Dawes-man

In their descriptions of dismantling an SA hub, a couple of info sites say "Next, unscrew the right-hand ball ring but because it has a two-start thread and must be replaced in its original position, that position must be marked." while others make no mention of it.

Does anyone know why they say to do this or if it's really necessary?

If it is necessary, is there any way of making sure the ball-ring is replaced in the right orientation if no note of the original position was taken?

rhm

Yeah, good question.

I have switched the internals from one hub to another many times, and obviously if you are taking the guts out of one hub and inserting the guts from another, you can't put it back in the same way as before. I can't really say whether I have had trouble caused by putting the guts in backwards; some hubs work better than others, for sure, but problems are hard to diagnose.

The only advice I can offer, if you really want a definitive answer, is to mark the hub and try it both ways. If it works better one way than the other, then there's your answer. And please let me know what you learn!

tcs

Over on the Yahoo Internal Gear Hub list the universal feeling was the "marking the two start thread" advice can be ignored. Everyone that responded either had never bothered to do this or had never found it to make any difference.

rhm

Sturmey Archer overhaul instructions generally tell you to put a hub back together the same way as it was before, except for replacing the parts they tell you to replace. They don't tell you the correct sequence of washers and spacers, for example, but rather tell you to note their correct position before disassembly and put them back in the same order and orientation.

Do you think that's the rationale behind noting the orientation of the ball ring?

Dawes-man

Thanks tcs. Looking at the parts I couldn't see any difference it could make.

Dawes-man

Thanks rhm. I'm sure it is. I think there is a, perhaps old fashioned, idea that parts get used to each other and thus it's better to put them back how they were so they'll perform the best they can. I don't know where I got that idea from but I've always tended be conscious of it and followed it.

On this occasion, I saw the advice after I'd removed and replaced the ball-ring, and another 3 or 4 before it. And wondered...

markk900

There are a number of sites that repeat the original instructions from SA with extra intensity, and there are a number of people who have ignored that particular instruction with no ill effect. Like rhm I have replaced guts from one shell to another, and dis/reassembled several others, and have generally forgotten to mark the ball ring.....

I think you are safe to stop wondering!

Mark

David Newton

I've noted over the years of working on older Brit cars, motorcycles, and now bikes, that there is the assumption (gathered from the old-school mechanics) that parts that have "lapped" together over time will work better if replaced in the same position. This also assumes that if the parts are replaced in other position, the "newly mated" parts will have to lap (and wear) before they are happy again.

cudak888 

Supposedly, the AW has double-start threads on the shell and the ball ring. As with the other fellows here, I have yet to hear of anyone encountering difficulty from threading the ball ring as if it had a single-start thread. Sutherland's manual concurs.

-Kurt