The science behind tube punctures?

Okay, so I put on my nice new Gatorskins yesterday, pumped them up to 110psi and was on my merry way. As I rode from work this evening I had to ride onto a footpath temporarily. Hey, no drama, I’ll just ride onto the corner section that has the ramp bit.

As I negotiated the ramp, my front wheels rolled through fine, and I gently accelerated my rear wheel to get up. As I did so, I just heard a massive ‘whoosh’ and noticed the rear tyre was flat in seconds.

Now, you’re probably wondering why I would post such an apparently banal story? Well the answer is that I’m fed up with punctures and I want to know why I get them, and how I can avoid them!

Perhaps I’m annoyed because I thought I was doing all the right things- good quality tyre, tube, deep-v rim… so what’s the problem? I mean before when I was running those awful Maxis Detonators at least I was always expected them to fail (which they did frequently)

Peoples thoughts on puncture tips would be greatly appreciated thanks!

Blakey- if you’re reading, yes, I need those tyres liners please! :roll:
And for the record I weigh about 78kg if that has an scientific bearing on why I’m getting punctures.
And lastly I can’t find any glass or other material that might have caused it- pinch?

Yeah you’re too fat.

Check where the puncture is. If it is on the inside - check that the rim tape smoothly covers all spoke holes, and that there is no metallic debris (deep vees are notorious).

you just need to be more at one with your environment. try and repeat a soothing mantra as you ride

It’s hard to be zen when you’re looking at your flat tyre and you feel really pissed! :lol:


ndf- okay I just looked closely at the tube, and it’s interesting:
There are two identical horizontal slits in the tube, about 10mm in length (horizontal in line with the tube length. The slits are both on the upper and lower side of the tube… so is this a pinch then? How do you avoid that?

Don’t ride up gutters.

Well it was more a gutter-ramp if that’s any different?

I’ve checked the rim tape and it’s all looking pretty good, no obvious missing areas of debris.

I should say slow down going up gutters.

If you run a low tyre pressure you can get pinch flats but 110 is not low.

Most likely it is

when you refit your tube after a flat, always do 2 things to help prevent pinch flats:

(no apologies if this is telling grandma how to suck eggs)

  1. make sure there is a little air in the tube when you fit it - helps to ensure that the tube will seat properly inside the tyre

  2. Inspect the tyre and tube fit on BOTH sides before you fully inflate - by this I mean roll the tyre back from the rim a little so you can see if the tube is seated properly and check that there are no stray bits of tube poking out underneath the tyre bead (if there are, gently work them back in behind the bead, where they belong). Work your way around the tyre, do this on both sides, be thorough. Only takes about 30 seconds, much less time than changing another pinch flat.

Pinches tend to happen more when the tyre fit on the rim is very tight and you have to wrestle it on with tyre levers.


  1. Don’t bash up gutters.

Okay CaptainC, thanks for the advice. Obvious stuff I know but it’s good to be retold it properly. :slight_smile:

I’ll see how I go next time.

One of these is the cause of the other / Lrn 2 bunnyhop?

Did you have a shirt on?

Always use the cheapest tubes you can find. They’re generally thicker and more durable than the more expensive ones.

Also you live in Fitzroy, an area natorious for broken glass on the roads.

Tyre liners would be a good idea.

Anytime man. Shoot me a PM to work out when.

I’ve blown out a tube before from pinching between rim & bead. Just after I pumped it to 120 and still had my head over the wheel. Shellshocked. :-o Taught me to check properly from then on. Looks different to a snakebite flat though, radial tears, unpatchable.

Ah, thanks for the tip. So buy a pack of Yum-Cha brand eh?

haha not for long- Elwood here I come! No more douche hipsters to deal with (only cashed-up bogans now…) :wink:

snowflake- the weather has been hot, so… :evil:
spud- bunny-hop you mean jumping onto a footpath? That’s hard man!
Blakey-PM will be coming cheers

use vittoria randonneurs


Do they get better pinch-flats? :wink:

don’t know, never had a flat with em.

Yes well not everyone knows how to mount a tube properly you know…

When I was in BSC yesterday buying tubes one of the dudes there was telling me how he used a tubeless setup on his MTB- is this a possibility for road wheels? I’ve heard about the Hutchinson Tubeless system want about this for the street?

It’s expensive and not very reliable. Definately not for commuting. If you’re racing, you’d use tubbies anyway. If it hasn’t already, this system will slowly die out unless the prices drop and the tyres actually hold air for decent periods.

dont get too excited, i live in elwood and theres glass everywhere and potholes that lead straight to hell