Frequent and strange punctures

captainfirecat

Hi all

I have a Carrera racing bike and I am getting what I would call strange punctures. Or not, you tell me!

I bought the bike, got a puncture at around mile 50. Changed the tube, checked the old one and found a pin prick hole, fair enough.

50 or so miles later, another puncture, this one after a pot hole. Fair enough, especially as in hind sight I had my tyre pressure at around 50psi (rookie mistake), rather than the max of 110psi.

I then managed around 100 miles before my next (pot hole) puncture. Again, no complaints. I pumped the tyre best I could by the road (to 60/70psi) then trundled home and put it up to 110 with my track pump. I then left the bike upside down while I fixed another bike, and about 15 minutes later I heard a gunshot (which isn't odd as we live in the countryside). Thought no more of it until the next day when I found the gunshot had been my tube exploding (no pin prick this time, it was a 3 inch tear along the inside, about 10 inch from the valve).

I changed the tube, pumped it to 100 this time, cycled to work, all fine. I return to my bike 7 hours later - flat tyre, on removal there was a hole of about 2mm across next to the valve on the inside.

Pumped new tube up to 70psi, set off home. I was almost afraid to look, but I still had pressure this morning. However, left the bike at home today as, well, I'm not feeling myself and another puncture would not be good for my health.

If I was getting all these punctures on the road I would say new tyres, in fact I'm getting new tyres (any suggestions? Something that will reduce punctures but will still let me use my race bike as a race bike), but given the 2 'serious' punctures (that seemed to involve explosions) were while the bike was under no strain (upside down one day, just leaned on a bike post the other) I... am at a loss. The inner tubes were low end, but Halfords sold them to me to use with that bike and stated to keep them at 110. But should I get better quality tubes? I will be getting some Velox tape per the suggestion in the other thread.

I'm planning an online shopping trip at lunch, all suggestions re the above gratefully received!

antsmithmk

Sounds like the combo of poor quality tubes and poor quality tires. If you can fit continental gatorskins... They are bullet proof! Might be worth checking the rim tape is covering the spoke holes and that there is nothing hiding inside the rim... Stones, glass etc.

Good luck

sungod

a tube can only explode if it's outside the tyre

commonly this is caused by nipping the tube between rim and tyre when installing, the tubes eventually forces out under pressure and goes bang, it can happen fast, or it could be ok until days after fitting

check for any rough edges, misaligned/damaged rim tape, burr on the valve hole, etc.

check the inner surface of the tyre, a cut with rough edges can wear a hole in a tube

look for marks of the outside of the tyre that may indicate something penetrated, even a tiny piece of embedded wire or glass etc. can do it

when fitting the tyre, do it so that the name/logo is always in the same position wrt to the valve, that way you can backtrack from the hole in the tube to the matching position on the tyre and check it is ok

new bikes often come with cheap tyres, getting some with better puncture protection is certainly an option

captainfirecat

sungod wrote:

a tube can only explode if it's outside the tyre

commonly this is caused by nipping the tube between rim and tyre when installing, the tubes eventually forces out under pressure and goes bang, it can happen fast, or it could be ok until days after fitting

check for any rough edges, misaligned/damaged rim tape, burr on the valve hole, etc.

check the inner surface of the tyre, a cut with rough edges can wear a hole in a tube

look for marks of the outside of the tyre that may indicate something penetrated, even a tiny piece of embedded wire or glass etc. can do it

when fitting the tyre, do it so that the name/logo is always in the same position wrt to the valve, that way you can backtrack from the hole in the tube to the matching position on the tyre and check it is ok

new bikes often come with cheap tyres, getting some with better puncture protection is certainly an option

'Explode' may have been the wrong word for me to use, perhaps 'rupture' would have been better. I will get some better tyres and some better tubes, retape the inside of the wheel and see how that goes. I will also google (or I imagine there is something on here I can read) how to make sure the tube isn't pinched, as I was as careful as I could be to make sure it was up in the gap in the tyre, so my technique may be poor.

Thanks.

slowbike

CaptainFirecat wrote:

I then left the bike upside down

Please don't ... it makes my brother pull his hair out ... he hasn't got much left ...

You don't turn your car upside down to change wheels do you? Then don't do it to the poor bike!

desweller

Slowbike wrote:

CaptainFirecat wrote:

I then left the bike upside down

Please don't ... it makes my brother pull his hair out ... he hasn't got much left ...

You don't turn your car upside down to change wheels do you? Then don't do it to the poor bike!

Bike's not full of oil, water and petrol, is it. Perfectly OK upside-down.

Re: the OP, try dusting your inner tubes with some talcum powder and fit them partially inflated. The talc helps them to move around inside the tyre, so they can settle into position, and fitting them partially inflated helps avoid pinching.

captainfirecat

So tube into tyre, add a bit of air (I'm guessing not much as they tend to... swell in one area), THEN onto wheel. I'll give that a go, I have always put them on 'flat' till now.

k-dog

I would be having a look at your rim tape too - a few prominent spoke heads could give these symptoms.

captainfirecat

k-dog wrote:

I would be having a look at your rim tape too - a few prominent spoke heads could give these symptoms.

I'm on it, ordered a new set of tyres, some non-bargain basement tubes, and some rolls of tape.

mididoctors

CaptainFirecat wrote:

So tube into tyre, add a bit of air (I'm guessing not much as they tend to... swell in one area), THEN onto wheel. I'll give that a go, I have always put them on 'flat' till now.

no

tyre on rim one side only

then tube with very slight inflation then other side of tyre

captainfirecat

New tyres, new inner tube, velox tape, all set up and first ride no issues (well, other than as outline in my other topic today... hehe).

Actually got lightheaded pumping the tube to the 'recomended' 130psi, so that'll be fun every few weeks getting it back there. But I imagine I will get the hang of it!

The difference between the tape that was in, which was glorified sellotape, and the Velox stuff is huge, so glad I changed it.

keef66

I cannot imagine riding a tyre inflated to 130 psi on the kinds of road surface I normally encounter. You must be shaking your fillings out :shock:

sungod

^^^this

which make/model/size tyres are these?

smidsy

The stated psi on the tyre wall is normally a maximum. It is in no way a recommended pressure.

90 to 110 depending on weight/wet dry/23 or 25mm etc. is more usual.