MinnMan

Has anybody else had this problem?

My Warbird has a Shimano GRX 600 RD and internal cable routing. Twice in the last few weeks I've been riding it at icy conditions near freezing, and the shifting froze, giving me a two speed (FD worked OK). I've had this problem occasionally with the other bike I use for winter, but that has external cable routing and I've been able to see the ice on the cable and remove it. With the Warbird/GRX, I have no clue where the freezing is happening. On a cable? The spring or someplace else in the mech? I look at it, move the parts around, and it has no effect. But once the bike is brought back inside, the ice melts and RD is fine.

The Warbird isn't my only winter bike option. I thought that it would be better for this because of the internal cable, but in this respect, it seems to be worse. If this keeps happening, I just won't use it unless temps are above or well below freezing.

sloppy12

I have definitely had this issue. I have not had it with fully enclosed housing. always seems to freeze at the derailleur anyway so I don't know if the housing would make much difference in the long run.

I am kinda here to see if there are any solutions as well. lol. I usually just hit the derailleur with my foot if its real bad or if the cable is exposed I will yank on it and it usually frees up.

Trakhak

Frozen cables: I've been there. Riding off-road in 20-degree F weather, I once tried riding over a narrow rivulet on a sheet of ice that, it turned out, wasn't quite thick enough. Luckily, it wasn't too deep, so I got soaked only up to my knees. The bike was completely submerged, though. The cables froze instantly: the gears didn't work, the brakes didn't work. I had to bash the front brake cable housing between two rocks to get that to work at least. Again luckily, the car was only a 15-minute ride away, and I'd been riding hard and was very warm, so no ill effects. It was interesting to watch steam coming off my feet and legs as I rode back to the parking lot.

Here's what I'd do with your bike:

After noting how the inner wire is routed at the rear derailleur pinch bolt, pull the inner wire out of the rear derailleur cable housing (leaving the housing in place). Confirm that neither the housing nor the inner wire has kinks or frays that might add friction.

Might be best to simply install a new inner wire or new cable housing or both at this point, as cheap insurance against future failure. (If you do decide to replace the housing, leave the inner wire in place temporarily and slide the housing out of the frame. That way, you can use the inner wire to guide the housing back through the frame.)

Drip some light oil (Triflow or equivalent) into the cable housing at the shifter end. Reinsert the inner wire and run it back and forth in the housing a few times to distribute the lubricant evenly in the housing. Reconnect the cable to the rear derailleur and adjust the tension to ensure correct indexing.

ClydeClydeson

Shimano ratcheting shifters (STI and Rapidfire) sometimes have an issue of the internal lubrication - a translucent green grease - getting hard over years of use, esp. after a few seasons of freeze-thaw cycles, and occasionally just when the weather gets cold. This might be the issue here - the internal workings of the shift lever are gummed up in the cold.

It could also be that some moisture got into the shifter, a segment of cable housing, or into the derailleur, and this froze. I left my fat bike out in the weather last week and when I went to use it there was no shifting. I removed the bottom cover off the shifter and sat it in front of the fireplace to dry out and it works fine now, The same effect would result from moisture in the cable housing. I think it's less likely that the derailleur itself will be affected by this, but it's possible.

gecho

Moisture gets into the loop of cable housing going into the rear derailleur and mixes with oils. Removing the housing and giving it a good degreasing always fixed the problem for me.

I found it to be less of an issue with derailleurs with direct cable routing, and have never had it happen on bike with full length cable housing.

79pmooney

I always ran full length rear brake housings in my Ann Arbor and Boston year round car free days.

And second bikes for winter - beater fix gears! Mafac brakes. About as reliable and maintenance easy setup as you can run. (But start learning those fix gear skills in June, not now!)

rumrunn6

clean & dry all the affiliated cables & housings? at least for me, it was caused by moisture from a post-ride rinse & then leaving the bike out overnight to freeze. just a few squirts from my water bottle was enough to create a future roadside repair, in the dark, below freezing, at 5am. so I don't wanna do that again hehe

MinnMan

It's interesting to me that the consensus seems to be that the frozen part is in the cable housing. Could be true. There's that loop of cable that emerges from the internal routing to the RD itself. And like rumrunn6 notes, that bike gets washed down when it comes back dirty (which is usually). So maybe there was water in their already.

I could be wrong, though, but I think that the problem comes from water picked up from the icy road surface that then freezes onto the bike at slightly lower air temperature. The problem doesn't occur when the weather is cold and dry. For this reason, I thought it must be something exposed that was collecting moisture and then freezing - as in something in the mech. There just isn't that much exposed cable in that Warbird design. For similar reasons, I tend to doubt that the problem is any where near the shifters - ice isn't collecting up there.

rumrunn6

there are various kinds of end caps you can get for the housings to help keep moisture & dirt out. what do your housing ends look like?

MinnMan

Well, before I had the chance to do much investigating or maintenance, the opportunity arose to ride the Warbird again and, yup, the same thing happened. A few miles into the ride and the RD stopped shifting. (And like I said before, it works fine in my basement, before and afterwards, so clearly something is seizing up because of ice.)

Tonight I did a little investigating of the cable routing. I guess I am dumb, but I hadn't realized that the part of the cable that goes through the frame has cable housing over it. I suppose that makes it easier to push the cable through (or protects from the cable rubbing against the interior of the carbon frame?) Anyway, I don't really see much evidence of moisture in any part of the cable or housing that I can see down near the RD, but maybe the freezing is happening in the part of the cable in the frame? Then I think I need to pull the whole cable out, remove the housing, dry, clean and oil, and then put it back together. It looks like that will be a PITA, but...

Is there a quicker fix? (Apart from taking it to the LBS and paying somebody to do it?)

rumrunn6

if it's just the one cable & you'll go thru all that trouble, I'd bring it in & have a pro who is doing stuff like that all day long, replace w/ a new cable & housing. treat yourself. then do your best to keep it dry. do it, then move on w/ your life, you have some riding to do ... ;-) mine are external. I've replaced many over the years. the modern road bike is a little more difficult. I did one, but used 2 cables to get it done right. next one I brought to a shop, easy peasy

wolfchild

IME fixed gear is the most reliable set up for winter commuting. No shifting and you can stop even if your brakes are frozen.

MinnMan

I took the Warbird to the LBS. Yesterday was unseasonably warm - well above freezing- and it rode perfectly. The weekend looks to be good riding weather, but cold. Am wishing the LBS will turn it around in one day (possible this time of year, but can't count on it) so I don't have to ride with studs on the weekend. The road surfaces will be clear and riding with studs will be a burden. We'll see.

Edit: Hah: I dropped the bike off at 2 PM today and they called at 6:40 PM to say that it is ready. They didn't promise any such quick turnaround. I'm very pleased.

Viich

You very well could be getting ice on the actual derailleur as well - but the cable pull should be enough force to move it anyway.

I usually carry a lubricating lock de-icer and spray the derailleur when this happens and/or the snow buildup jams up the chain.

MinnMan

At first I thought it was in the derailleur - like maybe the spring. But physically forcing the derailleur back and forth did nothing, so I became convinced that it was in the cable housing, hidden inside the frame.

I think the problem probably started from hosing down the bike, post-ride. In the future, I intend to be more careful about where I aim the spray.

Now there's a new cable and housing and tomorrow will be cold but dry. So I'm optimistic.

Wilbur Bud

This is annual maintenance for me, around end of November each year, pull all the cables and squirt WD40 or some other water attractant through all the housing to eliminate the moisture gathered during the rainy season. dry and lube lightly cables prior to reinsertion. Nothing more exciting than no brakes or no shifting at an intersection.

MNBikeCommuter

I hope you found clear roads this weekend. I sure didn't. Three days with a 1" give or take snow sure messed up Wed's extraordinary thaw for the north metro. The ol' hybrid with studs has been in constant use the last four days. I'd been planning on the road bike this weekend too based on the earlier forecasts...

MinnMan

I had excellent rides with the Warbird Saturday and Sunday. The Warbird has 43 mm Teravail Cannonballs (no studs) at the moment - run at low pressure, they're quite good on pretty much all surfaces except for glare ice or deep snow.

Saturday morning there was modest snow (< 1 inch) on the ground and surfaces were pretty slippery. But we did about 50 miles on mixed trails and roads. It was 12 *F for the first half, but I was toasty warm with bar mitts and other season-appropriate gear. Sunday afternoon most roads were clear, though some trails and side streets had snow or ice. Much warmer, though with kind of a biting south wind, I got in about 35 miles.

And the shifting works.