Thursday, April 28, 2011

Bolt-On Moped Power

My friend (and motorcycle/moped sensei) Barry dropped by the other day with this inexpensive cruiser on which he'd mounted a bolt-on 49cc engine kit. I took it for a ride, and frankly I was surprised at the performance. The engine is a simple 2-stroke affair that delivers power to the rear wheel via a sprocket that clamps on to the left side of the wheel. There's a sharp looking fuel tank, a twist throttle, and a left hand clutch lever, just like the big bikes.

Performance is surprisingly zippy.  You start the engine in traditional moped style by pulling in the clutch and pedaling up to speed. Braking on this particular bike is done via the coaster brake, but I'd add a front caliper brake if it were my bike.

Barry tells me the supplier of these engines also has a kit that uses a freewheeling front crank and a jackshaft to route power through the crank. This allows the engine to take advantage of the bike's derailleur or hub transmission, meaning you can have a 50cc moped with a 16 speed (or more) transmission. I'm not saying this will make a bicycle into a TT competitor, but it would be interesting to see exactly how fast such a bike could be made to go. And you know, I think Barry has some cans of Nitrotoluene-spiked 2-stroke racing oil in his garage...

I don't have a suitable bike  to bolt one of these kits on at the moment, but I think I'm going to keep my eyes open for a large cruiser frame- and maybe a 5 or 7 speed rear hub, too.

1 comment:

cRiPpLe_rOoStEr a.k.a. Kamikaze said...

It's not hard to find models in the 40cc displacement range in Uruguay, with Chinese chainsaw engines.