5speed engine?

[Fablab]

Hey guys,

In the process of building a postie bike as a weekend parts runner.
Just wondering if any company's are making a 5 speed pit bike engine?
The plan is to swap out the motor for a 160 or even a 190. The problem is, I rode a friends postie with a 140 which was great fun, but it was topping out at avout 70ish k's. Most of the roads around me are 80. So that would have to be the minimum as it would see regular use.
If not, has someone got a formula to work out sprocket sizes vs rolling diameter?

Cheers, Ben.

 

[xLOCOx]

cool as!! we had a few blokes come into the shop and got their posties serviced then rode'em half way across australia! LOL
Yeah looks like your out of luck on the 5spd gbox engines, but if your handy with a spanner you could put one in, only that that gbox will cost dollars!!! Takegawa TAF 5 Speed Transmission - Lifan Engines
i personally would reccomend the yx150 to you due to the fact it has lighting/charging coils and a elec start, whack some goodies on the topend (high lift cam roller rockers port polish) then slap a oko26 on her, then you've gotta work out the sprockets... 17t then 44? maybe 48...
hope some other miniriders can enlighten you further on this subject!
cheers loco

 

[my67xr]

Welcome to Miniriders,

Drop in and say hello in our Introduce Yourself thread too.


use this one to calculate your gearing,Gearing Commander: Motorcycle Speed, RPM, Chain & Sprockets Calculator
there are 2 extra lists where you can change sprocket sizes, also tyre sizes, it will even tell you how much extra/less wear you'll have if you fit lower/higher gears

it has already got a CT70 listed there so edit the gears and away you go
if you email them the specs of your bike and the pdf manuals they can add it into the list too.
i had them add my Braaap Pro Factory 190 to it, takes about a week to update.


Cheers, Craig

 

[gottagetacheaperhobby]

Daytona now have a road going version of their 190 4 valve beast available, and while it is a 4 speed, it is 1 down 3 up box and while get you well over 110 kmh depending how you gear it. It is expensive however, and the last pit bike engine I threw into a postie needed a custom bracket made for one of the engine mounts. If the cash is available though, I would definately be getting a 190 anima.

 

[my67xr]

I would also ring the RTA or your State Motor Rego office and check what engine size is legal too.
Most of them don't like engines bigger than +10% of the original size.
It could require an engineers report, along with upgraded brakes and tyres etc etc

as a comparison, it's a bit like me wanting to upgrade my 351 to a 700ci engine legally, it would be hard work !!