I dont mean accidents, or when you hit a curb & bend the rim or pop a spoke. And I dont mean upgrades. I mean wear/tear or a defect. Ive had to replace 4 rear wheels in less than 3 years. Two on each of my bikes. All four because nipples, on the chain side, are pulling thru the rim. And, I think its because on any new bike/wheel, after 30 days of riding, my LBS has this habit of tightening the spokes. He tightens ALL the spokes the same amount, no matter what. I thinks hes overdoing it! A new wheel will 'find itself' after a while; I get that. But it just has to be trued again- each spoke will be different. Am I wrong?

You need a different LBS. If you have had to replace 4 rear wheels in less than 3 years, you can't afford to keep using your current shop. I have numerous wheels, front and rear, with 30,000- 50,000 miles on them and still in good condition. The earliest I've ever had to replace a rear wheel was due to rim failure at 17,000 miles and that was from brake track wear on a known fragile rim.

The only time that I have replaced rims was because of brake wear and those replacements are infrequent. If your rim are consistently cracking at the spoke eyelets it is definitely likely that they have been over-tensioned. Doing a 30 day adjustment on a properly built wheel is unnecessary unless there is a clear issue. Find yourself another mechanic.

Of course if you can crank out power like Erik Zabel, that could be the the cause.

A lot of it also depends on your weight and how many miles you're putting on the wheels. You didn't mention the type of wheels you're using as original or replacement. Entry level and even mid range bikes have pretty low quality spokes on the OEM wheels. I've seen lots of folks that are over 200lbs. and ride quite a lot (100+ miles weekly) that go through an OEM wheel (broken spokes, cracked rims at the eyelet, Etc.) in under a year. A competent, experienced wheelbuilder should be able to guide you into a more robust wheel that will handle your needs. If your local shop keeps putting you on the same wheel you're having issues with, nothing will improve. If that's the case, as the others said, you may want to look of a new bike shop.

I have had 1, maybe 2 rims with cracks around the nipples in 40 years.

In a family of four daily bike commuters (two for work, two for school), I only remember replacing one wheel ever, and it was due to brake wear caused by neglect.

I do believe in at least checking out the tension on a new machine-built wheel, and my own builds have typically needed minor truing after a few weeks (I'm not that good), but never total re-tensioning unless there is an actual problem.

Of course it's proportional to miles, but still, the total mileage of my family's fleet over many years is a pretty good measure.

Oem & oem replacement wheels were lbs regulars, making a visit to have spokes replaced everytime.
went to a low quality aftermarket wheel & not one issue in the equivalent amount of time & use. Even after riding on a flat getting over to the side, the aftermarket wheel is still a trooper. The hubs tho, they are slightly less smoother compared to the oem.

My bike/wheels are 34 years old and still as good as new. As has been mentioned, you need a new wheel-man.
Jon

Never, if I can help it.

The last time I had to replace a wheel that failed was more than 30 years ago. I'm still riding wheels I built more than 40 years ago.

Use sensible spoke counts and hand-built wheels and you should be fine.

Never had to replace a wheel for any reason other than rim wear.

Failure at the rim happens sometimes, but that seems like a lot. This is sometimes the result of excessive(or uneven so that some spokes are excessive while average is not) spoke tension, sometimes the result of poor materials or manufacturing of the rim, and occasionally can relate to particularly high torque loads placed on the wheel. Still, with your history, I'd recommend getting some sturdy, conventionally designed wheels hand built by a reputable builder. Well built wheels should not loose much if any tension during use because they will be built at high, even tension and will have the spoke line set during the building process and will be properly stress relieved, and will also have some mechanism of thread locking on the nipples to keep them from unthreading if and when the spoke is detensioned during riding.

Outside of getting hit by a car, and one failing because of metal fatigue, I have never had to replace a wheel. My oldest is nearly 30 years old and is still fine. But I also do not use rim brakes, only drum. If you are having to replace them that often, either their is something wrong with your LBS, or they are ordering bad rims. Guess it could also be your riding style if you ride hard and jump obstacles.

Never. Your mechanic is an idiot.

To answer some questions: I'm about 180#; do 5K miles/year(split between two bikes); on the road only, nothing aggressive (unless you consider potholes).
The guy @ my lbs has a 'reputation' for great wheel building. Now, I seriously question that.

[MENTION=129665]epnnf[/MENTION], time for you to get a copy of "The Bicycle Wheel" by Jobst Brandt. Read it a time or two, pick up a truing stand and a spoke wrench, and fix the wheels the "expert" screwed up before they break. You'll save money within a few years.

To answer the original question, on average every 6-7 years. (I'm still learning!) I've replaced one rim whose brake track wore out, another lightweight rim after I found some amazingly bad expansion joints that were closer to curbs, and one wheel with I failed to keep the bearings clean and greased.

Try Cleveland, one of my friends , knew from here, moved there (houses cost less),

and works in a shop, there, said ... they passed business down, in family, over many generations,

so still running since 1920 or so.






....

Put me down for one brake track wear, one set on our used Trek T50 tandem; actually cracked right through the brake track.

And one cheap wheel where the cup wore out..

I have never pulled a spoke thru a rim, despite building "high tension" wheels for my significant weight.

At less than 50 miles per week per bike, why are you having your wheels re-trued at all?

I go with a different brand of rim, and a different shop.

If your having that many problems ask them to use a tension meter on the spokes, different size spoke require different tension but each sides spokes should be relatively close to the same tension. To be fair the chain side usually requires more tension than the other. I have had to retension factory built wheels before but usually if I'm going that far I'll relieve all tension, lube the nipples and true and tension from scratch, so not very often.

If they don't have a tension meter, find a different shop.

Even if they do have a tension meter, find a different shop.
Or if you're curious, ask the current shop for theories as to why this is happening so frequently, and then find another shop.

P.S. It's been fun to watch this thread stay in the "recently commented upon" rotation without getting very long.

The only times I've replaced wheels have been due to boredom/upgrading. The old wheels hang forlorn on pegboard hooks, wondering if they will ever get used again...

I've wrecked them. I've sold them. I've torn them down to use the hub on something else. I've never worn one out.

I buy pretty much all used stuff on craigslist,

& had a high mileage Bontrager rim fail, but they all did...

An older set of carbon race wheels give up after some years,

and my EC90 brake tracks are going, but I put probably the second 10k miles on them.

Never wore one out all on my own...

I replaced my Shimano WH-RS550 wheels, ten years old, when a wreck damaged the front wheel beyond repair. I replaced them with Fulcrum Quattro LG's, which is a bit of an upgrade. I put an older (but not worn out) 12-25 cassette on the old wheel (I run an 11-28 currently), and keep it as a backup with an older (but still usable) Conti Gatorskin on it. Maybe it'll come in handy someday. It runs fine.