CliftonGK1

I haven't seen this one mentioned before, but it's the second rim I've done this to.

Lots of us have popped a spoke or three.
The urban riders may have pac-manned a rim on a curb.
The offroaders have likely pringled a rim or two.

How many other people crush the braking surface like a pop can? Literally, pinch it inward so that the bead is splayed out at the top edge if you looked at a cross section?

I know what caused it: I've got around 5500 miles on this rim, year 'round in the PNW. That means wet road grit. That means sand and cinders. All those lovely things which wear down a rim quickly. Between the metal getting thin, and the wide profile uber-strength cantis, and all the hills I have to stop my 250 bulk at the bottom of, the rim got worn and finally started to warp!

So, how about it... anyone else crushed a rim like a pop can?

funrover 

I have one friend that pushed the side of her rims in like that.... you are the only other I have heard of doing that!

CliftonGK1

OK, so I'm not the only one who doesn't pay enough attention to rim wear. I've done this once before, and I was beginning to feel like more of a Sasquatch than usual.

I picked up an Open Pro/Ultegra from Performance on my way home. I've never ridden 14/15 double butted spokes, so we'll see if I notice any damping effect from them. I got the wheel home, popped the cassette off the old one and chucked it in a bucket of spirits, and put the wheel up on my stand:

Well, seems straight enough. Maybe 0.5mm play on it.
The next check? What about stressing? I put the wheel on the ground and pressed on the rim: Ping Poing Spang! Like any machine built wheel it wasn't stressed or tensioned (I plucked a spoke or two and got some very dissimilar tones.)
Back on the stand, a quick couple run arounds with the spoke wrench, and things were back to true and evenly tensioned. A wrap around with some Forte cloth rim tape and the tire went on pretty easily (Ultra Gatorskins on Open Pros are an easy fit, btw). Tomorrow's commute will truly tell the tale, but a quick zip around the parking lot proved it to be sturdy.

Next month, I'll order my DT RR1.1 so I can rebuild the old hub into a wheel that matches the front rim since I've been very pleased with the RR1.1/SON28 I built up front. (I just didn't have time to wait around for a DT rim to arrive before the 200k next Sunday!)

jaxgtr

So I am thinking you need to move to disc brakes.

Wogster

That's what I was thinking....

DieselDan

When the wear indicators disappear, replace the rim.

Mr. Beanz

I had an Open Pro split at the center of the braking surface. Not much more than 3,000 miles!..But I've never had good luck with OP's. 3 rear wheels built by 3 local builders, never more than a year or 5,000 miles. Not to mention the noise and popping eyelets

CliftonGK1

Unfortunately Alex DA16s that stock on the Cross Check don't have them. That's why I'm replacing it with an RR1.1


Beanz, the OP wheel is just a spare to keep around until I build the RR1.1, then it's my 'back up' wheel.

justin70

I'm not familiar with this concept, would you explain it?

cyccommute 

I've had several rims wear out like that. Mountain bike rims flare out nicely due to the wide tire and narrow rim. I've also split a rim along the braking surface, split several rims down the center between the eyelets inside the rim on the secondary wall (not on the outer wall where the spokes attach). Big guy, wide tires, narrow rim, jumping off of stuff...none of that is good for the rim

Oddly, I've never tacoed a rim and few of my wheel failures have been due to impacts.

Ka_Jun

Yeah man, but I run discs, and it happened because I took a bad line. My fault, user error, not any fundamental weakness w/ the hardware. Have a new wheelset inbound.

CliftonGK1

Many rims have a recessed line, or series of small dimples recessed into the machined braking surface (and usually painted black or red so you can see them more easily.
These recessed areas are the maximum depth that you should let the rim surface wear down to before replacing it.

Just to hype up the rim some more, check out the DT RR1.1 for an example of "divot style" wear indicators. The new DA16 has a wear line indicator, but I did not notice one on the stock DA16 rims on the '08 Cross Check. I can look at the front rim hanging in my shop when I get home, but I don't think it has one.

I know the Open Pro doesn't have wear indicators.

Mr. Beanz

Back up rim, that will work!

Tires also have wear indicators. Gina's Continental 4000's have dimples on the wear surface. When they are gone, I guess the tire is too!..Took me a couple of minutes to figure out why tires were equipped with holes already in them!

CliftonGK1

Mr. Beanz,
The casing threads are not the appropriate indicator of tire wear/lifespan.

Sincerely,
- Continental R&D Group

DieselDan

The rim wear indicator is also a European Union safety standard. Riders who ride mountains and hills, and therefore feather rear brakes often, wear out rims faster then us flat land riders. My newer CXP 33s have a line in the middle of the brake track the full circumference around the rim, while Bontranger uses a series of dimples. My Open Pros were NOS, no wear indicators on them.

The US CPSC does not yet require them. Rims made just for the US market probably won't have them.

CliftonGK1

Exactly why I'm using a rim with them for my new build.

cyccommute 

I don't like the continuous wear indicator on rims. The line in the middle of the brake track is where the rim is thinned and just seems to me to be a great place for a stress riser. It would be exacerbated as the rim thins out and be more likely to break.

Mavic machines (or did) a dimple on the back of the braking surface so that the rim shows a small hole when it's worn through. Much better design.