# Upcoming Roadmaster project



## hillbilly_handshake (Aug 21, 2014)

I am in the process of building a completely custom (some pre-fabricated parts, but this is not a kit bike) 1956 Roadmaster motorized bicycle. Here are the particulars.

Frame: 1956 Roadmaster boys' frame

Fork: Suzuki K10 hydraulic forks of unknown year

Handlebars: Bikemaster chrome universal Clubman (cafe style) handlebars

Wheels: custom, built by me. Front wheel is a 24" steel rim with 130mm Yamaha MX125 drum, 11g spokes. Rear wheel is a 24" bicycle rim with 94mm Motobecane moped hub (not vintage) 11g spokes

Tires: 24x2.4" Cheng Shin "Cyclops" tires

Motor: 79cc Harbor Freight "Predator" engine, governor disconnected externally

Pedal system: Since the moped hub is considerably wider than a bicycle hub, I had to widen the rear dropouts quite a bit. I'm almost certain that the chainring will not line up with the moped freewheel, so I've decided to use a jackshaft on my pedals for chain alignment. The jackshaft will NOT be connected to the engine drive. I'm going to install the bottom bracket with the chainring on  the left. Then I'm going to mount a jackshaft from Sick Bike Parts on the seat tube, under the engine mount. The jackshaft will be 1:1. One chain will connect the chainring to the jackshaft on the drive side, and another will connect the jackshaft to the rear freewheel on the pedal side. 

Seat: 13" wide Worksman seat.

Gear reduction: A company called Affordable Go Karts sells jackshaft plates that bolt right up to the Predator engines, this will provide the reduction to my drive system

Clutch: MaxTorque, modified to engage at roughly 2600 rpms

Gearing: this bike will be geared 13.5:1, roughly 30 mph at 6k rpm. I'm after hill climbing and takeoff, not speed.

Electrical: moped headlight, separate tail light and brake light, powered by a 12v, 1.4ah sla battery, which will be charged by a 12v bottle dynamo fed through a scooter rectifier.

Thats about all I can think of for now.


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