Cold-Weather Shifting

[kfergos]

This morning it was 6°F (or 10°F, depending on who you ask). About 10 miles into my commute, I tried to shift down in the front... and nothing happened. The shifter moved freely, like it was totally disconnected from any cables or anything. A little later I tried again and it shifted, albeit extremely reluctantly.

Why would this be?

[lph]

I'm guessing it's because inside your shifters you have a disc of some sort, with retractable springloaded "hooks", that catch the gearing lever when you gear by tightening the wire, but allow the lever to slide past when gearing the other way, loosening the wire. These hooks can freeze in place or get very slow when it's cold. But I'd think it would be a problem when shifting up, not down

At least this happens to the pawls in hubs, so I'm guessing this is similar.

[smilingcat]

Either the front deraillure mechanism froze (with ice) or the cable has enough ice build up and again froze. At 6F, I wouldn't think there would be enough water (liquid form or super cooled water) to have splashed onto your bike and then freeze.

However, it is most likely the cause.

When you said shift down, I presume it was the front deraillure? or was it the rear deraillure.

On the front deraillure shift down requires yout to "lead out" more cable and allow the spring on the mechanism to do the shifting. Shifting up (to a larger chain ring thus making it harder to pedal) will require to "pull in" or shorten the cable thus you are physically pulling the deraillure to the larger chain ring. I hope this makes sense.

smilingcat

[lph]

Hey, I think we can agree on something definite here:

"It was blinking cold and your bike froze."

How's that?

[smilingcat]

Totally LPH

are you healing up okay?

smilingcat