In the last 3 months I have had two rear tyres fail in the same way. The sidewall rips just above the bead over a length of 8-10 cm, the tube bulges out and before I can stop, there’s a mighty bang. It’s not brutal misuse- I am one of the World’s great mincers.

One was a Trail King which lasted over a year, and the other was a Nobby Nic which died today in asnowstorm after less than 3 months.

Both have failed on the drive side so I am wondering if I am getting a bit of cleaner, or oil or something like that on them and it’s eating them? However, I treat the other mountain bike exactly the same way (Maxxis Ikon on that), and have had no troubles with that (so far!)

Any advice from the collective mind, please?

Sharp edge on rim?

Don’t think so. I had a good look at the rim this afternoon and ran my fingers carefully round it to check for damage. It seemed OK but I’ll have another look

What rims are they and what size are they? And what make /size tyre is on them..

The obvious thing is the rim of multiple tyres are failing in the same way.

Also what pressure are you running, and what tubes?

As mentioned, sharp edge would be first thought.

If the bead isn’t seated on the rim properly then I’ve heard of this happening where the edge of the rim cut’s the side wall.

[90’s problem] You’re not using v-brakes are you and the pad’s catching the tyre [/90’s problem]

Thanks All

Rims = Hope Tech XC so 19.5 mm internal width

Tyres which have failed = Trail King 2.25″ and Nobby Nic 2.25″

Schwalbe tubes at about 40 psi

Not using V-brakes! I’m pretty trad, but not that much

Actually, thinking about it, the wheels are about 6 months old and I moved the Trail Kings on to them when I got the wheels, so they survived about 3 months on the new rims, and the Nobby Nics I replaced them with managed the same. I think I need to look very hard at the rim, don’t I?