I went for a ride today and got pressure punctures on my rear wheel twice in the space of an hour. Was going down a steep hill both times and had the breaks on fairly hard, but didn't seem to hit anything which would have caused it so I'm slightly baffled. Checked tyre for any dodgy stuff but didn't see anything inside the rim etc. Anyone know why or how to stop this?!
Pressure puncture on downhill
- Thread starter cmac
- Start date
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deptfordmarmoset
Full time tea drinker
- Location
- Armonmy Way
Why would it be a pressure puncture, not that I really understand what you mean by the phrase? Braking downhill will put the pressure on the front.
OK maybe not a pressure puncture but felt like that. Rear tyre went flat almost instantly.
RWright
Guru
- Location
- North Carolina
I would check the rim tape to start with, make sure everything is smooth around the rim. If it is a snake bite on the inside of the tube it could either be not enough air pressure or the inside of wheel needs tape...or both.
Smurfy
Naturist Smurf
- Location
- Smurfette's Kitchen
Blowout due to heat from braking raising the pressure in the tube?
byegad
Legendary Member
- Location
- NE England
If you were braking on the rear wheel only and the rim got hot that would blow the rear tube. My first wife was an over cautious descender and only felt safe using the rear brake, for an unwarranted fear of going over the handle bars.
She was on a 20" wheel steel rimmed bike, this was some 35+ years ago, and the bang sounded like a cannon going off.
The tyre was blown off the rim and this didn't happen until some distance off the bottom off the hill on the flat when we hit a bit of bumpy road. I actually burnt my hand on the rim as I bent to examine the damage. The hill was only about 15% and I, on a similar bike, had gone down at 20-30mph alternating front and rear brakes to stop it going any faster. She had gone down at 10-12mph and rode the rear brake all the way. Not so much wind to cool the rim, much more work going into the rim and the result was that the tyre was blown clean off the rim when it hit a bump.
She was on a 20" wheel steel rimmed bike, this was some 35+ years ago, and the bang sounded like a cannon going off.
The tyre was blown off the rim and this didn't happen until some distance off the bottom off the hill on the flat when we hit a bit of bumpy road. I actually burnt my hand on the rim as I bent to examine the damage. The hill was only about 15% and I, on a similar bike, had gone down at 20-30mph alternating front and rear brakes to stop it going any faster. She had gone down at 10-12mph and rode the rear brake all the way. Not so much wind to cool the rim, much more work going into the rim and the result was that the tyre was blown clean off the rim when it hit a bump.
youngoldbloke
The older I get, the faster I used to be ...
Excuse my ignorance but what is a 'pressure puncture'? I've never heard the term - is it a puncture caused by increased pressure, as suggested by Yellow Tim and others, and if so how can you tell? You say it felt like one? What does the tube look like?
