'Immaculate' punctures occuring without penetration through the tyre!

[king-slim]

Hi

I'm currently in Uzbekistan after a year of cycling. I bought new Schwalbe Marathon Plus tyres in Istanbul after hearing that decent ones were hard to come by in Central Asia. After nearly 9000miles I have had to change my original rear Schwalbe Marathon Dureme tyre finally, but immediately started getting what I call 'Immaculate' punctures where the tyre's integrity (and reputation!) remains intact and is not caused by an internal sharp object.

I tried various fixes...
1) Reinforcing the rim tape with paper and sellotape (as its all that I can get my hands on), the rim tape did present a few possible 'sharp' edges, nothing I could think of ever cutting myself on but its all I could think of and since the inner tube is under pressure in there I thought it might be the issue.
2) I tried the other tyre in case it was something to do with that tyre
3) Trimmed away any excess rubber moulding from the tyre itself
4) Obviously have checked thoroughly for sharp objects inside the tyre and the inside of the wheel rim.

Nothing seemed to solve the issue and I was having to change two punctures a day on my fully laden bike and it was getting to be a hassle.

Finally in desperation I fitted my old Schwalbe Marathon Dureme that I had not yet needed to change from the front wheel onto the rear wheel that was experiencing the problems. Magic, no punctures for the next 80 mile day!

The only difference is the rims. I had to get my wheel rebuilt in Trabzon and the new rim is very slightly thinner from sidewall to sidewall. I can only think that the Marathon Plus tyres I'm trying to use, are not compatible with the slightly thinner rim, and that the inner tube is getting pinched somehow between the tyre and the rim wall.

Does this make any sense to anyone? Eventually I will need to replace my one original Marathon Dureme (and very soon I think), so the clock is ticking on this issue. Today I have tried a temporary fix trying to insert strips of tea towel fabric between the inner tube and the rim covering the tyre rim interface (hopefully,,, its not an easy thing to cover over)... in the hope that this will stop any pinching occurring here.

The punctures themselves are small not very deep slits running along the tube in the direction of rotation that in one place become deep enough to let air out. As though there's some rubbing along the direction of rotation on the inside face of the wheel towards the rim and spokes that eventually breaks through the inner tube rubber.

Any help would be welcomed. I'm heading into the Pamirs soon and need to be able to cycle there with confidence!

Regards
Dylan

[jags]

Terrible tyres those marathon plus,get rid of them .the supreams are way better but the side walls are light.
Hope uget sorted ,tour sounds fantastic.

[StuntPilot]

I have Schwalbe Marathon Plus 1.75 front and rear on Rigid Andra 30 rims. Not one puncture during London to Edinburgh and Scotland to Istanbul touring.

For peace of mind in the Pamirs I would use Rigida Andra 30 rims and Schwalbe inner tubes with the Marathon Plus tyres. Ideally Marathon Mondials may be even better.

[jags]

when i was training to do the camino on my look kx light using mitchlins pro 3 tyres i done 8000 miles  not one puncture. first 20 miles on the marathon plus i got a puncture .i ordered  supreams the next day.

[mickeg]

Was the puncture on the inside side of the tube where it contacted the rim (or rim tape) or the outside side of the tube where it contacted the tire?

I always mount the tire with the tire label where my valve stem is.  Then if I can find the puncture on the tube, I know approximately where to look on the tire for the problem.  (Might have to look in two places on the tire if you might have flipped it over.)

I have not tried this myself, but I have heard that if you can't find a sharp object in your tire that may be causing punctures, if you gently wipe it with a cotton swab that the cotton may snag on the sharp bit to make it more obvious where it is.

I had a tire that I could not find what was causing my punctures.  I had a spare (punctured) tube.  I slit the tube all the way around on the inside side of the tube (where the tube contacted the rim) and removed the valve stem, I then put my good tube inside of that slit tube so that slit tube became a tire liner.  I stopped having flats because whatever sharp bit in my tire that was causing the flats was separated from the good tube by that tire liner.

Good luck.

[Andre Jute]

Thanks for the tyre liner advice, George, as I'm having the same problem as the OP, with the difference that mine is a slow leak every time, with brand new tubes.

Best of luck in finding a solution, Dylan.

[mickeg]

Thanks for the tyre liner advice, George, as I'm having the same problem as the OP, with the difference that mine is a slow leak every time, with brand new tubes.

Best of luck in finding a solution, Dylan.

Slow leaks are often the valve.  If shrader it is easy to see if it will bubble if you put some water or saliva on it.  Presta is a bit harder to test for bubbles, but it can be done.

[ridgeback63]

Some really good advice there mickeg,thanks

[jags]

yeah slow leaks are valve problems .most punctures are just bad luck  unless your tyre or even tire is knackered .

[king-slim]

So.... since I put in the fabric liner I have had no issues no punctures, it was a bit fiddly to get the material between the inner and the rim AS WELL as tucking up inside the tyre wall so that the INSIDE of the tyre and the sides were covered where the rim and tyre meet. But it worked.

Like the idea of using an old inner tube slit open. I'll try that next.

Thanks everyone

D.xx

[Pavel]

I'm glad that is fixed.  I'm always suspicious of these immaculate sort of events. It seems that it is often, just as in your case, a situation where some little thing gets in where one did not expect it to be, and causes all sorts of consternation. 

It was probably a bit of sand or wire, or perhaps a small shard of glass, hard to spot and lodged where it shouldn't be.