Need help choosing a Freewheel

[Tim Bailey]

I hope this is not to far off the bike business: I'm trying to make an electric start for a generator and Id like to attach a "cut down" wheel hub to the flywheel of the engine and then attach a freewheel with a large sprocket. I would like a freewheel that has a 4 hole bolt pattern for a blank sprocket and it needs to drive in the clockwise direction, like a standard BMX bike. I'm assuming most freewheels designed for motorized bikes drive in the counter clockwise direction. Any recommendations for such a devise will be greatly appreciated.

 

[Sidewinder Jerry]

They do make left side freewheels they have left hand tread inside of them. Staton Inc has a lot of custom adaptors for freewheels.

Staton Inc

Staton-Inc a world class manufacturer of motorized wheelbarrows, motorized bicycles, bike engine kits, gear drive kits since 1984.

www.staton-inc.com

 

[5-7HEAVEN]

Most people use pocketbike freewheels, and most freewheels spin clockwise.

Pocket bike freewheels have M6 4-bolt or M5 5-bolt patterns. The sprocket will need to be bored to a 54mm diameter.

Freewheels and properly drilled and center-bored sprockets are widely available on ebay, at reasonable cost.

 

[Sidewinder Jerry]

Here is but one of several left side freewheels I found on eBay. They have a left hand tread and yes they spin counter clockwise.

Clutch Bearing/Freewheel Left Handed Thread FOR BIG WHEEL CAMODO GAS SCOOTER | eBay

Find many great new & used options and get the best deals for Clutch Bearing/Freewheel Left Handed Thread FOR BIG WHEEL CAMODO GAS SCOOTER at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[Tim Bailey]

Thanks a bunch, I found Staton and I think they have a great selection. Most freewheels I've seen don't really mention if there clockwise or CC and some don't mention thread direction. This was the unknown at the start of the day. And while I have some helpful ears: Can I assume most 26" wheel hubs are 1.375 x 24 TPI? I'm not sure of the ratio I need for the project yet but assuming a 5:1 or 6:1, I'll need a small sprocket for the 1/2" shaft of the motor and a larger one that will be machined to fit the freewheel. I think a 1/8" bike chain is strong enough but I want to select a size that was sprockets that fit my needs. Would I be better off using chain size #25 for availability reasons? Thanks again.

 

[Tim Bailey]

Pocket bike parts seems to be what I'm looking for. Thanks for advising ebay.

 

[5-7HEAVEN]

Pocket bike chains and sprockets come in #25 and 8mm, commonly known as T8F. BMX chain is strong 1/2 x 1/8, aka #35 chain.

If size matters, a 60 tooth 1/2” pitch sprocket is 9.55” diameter.

Same size in T8F (.315” pitch) is 6”.

Same size in #25 (1/4” pitch) size is 4.77”

 

[5-7HEAVEN]

Re: freewheels, about 97% of them are right hand threads with 1.37 x 24tpi. Right side wheel hub is right hand threaded; left side is the rare left hand threaded, except for fixie wheel hubs. Staton has left and right hand sprockets with built in freewheels.

Staton also has small sprockets with 1/2” bore. They have 8 tooth up to 20-something, I believe.

They also have 40t and 48t that’ll bolt directly onto the freewheels.

As does EBay.

What only Staton has are the adaptors that match the freewheels to the 1/2”, 5/8”, 3/4” and 1” shafts.

 

[Tim Bailey]

I'm totally impressed with all the help and detailed data that you all have shared. You answered all the questions I wanted to ask but I was afraid I'd wear out my welcome. This has been a real pleasurer and I look forward to sharing the results of my project. Thanks again for your help.

 

[5-7HEAVEN]

Any pictures or drawings of your project?