Recurrent punctures on the inside of tube using Andra 30 rim

[CT6]

Hi,

I have an Andrea 30 touring rim with a rohloff hub. I have been getting recurrent punctures on the inside of my inner tubes. There are no protruding spokes or burrs, the rim tape is even and I have experimented with several different rim tapes, but every time I get the same problem leading me to believe this might be a problem with the rim itself.

There is always significant wear in a small band on the inside of the tube where it sinks into the depression inside the rim. I'm inflating to the recommended pressure and have around 35 kg of gear with me.

Any advise would be hugely appreciated - is there anything I can do about this? Have other people described a similar problem? Is this a fault of the rim?

Many thanks

Steve

[Danneaux]

Steve,

Are the punctures always in the same place on the inside of the tube? If so, that should lead one directly to the source. If the punctures are in various places on the inside, then detection will be a bit more complicated.

Best,

Dan. (...who has always indexed his tubes and tires with the rims to aid in tracking down flat sources)

[onrbikes]

Next time it happens.
Before you remove the tube mark the rim, tyre and tube. Then find the leak and lay it all together again aligning all the mark you put on.

This will indicate where the culprit is. If its the tyre, be rough with it and really inspect the area.

I had one similar this year and find a very small bit of beading protruding from the tyre that only came into action when the tyre was inflated. I fixed it by putting a patch on the inside of the tyre as well as the tube.
In your case it may be something like a tiny burr.
 
Presto!!!

[CT6]

Thank you guys. I will try that, but the punctures appear to happen in several places - the entire tube has a strip of wear along it after quite a short period of time, and there are many small defects that are not quite punctures as well. This occurs with every tube I use.

Do I need to contact the rim company?

Cheers

Steve

[jags]

obvious question is the tyre and tube in good nick and  what pressure are you putting in it.

run your finger aroung the rim if its rough get rid of it.

jags.

[Slammin Sammy]

The Andra 30 rims have no eyelets, and the edges of the spoke holes can be sharp, but a good rim tape should cover them off well. Check for burrs on the holes.

From your description, it sounds like you might be getting pinch flats along the bead, or have a tiny sliver of something sharp trapped in the rim. But the wear you describe could only be caused by movement of the tube within the rim. Is this possible with the pressures you're using?

I presume you're using a good quality tyre and tube, and that the tube is the correct size for the job?

[mickeg]

I had several punctures from a tire but could not find the sharp bit that was causing them.  I suspect it was a bit of thorn that only became apparent when under pressure.  I took one punctured tube and slit it lengthwise and cut out the valve.  That became a tire/tube liner that went between my tube and tire.  No more flats.  Not sure if that would work if the rim is the fault.

I always mount the tire so that the text of the tire label is at the valve stem.  Being consistent sometimes helps me find tube punctures quicker for patching.

[Dave Whittle Thorn Workshop]

Swap the tyres front to back and see if the problem moves.