I just got a new pugsley white "complete" bike and went for a first ride tonight. It was about -15F and fairly often when I would press the rear derailleur thumb shifter it would have no resistance as if the cable wasn't attached at all...a few presses and then there would be pressure and I could get it to change gears. My other mtn bike with SRAM7 (?) levers/derailleurs has no such problem. I'll be talking with the lbs today but wondered what your thoughts were. GoreTex cables? A different set of levers or derailleur? The levers are some type of Deore. I got one of these for myself and one for my wife (present, actually, from our daughter and husband) and want to get this figured out before it gets colder...We were out riding at -25F the other day with no shifting problems on our other bikes....

maybe the grease in the cable housing needs to be cut down with something lighter like WD-40?

When new bikes have cold weather issues that old bikes don't, suspect over-thickened grease.

Old bikes don't have these issues because most of the grease is gone.

i use anti seize on my cables but it sounds like your de-railer froze in one of the easier gears. i notice this happens sometime after there is a warm day and then it gets freezing cold out at night.

I am so not worthy...

My derailleur only freezes when I have liquid water involved, like spray from a salted road in cold air, or freezing rain.

Shifters can act up from cold temperatures alone (usually below -20C, rare in Toronto but common further north).

Usually the shift levers still move normally, but there is no ratchet or 'click' to it. It's the grease.

I am considering replacing an old cable and housing that I belive is having issues in the cold, and wonder if using a complete housing all the way the derailer is wise? The idea being, fewer points of entry for water. I have friciton shifter on my winter bike, so shifting precision is less of an issue.

It happens to my bikes every once in a while when the temps drop. Normally I can get the gears to engage, if I fiddle with the shifter (apply very slight amount of pressure until it "catches"), and after a couple of shifts it works okay again. When all else fails, I just put some oil or penetrating oil on the shifter, or lightly spray it with some WD40... whatever's at hand. That usually fixes it. I don't even try to diagnose it when such a simple trick solves the problem every time.

I went with friction shifters so that I wouldn't have shifting issues in the cold, I heard abut the concept on the now defunct Icebike site.
My bike came with rapid fire shifters, I noticed condensation in the gear indicator windows, I figured if there was condensation in there, that could be an issue in the winter. So I switched to Shimano Fingertip shifters. I have not had any shifting issues in the last two years.

I decided to run a full length rear brake cable after I had issues with the rear brake cable freezing up. Seems to have taken care of the problem.

If there is no resistance at all in the lever it is not a cable issue at all. Its actually a very easy thing to fix and is fairly common when bikes dont get ridden alot or in cold weather. There is a pawl inside the shifter that catches teeth when you push the shift lever moving the cable. Alot of times that pawl will quit moving freely which will keep it from engaging which in turn keeps it from moving the cable at all.

I have saved a number of shifters the owners were expecting to replace by cleaning them out by spraying some brake clean from auto parts stores. Just spray it into the hole that you replace cables through while moving the shifter. If that does not work pull the bottom cover off the shifter and find the pawl I am talking about and taking a pick or sharpened spoke move it back and forth while spraying it with brake clean.

Hope this helps, I have saved alot of shifters by doing this and it only takes about 10 mins to do.

I too moved to friction shifters on my winter bike, after being fed up with indexed shifters that froze in cold. Works a lot better.

In 3 whole winter of commuting, I've had the rear derailler freeze up on me a few times before. Once it was after a cold weekend. It took me a few minutes to realize that on Friday it has been raining hard. Saturday heavy freezing set in, and my rear cable froze before it dried out. After a few hours in my office, the bike defrosted and dried out. The other tires, I was riding through some wet sloppy snow and the whole unit was solidy encrusted on slush.

I've never had my shifters not work. I do use Poggies, and they keep cold and moisture away from my shifters and that may be helping.

Happy riding,
André

I run these shifters on my Pugsley and they have been flawless. -8F is the coldest I've ridden in so far. Did great today on a 15 mile ride at 1F.

https://www.interlocracing.com/shifters.html

I use pogies too...and even though mine are pretty nicely made I find them somewhat constricting for thumb shifters, which is one of the reasons I'm looking at grip shifters. I see some sram varieties but am not really familiar (yet) with the various grip shifters on the market. I'm hoping the issue with my first pugs was an oddity and my replacement bike will show no such problems. Neither of my other mtn bikes have problems shifting at -20F so I don't think it's going to be a big issue...might take a shifter replacement but I may do that anyway to get the convenience of grip shifters inside pogies.

so far my bike has had not problems what so ever and i have been parking it outside every night and i have been doing lots of biking on very crappy maintained sidewalks. if i can bike on the street i will.
this is pretty much the same shifter i have on my bike except that mine is a 7 speed shifter. i don't think the shifters make a difference. i think it has more to do with your derailleurs and cables.

On a new bike it is probably the grease in the shifters congealing and keeping the pawls from moving freely although the problem could be in your housings, or you may have some poorly finished cable ends that are causing things to hang up.

You are riding at some seriously cold temps and as such should be using lubricants that work in this environment (synthetic).

I had a chance to talk with a very experienced Winter bike guy...he confirmed it is the shifter and pointed me to the setup local high-end users have...which is a shimano bar-end shifter with an adapter for use on mtn bikes. The grease in the factory direct pugs shifters can cause problems. If my replacement bike (due to frame size) also has issues I'll probably degrease the shifter and see if that takes care of the issue. If I continue to have problems I'll replace the shifters but it's not cheap so we'll try a simple solution first. I've not looked at them closely to see if they can be disassembled and greased with a Winter grade grease. We'll see...

The adapters are Paul Thumbies, which will convert bar end shifters to thumb shifters (same concept as my IRD shifters that I linked above). You might want to adapt the pogies for thumb shifter use or find some new grease for the stock shifters.

mine does that every once in a shift as well. think it is just the shifter, like it is missing the ratchet or something. doesn't seem to matter how warm or cold it is... just random, so far.

sluggish shifting is common for me in cold weather. where are you located that you're riding in -25 f?

Here is something to try. Often my RD will skip under muddy or icy snow conditions, however a quick boot to the mechanism starts it working again. I finally figured what is happening was the g-pulley ices and clogs up. The g-pulley is the upper pulley on shimano mechs which has a certain about of horizontal float. On clear days this automatically centers the chain on the cassette cogs, but when ice or mud gets caked on the pulley can freeze all the way left or right. Now your chain will skip until you knock the pulley free. What i've yet to try is switching the g-pulley with the lower pulley, it has no play. You can only do this with shifters which aren't indexed or indexed shifters which are perfectly indexed. The advantage now is you can fine-tune the mech with the friction shifter to exactly where the chain aligns with the cassette. The lower pulley will stay true since there is no play and if you've got the b-screw setup tight this system should work better. In theory.

Another thing i would like to swap is to a top-normal rear mech, like shimano saint or xtr. These should perform better in the muck with sticky cables since the springs are stronger.

so...does one only need to worry about this if one parks a bike outside for several hours? or is this going to happen to me on my hourlong ride to and from work this winter?

I live in North Pole, Alaska... . Today it warmed up to 0F and my wife was joyous and immediately called for us to go out for a ride since it was balmy...

Is what going to happen to you?

in other words, will it be too cold to shift only in cases where I've left the bike outside overnight or all day (extended period of time), or could it also be too cold to shift even if I just go out for an hour's ride after having stored the bike inside?