Repeated punctures of the rear wheel - what is going on?!

gcbadger

New Member
Hello

I have 23 year old Marin Bear Valley mountain bike with 5 year old 26 inch mach1 wheels on it labelled ETRTO (559 x 17c (which does not seem to make any sense)). Since I mostly use the bike on the road I have Continental SportContact tyres (26 x 1.6) on it. They have been absolutely fine for many years until a week ago when I had a puncture. There was no obvious reason for the puncture (no thorn etc) on the rim side on of the (26 x 1.0-1.25) inner tube. I assumed that I had pumped it up too hard or something so I patched it but it didn't hold properly and went down over time.

No problem I thought - just buy a new inner tube. Got one (26 x 1.25-2.0) from Evans after showing them the wheel and tyre. It went on ok but on a short ride it blew instantaneously. I patched it and it did the same again - both on the rim side of the tube. I checked both times that I hadn't pinched or twisted it. The rim and tyre have no rough areas.

So then I bought another inner tube to match the one that had been working for years (26 x 1.0-1.25) thinking that the one from Evans was "just too big" and that went on ok but once pumped to 40psi or so - it just blew instantaneously again. The tube was so badly wrecked I think I must have twisted it despite reckoning to check it several times.

I'm at a loss now! Is this a tube issue or a tyre issue? Or maybe I have just been victim to a series of unconnected coincidences?! Surely a 26 x 1.25-2.0 tube should go into that size tyre?
 

Slick

Guru
I had the same problem a while back and it wasn't fixed until I put a new tyre on although if I was you I would check my rim tape first.
 

Broadside

Guru
Location
Fleet, Hants
I had something similar, blew 6 tubes in a row! The tyre sidewall has gone and there was a tiny tear along the bead, very hard to spot but enough to keep on blowing inner tubes.
 

CXRAndy

Guru
Location
Lincs
Fit new tyre, rim tape and inner tube, at five years old they could be passed their sell by date. Rubber doesn't last forever and depending how you kept your bike stored when not riding can age the rubber quite quickly
 
OP
G

gcbadger

New Member
Really appreciate all your replies - at least it's not just happened to me! Although I have checked the tyre and rim tape quite a lot already (as you can imagine), I will go over it forensically now. There are definitely no thorns or sharp bits but maybe the rim tape has moved a bit or there is tiny hole in the tyre somewhere. Does anyone have any comment on the 559 x 17c marking on the wheel? That looks like a mistake right because I can find no reference to a wheel that thin on the internet?
 
Fit new tube, if it blows, pull out the tube from the tyre leaving the valve still attached. Find the hole, mark the tyre and the rim.

Now you know exactly where the problem is, investigate, sounds most likely some issue with the rim tape.

This is good practice every time fixing a puncture IMO, makes finding the culprit much easier.
 

SkipdiverJohn

Veteran
Location
London
Fit new tyre, rim tape and inner tube, at five years old they could be passed their sell by date. Rubber doesn't last forever and depending how you kept your bike stored when not riding can age the rubber quite quickly
Tyres last a lot longer than five years. I have several 20+ year old tyres in regular use and am running one pair of tyres that is over 40 years old, but it has not yet punctured in my ownership. Perished tubes are obvious from the change in texture, and shabby looking external sidewalls and treads are a purely cosmetic feature so long as the underlying cord structure is sound.
The OP's problem sounds rim-related to me, or a foreign object was not detected and removed during a previous repair..
 

rrarider

Über Member
Location
Liverpool
To see if there's anything really tiny still poking through the tyre, you could try rubbing a cotton wool ball around the inside, to see if it snags anywhere.

Fortunately I'm no expert on punctures, as I don't often ride on rough surfaces. I was so pleased on Sunday to find that my usual early morning ride down the dock road to the Pier Head is still possible on a good surface along the officially closed road, by just veering around the barriers. On the way back I had the first puncture for a long time and fitted my spare tube. I have MA40 wheels which are notoriously difficult to fit tyres on. I usually managed with my old PMD levers which broke a while ago and I nipped the tube with Park Tools levers which replaced them. I then had to patch a tube by the side of the road - a procedure I hadn't done for over 30 years. I realised that I had to win the struggle of doing it by thumb pressure alone and practised yesterday until I managed it four times in succession. It's really difficult but I can just about manage it. I also practised patching a tube with just the stuff in my seat post bag. That's a bit awkward without the aid of a G clamp and a container of baby powder.
 

Sharky

Guru
Location
Kent
To see if there's anything really tiny still poking through the tyre, you could try rubbing a cotton wool ball around the inside, to see if it snags anywhere.

Fortunately I'm no expert on punctures, as I don't often ride on rough surfaces. I was so pleased on Sunday to find that my usual early morning ride down the dock road to the Pier Head is still possible on a good surface along the officially closed road, by just veering around the barriers. On the way back I had the first puncture for a long time and fitted my spare tube. I have MA40 wheels which are notoriously difficult to fit tyres on. I usually managed with my old PMD levers which broke a while ago and I nipped the tube with Park Tools levers which replaced them. I then had to patch a tube by the side of the road - a procedure I hadn't done for over 30 years. I realised that I had to win the struggle of doing it by thumb pressure alone and practised yesterday until I managed it four times in succession. It's really difficult but I can just about manage it. I also practised patching a tube with just the stuff in my seat post bag. That's a bit awkward without the aid of a G clamp and a container of baby powder.
It's a long time since I rode down to the Pier Head and took the ferry across and onto North Wales - happy days.
 

Ian H

I am an ancient randonneur, & I stop often for tea
Location
East Devon
The first thing to do is mark exactly where the puncture occurs on both the tyre and the rim. Then carefully examine both at those points.
 
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