What hub is this? 3 speed, 1 rear sprocket?

[oliveclown]

My dad has this 20 year old bike, called a freestyle fs 3. It has one front sprocket, one rear, but three speeds. The gearing is inside a drum on the rear wheel. I've never seen this type of setup before, but I'm sure you guys would know from just the description. Also, would it be possible to put a bigger rear sprocket on and power it through a jackshaft from a motor. How would I still pedal? Could I put the front sprocket on the left side, and add one sprocket to the left of the rear wheel? I'll put some pictures up if you need em. Thanks!

 

[andyinchville1]

HI,

Yes I am familiar with what you have, 3 speed internal geared hub....Fairly common....Can even shift while at a complete stop....Some say not beefy enough to use under engine power BUT half the fun is trying!

Ghost and Pablo make a jack shaft kit for the HT engines to allow use of rear gears...look them up in the vendors section here...Yes, you can still pedal and ride the bike like normal because of the front freewheeling crank....Check it out...Really a great idea and now they have a kit out to make it all happen...I'll get a kit when i get my new bike

Hope this helps you

Andrew

PS - Welcome to the forums!

 

[oliveclown]

Thanks for the welcome, and yes it was very helpful.

 

[andyinchville1]

Oh....For some really neat gearing you could try a SRAM Dual Drive....A 3 Speed Hub with the ability to use a Casette (9 gear cog or more possibly)...that makes for 27 rear speeds!...Plus the ability to select gears at a stop...

Andrew

 

[duivendyk]

These old 3 speed hubs typically have ratios of 0.74,1.0 and1.34, overall therefore about 1.7. The Shimano ones are fairly rugged,when kept properly lubricated (with oil).The max. torque they are subjected to from a 50 cc engine (with suitable reduction) is no higher than a cyclist standing on his pedals.The real problem is that an extra rear sprocket is needed on the hub to drive it with an engine and also maintain normal pedaling capability.(this is difficult to do)The SRAM dual drive might make this possible.The overall reduction needed from engine crankshaft to rear axle is,around 15-25 (depending on engine size)

 

[Mountainman]

Do you think that maybe it could be older than 20 years ?? If it has a little pull chain going into the hub -- may be English made. Happy Riding from - Mountainman

 

[duivendyk]

Could well be, both the Sturmey Archer and the Torpedo hub(Sachs) had this chain setup (the most vulnerable part of the thing).You can read up on these hubs in the Sheldon Brown web site: www.sheldonbrown.com .