Pinch flats.

rockmonkeysc

Im getting a lot of pinch flats and not sure why.
Its on my Boardman road race. Standard tyres, halfords tubes and 100 - 110psi.

Any suggestions for what it could be?

chrisaonabike

RockmonkeySC wrote:

Im getting a lot of pinch flats and not sure why.
Its on my Boardman road race. Standard tyres, halfords tubes and 100 - 110psi.

Any suggestions for what it could be?

Standard snake-bite holes in the tube?

If so, have you calibrated your pump against another one to make sure it really is 100-110 psi?

Speaking as a complete non-expert (I've had all of two punctures and both were pinch flats), one was when I hit a speed bump at moderate speed with tyres that were too soft, and I could feel the tyre squish to the rim and knew immediately what was about to happen.

The second time the tyres were good and hard, and I hit a complete bastard of a pothole at about 25mph.

So unless you ride on truly terrible surfaces all the time, I'm suspecting that maybe the tyres aren't as hard as you think.

After all, somthing is letting the tyre squish the tube against the rim, so if everything's fitted right, there aren't many options.

scoobaru11

Last year I really suffered with punctures. Mainly due to debris not pinch flats but that aside I changed my tubes to Slime ready filled and so far I've had one puncture that healed itself and completed a 60m ride.
There has been no difference in speed or ride so a complete thumbs up from me :-)

jds_1981

How are you sure they're pinch flats? Lines in the inner tube that match the rim?
How much do you weigh?
I can only recall 2 pinch flats - one was hitting a complete bstard of a pothole, the other was hitting a small drain cover that was protuding about 5 cm... Both of these incidents north of 20mph.

nochekmate

Tyres are probably shite!

rockmonkeysc

They are pinch flats. A pair of slits in the tube.
Im 14 stone.

gubber12345

soft tyres I suspect as well.put a few more pumps in when inflating before your next ride and see how you go.

andrewjoseph

RockmonkeySC wrote:

They are pinch flats. A pair of slits in the tube.
Im 14 stone.

Try bigger tyres. 25 or 28 or even 30 if they fit. 14st is not particularly heavy. I'm 12.5 st, use conti 25mm 4000s at 80psi front and 90 rear. I got a good pinch flat a few weeks ago hitting a nasty pothole at speed. First one I've had for years.

Might be an idea to check over your rim for sharp spots from a big hit. It may be that the rim is cutting/rubbing the inner tube. Also check you tyre bead for exposed cables.

diamonddog

Reckon tyre pressure is too low, chart I have recommends pumping to 8bar/117psi for your weight.

rockmonkeysc

Thanks for the tips. I'm commuting down a lot of single track lanes and city streets so maybe some wider tyres might help smooth out the rough surface as well.
I have no idea about road kit, big, bouncy mountain bikes are more my thing for fun. What's a good, reasonably priced 28mm tyre?

whyamihere

Unweight the bike as you go over any big/sharp edged bumps, similar movement to a bunnyhop, just far less energetic so that you don't actually leave the ground. Otherwise, the only way you're going to be getting pinch flats is if your tyres are as soft as the average Premiership footballer, so I'll echo the advice to pump them up more.

wishitwasallflat

Take off the rim tape that's there now and fit Velox - no more pinch flats

andrewjoseph

RockmonkeySC wrote:

Thanks for the tips. I'm commuting down a lot of single track lanes and city streets so maybe some wider tyres might help smooth out the rough surface as well.
I have no idea about road kit, big, bouncy mountain bikes are more my thing for fun. What's a good, reasonably priced 28mm tyre?

Check you frame can take them first.

MickTheMove

Tyre pressures. get a decent track pump and make sure they are up to 110 before each ride.