Possible reason for puncture in new inner tube

[andrecapetown]

On Saturday I change my MTB tires to slicks, I used brand new tubes, the correct size.

 

On Sunday I had a flat about 5km’s into the cycle, then another on the other tyre, at about 40km’s.

 

Both puncture were exactly the same, it has a long scratch along the length of the tube, with a small cut-hole in the middle. It is on the inside in the middle of the rim, the band, along the inside of the rim, is also in good condition..

 

As I mentioned both looked exactly the same.

 

I took great care fitting the tyres.

[David Marshall]

Sounds like the tube has been pinched. Either with tools when fitting or more likely between the tire and tube when pumping up. I always fit tyres with my hands alone and make sure that there is just a little air in the tube when doing so. Then pump the tube a little more and check the tire is seated in the rim all round and the tube is clear. Squeeze and move the tire to check this. I then press the valve stem into the tire to check that it is free, as this is the area where pinching happens most. Pump to full pressure and then screw on the valve retainer.

[andrecapetown]

Thanks, C

 

I'll take out the tubes and investigate....

[scotty]

Also Check the tyre itself to see if the wire bead is still ok and not damaged. I once bought a new tyre and had similar thing happen, took it back to the shop and they swopped it out.

[Neg]

Are you using tires liners? i had exactly the same thing on my tandem yesterday... a cut/split about 2" that was not through except for the middle of the cut, about 10mm. ??