neilfein

The SRAM 3-speed T3 hub on my Dahon Curve D3 (unlike the Shimano Nexus 3-speed hub on my cruiser) has no adjustment indicator. When hooking the shifter cable back up (after changing a flat or doing adjustments), there's really no way of knowing when the tension is correctly adjusted; one has to guess, ride the bike, then guess again.

I've found that I can't get all three speeds back on the hub; it's either adjusted so gears 1 and 2 are the same, or 2 and 3; I can't find the correct tension to access all three speeds.

Has anyone else had this problem? Is there perhaps something wrong beyond amateurish adjustments, possibly a problem with the hub itself? My shop was able to fix the problem once, but I'm not certain how they did it; their explanations are along the line of "just get the tension right."

Note: I originally posted this to the Folding Bikes forum.

tcs

And clearly weren't satisfied with the answer I provided there.

neilfein

As I said there. Thanks for trying, though.

rhenning

He told you how to do it correctly. It isn't rocket science. Roger

neilfein

That's how I've been doing it, and it's not working. Does that mean there's something wrong with my hub?

This unfriendly attitude isn't really helping.

fietsbob

Have you read thru SRAM's online manuals? how about ..
https://hubstripping.wordpress.com/t3-sram/

May require going to a Bike Shop, since no visual analysis is possible here,
on this mere web list.

Batavus

Set the cable tension so that in third there is tiny bit of slack in the cable. should be perfect then. if not, check for excessive fricion in cable. Pull the rod out and see how much grease, oil sticks to it. If a lot of gunk sticks to the rod, the hub needs to be taken apart, cleaned, greased and rebuilt.

Hubs in folding bikes tend to wear out faster because of the smaller wheels. The t3 is also not a very well made hub, it just doesn't last very long, but that may not have anything to do with your problem.

neilfein

Yep, that's how I set it up, although I've also tried it with a little more and a little less tension to see if it helps, but no dice. By "excessive friction in the cable", do you mean the cable from the shifter, or the chain-cable-thing leading to the rod?

There's black, dirty oily stiff on the front half of the rod, so it seems my hub needs to be serviced.

That's why I didn't get an internal hub for my other folding bike; I got the same impression about the T3. Oh, I shoulda waited for the Dahon with the Shimano hub.

Is it possible to service an internal hub on one's own, or do I need to send it back to the factory? Based on the little I can understand about what goes on inside internal hubs, I'm guessing the latter. If we're talking about a lot of money, I'm not going to be able to do it just now and my Curve will either have to stay like it is or I'd have to hunt for a used hub.

neilfein

Interesting site! I'm considering replacing the hub, or seeing if I can replace it with another hub (like an SA or a Nexus), so this may be a big help.

tcs

Well, you said the shop was able to get it to shift correctly in the past with no problem.

tcs

SRAM's are generally the easiest of the IGHs to work on. Example:
https://www.youtube.com/watch?v=byJ3LmaF_fI

Dan Burkhart 

Yeah, but he cheated. He used the planetary timing alignment tool.

neilfein

They did, but that was over a year ago. Also, if I have to bring the bike into the shop after changing a tire (i.e., every time I need adjustments), then that's a whole 'nother problem.

neilfein

Have purchased a rim with a Sturmey-Archer 3-speed hub in it, an SA SRF3, taken from a Dahon Curve that was modded to get more gears; will install later this week, but this should solve my problems. (This older thread should help me with adjustments.) I unscrewed the shifter rod from the hub, and it looks to be quite clean.

Thanks, everyone! Will report back with how the installation went. (I'll need to put on the new grip shifter as well.)

neilfein

I had to get some spacers, the wheel with the SA hub actually is about 1/4" narrower than the SRAM wheel. (I cheated and had my shop do it; I needed a new rear brake cable in any case.)

Everyone, thanks again for your help!