I assume it's the little hole that appears like magic. Is this like the fuel light in my car? I now know I can go another 10 miles before she runs out of gas...

depends on the rim. mavic CXP22 for instance has a wear indicator that's clearly visible from the start.

Are you trying to see if you can get a Rim Job on the forum?

They are Bontregor Selects, I beleive. I run them on one of my beater bikes. Does this mean the rims are in jepordy of nuclear holocaust.

not sure of those rims, but that's probably the case.

on the DTs the hole is there and disappears when it is time to replace them.

Is there a risk of contiued use?

Yep, most wheels are like this. It would be near impossible to insert a pore exactly where you'd want it during manufactoring. Making the wheel as normal, and drilling an indicator spot is much easier.

I just looked at my Daughter's selects. They are about 2-1/2 years old. They have the hole and it looks like when it's gone then you will die. I know her rims are not worn because she doesn't use the brakes very much. In fact, during crits, she is always yelling at the boys for braking into the turns as she passes them.

Regarding risk when down to wear indicators, they're there because when "serious" riders finally started riding clinchers, they rode them a lot. The first indication of any problems was with mountain bikes - with mud etc the rims would wear pretty quickly. They'd ride them until the rim sidewalls were carved out by the brake pads, sort of like a worn disc brake on a car. Then, one day, the rim sidewall would spontaneously let go, and there'd be a big explosion and sudden lack of control.

Wear indicators were first extensively used on mountain bike rims. Now they're on road rims. They are used to indicate when the manufacturer will disavow all responsibility for any problems arising from continued use of the rim. Or something like that

Personally, if the rim looked/felt thin (i.e. without a tire on, or just gut instinct) I'd get a new rim. I've seen the aforementioned blown out rims and they are not fun at all. A foot of the top bit of the rim (the hook area) like a big "C", separated from a thin worn out unusable rest-of-the-rim. Usually a big blowout, some aluminum shards, and a big "wtf" before figuring out how to get home.

cdr

Muchas Gracias... I took a look at my Ksyrium's this morning and they've got an indicator too. Thanks for the info.

I forgot one minor detail. Before wear indicators and good clinchers, most "serious" riders rode tubulars. And since tubular rims don't support any air pressure, they could get really thin without a catastrophic failure. They'd just dent/bend easier.

The other crowd of serious riders were either tandem or loaded-touring type riders. They used really heavy duty rims and usually bent something before the brake wear got out of hand.

cdr

Lennard Zinn talked about rim wear indicators in Velonews earlier this year:
https://www.velonews.com/article/86509

Thanks Johnny. Good article. I live and ride in the mountains. It's the "catastrophic failure thing" I'm concerned about....but now I know.