What in the name of god is wrong with my Mavic!!!!

Dave11

Lads,

Just in the door having suffered my sixth deflation in last two weeks and I mean deflation. It's not a blow out or anything similiar. Last six tubes I have fit, I have put in, put to correct psi, gone out and by the time I'm 15-20k into a spin I notice its deflating. By the time I get home I'm struggling to get back! Give it half an hour after I get home and it will be totally deflated!!!

The wheels are 2007 Mavic Cosmic's. The tunes are 80mm Schwalbe. I have checked the tyre and can't see or feel anything. I have removed the strip and checked spokes and nothing up there!

Any ideas lads before I bring it my LBS.....it's driving me up the F'in wall :mad:

Cheers

07Lapierre

Examine the tube and find the leak. then examine the other tubes and I bet you'll find the leak is in the same spot. ( that is the same distance from the valve). match the tube up to both the tyre and the wheel and check for shapr edges on the wheel or something still stuck in the tyre.


Do you use tyre levers to put the tyre on the rim? If you do, don't. refit the tyre with your hands only.

AstraMonti

I had the same issue with much cheaper mavic, the aksiums. It was driving me mad. I ended up using sand paper around and in the valve hole to make it smooth. That solved my problem.

Dave11

Cheers for the replies lads.....I'm pulling my hair out here looking at the bloody things!

07Lapierre....good thinking to compare the tubes! I have kept two of them so I'll do that alright. I do use my hands for putting tire back on so it's not that!

AstraMonti.....I'll have a look and consider the sandpaper route alright!

The wheel was only re-built two odd months ago so must be somthing to do with it just bedding in and then I'm sure all will be ok!!

ednwireland

tube bowl of water ? see if its leaking and where
my schwalbe tubes had removeable valves (which came off with the dust cap !) are they tight, is your pump loosening them somehow
(not as bad as my vittoria inner tubes, brass valve stem steel screw in valve when i use my mini pump - which screws onto the valve it heats up expands and the valve unscrews have italians never heard of differential expansion !!!!!!)

Raam

Try a new wheel to see if you bought a bad batch of tubes.

goldencleric

new rim tape?

Dave11

Have had a good proper look there no lads and ran the two tubes thru water and no bubbles!!! I was thinking dodgy batch of tubes but bought one yesterday from a different shop thinking that it might make a difference and no....it's still happening!!! Rim tape look fine and is 100% smooth the whole way round so that shouldn't be the cause! There is a small nick on the inside of the tyre which could be the problem but with no visible bubbles I can't match it up to see it that is the problem....LBS it is i think!!

Moflojo

Sometimes if you run a cotton bud along the inside of the tyre, or along the rim, anything that is sharp will snag some of the cotton wool.

Lumen

Dave11 wrote: »

Have had a good proper look there no lads and ran the two tubes thru water and no bubbles!!! I was thinking dodgy batch of tubes but bought one yesterday from a different shop thinking that it might make a difference and no....it's still happening!!! Rim tape look fine and is 100% smooth the whole way round so that shouldn't be the cause! There is a small nick on the inside of the tyre which could be the problem but with no visible bubbles I can't match it up to see it that is the problem....LBS it is i think!!

Leaking valves?

My Conti tubes are really bad for that. They'll lose 10psi overnight if I don't screw the valve down tight. I wonder whether the long valve stem is rattling against the fairing and causing the air to leak out.

griffin100

Lads,

Just in the door having suffered my sixth deflation in last two weeks and I mean deflation. It's not a blow out or anything similiar. Last six tubes I have fit, I have put in, put to correct psi, gone out and by the time I'm 15-20k into a spin I notice its deflating. By the time I get home I'm struggling to get back! Give it half an hour after I get home and it will be totally deflated!!!

The wheels are 2007 Mavic Cosmic's. The tunes are 80mm Schwalbe. I have checked the tyre and can't see or feel anything. I have removed the strip and checked spokes and nothing up there!

Any ideas lads before I bring it my LBS.....it's driving me up the F'in wall

Cheers

I had the exact same problem with my Carbone SL's - it drove me mad. It just kept happening on the rear wheel. After changing tyres and tubes to no effect I tool an LED light and carefully examined along the entire inside of the wheel. I found a very small flaw in the rim material where it looked like a piece of the rim material hadn't been sanded off properly in finishing process. It was a small knot of rim that didn't feel too sharp but could easily puncture a tube at 110psi. I sanded it gently off and hey presto, over 2,000kms later and not a single puncture since.

Dave11

Lumen wrote: »

Leaking valves?

My Conti tubes are really bad for that. They'll lose 10psi overnight if I don't screw the valve down tight. I wonder whether the long valve stem is rattling against the fairing and causing the air to leak out.

Could be that alright! I'll pick up a samller valve lenght and see what happens!

Hermy

Moflojo wrote: »

Sometimes if you run a cotton bud along the inside of the tyre, or along the rim, anything that is sharp will snag some of the cotton wool.

Good idea.

trad

Not familiar with that type of rim but if there is a join in the rim check there to see if there is any roughness there, could be the cause. File it with a very smooth file or emery paper.

You could swap the front tyre with the rear and see if the problem follows the tyre.

07Lapierre

Dave11 wrote: »

Have had a good proper look there no lads and ran the two tubes thru water and no bubbles!!! I was thinking dodgy batch of tubes but bought one yesterday from a different shop thinking that it might make a difference and no....it's still happening!!! Rim tape look fine and is 100% smooth the whole way round so that shouldn't be the cause! There is a small nick on the inside of the tyre which could be the problem but with no visible bubbles I can't match it up to see it that is the problem....LBS it is i think!!

Are you inflating the tube enough? With this type of puncture, you have to inflate the tube as much as possible (It may "bubble", but that is normal). If you don't then you may not see any bubbles. Inflate the tube pretty hard and then put the tube in water. Move the tube thru the water (slowly). Pay particular attention to the valve.

DirkVoodoo

Lumen wrote: »

Leaking valves?

My Conti tubes are really bad for that. They'll lose 10psi overnight if I don't screw the valve down tight. I wonder whether the long valve stem is rattling against the fairing and causing the air to leak out.

Yup same for me, I think Home:Ballyhoura reported the same problem.

Dave11

Cheers for all the replies and ideas!

I have swapped the front/reat tyre to see what happens as it's only the front which is deflating! If the front now suddenly goes then happy days its the tyre....

Ran the tubes thru the water alright with plenty air in them and defo no bubbles!

Will be back out again in the morning and we'll see what happens and I'll let ye know!

07Lapierre

Dave11 wrote: »

Cheers for all the replies and ideas!

I have swapped the front/reat tyre to see what happens as it's only the front which is deflating! If the front now suddenly goes then happy days its the tyre....

Ran the tubes thru the water alright with plenty air in them and defo no bubbles!

Will be back out again in the morning and we'll see what happens and I'll let ye know!

In that case Its the valve..has to be, no question. Either the valve is faulty or just needs to be tightened.

petethedrummer

Dave11 wrote: »

Ran the tubes thru the water alright with plenty air in them and defo no bubbles!

Sometimes if the hole is (really) tiny you won't a stream of bubbles. Sometimes just one bubble will form and stick on the tube. Wipe any bubbles off and see do they reform under the water.

Dave11

petethedrummer wrote: »

Sometimes if the hole is (really) tiny you won't a stream of bubbles. Sometimes just one bubble will form and stick on the tube. Wipe any bubbles off and see do they reform under the water.

Really should have tried that!!! Bloody amateurs :rolleyes:

Both the tubes I kept have bubbles after all!! Defo putting it down to small nick inside the tyre! Switched front tyre to rear and no deflation so far anyway....

wersal gummage

Dave,

Mind me asking how you find the mavics overall - aside form your current problem ??

Am thinking of getting a set but would be using them as an everyday wheel - i.e. not TTing etc.

Thanks.

Planet X

I reckon it's a piece of fine wire embedded. Happened to me two years ago on the Bray randonnee. 5/6 punctures till we took the tyre off completely. Mate found a tiny piece of fine wire. Bingo.


DV: Still owe you a tube from that spin.

DirkVoodoo

Planet X wrote: »

I reckon it's a piece of fine wire embedded. Happened to me two years ago on the Bray randonnee. 5/6 punctures till we took the tyre off completely. Mate found a tiny piece of fine wire. Bingo.


DV: Still owe you a tube from that spin.

Ha, don't worry about it, I'm about half way through that box of tubes.