servicing a 3 speed Sturmey Archer hub

[ScillySuffolk]

I've got a little fold-up shopper for a friend, but sometimes, when pedalling quite hard, it loses drive: the pedals just spin; stop pedalling briefly and all is well again.

So I figure a strip and rebuild of the hub is in order: it's not something I've attempted before.

I've got some fairly detailed guides from Sheldon Brown, but would be grateful for advice and tips from anyone with hands-on experience; if anyone can suggest what the problem might be and what might need replacing I'd be grateful for that too, as I won't know what looks worn-out and what doesn't.

Thanks in advance of your time and trouble.

 

[originalshinkicker]

You rarely, if ever have to strip a sturmey hub. Typically it's just bad cable adjustment. Does is slip in a particular gear? Normally on a 3sp hub it will be 2nd that it slips in. I've stripped them before but only when required, for example, replacing the axle key where the toggle chain screws into as it was stripped. I used the Sutherlands Guide as a reference and it was fine, just take your time and note all the bits that come out.

First though, just spend some time making sure you have all the axle washers and nuts in the correct place and that the gear is adjusted correctly before diving in.

Neil

 

[bm0p700f]

It is so easy. Take the sprocket off and use a punch and hammer to unscre the hub internals from the shell. Everything come out in one go.

Many parts for the older hubs are still availble. There is a you tube video is you do a search. It really is easy. The problem you describe could be bad cable adjument worn internals.

 

[ScillySuffolk]

Thanks for the above.

I can't remember if it slips in a particular gear.

I hadn't considered cable adjustment as it changes ok.

I'll have another fiddle and give it a ride before stripping.

 

[Iwasgoodonce]

Flashback Mode!

If I can remember back over the decades to the only bike I had with S A gears, the symptoms you describe suddenly rang a bell. If you fiddled with the gear lever, sort of by shifting gear very slowly, as you were sort of between gears, the drive would free wheel in both directions. If the adjustment isn't quite right, your friend could be having this as a result?

 

[Jonny69]

Something else you might want to try is lubrication, because once the old lube dries up and it gets gunked up inside, it does exactly as you describe. Fine the little plug on the barrel and pour in about a dessert spoon of light oil. Ride it around a bit and keep shifting gears and it should free up anything sticking inside. Then you'll be able to adjust it up nicely. If it doesn't have a filler plug then pour it down the side where the chain goes in.

 

[keithglos]

Could be the pawls a bit stiff, or adjustment, or wear because of bad adjustment. If oil fails, then take it apart. On the end plate behind the cog you can use a flat chisel, it's obviously right hand thread, but mark the plate and the hub shell. It has a 2 start thread, if you put it back on the wrong start you will have to true up the wheel.

 

[ScillySuffolk]

Thanks all.

 

[WilliamC]

If you do dismantle it be careful not to lose the tiny hair springs that bear on the pawls. Come to think of it they may be the problem - if the hub isn't lubricated properly and starts to rust inside these will be the first to go. They are the only really delicate parts.

 

[bigpantswheels]

If you have an older Sturmey then it's probably a cable adjustment or the hub needs oil. The older ones were very sturdy and last forever. The new ones are made in Taiwan and are complete junk. I wore out a pawl in about 200 k and when I took it apart I found the pawls were made of a very soft metal, not even sure if it was steel.