Bicycle Mechanics - rear wheel

Hi, I'm new to these forums. Anyway, I've been riding around on my dad's old Schwinn; it's a road bike and light weight and skinny and has the bent under handlebars and everything. It can go pretty fast I dare say. To get to the point, the rear wheel is weird now; it doesn't rotate smoothly, but rather "wobbles." It makes this "chunking" noise — for lack of a better word — as well. I'm having a real trial trying to describe this, but you all probably know what I'm talking about. Is there anything I can do to fix this other than get a whole new wheel? I've tried not to be too hard on the bike (avoiding curbs and bumps etc.) Any help or insight would be appreciated.

Is the clunking noise the sound of the rim hitting the brakes?? Sounds like it may be out of true, LBS should be able to true it up pretty easy if that's the case. Light and skinny is good but a true road bike is made to ride on the road and won't hold up well to uneven sidewalks, speed bumps. potholes and curbs. I just wish I could find the roads the bikes were made to ride on, with the weather around here there is no such thing as a smooth road unless it was just repaved and hasn't seen a winter.

could be a lot of things... try decribing it a little better. i would suggest truing the wheel and rebuilding the hub.

yeah, my best guess is that what you're describing is a problem with the hub not being tightened enough.

You should be able to look up on barnetts manuals (thread stuck at the top of this forum) to find out what the parts of the hub are like. Then it's just a matter of getting the nuts that hold the ball-bearings screwed down tight enough (but not too tight.)

Oh, by the way, before you do that, the way you can check to see if it's a problem of your hub not being tightened enough (this isn't foolproof) is to simply stand next to the bike, hold it upright (wheels on the ground is best) and try to wiggle the rear wheel.

Also, if the nuts that attach the wheel to the frame (different from the ones that hold the ball bearings) are loose, it's possible to get a problem like the one you describe.

Those nuts should feel "tight" but not "extremely tight" and not "extremely easy to turn with a wrench". the wheel should be screwed down so that there is equal space between the frame and the wheel on each side.

Is the clunking noise the sound of the rim hitting the brakes?? Sounds like it may be out of true, LBS should be able to true it up pretty easy if that's the case. Light and skinny is good but a true road bike is made to ride on the road and won't hold up well to uneven sidewalks, speed bumps. potholes and curbs. I just wish I could find the roads the bikes were made to ride on, with the weather around here there is no such thing as a smooth road unless it was just repaved and hasn't seen a winter.

I know it's not rubbing the brakes, I checked that out first. If I took off the brakes entirely, I would still get the sound. Usually, when I hold up the rear end of the bike and just spin the wheel it makes that small clicking noise (the noise when the wheel moves but the pedal is stationary). But this noise is less frequent. It only makes the noise about once per revolution. I always figured the word "clunking" was deeper than clicking. I guess it's really hard to describe bike sounds in words.

eeww... yeah, sounds sorta like messed up hub bearings. i had that happen on my bmx bike. a few of the ball bearings were crushed/ground down so they were basically only half spheres. if the bearings aren't sealed, it's not that hard to rebuild them as long as you're careful about it, and if the ball bearings are messed up, you can generally find replacement ones. to do that, you'd have to unscrew the cones, take out the ball bearings and put them in a container, wipe out all the old grease and gunk, repack the bearings with bearing grease and the ball bearings, and then put the cones back (generally the bearings will stick to the grease, so they're not as likely to fall out and roll around all over the place).

or, like has been said, it could just be that the bearing cones are loose, in which case you just screw them tighter, just to the point that the wheel doesn't wobble but can spin freely. and if you have a cone wrench, you can lock down the cones with the nut next to each one.

If you can wobble the rim from side to side, and feel some play, then you need to adjust the bearings using the locknut and cone-nuts on the axle. If the bearings are worn, you may need to replace the cone nuts and ball bearings, and regrease. You may have to remove the freewheel (cog) assembly) to reach the drive-side bearings.
You need some special tools: a thin cone wrench, a standard wrench (or another cone one), and a freewheel remover. The remover is best used together with a bench vice, rather than a "chain whip" which is usually recomended. I often borrow a vice from the local car mechanic's garage.
Read up the advice on the park tools website.

Thanks for all your help, everybody. I tightened those hub nuts you were talking about. It took me quite a while to get them to just the right spot so that the wheel would spin freely but not too loose or the wobble would come back.