Why don't all rim brake rims have wear indicator grooves?
 

Both my Giant Cypress and my Trek Verve came with rims with wear indicator grooves. However of the aftermarket rims I've been looking at, I don't think I've seen any that have them. Anyone have insight into why this is?

Because for decades the risk of blowing out a rim due to pad wear has been thought to be the rider's responsibility. Maintenance and precaution stuff. It wasn't the job of the rim manufacturer to tell you when you wore out your rim. Andy

are the aftermarket rims you're looking at nicer or cheaper than the rims that came on your bike? a wear indicator seems like more of a luxury thing.

more importantly, most people don't know what a rim wear indicator is, so I would not be surprised if most companies don't bother with a feature that everyone will ignore.

Maybe the manufacturers get tired of folks returning the rims, thinking those holes are mfg defects.

Check carefully for some small drilled divots instead of the grooves; there may only be one or two per side.

I have them on my Bontrager rims and the divots do give peace of mind. I have over 40,000 miles on the rims and divots are still there. For the relatively small effort to create the divots, it offers much more in safety and peace of mind.

Same with tires. My Continental Gatorskins and Specialized Armadillo All Condition tires have wear divots. It's a great visual indicator.

Which I blithely ignore and get another 25-50% tire life before I see threads or start getting too many flats.

Because most rims are replaced due to an accident long before they wear out?

This is the greatest pro disc brake argument there is. Disc brakes do not in the end destroy high priced rims.

The rims I'm looking at are probably at around the same level as the Bontrage AT-750's that came on the bike. The Sun Rhyno Lite I ordered might be a little nicer since it has spoke eyelets - like the Bontragers it's double walled, machined. If there are any wear indicators it isn't obvious to me from photos - they definitely don't show a groove like the Bontrager rims.

Ride or Pie?!: Measuring rim sidewall thickness

I've measured mine using the caliper and bent spoke method.

Well, on the rear at least.
When I do discard the threadbare rear, I move the front to the rear (thus getting yet another 50% of tire life) and buying one new tire (for the front.)

I never saw rim wear indicators before machined brake tracks became fashionable. Machining the brake track removes material from the rim, shortening the useful life. Maybe the wear indicators are a CYA type of thing?

My rims are chromed, or some other kind of plating, does this count as wear indicators?

;)

Really don't see a need for it. When the side wall of the rim starts cupping, replace it.

A $6 dental caliper works fine - just replace when less than 1mm remains.

https://cimg6.ibsrv.net/gimg/bikefor...58984fc72a.jpg

Gap calipers . . .

. . . so long as sidewall thickness is .5 mm or more, there's some life left.

Most rims start at 1.4 to 1.6mm

=8-)

Like this!
https://cimg0.ibsrv.net/gimg/bikefor...9a7ca08bf.jpeg
On this rim, diametrically across from the valve hole.

This is consistent with my observations on several new rims and several worn-out rims. The dental thickness gauge, known also as a "crown thickness" or "Iwanson" gauge, is good for rim wear measurements.