SA 3 speed MTB is this possible?

[A.D.R]

I have my old Carrera Krakatoa sitting unused in the shed with worn out chainrings and cassette, I also have a number of sturmey archer 3 speed AB (90mm drum brake equipped) rear hubs and BF front hubs...can you see where I'm going with this? .

The big problem is the AB hub has an OLD of 114mm with and axle of 154mm. Now I think SA hubs need quite a bit of the axle extended past the drop outs for the indexing to work, so is there a longer axle available for use with MTB 135 mm OLD dimensions.

Cheers Andy

 

[velomaniac]

The answer is yes, particularly as new SA (Sunrace) 3 speed hubs come in a 135mm OLN disc brake ready flavour.
Further i remember a Peugeot atb/mtb that came with a 3 spd SA hub.
A good source of SA kit is SJS cycles : http://www.sjscycles.co.uk/
Bung a double or triple chainset on aswell and up your gear choices, I believe you can get SA sprockets in 3/32nd " pitch.
Cant beat a good old SA 3spd hub in my book but I wouldnt want to service one with a built in drum brake, 135 seperate component parts I was informed by a mechanic :shock:

 

[fatfixie]

They did make a 156mm axle also BITD, took a no.2 toggle chain. Came on some raleigh roadster tyre bikes from memory

easy hubs to service, used to do a standard AW in 4 mins........

Andy

 

[A.D.R]

From what I've read the AB is mechanically identical to the AW, there are a couple of clips on youtube that make it look (note I said make it look ) fairly simple to break down and rebuild so I'm willing to have a go :? , I've got at least 6 of them and some complete internals too along with various axle nuts. I happened to be in the right place at the right time when they were going to be scrapped, nothing wrong with them apart except that apart from two 26inch wheels their all built into 650b westwood rimmed wheels of varying degrees of rustiness and trueness.

I found this on Sheldon Browns site;

"An axle generally needs to be 1 1/4 inches (31 mm) longer than the bicycle's overlocknut spacing, for full thread engagement with the axle nuts. Another 6 to 10 mm is OK, and may be needed if the bicycle has thick dropouts. Too much axle length on the right side may prevent a flared right-side axle nut from being tightened down all the way, and may interfere with operation of the pullchain. When in doubt, test or measure."

"Older hubs had a rather limited selection of axles, as the standard overlocknut spacing was only 114 mm or 120 mm when these hubs were made. Common axle lengths for the classic AW hub were 5 3/4 inches (146 mm) and 6 1/4 inches (159 mm). A 6 7/16 inch (164 mm) axle suitable for 126 mm dropouts was also made for this hub and its near-relatives. The length difference is at the left end of the axle. The right end is the same for all of these axles."

(If posting excerpts from other websites isn't allowed I'll remove this)

I dunno if I'm reading that right but seems the axles for the AW /AB may not be long enough.

 

[A.D.R]

A wee update; it seems, according to Sheldon, that the AB's internals are the same as the SR-F3, which has axle length options of 148, 163 and 175mm.

Velomaniac: I'm currently trying to decipher which, if any, axles from SJS would work. Thanks for pointing me in their direction

Fatfixie: If I can get this to work I may be asking more about servicing one. And I happen to have rather shabby Rudge Roadster in the shed in bits I rescued from the recycling centre.

Andy

 

[retroyetirigid]

I seem to recall reading somewhere that Sturmey Archer don't recomend their hubs being run on anything less than a 2:1 gear ratio as it can cause stress to the internals and strip teeth. So while a 36:18 would be ok a 32:18 may cause issues. :!:

 

[fatfixie]

I seem to recall reading somewhere that Sturmey Archer don't recomend their hubs being run on anything less than a 2:1 gear ratio as it can cause stress to the internals and strip teeth. So while a 36:18 would be ok a 32:18 may cause issues. :!:

Thats certainly applicable to the 5 or more speed hubs. However the aw/ab is bulletproof- were used on tandems for may years.

 

[fatfixie]

A wee update; it seems, according to Sheldon, that the AB's internals are the same as the SR-F3, which has axle length options of 148, 163 and 175mm.

Velomaniac: I'm currently trying to decipher which, if any, axles from SJS would work. Thanks for pointing me in their direction

Fatfixie: If I can get this to work I may be asking more about servicing one. And I happen to have rather shabby Rudge Roadster in the shed in bits I rescued from the recycling centre.

Andy

Presuming its an old steel wheel ab the 163mm stdbaw axle is mst likely, although in strip it down and check first....

The ab from memory was a pretty crap brake... :-(

Andy

 

[Ductape]

My SA equipped thee speed MTB:

 

[Ductape]

My 6 speed was too much for the old frame. Swiyching to 5.