Rear Casette Problem
 

Hi everyone.

I tried searching for this problem in the forums, but I wasn't able to find anything. I apologize if this is a duplicate posting from a previous thread. If so, please feel free to throw things at me and direct me on.

I have a Nomad GT which I use for exercise and light commuting. When I am pedaling, the rear cassette turns fine and the chain shifts back and forth with the derailleur with no problems. The problem arises when I'm not pedaling; the rear cassette seems to catch or something, the chain backs up and becomes really loose until something catches or I start pedaling.

I'm not sure if I'm describing it well and hopefully can get a video up soon. I have lot of degreaser on hand, and I'm going to buy a chain-whip tool today so I might be able to get it apart to look at it today.

Thanks for any help which you can provide.

The google hits I get on Nomad GT has it down as a 7-speed, freewheel bicycle - not a cassette. The problem you are describing fits nicely with a sticking freewheel mechanism. Do a search for "freewheel servicing", or "freewheel sticking, or maybe "freewheel flushing" and you should come up with a few pointers on how to rinse the mechanism out w/o disassembling anything.

Assuming it's a freewheel, a chain whip won't be of any use at all to you.

+1 on Dabac's points. have a local shop remove the freewheel, or buy a tool and learn how to do it yourself, and soak it in solvent to flush it out.

The best way is in an old cookie tin or coffee can using naphtha or mineral spirits. Give it a long (hours or overnight) soak, agitating occasionally. Near the end when the solvent has loosened everything agitiate more aggressively to flush it clean.

Shake it dry then leave it in a warm place so the last of the solvent evaporates then run some oil in at the gap between the moving parts until it feels and sounds nice. Drain it on a paper towel overnight then install.

The wash and oiling can be done on the wheel, but it'll make a mess as the stuff spins out all over the place.

Not to mention you risk removing the grease from your wheel bearings, which don't do too well with just oil as a replacement.

Also verify that if your rear wheel has a spoke protector (typically a plastic disc), that it's not in contact with the freewheel and attempting to turn the freewheel with the spokes.

Thank you all for your responses.

I took the wheel off today and shot the backside of it apart with WD-40. I also removed the plastic disc, which did have a large crack in it and was very brittle, so I suspect that may have had some play in the matter. Eitherway, it seems to have corrected the problem. I have the tool to remove the freewheel now, but it's on extremely tight and I haven't been able to get it off yet. It's a older bike and was passed onto me, so I'm slowly replacing parts on it as I save up for a new one.

Anyways, thanks all for your help on this one. :)

Just make sure you follow up that shot of WD40 with some real oil... WD40 is 90% solvent and the oil in it is too light for most bicycle applications.