Is an innertube blowout due to heat likely in the uk?

[Waspie]

Last Thursday on a steep descent I had a front tube blowout. I was braking heavily on a 1 in 5 slope to allow a convoy of lorries around a tight bend (for riders who know East Lothian this was on the steep bit of Redstone Rigg heading off the Lammermuirs on the way to Gifford ) . Just as I slowed to almost walking pace the tube went pop.

I'm running Michelin Aircomp latex tubes on a rim with veloplugs rather than rim tape. I had been running this set up for a good couple of thousand miles with no problems so I don't think there was an issue with tubes getting pinched.

The only thing I can think off is that the rim was too hot, it was very warm but not painful to touch when I recovered my composure and checked. It was absolutely roasting that day, to the extent that there were patches of melted tarmac. I hadn't been braking for long, but was braking very heavily.

I had thought that this sort of issue would only occur on long alpine style descents. Any ideas?

 

[HLaB]

You braked hard and sharp, you probably just pinched it rather than it being heat related, the hot rim is only a coincidence. I ran those Long Alpine descents in heat a few weeks back and never had a problem even with my heavy braking

 

[byegad]

The thankfully ex-Mrs Byegad blew an inner tube after sow;y following me down a reasonably long, steep hill. Nothing out-standing, just a normal big hill and a coolish day. I rushed back to see if she was OK and burnt my hand on the rim it was so hot. It turned out she'd rubbed the rear brake all the way down, as she was a) 'Scared to go too fast.' and b) Scared of using the front brake.' Those were her good points.

 

[Waspie]

You braked hard and sharp, you probably just pinched it rather than it being heat related, the hot rim is only a coincidence. I ran those Long Alpine descents in heat a few weeks back and never had a problem even with my heavy braking

Still not sure why it would decide to fail after that length of time, never had anything like that happen before.

Hadn't realised you'd been in the Alps. Just had a look on Strava, well done on doing the Marmotte.

 

[Waspie]

The thankfully ex-Mrs Byegad blew an inner tube after sow;y following me down a reasonably long, steep hill. Nothing out-standing, just a normal big hill and a coolish day. I rushed back to see if she was OK and burnt my hand on the rim it was so hot. It turned out she'd rubbed the rear brake all the way down, as she was a) 'Scared to go too fast.' and b) Scared of using the front brake.' Those were her good points.

 

[Dan B]

Had this happen with a bike that was parked up on hot tarmac on several hours. Admittedly it was a loaded cargo bike with 20" wheels, so not directly comparable, but it does happen

 

[Oldlegs]

I doubt it would be purely heat related unless you pump your tires up to very high pressure to start with.

If I remember O level physics right. Say you start at 100psi and the air in the tyre goes up from 25C to 50C. The pressure is then 108psi - not enough to cause problems.

 

[zizou]

When i was doing hill repeats last week i was descending slowly dragging the brakes so i had a bit extra time resting and the rims got very hot to touch (burnt finger hot!) and the tyres were rock solid (probably an extra 30-40psi) so had to let some air out.

 

[Cycleops]

[quote="byegad, post: 2560332 Scared of using the front brake.' Those were her good points.[/quote]

And her bad points?

 

[byegad]

Too many to list in a lifetime!

 

[User482]

You braked hard and sharp, you probably just pinched it rather than it being heat related, the hot rim is only a coincidence. I ran those Long Alpine descents in heat a few weeks back and never had a problem even with my heavy braking

Ditto! On the other hand, on the way to the start, every hairpin bend on the Alpe had someone fixing a puncture. They were all using carbon rims as far as I could see.

 

[HLaB]

Ditto! On the other hand, on the way to the start, every hairpin bend on the Alpe had someone fixing a puncture. They were all using carbon rims as far as I could see.

Yeah, there was a lot!

 

[Waspie]

I doubt it would be purely heat related unless you pump your tires up to very high pressure to start with.

If I remember O level physics right. Say you start at 100psi and the air in the tyre goes up from 25C to 50C. The pressure is then 108psi - not enough to cause problems.

They would have been at around 120psi. I can't remember O level anything so I'll take your word for it!

 

[PK99]

Last Thursday on a steep descent I had a front tube blowout. I was braking heavily on a 1 in 5 slope to allow a convoy of lorries around a tight bend (for riders who know East Lothian this was on the steep bit of Redstone Rigg heading off the Lammermuirs on the way to Gifford ) . Just as I slowed to almost walking pace the tube went pop.

I'm running Michelin Aircomp latex tubes on a rim with veloplugs rather than rim tape. I had been running this set up for a good couple of thousand miles with no problems so I don't think there was an issue with tubes getting pinched.

The only thing I can think off is that the rim was too hot, it was very warm but not painful to touch when I recovered my composure and checked. It was absolutely roasting that day, to the extent that there were patches of melted tarmac. I hadn't been braking for long, but was braking very heavily.

I had thought that this sort of issue would only occur on long alpine style descents. Any ideas?

I had a tube explode (9inch gash when i took it out) on the front wheel of my mtb on one of the very long descents on the C2C. Tyre was undamaged. i put that down to cooking the tube by braking - this was a few years a go before I knew about feathering the brakes and was braking constantly down the descent.

 

[thegravestoneman]

When in Fuerteventura the bloke in the hire shop told me to keep the pressures down in my hire bike because of the heat, I remember the tyres going bang on the display bikes in the window one very hot day in the shop I 'worked' in.