mcours2006

I can't be the only one who's had a set of older shifters (4500 Tiagra triple) not shift in extreme cold. Temperature was -21C this morning. Neither side ended being able to shift into a smaller cog. I could push the paddle, but it wasn't catching on to whatever ratcheting system is inside the housing. So ended up riding bike as single-speed 50-23...yeah, I realized I wasn't going to be able to shift to a smaller cog, so avoided the 25T so as not to be cross-chaining it the entire 20 km commute.

Any ideas on how to remedy this for future reference?

alan s 

Move to Florida

Amt0571

Has not happened to me but I have a couple of ideas that can cause this problem.

1. Grease or oil inside the shifting mechanism hardened with the cold blocking its normal movement.

2. Water, maybe from condensation, inside outer cables freezed up.

You could try to heat the cables with a hair drier and see if it works. But my guess is that it's the shifter with solidified grease. In this case I think the only solution is degrease the whole mechanism and use a lighter grease that can sustain such a low temperature instead.

I'm not sure the shifters are built to withstand such temperatures though.

wolfchild

Fixed gear or singlespeed.

mcours2006

Thanks for the thoughtful and useful comments, as opposed to the ones that are useless and thoughtless.

I may try flushing it out with some WD40 and see if it works any better. We don't normally get temps in the -20 often, so having to deal with it is always like the first time every year.

HerrKaLeun

First identify if it is the cables or the shifter, or even the derailleurs.

If it is cables, replace both housing and cables. Use full-housing to prevent future dirt and water entry.

Shifters work at low temps. Obviously better quality MTB equipment will have a better fighting chance. Rode my 11-speed XT this morning at -22°C and it shifted smoothly.

Gresp15C

My ancient Sturmey Archer 3 speed ran just fine this morning at -12 F. The first really cold day each year is a good chance to shake out problems like old sticky lubrication and water incursion.

Miele Man

I love my Shimano Adamas AX shifters and derailleurs when it's really, really cold out. That's because there is no outer cable housing to trap moisture.

When moving a bicycle from inside with a temperature of 70F to outside with a temperature of -20 that's a 90F temperature drop and condensation is quite possible and then it freezes a lot of stuff, shifters, cables or even derailleurs oh and freewheels sometimes too.

I wonder if spraying anti-freeze inside the items once outside would free them up?

Good luck and cheers

Amt0571

To be fair, they may be useless but I had a good laugh with the Florida comment.

wipekitty

I've had similar issues in extreme cold.

+1 on re-lubing the cable housing (checking for the lowest operating temperature of whatever lube you're using.) Storing my bike in a cooler area (unheated garage, porch) helped somewhat. I'm assuming the bike is clean, but if any of that road grime, salt, or splashy stuff works its way into the housing, that can be brutal!

BobbyG

[QUOTE=mcours2006;21327547]I can't be the only one who's had a set of older shifters (4500 Tiagra triple) not shift in extreme cold. Temperature was -21C this morning. Neither side ended being able to shift into a smaller cog. I could push the paddle, but it wasn't catching on to whatever ratcheting system is inside the housing. So ended up riding bike as single-speed 50-23...yeah, I realized I wasn't going to be able to shift to a smaller cog, so avoided the 25T so as not to be cross-chaining it the entire 20 km commute.
I had an old Schwinn whose shifters would freeze up below 20F and it was definitely the cable guides. I ride down to 5F, which sounds more manly when expressed in centigrade (-15C). I have had some sticky shifting in freezing weather with my current bikes, but on the current bikes it seems to be ice building up on the actual derailieurs.

I guess I really didn't have anyting helpful to add to the thread.

So I will just say that -21C is about -6 F which is pretty awesome on your part. When I looked that up I also looked up MY limit of +5F which sounds more exreme when expressed at -15C, but it is still not as cold as your ride.

Litespeedlouie

My bet is on flushing and lubing the shifters with a light oil that works in low temps.

I don't have such low temps, but my 1997 Deore LX shifters definitely developed the problem. Actually, ALL my 90s Shimano shifters develop the old grease problem. I don't personally use WD40 as I've had it gum up after a few years.

mcours2006

UPDATE:
So I did the WD40 flush into the shifter housing yesterday. Today the temperature was at a mild -13*C. The shifters shifted great. No hint of any stickiness, well, the right side at least. Didn't use the left. So I guess 15 year old shifter that'd been heavily used gets pretty gummed up inside. All good.

Litespeedlouie

Very good. Be on the look out for dribbles of WD40 for a while, and you may have to repeat the flush.

grizzly59

The only lube that works reliably at -20F and colder is synthetic oil. Thinner is better.