drivetrain problem...

CLaRae said:

So, my specialized crossroads commuter finally decided it's had enough of chicago's salty, gritty winter streets, and has an interesting problem. I took it in to a local bike shop, who said several people had brought bikes in with similar concerns, and wrote it off to the cold... but it hasn't corrected itself this time (even though the bike is now indoors and warm) and something is definitely very wrong. When I pedal the cranks, the chain moves through the drivetrain with no resistance, and the back wheel remains stationary. I noticed what felt like the chain "skipping" the day before, and wrote it off to a missmatch of new chain/old cassette & chainrings... did this damage my hubs somehow? I'm sure they're long overdue for repacking... I suggested this at the bike shop, but the tech seemed to think if it were cold related (this day was about 5 degrees, but the problem has recurred at 20 or so, when I was riding with no problems before). Could it be my bottom bracket instead? Any thoughts? Also, the first time this happened, I was on my way to class, and put my bike on the bus rack... when I took my bike off the rack 20 minutes later, for several blocks, the cranks spun while I pushed the bike as if it were a fixed gear. I parked it outside school, and when I came out later in the day (much warmer) the problem was gone. Anyone experienced this sort of thing before? I'm probably taking it to a different shop this afternoon, but welcome any feedback on what is going on here (aside from a poor maintenence schedule on my part- should have had those bearings regreased months ago... for shame). Thanks for your help!

I'll bet the freehub, the gizmo where the cogs live that is designed to allow you to pedal and then 'freewheel', is gummed up. Have the Einstein at the LBS overhaul your rear wheel and in doing so, remove said freehub body, flush it out really well and then reoil(NOT grease) it. I use Mobil One auto oil cuz it's cheap and doesn't get thick when cold.

Peter@vecchios said:

I'll bet the freehub, the gizmo where the cogs live that is designed to allow you to pedal and then 'freewheel', is gummed up. Have the Einstein at the LBS overhaul your rear wheel and in doing so, remove said freehub body, flush it out really well and then reoil(NOT grease) it. I use Mobil One auto oil cuz it's cheap and doesn't get thick when cold.

I agree it sounds like the freehub. One more thing though. If he brought his bike to the LBS with this problem and "Einstein" couldn't diagnose it, then it is definitely time to find another bike shop!

take it to Upgrade Cycle, they have good mechanics there.
Sounds like your freewheel is frozen, the pawls will freeze up, then it warms up and works or maybe time for a new freewheel, nothing to do with the bottom bracket, and I don't think your bike has a freehub body (don't think so) so I would say freewheel..... get a new one put on.

Jbucky1 said:

take it to Upgrade Cycle, they have good mechanics there.
Sounds like your freewheel is frozen, the pawls will freeze up, then it warms up and works or maybe time for a new freewheel, nothing to do with the bottom bracket, and I don't think your bike has a freehub body (don't think so) so I would say freewheel..... get a new one put on.

Well, if it does have a freewheel rather than a freehub/cassette, then take the freewheel off and flush then oil that. Essentially the same type system. Not necessary to throw it away.