Was 21-speed, now 3-speed

[wheeliebin]

I know it's cold...when my rear changer jams solid.

On my commute this morning I found I could change to a lower ratio, but trying to go back up again the gear cable just goes slack and the mech doesn't move. I got off the bike a few times and tried to waggle things around but I couldn't get it to shift into a higher gear. On any slight downhill I just had to spin as fast as I could and then coast. After a few goes at freeing it, the changer then jammed in one position, wouldn't change up or down. I could have broken something whilst fumbling in the dark.

It's jammed before, always when it's freezing cold. I assumed it was a bit of moisture that had got in and frozen as I have always managed to free it off before, but not this morning. The mech is fairly clean and well lubed but the amount of crap I pick up from the roads means there could be some muck in there. The spring inside the changer seems to be intact.

I can move the changer backwards and forwards by hand, but not sideways. The cable seems to be free where it comes out of the housing into the clamp.

If it makes any difference it's a Deore mech.

Any ideas welcome!

 

[VamP]

Most likely build up of crap and moisture in your last section of outer cable (between chainstay and mech). When that solidifies it increses the friction to such an extent that the derailleur spring is unable to move the chain. You could remove and clean, or, if you're like me, replace the inner, and the last outer section.

I do this 3 or 4 times a season on my cross bike.

 

[GrumpyGregry]

^ wot he said in my experience.
Sealed cable system will cure it at some expense.

 

[iendicott]

I had this happen last year but I put it down to extreme cold and moisture in the cables freezing. Rear brake was like it today but again put it down to the same thing as it's normally fine.

 

[wheeliebin]

Update - the bike has been in the weak sunshine all morning, went out at lunchtime to see if I could free it, and without doing anything to it it is now fine. So nothing permanently broken, and definitely temperature-related.

I guess my next step is to do as VamP said, change the inner and last outer section.

Thanks for the advice all.

 

[bicyclos]

I buy inner brake and gear cables in bulk as they are a cheap item and change the inner cables on my bikes once a year when they get a major service.

 

[fossyant]

One other point. If we've got a period of sub zero temperatures, and the bike is notmally kept in a cold place (garage or shed) might be worth bringing the bike in the house overnight so cables etc dry.

Washed the bike last night, kept in the garage near a heater, but back brake froze this morning.

Last year in the -15 snow, the bike was certainly inside to de-ice between commutes.

Wait till your freewheel freezes. There is a way to un-freeze out on the road, but you don't want to be doing it in public places

 

[wheeliebin]

Mine is kept in the shed normally, next time a freeze is forecast I'll risk the wrath of she who shall be obeyed and bring it in the kitchen overnight.

Unless of course I have attempted the fix by then and will need to leave it to freeze to see if the fix worked!