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Old 09-09-2008, 04:11 PM
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Revorunner Revorunner is offline
Motorized Bicycle Newbie
Join Date: Sep 2008
Posts: 12
Default Re: HT "80cc" Horsepower?

Originally Posted by Jemma Hawtrey View Post
Its not a separate transmission as such. The Fantic TI sportmoped had a completely deranged motor coupled to a 6 speed tranmission in the casing ala the standard motorcycle practice.

However.... this could be made, or at least something similiar could be. The shifter kit that pablo does is a great idea, but all the cassettes for derailliers are for cycling speeds... so you might get several ratios but you are limited to the available ratios that are fairly shallow for a motor vehicle because they are designed for pedalling.

To get a fantic-esque type of performance you would need to make up a cluster that has ratios more suited to an engine application than a pedalled one. A good trick would be a low first and second ratio (in case of emergency cycling) and then a gap to higher ratios that are more motor friendly.

However as compared with the CIF engines the Fantic mill was impressive to say the least. Below 50ccs displacement - 12:1 compression ratio (the CIF are something along the lines of 7:1) and either a 14mm dellorto carb (6.5hp) or a 19mm carb running the motor up to 7.2hp.

The only engine that comes close really is the morini engine that some have used on here and that so far as I know doesnt have an integral transmission.

hope that helped

Jemma xx
Thanks for the info Jemma,that's alot of horsepower for a bike.
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