IGH freezing??
 

I live in Chicago and have a 10 mile commute via my SRAM S7 IGH.

I noticed this past week with temperatures dropping well below freezing all of a sudden, my shifting became substantially less crisp. This happened last year too, but I just attributed it to wearing bulky gloves. Well, the difference this year is that it wasn't just mushy, but it gets entirely stuck. If I downshift (it's a twist shifter if you're unfamiliar), the housing comes out of the shifter and of course the gears don't actually change. It does start clicking and slipping and being terribly unruly.

This only happens after I've been out riding for maybe 20 minutes. Once I bring my bike inside, it starts working again normally very soon. So, I'm quite sure something is freezing, but the question is, what? Follow up question would be what is to be done?

Thanks!

the IGH is probably using a thicker, general purpose oil, which can freeze or get highly viscous at lower temperatures.
solution is to add a lighter oil to it, although I'm not sure if SRAM S7 IGH has a filling port.

It's pretty similar to how you use a lighter engine oil during winter for your car.

use a 5w- multigrade oil. These are made to stay thinner at low temps, so your engine can turn over. Synthetics offer the greatest viscosity across temperatures.

This sounds to me like there's some moisture in the housing, which freezes in the cold and seizes up the cable. Then when you downshift and let the cable go slack, it takes the housing with it, instead of sliding through.

You might be able to flush the water out with WD-40, but if I were you, I'd just replace the cable and housing. Cables and housing are cheap, and you can think of it as preventitive maintenance as well as solving your current problem.

I've thought about that, but I can get the cable to slide through the housing without difficulty when this happens... The only mechanism I can think of is that the sliding pin that goes into the hub is sticking, so the little finger in the clickbox that pushes it doesn't move even when cable is let out. Thoughts?

Hm. Well I'm out my element then. I don't have much experience with SRAM IGHs. I know lots of folks have had luck improving cold weather shifting by replacing factory grease with lighter, synthetic oil, like the previous posters mentioned. Any tutorials I've seen have been for Shimano hubs though.

There are a few gear hub gurus around here, hopefully one of them will chime in.

Woah up there. The S7 does not use standard cables and housing. The shift cables on these things are thicker than a brake cable.
It is possible that the clickbox or shift rod is freezing. I used to have one of these hubs, and it did get a bit sluggish in the cold, but I kept it working by putting a bit of light oil into the axle and on the shift pin.

Thanks. Will give it a try this morning and report back.

I don't stop riding when it rains, so it does seem likely to me that some water has gotten into the axle. I wonder how this could be prevented...

The S7 uses SRAM 0369 135 200/...201 "special" grease lubrication.
The S7 does NOT have an oil port.
The S7 is easy to disassemble and would be easy to swap to oil-dip lubrication if you wanted.

Yep. Condensation from the warm/cold/warm/cold cycle of bringing the bike indoors/taking it out to ride.
1) Put a little light grease on the shift rod/sleeve to form a seal.
2) Just leave the bike outside in the cold all the time (I know, may not be practical).

HTH

You have H2O in the hub, time for an overhaul, here's the manual:
http://www.sram.com/_media/pdf/sram/...glish-RevA.pdf

I use ATF and synthetic grease to keep things running when it gets cold. I'm in the area if you need some help.

Again, I'm obviously out of my element. I'll stop confusing the issue and shut up.

Well, dripping some light oil into the axle via the shift pin did a lot of nothing.

Yes, it does seem time for an overhaul. It seems that the effects of SRAM's "special" grease vs oil would be pretty different. Anyone have opinions on what would be better?

I use 3-in-1 oil from Canadian Tire. :)

In N.A. probably more IGHs have been rendered inoperative by lubrication with 3-in-One than for any other reason.

On the Yahoo Groups IGH page, I found a copy of an email that SRAM sent to the moderator, who had the same problem a few years ago:

"Yes, in below freezing temperature the internal lubricants can begin to slow.
You can open your hub, pull the planetary gear carrier out and dip it into a
low temperature motor oil. This will help the small parts and planetary gears
move and function more smoothly.

Dismantling instructions can be found here starting on page 60:

http://www.sram.com/en/service/sram/...nuals_2009.php

2009- gear hub systems.

Regards,
Tim Jones
SRAM Dealer Service USA
800.346.2928
www.sram.com"

I'll give it a try (well, I'll probably first try introducing it via the shift pin hole).

So, oil via the shift pin did a whole lot of nothing. Well, it did get oil everywhere, but other than that, nothing productive.

So, I pulled the hub apart tonight after many hours of agonizing over the lubrication question.

After doing it, I think the question is almost moot. The stock grease had turned brown and crusty--think 1970s Schwinn hub that you're opening up for its first breath of fresh air in 40 years. How in the world such a well sealed hub with presumably well thought out and quality grease could turn that bad so quickly is beyond me. Especially when SRAM says the grease is good for the life of the hub.

I used Phil Tenacious Oil, against my better judgment in some ways, but so it goes. It is vastly smoother and an improvement in every way over the chewing gum and clots that were in there.