Repairing hub gears

[TC99]

I have a Bromton with a Brompton/Sturmey Archer 3 speed hub. It's slipping in third. It's not the cable but is definitely a hub issue. Any one know of people who do repairs who they could recommend?

 

[Sharky]

What's your location?

 

[FrankCrank]

First step, look up how to carry out adjustments. Very unlikely to be a faulty SA hub.

 

[TC99]

What's your location?

London

 

[Chris S]

There are two types of Sturmey Archer 3-speed hubs. I assume your bike is less than 25 years old so it will have the No Intermediate Gear version.

Here's a video showing a complete strip down and rebuild of the hub. Slipping in 3rd gear would suggest a weak spring or worn planet pinions (they act as dogs for the clutch). However as an earlier posted suggested it's more likely to be incorrect adjustment. This can also occur if the wheel has come loose and is slipping in the dropouts.


View: https://youtu.be/7Y-WiiCDBqs?list=PLv-LgXuO5dtTj1uDEruX04EC_OC-UH228

 

[Chris S]

Here's a PDF showing how to adjust your hub correctly. Make sure the indicator chain is fully screwed in and then undo it half a turn first. I've noticed that they can unscrew themselves with use leading to incorrect adjustment.

https://sturmey-archerheritage.com/files/view-1145.pdf

 

[Chris S]

And here's a video showing you how to do it.


View: https://www.youtube.com/watch?v=-mGfuqxilO4

 

[Big John]

Having taken a few apart (just for the fun of it) I'd be surprised if anything inside is at fault. They're virtually bomb proof. Nothing flimsy inside to break. Whoever designed them built them to last. That's why they weigh a ton.

 

[Sharky]

London

I was going to suggest Harry Perry Cycles, in Woolwich, but sadly, they seem to have closed. The owner Paul, would have given you some good advice if he could.

There is also an excellent mechanic, based in Medway, that a lot of club and top riders use, but could be a bit out of the way for you.

 

[gizmo1994]

It is actually pretty straightforward and rather fun to service your own SA hub without many specialist tools but access to the right grease. Failing that then the best in London has to be Matt Styman at Brompton Haus. https://www.bromptonhaus.com/

 

[Chris S]

Having taken a few apart (just for the fun of it) I'd be surprised if anything inside is at fault. They're virtually bomb proof. Nothing flimsy inside to break. Whoever designed them built them to last. That's why they weigh a ton.

That was the original AW hub with a physical gap between 2nd and 3rd gear. The later SRF3 has a freewheel on the driver to stop 2nd and 3rd gear being driven simultaneously. It's covered by a flimsy actuator plate which breaks. They've also got two pairs of dual pronged pawls which also break.

The good news is that it uses the same shell as the earlier AW. I took the internals out of mine and put some in from an old AW hub. I've had no problems since.