Subzero temperatures = crunchiness

alomac

Hi all,

I'm currently living in Sweden and now that temperature has dropped below zero pedalling my commuter feels something akin to operating a coffee grinder. I'm assuming that the grinding is coming from the bottom bracket, and that the grease has clagged up in the cold, but I don't what I should do about it or replace it with.

The bike itself is an old three-speed with one piece cranks and a Sachs hub. I only need to keep it running for the next five weeks until I get home, so I don't really want to do anything too involved. So long as I'm not gringind metal or breaking anything, I could even just leave it.

Cheers,
Adam.

nicklouse

It is a bit cold in Uppsala at the moment.

did it have this feel before the cols snap?

Or does it go if the bike is warm when inside?

Oh and what is the make and Model?

biondino

I think grease has quite a low freezing temperature (though for properly cold you can get non-freeze grease). Is it possible there's water ice in there? Does it get better the longer you ride?

alomac

Heh, it is a tad. Mountain biking over the frozen hardpack is a hell of a lot of fun though (until you fall off)...

The grinding came the cold snap. There was an intermittent, mild grind in the days leading up to it, but nothing like the way it is now. The hub has also been acting strangely - ghostshifting, going into a sort of 'neutral gear' - but I thought that was just a problem with the cable tension and have been trying to adjust it out.

I haven't had the bike indoors since the cold began. It usually lives outside because two bikes are a bit a squeeze in my apartment (my MTB is my sambo). I should probably start making a home for it in here though. I will bring it inside to warm up and see if that helps.

The bike itself is a Crescent Sprint 3.

My commute is quite short, 7 to 8km, but it does not seem to improve in that time.

nicklouse

the shifting will be the crud in the cable causing more friction as it is getting more solid in the cold.

Mmm Crescents from the 70s (surprised it still works)
if you grab a crank arm can you move it? get some play.

if yes new bearings are cheap and easy to fit if you have some big spanners.

if there is no play i would not worry too much.

Parktools have a guide

http://www.parktool.com/repair/readhowto.asp?id=92

Not got above Zero down here all day and everything is still covered in Frost.

alomac

The grinding does go away if the bike is warm and the cranks have no play, so I'll just leave it. The bike does work, but it's been no end of trouble since I got it. I very much look forward to getting something better when I return home.

I think today's max. was -1, it's so frosty I could swear it snowed.

As always, thanks for your time.

Adam.