Open Pro rim wall thickness?

[Polar Bear]

The depth of wear indicators on DT rims seems to be (predictably) specified by the marketing department rather than the technical department.  This is a rim which where the "pits" were just about to disappear, to the extent that I didn't trust it anymore as a front wheel:



Bastards, eh?  It's barely worn at all.  And it's also braced right in the middle of the brake track, so it would have to be paper-thin in order to fail.

Out of interest Roger, what rim was that?

[frankly frankie]

It seems to me that this:

Open Pro:

leads fairly logically to this (eventually), even assuming the brakes are well set up:

Here's an Open Pro that I dismantled tonight:

[gordon taylor]

It does show the importance of positioning your brake blocks high up the rim.

But a failure at near the edge of the rim goes BANG! Whereas the failure above was just a steady deterioration over a few weeks and some peeling aluminium.

Tewdric - yes, that bike has cantilever brakes. How can you tell?

Off topic: the rim in my photo is from Mrs Gordy's commuter. She wears through rims at twice my rate.

[Biggsy]

The braking tracks on the Open Pros I have are so narrow that there's virtually no choice of where to position the brake blocks.

[Manotea]

Gordy, what is interesting about that shot is that measuring the rim that you could have got to before cutting it would have shown reasonable thickness.

Indeed, but it is an extreme case given that he's actually worn through the rim at one point.

It does show the importance of positioning your brake blocks high up the rim. It's also why people bin rims at 1mm or 0.7mm thickness rather than thinner.

Funny you should say that. My front wheel Open Pro rim is looking distinctly concave. Just measured it with one of these and it shows ~1mm compared with ~1.3 for a new rim.

Now, I'm riding up to York on Thursday. Should I change the rim or leave well alone for now?

I'm slightly paranoid about this as I've had a rim blowout on the road before, so I'm tempted to do it now, though this is offset by a certain natural laziness and concern about rebuilding the wheel before a longish outing. The last wheel build was the day before LEL2009, not by choice I hasten to add. I haven't done THAT much mileage on it, 50k 5km km, tops. Still, as I remarked on another thread, the curiosity one feels as to how long a component will last evaporates as soon as one finds out.

[GrahamG]

Funny this thread should pop up again - after barely 4000 miles the open pro on my back wheel is feeling pretty concave.

[gordon taylor]

Since my photo of the spilt above, I've persuaded Mrs G to get a disc-braked bike for commuting.

That's one fewer set of rims to worry about. 

[Oaky]

Since my photo of the spilt above, I've persuaded Mrs G to get a disc-braked bike for commuting.

That's one fewer set of rims to worry about. 

I'm not sure that this failure had much to do with rim-braking.