Bicycle Mechanics - Sturmey Archer Overhaul

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View Full Version : Sturmey Archer Overhaul


tommyd49
09-07-10, 07:44 AM
So, I picked up an old Raleigh Chopper at the dump (it has a three speed AG dynohub). When I took it home, I realised it wasn't shifting at all. I adjusted the cable nice and tight, but it didn't work. Then I repeatedly flushed the hub out with WD-40, then put some engine oil, but still no luck.

So I looked on the Sheldon Brown website (here: http://sheldonbrown.com/sturmey-archer/sprinter5-troubleshooting.html#13.) which suggested either the pawls need cleaning or the gear selector key needs replacing. I figured the first explanation was unlikely because I'd repeatedly flushed out the hub, so I reckoned the gear selector key needed replacing.

This morning I decided to take the thing to bits, which I did successfully, managing to keep all the bits together. However, I cannot find the gear selector key (nor do I really know what it is). Looking on the parts list on SB's website (http://sheldonbrown.com/sturmey-archer/names.html), I cannot find the bits described as "vital bits from right in the middle". Perhaps the AG doesn't have these, or do I need to dismantle one of the inner parts? Maybe the AG doesn't have a gear selector key and I need to do something else?

I've attached two pics to show what I've found so far.

Suggestions would be greatly appreciated. Thanks!


FBinNY
09-07-10, 08:51 AM
SA hubs are mostly identical in the basic concept, but the exact parts configuration varies. Odds are you're not missing any internal parts, though you'd have to search on-line for an exploded view of the AG to be sure.

I think that what SB refers to as the gear selector key is the cross shaped part which slides in the driver unit and carries the torque out to the rest of the hub. Often these get chipped, and don't engage properly either against the pins sticking up from the planet cage or the right side ring gear unit. However the single most common problem is pawl engagement, and you should start by making sure all the pawls are undamaged, well sprung, and move freely.

Look for a tutorial on your hub or SA hubs in general, or build it back up on the axle and see how things fit and work before putting it back into the shell.

tommyd49
09-07-10, 11:00 AM
Hi, thanks a lot for the advice - you're a lot more helpful than my LBS! When you talk of the cross shaped part that goes in to the driver, are yout talking about the sliding clutch?


airwulf
09-07-10, 11:45 AM
You can find others with quite a bit of SA 3spd knowledge at www.raleightwenty.webs.com (http://www.raleightwenty.webs.com). This is a new web site for R20 owners and it's very good.

hartleymartin
09-14-10, 07:14 AM
You can find others with quite a bit of SA 3spd knowledge at www.raleightwenty.webs.com (http://www.raleightwenty.webs.com). This is a new web site for R20 owners and it's very good.

It's nice to know one's work is appreciated.

davidad
09-14-10, 04:14 PM
I think clutch is the right word. Go to your local library and find an older Sutherland's Bicycle handbook. They have a section on the SA hubs. You will have to go back to the 4th or 5th edition to find that hub.

choteau
09-14-10, 05:05 PM
Try the Sturmey Archer Heritage website, here's the link to the AG schematic. Tim
http://www.sturmey-archerheritage.com/images/photos/pic-66.1.jpg

cny-bikeman
09-14-10, 06:48 PM
Here's a great video from a Brit of the entire overhaul procedure. Very well done and refers to the proper terminology as each part is removed. http://www.youtube.com/watch?v=ea6krXSs-lc

tcs
09-15-10, 06:18 AM
AG schematic w/ reassembly procedure:
http://www.users.globalnet.co.uk/~hadland/sa/saag.pdf

Fault find chart (AG on page 2):
http://www.users.globalnet.co.uk/~hadland/sa/safaultfind.pdf

Good S-A advice:
http://bikesmithdesign.com/SA/SA-Tips.pdf