Consistent circular cuts around the valve

[PIGEON]

Ok I'm really getting frustrated with this. A couple of months ago I bought myself a Klein. I was well chuffed with it and I gradually changed some of the modernish components to retro ones. Then one day I got my hands on a pair of almost new biscuit colour Panaracer Magics. They turned up in the mail and I gave them a good clean before installing them. I re-used the inner tubes that were already on the bike. One thing I noticed is how loose the beads on the Magics were. I can easily get the tyre onto and off of the rim without using tyre levers. With the tyres installed and inflated, I took the bike for a spin. After about half a mile, I had a flat rear tyre :roll: Walked the bike home, removed the tyre and inner tube and I noticed there was a half moon cut around the valve. Thinking the valve hole in the rim might have a sharp or serrated edge, I filed and sanded it round and smooth before installing a new tube. When I took the bike for a ride with the new inner tube, the same thing happened. I did notice the tyre wobbled about a bit, the thread not running perfectly straight, almost as if the rear wheel wasn't true. Also before the cut occured, the rear tyre started to squeak with every rotation (stopped to see if it hit the frame or brakes at all but it didn't, the squeak definitely came from the tyre). So I installed another inner tube. After less than a mile: same thing.
What am I doing wrong??? Both the wheel and the inner tube were fine beforeI installed the Magic rear tyre. I really want to ride that bike but it just doesn't seem possible. Each time the same half circular cut around the valve occurs. I'm getting desperate here, does anybody have any clue w'hy I keep getting these flats?

 

[orange71]

bead may be split inside so now not holding on tightly and therefore rotating around the wheel under braking. This will cause the problems you are having. no fix unfortunately.

 

[Tazio]

If the tyre is moving around then it will be moving the tube around. As the tube moves around the natural place to get damaged is the only point it doesn't come against a flat surface, the valve hole in the rim.

Give up on the look and get a set of nice practical tyres, sounds like the Panaracer is knackered. The very fact you can get it on so easily points to this, I normally break sweat trying to get a new tyre on.

 

[Benandemu]

Sounds obvious question, but are they the right tubes? They need a 2.0 to 2.3 for the Magic tyres.

It sounds like the tube isn't getting enough expansion to hold the whole lot together, and then when you pedal, the tyre is pulling the tube and causing it to be jammed up against the rim hole with such force that it cuts into the tube.

Try a bigger tube, as I know I had 2.1 to 2.5 tubes in mine.

 

[Andy R]

Very loose bead = tyre creep under acceleration or braking.

Not a lot that you can do really, some tyres are more susceptible to this than others.

 

[PIGEON]

Ahh this sounds plausible, I really didn't think of that. Luckily I didn't pay much for the tyres, although it's probably too much for a set of tyres that I can't use. It's a shame, they really look cool... Thanks for the advice guys, will put the Schwalbe Racing Ralphs back on until I can get another pair of biscuit tyres for cheap

 

[MikeD]

Talcum powder on the tubes. Won't stop the tyre creep, will stop the inner tube getting dragged around too. Maybe. Worth a try, though. Although as others have said, if they're moving that much over that short a ride, it's not a good sign...

 

[Anthony]

You haven't said whether you're using Presta valves or Schraeder, or whether you have liberally applied talcum powder to both the tube and the inside of the tyre, or what pressure you're running it at, or whether swapping the front tyre to the rear makes any difference.

 

[Andy R]

Ahh this sounds plausible, I really didn't think of that. Luckily I didn't pay much for the tyres, although it's probably too much for a set of tyres that I can't use. It's a shame, they really look cool... Thanks for the advice guys, will put the Schwalbe Racing Ralphs back on until I can get another pair of biscuit tyres for cheap

Or convert them to ghetto tubeless.....

 

[PIGEON]

You haven't said whether you're using Presta valves or Schraeder

Tried both, the rear wheel came with a presta valve in a schrader rim, didn't prove to be a problem when the Schwalbes were still on it. When I first tore a cut in the tube after I fitted the Magics, I replaced it with a schrader because I thought that the skinnier presta vave in the schrader drilled rim might have caused the cut. But it didn't because the schrader tube was cut in no time too.

or whether you have liberally applied talcum powder to both the tube and the inside of the tyre

Not deliberately but the second tube was drenched in it, I was amazed what a mess it made when I removed it after it had been cut.

or what pressure you're running it at

I don't know, I inflate my tyres to the point that they're firm and since I didn't plan on taking the bike off road, I put a bit more air in them than I might have done otherwise.

or whether swapping the front tyre to the rear makes any difference.

Magics are front and rear specific, front is skinnier. I could try it to definitly rule out the rim as the cause of the cuts, but the tyre dragging the inner tube about sounds so plausible and is also consistent with the shape and location of the cuts that i think it won't be necessary.

Or convert them to ghetto tubeless.....

Getting rid of the tubes alltogether might not be the best idea in the world but I could try to glue the tyre bead onto the rim with the tube already installed... But that would probably ruin the rim and make punctures almost impossible to repair. I'm afraid I have no choice but to accept it's not going to work