Checking for Rim wear.......

[Daddy Pig]

Hi all

I'd be interested to hear how you guys check for rim wear? Obviously some newer rims have 'indicators', but not the more retro kit.

To complicate matters I have a pair of Campag Stheno rims which I really like, but they are concave by design so I'm never really sure how to tell how worn they are.

Im still using some Mavic 231s from 94 that have had a pretty tough life. They seem to look and feel ok, but must be getting near the end of their life.

 

[Anthony]

I just put a mm straight edge across the braking surface and compare the depth of the concavity with a mm. You can see reasonably accurately whether it's a mm, or half of a mm etc.

I take an X517 as a reference and as near as I can measure a new X517 braking surface is c1.7mm thick, so if an X517 is now 1mm concave, it is well over half worn out and there isn't all that much left to sustain structural integity. I have no idea how an M231 compares to an X517.

Personally, I would still use such a rim for a while, but I wouldn't sell it. However I find that many people convince themselves that what I call a 1mm rim has what they call 'loads of life left' and they feel justified in selling it. I expect this is just ignorance, but it's still selling by false description to my mind. As a pure guess, I would expect a rim to be on the point of collapse when it got below 0.5mm thick, so I doubt whether it is true to say a rim that is 0.7mm thick has 'loads' of life left.

I agree that there is no easy way of assessing the wear on rims that are concave by design, but I would say they were stupid even when new, and even worse when worn.

 

[Woz]

I know this may sound silly, but I can't resist. I check for cracks.

I did think about making my own indicators but eventually couldn't be arsed; from my own experience they split gradually and usually you will feel it through the lever when it starts.

 

[Takingabreak]

Stheno rim wear

I've got some New Old Stock sthenos tucked away somewhere, I'll dig them out and measure how concave they are.

 

[Daddy Pig]

Good answers chaps, thanks very much!

NOS Stheno's ......hmmmm......

 

[michael franks]

Daddy Pig wrote:

NOS Stheno's ......hmmmm......

+1

 

[Takingabreak]

and ateks...

 

[Takingabreak]

I've measured the sthenos as best I can using some verniers, they are concave by about 0.5mm

Not sure how helpful this is as I measured a set with some obvious wear on and the depth wasn't much different, the concaveness was just a different shape... :cry:

 

[MikeD]

I ran Maguras on Sthenos and wore actual brake-pad sized trenches in the sides. But that's by the by.

I'm still a fan of the bang-shit test. I know it seems a bit "witch trial" to some, but if it fails it didn't have much life left in it anyway and if it passes you know it's got loads left.

Anthony's method is quieter and safer for rims with originally-flat sidewalls, though

 

[lewis1641]

I'm still a fan of the bang-shit test.

what's that then?