How to stop pinch puntures when you're heavy?

defdaz

Hi all,

I'm so frustrated. I've got a new road bike with 700c x 23 tyres and in less than 15 miles I've had two pinch punctures. I swapped the first inner tube for a slime tube and pumped the tyre (rear) up to 105psi but within 1.4 miles it punctured again. I'm at a loss on what to do.

It has kendra bog-stocker tyres on at the moment - will changing them for botrager race lite's or maybe marathon plus' stop the pinching?

I've lost all confidence in being able to ride the bike now. Am I too heavy at 19 stones? Thanks for any and all advice.

Daz

desweller

I'd go for wider tyres - 28 as a bare minimum but possibly 32 if you can fit them on the rims and inside the brakes and forks.

The required air pressure in your tyres is a function of the downward load (your weight and the bike's weight) divided by the area of the contact patch. So if you increase weight, you can compensate either by increasing contact patch area (wider tyres) or air pressure, or both. Since you're a pretty big guy you may find you need to do both, especially if the roads are poor in your area.

Hard wearing tyres tend to have stiffer structures and consequently better resistance to pinch punctures in my experience, due to higher levels of carbon black in the rubber, but they will be less grippy. However, they are often better for your wallet...

defdaz

Thanks DesWeller, much appreciated. I'll order some wider harder tyres and hope for the best.

ColinJ

defdaz wrote:

Thanks DesWeller, much appreciated. I'll order some wider harder tyres and hope for the best.

You may well struggle to get large tyres to fit so check what clearances you've got with your 23s. My Basso will take 25s but I think my Cannondale would be very tight. Neither would take 28s or larger.

pottssteve

Yep,
28s are the way to go, if you can get them on.

Infamous

I'd go for a decent 23 or 25 first before going to 28. Kenda tyres are a bit rubbish.

nferrar

I'd check your rim tape is intact as well, unless you aim to hit every pothole then 2 pinch flats in 15 miles is a bit odd even at 19 stone.

Simon Notley

You might want to try pumping the tyres harder than 105 psi, that's a little soft for someone of your weight. I would pump to the maximum stated on the tyres, probably around 120. That might help. If you're getting new tyres, I'd probably just opt for a 25 or a 28 but no wider.

robthehungrymonkey

I'm also pretty heavy, and have my rear pumped up to 120psi. I've never had a puncture.

irideredthebike

I used to have regular pinch flats on 28s, because I didn't pump up my tyres enough. Now I run 25s and never have a problem. Two flats all of last year, both from running over nails - and one of those was on my car.

robthehungrymonkey

robthehungrymonkey wrote:

I'm also pretty heavy, and have my rear pumped up to 120psi. I've never had a puncture.

These are 23's by the way.

defdaz

Thanks all, much appreciated - I'll up the psi to 120 and pray for the best.

FOAD

I weigh 21 stone and have Schwalbe Ultremo R's 700 x 23. I have done 100's of miles without a puncture and have the rear at 120psi.

I would suggest getting some better tyres rather than going wider, if that really is the problem, but I would not be suprised if the flats were from the spokes piercing the rim tape, rather than pinch flats mate.