# S-A 3-speed hub adjustment



## webtwo (Nov 8, 2010)

I have a new CS-RK3 hub and when pushing hard on the pedals, can force the high (1.33/1) and direct drive gears to slip. It happens most in the high gear when I am trying to maintain speed on slight inclines.

The instructions that came with it said to place it in second gear. Then align the painted mark on the shift adjustment chain so that it is even with the end of the axle while looking through the "window" of the axle nut. I did that, and also tried adjusting the cable a little tighter and looser, but still can make the gears slip and I always ease up on the pedals when I shift.

I am using the S-A bar-end shifter, and the cable travel is super smooth. I think I have about 1st gear: 50.6 gear inches; 2nd gear: 67.5 gear inches; 3rd gear: 89.8 gear inches.

Can anyone with some S-A experience offer any advice? I am just about ready to go to the other "S" company's Alfine hub.


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## Velobike (Jun 23, 2007)

S-A 3 speeds are stone axe reliable if properly adjusted. 50,000 miles was not an uncommon mileage to get out of one, and then it could be fixed cheaply because parts are available. Their biggest enemy are mechanics who don't know how they work.

It will almost certainly be a cable problem (I know you said it is smooth).

Barend shifter usually means some tight curves are introduced into the cable. Try unwrapping the bar tape and loosely fastening the cable so it is in nice easy loops and see if that makes a difference.

If it doesn't, try removing the inner cable and check it for kinks, especially near the shifter. What happens is that the cable works ok under tension, but when you let go off the shifter the kink pulls it back a wee bit and puts it out of adjustment. Of course outers can be kinked, but this is visually obvious without dismantling.

Another prospect is if someone has stripped the hub or adjusted the bearings. There is a critical distance for the rhs axle and if it gets adjusted away from that, the marks will be in the wrong place. (Right axle protrudes 24mm on mine)

(Been riding S_A 3 speeds longer than most people have been alive  )


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## itsdoable (Jan 6, 2004)

Velobike said:


> S-A 3 speeds are stone axe reliable if properly adjusted...
> 
> (Been riding S_A 3 speeds longer than most people have been alive  )


Keep in mind that Sturmy-Archer went under, and was resurrected by SunRace in Taiwan, and the current hubs, like the CS-RK3 are not the original SA designs.









The CS-RK3 looks like a copy of the Sachs/SRAM 3x7 dual-drive hub.


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## Velobike (Jun 23, 2007)

itsdoable said:


> Keep in mind that Sturmy-Archer went under, and was resurrected by SunRace in Taiwan, and the current hubs, like the CS-RK3 are not the original SA designs.


I'm well aware of that. The internal design has been slightly improved and they are using better equipment to make them. The last British S-A hubs were made on clapped out machinery and it was only because of the skills of the machinists that the hubs were any good.

I doubt S-A are copying anyone. If you look back through their history they have made just about every conceivable combination of hub, including versions that had multiple cogs. (I've got one in my collection).

Slightly OT, if you want a mtb brake that you can use in foul conditions without having to replace brake pads every few hours, take a look at their drum brakes.


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## itsdoable (Jan 6, 2004)

Velobike said:


> I'm well aware of that. The internal design has been slightly improved and they are using better equipment to make them. The last British S-A hubs were made on clapped out machinery and it was only because of the skills of the machinists that the hubs were any good.
> 
> I doubt S-A are copying anyone. If you look back through their history they have made just about every conceivable combination of hub, including versions that had multiple cogs. (I've got one in my collection)...


I don't recall ever seeing a full derailleur cassette 3-speed hub from anyone but Sachs (my version is post SRAM).

Even though they are really only S-A in name, I'm glad they brought back a full line of hubs. I'd like to try out one of the 2-speed kick-back hubs.


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## john_dalhart (Nov 6, 2009)

webtwo said:


> I have a new CS-RK3 hub...I am using the S-A bar-end shifter.


Weeellllll, there's your trouble right there, isn't it.

The CS-RK3 hub is NOT designed to be used with a traditional Sturmey three speed shifter. As all available and pertinent Sturmey Literature says, the CS-RK3 is supposed to be shifted with a "standard MTB/ATB left hand shifter for front triple chainwheel".


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## Velobike (Jun 23, 2007)

*Here it is*

With benefit of hindsight, that's an obvious move for S-A to have made. 

Does this mean it would work with a dropbar lever, eg Ultegra? (I don't know the amount of pull on a front derailleur on a MTB, but they seem to move the same distance as road versions).


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## webtwo (Nov 8, 2010)

john_dalhart said:


> Weeellllll, there's your trouble right there, isn't it.
> 
> The CS-RK3 hub is NOT designed to be used with a traditional Sturmey three speed shifter. As all available and pertinent Sturmey Literature says, the CS-RK3 is supposed to be shifted with a "standard MTB/ATB left hand shifter for front triple chainwheel".


Yes, I was totally aware of that when I bought it. I had read on the bentonline forum that the S-A bar-end was being shipped by the distributor as being compatible with that hub and was working for at least one early adopter.

However, even when I adjust the hub per instructions in 2nd gear (100%) and do not ever shift it, I can still force the hub to slip with sufficient pedal force. This should not be happening.


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## Velobike (Jun 23, 2007)

webtwo said:


> However, even when I adjust the hub per instructions in 2nd gear (100%) and do not ever shift it, I can still force the hub to slip with sufficient pedal force. This should not be happening.


Sounds like a defective hub.

Have you checked how much axle is protruding?


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