Persistent Flats

Ailsabob

Hi,
I'm at the end of my tether, and would appreciate some advice.
I recently bought a new wheelset - Camp Zondas. They're lovely, however, I am getting a flat on EVERY ride.
Not a puncture. No sign of tyre being penetrated. Just a flat. A tiny nick or cut that takes a few hours for the tube to deflate. The nick is always in the same spot - maybe 1"-2" from the valve, and on the outer part of the tube i.e. the part that will make contact with the tyre.
I've had 2-3 punctures on the rear, and 2-3 punctures on the front.
I have inspected both rims carefully and can see nothing.
My rides have all been between 25-60 miles.

I am riding:
Continental Race 28s 18-25
Continental 4000S 700x23 tyres

I typically inflate to 100 PSI. The tyres have a recommended range of 85-115 I think.
I weight 13 stone and a bit, or c.84 kg.

Not only am I at a loss to explain why this is happening, I don't know whether it's my rims, my tubes, my tyres, or me who is at fault!
I'd greatly appreciate some wise words here.
Thanks in anticipation...

sungod

i had something like this happen a few years ago

it was being caused be a piece of wire about 2mm long embedded in the tyre perpendicular to the contact point with the road

deflated there was nothing to feel, but inflated and ridden it must've been protruding just enough to make a pinhole in the tube

eventually found it by removing the tyre, a very slight mark was visible on the inside, probing the area revealed the buried wire

if it's in the same place and in an area where tube is only in contact with the tyre, take off the tyre and examine carefully

but it seems very odd to have it on two tyres, could be a production issue or someone methodical playing silly games with a needle...

ai_1

I find your post is a little confusing. There's no sign of a puncture but a small nick? Surely a nick or a cut is a puncture?

If these are occuring in the same place repeatedly then it's pretty certain the cause is a sharp edge or foreign object coming into contact with the tube repeatedly. However it is quite bizzare that this is happening repeatedly on BOTH wheels. I presume you've carefully run your fingertips over the area of tyre around the puncture site to feel if there's anything coming through? Tiny thorns, shards of glass, etc, that migrate through the tyre are not always visible from the outside.

Ailsabob

sungod wrote:

i had something like this happen a few years ago

it was being caused be a piece of wire about 2mm long embedded in the tyre perpendicular to the contact point with the road

deflated there was nothing to feel, but inflated and ridden it must've been protruding just enough to make a pinhole in the tube

eventually found it by removing the tyre, a very slight mark was visible on the inside, probing the area revealed the buried wire

if it's in the same place and in an area where tube is only in contact with the tyre, take off the tyre and examine carefully

but it seems very odd to have it on two tyres, could be a production issue or someone methodical playing silly games with a needle...

I put the tyres back on randomly after a puncture. I don't align any part of the tyre with the valve, for example. So I think that rules out the protruding wire theory. Also, fairy confident that nobody is playing silly buggers.

Ailsabob

Ai_1 wrote:

I find your post is a little confusing. There's no sign of a puncture but a small nick? Surely a nick or a cut is a puncture?

If these are occuring in the same place repeatedly then it's pretty certain the cause is a sharp edge or foreign object coming into contact with the tube repeatedly. However it is quite bizzare that this is happening repeatedly on BOTH wheels. I presume you've carefully run your fingertips over the area of tyre around the puncture site to feel if there's anything coming through? Tiny thorns, shards of glass, etc, that migrate through the tyre are not always visible from the outside.

Sorry.
To be clear, tube has a small nick or cut on it.
But no sign of breach of tyre wall.
Yes, happened on both wheels, and always within 1" of valve....

dnwhite88

It could be a small burr on the rims, maybe a wipe over with fine sandpaper?

Ailsabob

dnwhite88 wrote:

It could be a small burr on the rims, maybe a wipe over with fine sandpaper?

Yes, will try that, although it's on the part of the tube that pushes into the tyre, not into the rim.
Also doesn't explain why cut is always in same sort of place (c.1" from valve).

I just don't understand, frankly...

sungod

as above, if you don't always align the tyre wrt the valve hole but the punctures are in the same position it only leaves the rim/rim tape, that's assuming you're patching the tubes

otherwise if you keep fitting a new tube it leaves the possibility of a batch problem with the tubes

Ailsabob

sungod wrote:

as above, if you don't always align the tyre wrt the valve hole but the punctures are in the same position it only leaves the rim/rim tape, that's assuming you're patching the tubes

otherwise if you keep fitting a new tube it leaves the possibility of a batch problem with the tubes

New tube every time.
Tried Vittoria tubes too.
But mainly Conti's

ic.

Sounds a bit weird. I'm not sure an inner tube behaves exactly as you think it might inside the tyre though. So when you say the cut is always tyre side, it's worth considering this may not be the case.

If you have changed tubes and fitted the tyre in random places then it simply must be rim/rim tape

Check rim tape is fully covering all holes, it only takes a very small hole for the pressure to force it through and cut it. If in doubt, replace rim tape

Next look at going over the rim with a very fine sandpaper.

If it still happens, contact the shop to talk about replacement or advice on the wheels if they're fairly new

ElectronShepherd

Do you use tyre levers to get the tyre on? Is there a burr on one of the levers that is cutting into the tube?

mamba80

Commonality here is YOU
could be how you fit the tires? if you finish nr the valve and are nicking the inner here? fit tire around valve first and then make sure valve is pushed up inside tire, before inflating or proceeding to fit rest of tire - make sure you finish away from valve, use plenty of talc on inner.

Ailsabob

Ha ha,
Yes I am the universal constant in this. But the other universal constant is my new rims.
I do use tyre levers, and I always start at valve and work away....

ElectronShepherd

So, there's three things that are always the same.

Seems obvious, but next time try starting opposite the valves and / or fit the tyre without using tyre levers (See http://www.youtube.com/watch?feature=pl ... 90xM#t=163).

rolf_f

Ailsabob wrote:

Ha ha,
Yes I am the universal constant in this. But the other universal constant is my new rims.
I do use tyre levers, and I always start at valve and work away....

But the rims aren't directly a constant as the puncture is away from the rim area.

Finishing at the valve is a good idea anyway - you can push the valve in to help seat the inner tube. But that said, you'd need to be wierdly incompetent to puncture a tube at the start of the process and not do it at the end of the process!

Ailsabob

Bit of light oil around where it normally punctures be helpful maybe?

Ailsabob

Examining the tubes more carefully, the area of tube directly where the valve is - on the outer face of the tube which faces I to the tyre , it is effectively an oval shape. The punctures manifest as tiny abrasion or scratch marks right on the edge of that oval. I really don't think I can have been so unlucky as to damage every single tube with a lever?

Ailsabob

Or maybe a pre-emptively apply a patch either side of the valve where I feel the tube is most susceptible?!

sungod

photo?

Ailsabob

This one slightly unusual in that it has more than 1 hole in. Most have the single hole....

mamba80

this is like one of those weird "guess the sound" competitions you get on commercial radio!!!

that looks to me like tube defect BUT as you ve replaced with different makes, then maybe a no!
it also looks like the tube has gotten itself folded and abraded itself during a ride, are these tubes rated for a 23 section tire?
If it were me, I d get some new tires, say Pro4's and some specialized tubes, use loads of talc, double check the rims/tape and fit without tire levers.
and I ll assume the comment about using light oil was a joke...that's a big no no

I do sometimes wonder whether folk just imagine a really weird problem and then post it, and sit back laughing at the replies!!!!

Ailsabob

Thanks for comments. Trust me, I have better things to do with my time than wind folk up!

Ailsabob

Right.
Talc purchased and used.
Patches pre-emptively applied to likely puncture site.
Tube and tyre carefully replaced. For the first time ever, i might add, without the need for tyre levers. Fingers now crossed. Thanks all.....

Matthewfalle

Ailsabob wrote:

This one slightly unusual in that it has more than 1 hole in. Most have the single hole....

That looks like an abrasion tear - the arc is where the tube has been pushed in grabbing the tyre/rim, the holes are where it's caught on something.

User error I'd say unfortunately.

Ailsabob

I'm in no position to confirm or deny. But it would beg the question why I have happily fitted these tubes to other wheelset/tyre combos without ever having a problem, in stark contrast to this tyre/rim combo where I have experienced nothing but problems. A little odd...