Is it possible to lose lots of tyre pressure through the inner tube valve due to a hard impact?

[Accy cyclist]

I was out the other day in the pouring rain when i hit what i'll describe as a ridge across the road that was like if you can imagine a drain pipe covered in tarmac. The front tyre sent out a cracking noise as i hit it at a fair speed. I stopped to check and it was ok. When i got home after about 20 more miles it felt soft so i checked the tyre pressure. It was around 40 psi. I normally have 80 psi,so i suspected a slow puncture. I inflated the tube back up to 80 psi and left it to see how it was in the morning. Four days later and after riding another 53 miles on it it's still at 80 psi, which leads me to the question of could the air have been expelled through the tube's valve due to the sudden high force of the impact? If not how could the air have escaped?

 

[vickster]

Had you screwed the valve up properly? Might be nothing to do with the impact. After an impact I'd expect the air to go more quickly

 

[Accy cyclist]

Had you screwed the valve up properly? Might be nothing to do with the impact. After an impact I'd expect the air to go more quickly

Yes the valve cap was tightened up.The tyres are Marathon Plus. so i wonder if the cracking noise was the hard puncture protection strip taking the brunt of the impact? I'm supposed to be going on a 50 odd ride in the morning. I hope it doesn't deflate while i'm out. Anyway i'll carry a spare, hoping someone will change it for me if it does.

 

[vickster]

Take a pump, tube, levers...strong thumbs

You do know how to change a tube surely? Even I do as an inept female (I don't always have the thumb strength though)!

 

[Accy cyclist]

Take a pump, tube, levers...strong thumbs

You do know how to change a tube surely? Even I do as an inept female (I don't always have the thumb strength though)!

Oh please! Not the you can't change a tube? stuff again.

 

[vickster]

Oh please! Not the you can't change a tube? stuff again.

Erm you were the one who said you'll need to find someone to change it for you!

 

[Accy cyclist]

Erm you were the one who said you'll need to find someone to change it for you!

Yes but you know that i can't fit new tubes. I thought i'd stop you from asking me why...AGAIN!!

 

[Milkfloat]

To be fair to Accy, they are marathon pluses.

 

[ufkacbln]

Take a pump, tube, levers...strong thumbs

You do know how to change a tube surely? Even I do as an inept female (I don't always have the thumb strength though)!

Posted before, but...

Changing tyre on roadside and charming young lady roadie stops to offer assistance, then chats

Get to putting tyre back on with levers, when she points out that it can be done with thumbs.

Then before I can say Marathon Plus................. she says " But, I suppose at your age the arthritis must be a problem!"

Cheek!

 

[Accy cyclist]

I wont be needing the spare for my ride as i woke up too late to go and it's absolutely peeing down so i wouldn't have gone anyway!There are pleasure rides,challenging rides then downright endurance rides. I don't do pain on a bike i'm not up for SAS selection or anything like that!

 

[mjr]

...and it's absolutely peeing down so i wouldn't have gone anyway!

Get a raincoat.

Edit: or take that nice green umbrella with you.

 

[earlestownflya]

to answer your question,accy..yes it's possible

 

[BrumJim]

I've see it on my car before. Hit a large wooden post in the road. Tyre deflated. Pumped it up again, and it stayed inflated.
However that one didn't have an inner tube.

 

[User32269]

I've had it happen on 26" m b front tyre last week. Didn't spot a kerb due to leaves (or being dozy) slammed into it. Lost air immediately out of tyre, pumped up tube when I got home and couldn't find puncture. Tube still fully inflated now! Cap was still tight on valve, no leaking from valve area?