flake 2 stage. why the company i bought this frame from painted it with this i dont know but its coming off for welding and new paint. its hard to see but trust me its pretty up close.

  2. She ought to be sweet, dig that seat. Find a used donor bike. It gets real expensive building a whole bike one part at a time.
  3. i have a few bikes i could use a donors but if im planning on exceeding the speeds im setting for my self, and make it sane at those speeds i cant cut any corners.