Puncture repair - what am I doing wrong?

Juju_uk_68

Never had a problem repairing mtb and bmx punctures, but I hoy a tiny little double puncture in my inntertube on a 700c x 23 wheel. And I've now had 3 goes at fixing the puncture, and each time, once the tyre is up to pressure, it starts to leak at the site of the repair.

Ive followed all the instructions - ie roughening slightly, and used both a sparing and the second time a greater quantitiy of glue - waitiing for it to get to a fairly tacky/dryish constisency - applying and smoothing out the patch, waiting iro 20 mins min before putting the tube in typre and putting tyre back in and then inflating.

Each time I can actually still air leak out from the repair site - each time i dunk in water and the airs only comming round the sides of the repair. Seems the high pressure of the re inflation is blowing the seal. Is there a technique for racing bike tyres? I have used three patches so far and more more concerning, half of my evening %)$" !

Any tips? I think a new inner tube every time I get a flat looks on the cards.,

aussie70

Don't check it!
Because you run at much higher pressures on a raod bike, a patch ain't gonna stay on without the tyre to push against. If you're convinced you've covered the hole for mthe original puncutre and you've stuck the patch on pretty well, refit it and pump it up. This'll soon tell you if it's holding pressure or not.

Slow Downcp

Only put a very small amount of air in the tube before you put it back into the tyre. As you're finding out the patch can't take the pressures. Once it's inside the tyre, it will hold against the inner wall of the tyre or rim. Having said that it is better to treat inner tubes as consumables - buy in bulk and you can get 10 very good quality tubes for £15-£18.

FSR_XC

Make sure you don't have a thorn (etc) still in the tyre.

Juju_uk_68

I've made sure I am not repuncturing the site, theres nothing there - I know as I altered the position of the tyre viz tube, and when removing the tyre/tube, the only hole is at the original site leaking round the patch. I am also not reinflating until the tubes in the tyre and on the rim....

I am using an old free kit I got off the cover on a MTB magazine - it seems the pressures of reflation are overcoming any seal the glue/patch can manage - are most puncture kits the same or is there a particuralty good one for high pressure tubes and tyres?

Slow Downcp

Does the glue have a shelf life? It may be past it's best?

I;ve just read you original post, and on the occasion I do repair I just give a quick rub with the sandpaper, one thin layer of glue, blow it for 10 seconds or so, stick the patch on, and then back into the tyre. I never put two lots of glue on, or wait for it to dry, and don;t seem to have any problems.

The only other thing I can think of is whether the tube is 100% dry - if it;s even damp you'll have trouble getting the pacth to stick.

FWIW I use small round patches with feathered edges, as they stretch better than the non feathered ones.

redddraggon

Is the puncture near a mould line on the tube? If it is you need to totally flatted the mould line otherwise air will find a gap as you won't get the patch fully flat.

on the road

You don't need to wait to put the tube back in, as soon as you put the patch on put the tube back in the tyre. The patch will be pressed hard on the tube by the tyre and will stick to the tube much better. And don't forget to powder the area around the patch otherwise the tube will stick to the tyre.

synchronicity

http://www.tenerife-training.net/Teneri ... right-way/

oldwelshman

I had this with one repair kit, it was crap glue and crap patches.
The best ones I have used, believe it or not are the ones in ed box from halfords and I usually use the repaired ones as spae but have got them up to 110 psi and no leaks.
I also put small amount of the glue over the patch after and around the seal and blow it dry whilst ensuring the patch is stuck flat.
I have not yet managed to have any tubes stuck to tyre even after doing this

Rich Hcp

I have repaired tubes, but they all leak in the end.

So now I replace the tube, making sure there is nothing stuck in the tyre

on the road

Mine never leak.

keef66

only time I've given up on a tube was on my mtb when I picked up about 15 thorns in one short stretch of lane which had just had the hedges trimmed.

Anyone else have difficulty removing the paper backing from feather-edge patches? Or have I got a particularly rubbish lot of patches?

synchronicity

Rich Hcp wrote:

I have repaired tubes, but they all leak in the end.

Then you haven't actually repaired them, have you?

Fixing innertubes is becoming a long lost art...
Yes you can fix them & they won't leak if you do it properly.

Panter

Juju_uk_68 wrote:

I am using an old free kit I got off the cover on a MTB magazine

I think thats your problem, as OldWelshman says.

I like the "Rema tip top" puncture repair kits, cheap, compact and I've NEVER had one fail. I think they are avaialble from Halfords too.

As for removing the backing from the feather edged ones, rightly or wrongly I don't bother. The backing thats left on negates the need for chalk IMO as then there is no possiblity of any stray vulcanising solution glueing the tube to the tyre.

HTH

Chris