tyre bead wear

[pumpkin]

have a tube blow out this am and noticed the bead has worn as tho the pads were touching (rim brake) but they arent. However the rim is a bit wider and the tyres are 26 x 1.0 so my question is do I need a slightly wider (1.25/1.50) tyre on this rim? not an issue I've seen on the front but that is an older school mavic (17 or 19mm inner width)

[mrcharly-YHT]

Is it wearing all the way round?
Or is it in a few spots?

I've had a rim out of round, and the pads touched in some places. Slowly rotate wheel and check.

I assume you mean that the sidewall has worn, cause pads can't touch the bead.

[BFC]

Some tyres don't get on with some rims! The protective layer(s) covering the tyres wrappings around the bead either don't extend far enough or are ineffective, the rim edge gradually wears through the tyres sidewall at the bead until it goes bang. Tends to occur on rears more than fronts due to greater tyre flex from the heavier loading. Tends to affect rigid bead tyres more than folding types.

There can be warning signs - the bike just feels wrong as the tyre starts to develop a bulge when one layer gets cut through (it goes bang when the second layer goes!).

Alex A class solo rims and conti hardshells were my combination to avoid on the fixed for commuting, and their grip was lousy. Other tyre (all folding) and rim combos have been fine.

Do check the rim for rough bits on the inside edges or discontinuity at the join.

[pumpkin]

Thanks. I suspect this rim. The wear is all round on both sides and there was a hole in the wall just above the bead. 2 x tyres on this rim but both were in the narrow category.  26 x 1.0 or 1.125. Have put on a 1.5 to see if that changes anything.

[fruitcake]

I agree with your initial assumption, i.e. that a wider tyre is the answer.

A 25mm tyre on a rim wider than 17mm is not advised according to Georg Boeger's chart of tyre widths on Sheldon Brown's site. Your one inch tyre would have been spread wide on your wheel rim with its profile being flattened and, as a result of this, the sidewalls being forced into a tighter curve than they're designed for. With the flexing of the sidewalls, you're likely to have seen premature wear there (as well as the tyre providing insufficient 'suspension' for the bike, i.e. a harsh ride.) A wider tyre would not suffer in that way.