Bicycle Mechanics - My rear cog is very rough when going backwards

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legalize
10-11-06, 03:31 PM
Sorry, I forget the terminology. But the rear cog (on the rear tire) is rough. You know how you can spin it backwards, and it clicks? As if you were riding along with the pedals not moving? Well, when I do this, the rear cog will 'grab.'

I took the tire off and I spin the rear cog backwards to make the clicking noise and it is exceptionally rough. This is happening to the point where it will move the rear derailler because there is too much friction for the rear cog to stay motionless while the bike is going forward.

The inner piece that the bolt goes through to hold the bike tire onto the frame moves like a charm and is fine. But when I try to move the cog itself, I feel roughness.

Is there any way I can clean this? I am feeling that maybe I need to lube it up. The bike has been used but not cleaned as much as I'd like and I am thinking it is a little dirty in there, or maybe it just needs lube.

I thought I'd ask before I start trying to take things apart.

Thanks

legalize
10-11-06, 05:51 PM
Did I describe this well enough for people to even know what I'm talking about?
Retro Grouch
10-11-06, 06:47 PM
Did I describe this well enough for people to even know what I'm talking about?

So what kind of bike? How old is it? How many cogs on the back? Freewheel or cassette?

legalize
10-11-06, 07:12 PM
It's a 2002 Specialized Comp XC Rockhopper

I dont know what freewheel/cassette is...eek
Retro Grouch
10-11-06, 07:27 PM
So that's a mountain bike and a Rockhopper that new will have a cassette/freehub body. What kind of life has it led? Have you done any deep creek crossings with it or anything like that?

Quick dirty answer:
Remove the rear wheel. Lay the wheel over a trash can with the freehub facing up. Try to drip some light chain lube into the crack between the moving and stationary part of the freehub body.

"A" answer:
Remove the rear axle, bearings and cones (requires some special tools). Use a 10mm allen wrench in the space the axle came from and loosen the bolt that holds the freehub body in place. Install a new freehub body (about $30.00).
legalize
10-11-06, 07:34 PM
i have been using it pretty hard and havent cleaned it too well lately, which is probably why

was jst wondering if this kinda part is fixable or cleanable. looks like both?
operator
10-11-06, 07:45 PM
i have been using it pretty hard and havent cleaned it too well lately, which is probably why

was jst wondering if this kinda part is fixable or cleanable. looks like both?

It may be fixable or it may not be fixable. It certainly can be cleaned, if you can disassemble it that is.
legalize
10-11-06, 08:12 PM
Ok - now - I have a set of allen keys. And some wrenches. Can I do this?