Wheel rim wear

[hasta]

I have a pair of Shimano R500 wheels, which have four wear indicators, two on each wheel. I have used them for just over two seasons on my winter bike (probably about 5000 miles) and the wear indicators on the rear wheel are fine. However, one of the wear indicators on the front wheel has now disappeared. Should that wheel be replaced immediately, or is it safe to ride for a while longer? Can anyone help me here?

[patthebike]

Hi, i think the answer may already be there! You've already worn down the rim so far that the indicator has gone, therefore the rim is worn. The manufacturers put that there so we don't have to think "is it worn out or not?", amongst other reasons...

I personally would be junking the rim, although the manufacturers do err on the side of caution and there may be some life left in it. Your life, your decision.

Over the years, I've personally experienced too many pulsating brake levers on rims that I thought still had plenty of life left in them...

One club mate came to me with a worn rim like this, I even measured it and it was within the tolerances that Chris Juden wrote about in the CTC mag many years ago, BUT he did tend to over inflate his tyres so much he may as well have been riding solid tyres!

Another club mate lost 2 days of his memory when his front wheel collapsed because of this. There was no prior warning the rim was knackered.

At the end of the day, it's your decision, but like I said, I know what I'd be doing.

[meic]

Should that wheel be replaced immediately, or is it safe to ride for a while longer?

This is in "Dont Know" territory. Exceedingly unlikely that it will explode in the next five miles but bit more likely in fifty etc up to pretty certain in 5,000 miles.

You can "pressure test" it by pumping it up to a very high pressure (behind something protective like a door) if it doesnt fold the rim out and bang then you have a bit longer to ride it. I have had one rim fail before the wear indicators said it was worn because the wear wasnt in line with the indicators.

The best thing to do is to start the replacement now, by ordering the rim or wheel and replace at the first convenient opportunity.
Neither of my rims failed catastrophically they gave warning in a pulsing feeling when braking and the ride was finished which was another 50 miles on one (not using that brake if possible).

I remember seeing a tandem once with slits almost the entire way around the rims where they had worn exposing the cavity. They aborted the ride and went straight home when this was pointed out to them.

You have a safety margin here but it is a safety margin not an additional bit of safe lifespan.

[pwa]

Bin it.

I've let a rear wheel go on a bit too long and it collapsed as I was cycling home from work. No real drama other than a one mile walk with a bike on my shoulder. But if it had been a front wheel and it had given way under heavy braking.......

[tykeboy2003]

I have a pair of Shimano R500 wheels, which have four wear indicators, two on each wheel. I have used them for just over two seasons on my winter bike (probably about 5000 miles) and the wear indicators on the rear wheel are fine. However, one of the wear indicators on the front wheel has now disappeared. Should that wheel be replaced immediately, or is it safe to ride for a while longer? Can anyone help me here?

I just posted on another thread about a mate who's rim had worn beyond the wear indicator and the brake squashed the rim. He was lucky the wheel didn't completely collapse and that it was off-road (dog ran in front of him).

[horizon]

Just giving this a quick thought, here are ways of assessing rim wear in the absence of or in conjunction with wear indicators:

1. Noting the make and model of rim to give an indication of likely life (some are thicker/heavier than others) (and even checking rim thickness oneself at the outset).
2. Noting mileage as indeed the OP has done (and comparing to #1).
3. Noting conditions of use (e.g light summer).
4. Being very aware of any braking issues (this is how I picked up recently that my front wheel had gone below a safe thickness).
5. Using dental callipers (I then double checked with these). I now do this every time I do a tyre change for example.
6. Visual and finger-feel inspection looking for rim buckling and curvature.

And the pressure test of course!

Feedback and your views on any/all of these appreciated.

PS Some quick googling found no information whatsoever about rim thickness, not even on Mavic's own website. Is this remiss of rim makers or doesn't it matter?

[hasta]

That's very useful, but what exactly is the pressure test?

[rotavator]

See Meic's post above.

[tim-b]

Hi
There's a pair of wheels here for £77.50 Supra kit is fitted to one of my bikes, and I'm quite happy with it. There are plenty of bargains out there, is it worth the risk?
Regards
tim-b

[Sweep]

Interesting thread - for someone who once discovered two slits in his wheels and maybe had a narrow escape from his ignorance.

Can someone say more about this "pulsing" in the brakes - what causes it to make it such a useful warning?

[georgew]

Interesting thread - for someone who once discovered two slits in his wheels and maybe had a narrow escape from his ignorance.

Can someone say more about this "pulsing" in the brakes - what causes it to make it such a useful warning?

The "pulsing" is caused by the sidewalls being worn so thin that the tyre pressure is pushing the rim outwards at certain points. I've seen this on a friend's bike and I wasn't surprised as I'd been warning her that the rims needed replacing for a considerable time.

I'm not sure that this could be defined as "useful"... as the rims should have been replaced before such a thing could happen.

[meic]

I would certainly describe it as useful.
There may be some people here who check their rims every thousand miles, in twenty different places on each side and throw them away when only half worn.
The rest of us benefit from this early warning sign which will normally allow you enough time to ride home.

Here is a case where no reasonable inspection regime would have given warning but the pulsing did.
viewtopic.php?f=5&t=113113&hilit=tandem

[Brucey]

I have a pair of Shimano R500 wheels, which have four wear indicators, two on each wheel. I have used them for just over two seasons on my winter bike (probably about 5000 miles) and the wear indicators on the rear wheel are fine. However, one of the wear indicators on the front wheel has now disappeared. Should that wheel be replaced immediately, or is it safe to ride for a while longer? Can anyone help me here?

I'd measure the rim thickness carefully and if it was still OK I might use it for a little bit longer. But I'd be planning for a new rim or (more likely with those wheels) a new wheel. Probably the rim has worn faster than normal because the brake blocks are OEM type and/or contaminated.

The R500 wheelset is now obsolete but some stores still list odd front wheels for about £40. IIRC MADison want more than that for a replacement rim and you would still have to build it. IIRC the wheel is a 20 spoker, and aftermarket rims in 20 drilling are not exactly commonplace and would probably have a different ERD anyway.

The equivalent 'throwaway wheelset' is now the RS010 version, which is also 11s compatible. These can be had for about £85 for the pair. If you buy some of these I would recommend an immediate addition of more (more fluid) lube into the rear hub, without which the freehub body may soon fail in all-weather use. These clap out so often (with just the factory lube inside them) that they are presently difficult to source, and that freehub body is virtually unique to that wheelset.... By contrast with the correct lube inside, the freehub body would outlast the wheelset several times over....

My advice; for winter training it may be a better idea to use a wheelset with thicker/wear resistant rims or where you can replace the rim if the need arises.

cheers

[georgew]

I would certainly describe it as useful.
There may be some people here who check their rims every thousand miles, in twenty different places on each side and throw them away when only half worn.
The rest of us benefit from this early warning sign which will normally allow you enough time to ride home.

Here is a case where no reasonable inspection regime would have given warning but the pulsing did.
viewtopic.php?f=5&t=113113&hilit=tandem

I would have preferred that the "early warning sign" of the wear indicators disappearance had been noted and acted upon.

[Halla]

Having recently experienced tyre explosions, I have checked my Mavic MA3 rims for wear as a possible cause, the other possibility is incorrectly aligned brake blocks, which I have now replaced.

The MA3 rim (which does not have a wear indicator) shows wear of about 2mm when a straight edge is placed next to it.

Knowing that some Mavic rims have very thin brake surfaces, does anyone know how much wear an MA3 will take.

I have carried out a pressure test to over 100psi with a Durano tyre and there was no explosion and no additional deflection of the worn side.

Is it time to replace the rim or am I being too cautious.

I have put on some spare wheels to keep on riding.

It is my winter bike which I will probably ride about 400-500 miles on before the spring.

Any thoughts please.

Andy