Help! Rear wheel: Rebuild or Replace?
 

Hi there - I've been riding a cheap pair of Shimano WH-R500 wheels pretty hard (daily couriering) for about 6 months. No problems with the front wheel, but the 24 hole rear wheel is starting to experience some significant issues.

Initially there were a couple of spokes which would persistently loose A LOT of tension (to the point where I could wiggle the spoke like spaghetti with my fingers) which would cause the rim to lose its true. I'm no wheel expert, but retruing the wheel seemed a pretty simple matter of tightening the offending spokes whenever it occured..

Now however, the rim is again losing its true AND there are some *really* loose spokes, but the problem is that the rim is losing its true to the side that the loose spokes will pull to if tightened (thereby forcing it more out of true, if you follow me). I'm not really sure how it got as bad as it is, and now I'm trying to work out how to deal with it.

I recently had a spoke replaced and the bloke at my LBS told me the wheel was just about rooted. I know 'you get what you pay for' and this is a budget wheelset, however I was wondering whether there is any point in trying to rebuild this wheel, or would that be just sending good money after bad, and I should just scrap it and start again?

If I were to try and rebuild it (or even just lacing it up to the point where my LBS could true/tension it), what new parts will I need - just spokes? spokes and nipples?

Thanks a lot. Simon

IMO, unless the rim is very badly warped (potato chipped) or bent, you should be able to re-true the wheel. First, it was a mistake to be riding on 24 spoked weenie wheels for performing daily bike messenger work.
You should have stuck to a set of robust 36H conventional wheels.
Lastly, the wheel became in such a state for allowing the wheel spokes to be THAT LOOSE and still ride the bike.
Inspect the wheel from the side to inspect roundness, if it's bowed badly, it may explain why you can't dial the dish back in place after attempting to tension the spokes.
Pouring more money into the 24H rear will eventually get you back to where you are now. It's unable to cope with your courier duties.
Bear in mind, those few offending spokes could be damaged, ie. nipples are stripping. I would only try to replace the few spokes if possible and re-true the wheel and see.

+1 on the wheel being a poor choice for the intended use. I would be after a much beefier wheel with 36 spokes for that kind of use myself. The problem with replacing a few spokes at a time on wheels that have shown a repeated problem like this is the the spokes have been stressed at the elbow enough by this repeated loosening and tightening that they will eventually fail (one or two at a time). You cannot tell this by looking at them but the residual stresses will work their way out through repeated use. The real key to longevity in addition to choosing the right wheel for the job is enough evenly balanced spoke tension. I learned this the hard way and my LBS was not tensioning the wheel on my repeat trips to replace one spoke at a time. It gets rather time and money consuming to repeat this exercise in futility. If you need the bike to be a dependably daily bike rather than an occasional recreational ride, I would buy a proper wheel.

If tightening the loose spokes is going to pull the rim farther out-of-true, you obviously have a badly warped rim. The only real fix for that is to replace the rim.

Thanks everyone - I think a new wheel is probably inorder. I hear what you are saying regarding the wrong wheel for the job, unfortunately it was a question of (perceived) economy at the time (bike parts are expensive in Australia).