My first motorized bike attempt...5 or 6 HP LOL

The only reason it was done was because an engineering hot head told me it couldn't be done. Whats that? Oh, i DID strap a ginormous motor to the back of a BMX bike without hooking up the throttle control so i had to reach behind me to operate it....and it didn't have very good brakes...well i guess it was kinda dumb on my part, but no one was injured and i do not suggest doing it the way i did : )
Suicide Lawn Mower Engine Bike

On that note, I am thinking of going with a GX50 clone kit. I saw that there are kits that allow for this motor to be center mounted and rear mounted (both chain or belt driven) Any thoughts on which is better?

Hook up the throttle, get some decent brakes, and you'll have more fun than any human should be allowed to.

BTW- I have a frame mounted Honda GXH50 and I really love it, but from a thoroughly "practical" perspective, a rack mount is probably more functional.

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29/10ths cubic inches of raw power.
HoughMade at WIRED.com: http://www.wired.com/cars/coolwheels...memade_bicycle

That looks cool. Where did you find a 72t sprocket? I'm thinking the brake shoes are a bit expensive right now and you don't want them to wear thin or your toes will start to feel the heat...Kelly

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I'm racin' Spitfire, turnin', poppin' wheelies, burnin' evil chasin' pop,pop, pop,pop,pop.... (The Pixies-Tony's theme)

That is too cool! Make another video of a top speed fly by after you get the throttle hooked up. All I can say is....

Great work. I'd have to see it really go 50 mph but anything's possible. Ever get that throttle hooked up? The Briggs is a great, strong, reliable engine, much more so than the Chinese engines. If you go the clone route, I love a frame mount and it balances out the best, but chain alignment problems are a drawback and you have to alter the pedals to avoid hitting the engine. Dax's rack mount (Titan) appears to cure the chain problem since it adjusts up and down and no idler is needed. The main problem with the Chinese 4 stroke kits is the highly defective gearbox. There are 2 gearboxes out there and one of them will last about a mile. Don't know about the other one since I can't find one for sale. Dax's rack mount doesn't use those gearboxes. If I was in your shoes, I'd just use your Briggs setup and put it on a full size bike. No need to buy a kit. How'd you get the sprocket center hole perfectly centered when welding to the wheel?

I have the "other one". Works great.

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29/10ths cubic inches of raw power.
HoughMade at WIRED.com: http://www.wired.com/cars/coolwheels...memade_bicycle

That flat out rocks, You should do a write up on how evrything is built.