Friday, 10 August 2018
DANGER worn out wheel rims
Hi everyone. Those of you who were out last Wednesday will recall that I stopped to re-position my tyre on the back wheel. It was eccentric and bumping on every turn. Re-fitting the tyre with the aid of a tiny slick of liquid soap improved things a little. We discussed whether the rims were worn too thin and causing the problem. I didn't think this was the case as I knew the age of the wheels and roughly how many miles they had done. Had the rims been close to failing it could have been dangerous so I had the rims checked by two different bike shops who thought that there was plenty of life left in them. However, discussion with several people, including professional bike mechanics yielded the following points which may be of interest: 1. The tyre causing concern was a foldable gatorskin with plastic bead. The casing had worn and in one place and for about a quarter of an inch I could see the nylon bead, this allowed the tyre to sit high. I think this was the cause of the bumping. 2. Frequently check rim wear for dishing, replace when concerned. 3. The rim "flares" out at the top when it gets thin. 4. Replace when wear indicators disappear, these are either a groove which when it becomes flush with the braking surface indicates replacement, or a shallow drill hole, similar to the above but less reliable as it only indicates wear at that location. 5. A rim will normally fail when a spoke breaks unexpectedly or the inner tube pushes through the rim and bursts. Potential catastrophe, especially if its on the front wheel. Please respond here if you found this helpful. Especially if you disagree. Think safety. I will probably buy a new wheelset anyway and keep them on hand for the near / not so near future. Peter.