Repeated Rear Slow Puncture

Dizeee

I have been through 4 inner tubes now and every time they instantly lose air, deflating to empty over period of around 24 hours. The higher I pump it the quicker it deflates.

There is NOTHING in the tyre. There is NOTHING on the rim. The inner tubes are boxed and new at £9 a piece.The technique I am using is no different to that of the last 3 years with no problems, there is no risk of pinch puncture or tube being caught on the side. I am sick of it. It is just constant now, I replace the tube and all looks well until the following morning. I have never known anything like it.

I this morning took the tyre off and folded it inside out, there is just nothing there. It's only a month old. I don't know what to do.

gozzy

Time for new rim tape?

Tjgoodhew

Not a solution but have you tried a new tyre ?

If that solves the issue then you know it was the tyre, if it doesn't then you know it must be the rim.

And did you buy the tubes at the same time ? Could there be an issue with the tubes coming from a faulty batch ?

sungod

where do the tubes puncture? same place? rim side or tyre side?

if you don't always fit the tyre in the same position you need to learn to do that otherwise you can't properly check hen this sort of things happens

fwiw a few years ago i had two slow punctures, they were caused by a piece of fine wire about 2mm long embedded in the tyre, there was nothing to feel, it only protruded under pressure, but because i fit tyres in the same position it made it obvious that a closer inspection of the area was needed, just a faint blemish was visible, probed it and saw the end of the wire glinting

darkhairedlord

tubes at £9 each? are they latex?

keef66

+1 to the advice above. Mount the tyre in the same way each time. If you get 2 punctures in the same place and it's on the outside of the tube then it's likely the tyre, and you know which bit of tyre to scrutinise. On the inside suspect the rim. If you fit a known good tyre and still get a puncture in the same place you know it's not the tyre but the rim. Plus you'll know which bit of the rim you need to examine closely.

And why are you paying £9 for an inner tube?

darkhairedlord

have you checked where the tubes are leaking from?
Go on, stick it in the sink and look for the bubbles!
if they are all leaking from the inside at the same place its your tape, if from the outside it's your tyre, if it's from the valves its, well, you get the idea!

sungod

and get one of these...

http://www.chainreactioncycles.com/rema ... -prod46341

Dizeee

Cheers all, its a Fulcrum Quattro with a 6 week old Conti GP4000. The puncture hole is an inch away from the valve on the tyre side and is a small hole, so small that it holds air for long periods of time.

The only two things I have found before just adding yet another tube and inflating is a half peeled off white sticker on the inside of the rim, and also various point son the tyre which (I am not sure of normal as have never looked) have the diaganol strands of ply slightly visible. However the ply is straight and smooth and not broken, not sticking up and is very smooth to the touch. I can't see how that could cause it.

I will test ride again today and await tommorow's verdict, which if down again will be a new tyre. I will also be able to pinpoint the tyre problem location tommorow as I will remove the tube in sequence and hyper inflate to pinpoint the problem area.

drlodge

You need to pinpoint what is causing the puncture - tyre, rim or rim tape. It has to be one of those three. Try swapping the front and rear tyres over - that will tell you if its a tyre or wheel/rim tape problem.

Matthewfalle

But why oh why oh why oh why are you spending £9 on an inner tube? Pray, tell. And at £9 a tube, why are you not patching them? If they are just sitting in a pile in the garage can I have them please?

As above: change tyre. Add additional rim tape (insulting tape does the job perfectly). Get rid of all possible variables one by one.

Dizeee

Sorry the 60mm conti sells at 7.99 at my lbs - I have just bought 3 for ten pounds on ebay but they won't arrive till midweek. I simply HAVE to sort this problem so if that means buying a few tubes so be it. I hate patches, don't trust them and they never seem to work.

drlodge

Get yourself a TipTop TT04 repair kit and have a go...the patches stick like the perverbial and are very thin. I carry one in my saddle bag and bought a multipack of patches and big tube of glue off Ebay for peanuts.

gozzy

Are you using a glue and patch or those temporary ones?
Quite simply, repair patches work and are cheaper than replacing a tube every single time. Otherwise millions of cyclists around the world wouldn't use them.

Dizeee

Fair point, maybe I should give them a go before I cast them aside. Repair kit on order!

Went out and did 15 fast miles this afternoon, didn't seem to lose too much PSI today (only around 10) so am hopeful but tommorow will be the answer as I have just re inflated to 120 again.

Will report back tommorow.

sungod

conti inner tubes? with the removable valve?

the valve core is generally not tight when they're shipped, do up the body *tight* otherwise that alone can lose air

Dizeee

You need to do things to a pre packaged tube????

keef66

It's well worth nipping up the removable core on a Conti tube before use, especially if you have a screw-on pump head. I have a tiny adjustable spanner I use on the flats of the core, and hold the valve stem with a pair of pliers. If a core comes loose when you're out on the road, doing it up finger tight isn't good enough to obtain a perfect seal, and most multitools are useless for the job.

Last winter I had to cut short a ride because of this; topping up the tyres before setting off must have loosened the core. 8 miles from home the rear rim started hitting the road. Horizontal sleet meant I couldn't be arsed to change the tube, instead I pumped it up as much as I could and abandoned the ride and sprinted for home.

drlodge

I now carry one of those little plastic "spanner" things that came with a valve extension, in my little cash pouch just in case a core comes undone. I nip mine up reeeaaaal tight.

Dizeee

Well the tyre has held overnight, so I went to check the PSI and the second I loosened the nipple air started pissing out of the stem. I have not had this historically but have had this happen a few times recently, which is strange. Basically unless the nipple is done up super tight air pisses out so I have pumped it right up to 120 (it was only at 110 after the air came out) and tightened it up again.

Is this just a factor with continentals then? For the price I am surprised at the low quality.

keef66

You sure air was coming out of the valve rather than past the loosened core? My guess is that loosening the valve nut loosened the core.

It is just a by-product of having removable valve cores. Switch to another brand if you don't get on with them. TBH I've never replaced a core, so the benefit is wasted on me.

sungod

Dizeee wrote:

Well the tyre has held overnight, so I went to check the PSI and the second I loosened the nipple air started pissing out of the stem. I have not had this historically but have had this happen a few times recently, which is strange. Basically unless the nipple is done up super tight air pisses out so I have pumped it right up to 120 (it was only at 110 after the air came out) and tightened it up again.

Is this just a factor with continentals then? For the price I am surprised at the low quality.

they're not low quality, they're perfectly good, never had a problem with one in years

the valve cores are removable because it's useful - use of extenders, use of sealant, option to replace a damaged core

just tighten the core body properly before use - this applies to any tube/tyre with a removable core

no need to tighten the plunger more than finger tight, if there's some dust/whatever causing a poor seal simply depressing the plunger to let air clear it is usually enough

Dizeee

UPDATE and Further Advice please:

Today went out and did my usual fast 40 miles, all was well until I got home and found rear tyre flat again.

This time I tested the tube and found that there is ply exposed from the inside of my barely 2 month old GPS4000. I had a good play and I could not deal with it as the ply so microscopic, and I ended up exposing a few more of the strands so I was thinking the tyre was ruined.

However, I have covered the area with a thin strip of elastoplast ( the plaster strip ) and inserted a fresh tube, pumped it and left it. So far so good. Is this likely to work?

Dizeee

Nobody?

meanredspider

Dizeee wrote:

Nobody?

To be fair, I don't suppose anybody much has had this issue let alone tried an elastoplast to fix it

Unless funds are very tight, I'd be looking to change the tyre. If it's a GP4000S, I've not had much luck with their puncture resistance full-stop.

dennisn

sungod wrote:

conti inner tubes? with the removable valve?

the valve core is generally not tight when they're shipped, do up the body *tight* otherwise that alone can lose air

After reading this whole topic I'm casting my vote with "sungod". It happens that the core either is loose or can come loose. Buy the tool for this and use it. Park Tool VC-1

lapavoni10

Never had issues with conti's, puncture or wear...maybe I need to ride more
If your budget does not run to a new tyre, you may get away with using a Park tyre boot on the affected area. Have you tried running your old tyre for a couple of days to prove the theory that its the exposed carcas?

Dizeee

The plaster is holding well so far all be it I have not ridden it yet!