Persistant punctures

Ihatecycling

I have a Giant SCR 4.0 Entry level bike, I think it is 2007 or 2008 version. A few months ago my rear tire exploded. I replaced the tube and tire and I found out that the inside rim had a little nick in it, this was sanded down and tape was put inside the rim and I was able to cycle again, fast forward 3 weeks and my front tire has a small rip on the top of the tire(tire has been on a year) on a cycle, I brought back into the shop checked wheel new tube and tire, next cycle 3 miles out another flat, back to shop check rim and tire put on tape, wheel back on bike and then I notice the rear tire is flat. The tube is nipped on the side and in the same place the tire has slighty ripped. I checked the point on the rim where the puncture occured but I can see anything, This is driving me mental :mad:

The tires are continental Ultra Sport 700x 23c and the tubes are the same size. I put 100psi in them.

Any ideas???

Diarmuid

Your either very unlucky or doing something very wrong.

Buy some gatorskins and see how you get on for a few weeks, and watch what you are cycling on!

Lemag

With a nic like that are you really expecting much help here

07Lapierre

Tyres not pumped to correct pressure?

Lumen

Jealous pet?

dave.obrien

3 or 4 year old tyres?


No, you're right Lumen, it must be the pet...

Ihatecycling

07Lapierre wrote: »

Tyres not pumped to correct pressure?

says 120 psi on tires, I put in 100psi

Ihatecycling

Lemag wrote: »

With a nic like that are you really expecting much help here

:D

markdrayton

I can't quite make out what's happening from your description (sanding the rim? nips in the tube? Not sure what that means) but if you keep getting flats then something keeps puncturing the tube.

When you take the punctured tube out inflate it, find the hole and the line it up with the tyre to know where to start looking. Look very carefully for something stuck in the tyre. It coud be a tiny piece of glass, flint or wire so small you barely see it. It may only be visible when you flex or bend the tyre. Run your fingers around the inside of the tyre to find protrusions.

Check the tyre for holes or tears -- if the tube bulges out it'll eventually go, particularly if the brake rubs the exposed tube. Check the rim tape (the plastic or fabric strip covering the spoke holes) for holes, tears or sharp bits. Check no grit has crept into the inside of the tyre.

Ihatecycling

I patched up the rear tube and put the tire on, there is a slight tear on the tire where the puncture happened. As I pumped up the tube, I can now see other tear marks on the tire, about 3 of them one side. This was happening before also. It seams to tear at the thread part where the tire is just above the rim. Is this the weakest point of the tire, of is something catching it?

One other thing the tube and tires have been put on by the bike shop.

markdrayton

Ihatecycling wrote: »

I can now see other tear marks on the tire, about 3 of them one side. This was happening before also. It seams to tear at the thread part where the tire is just above the rim. Is this the weakest point of the tire, of is something catching it?

It sounds very much like the brake block is rubbing the tyre. Spin the wheel and watch what happens when you apply the brake. If the block is too high it'll catch the tyre. This can happen without you noticing -- if the block is too high at first it might not touch the tyre, but as the part that strikes the rim wears you can get a lip on the top of the block which touches the tyre as you brake.