Cycling UK Forum

Reading various threads about rim wear etc. reminded me of a near miss I had whilst returning home from an audax last year.We were driving home from Girvan on the river clyde and there was a sound like a stone hitting the window.We ignored this and carried on.Next day,on cleaning my bike,the front rim had "exploded" i.e.the top section of rim had separated from the rest due to wear.I replaced 3 wheels because of this incident which could have ended much worse.Don,t trust to luck.

As you might know, some rims incorporate a wear line giving indication of when they should be replaced. And it also matters what rims you buy in the first place. I'm using Rigida DP18 which is a very heavy, but seemingly very long-lived rim, at least in my experience.

To check the rim wall thickness, get an Iwanson gauge (£5-6 on eBay)
Replace at 1mm. Those rims I've had fail have done so at around 0.7mm.

Wear rates vary a great deal, depending on riding conditions, brake blocks etc. I've had some only last 5000 miles (7 or 8 months at the time), at which point the tyre on it still had enough life to go through a second rim.

Please read my post on the other thread on rim wear.
That Iwanson gauge sounds a good idea, but it won't be any use on my Rigida Chrina rim because of the internal profile.
No doubt other rims are like that.