Bicycle tyres.

[ian field]

Why do bicycle tyres with "Inflate to 50psi" stamped on the sidewall burst
at just a tad over 40psi?

TIA.

[Emil Tiades]

On Fri, 21 Nov 2008 17:25:13 -0000, "ian field"

Post by ian field
Why do bicycle tyres with "Inflate to 50psi" stamped on the sidewall burst
at just a tad over 40psi?

The psi is linked to the dollar and went up 30%
Adjust your gauge accordingly

[michael adams]

Post by ian field
Why do bicycle tyres with "Inflate to 50psi" stamped on the sidewall burst
at just a tad over 40psi?
TIA.

Surely it's inner-tubes that burst, not tyres ?

Given their construction and means of attachment to the rim I imagine
it would be impossible to "burst" a tyre casing simply by use of a handpump.


michael adams

...

[ian field]

Post by michael adams

Post by ian field
Why do bicycle tyres with "Inflate to 50psi" stamped on the sidewall burst
at just a tad over 40psi?
TIA.

Surely it's inner-tubes that burst, not tyres ?

So how do you suppose the inner tube managed to escape?!

Post by michael adams
Given their construction and means of attachment to the rim I imagine
it would be impossible to "burst" a tyre casing simply by use of a handpump.

It was a 12V tyre pump with a pressure gauge - on motor vehicle tyres I
always double check with a digital gauge so I know the gauge on the pump is
close enough.

This bicycle had tyres marked "inflate to 50psi" stamped on the sidewall (it
burst just over 40psi) some bicycle tyres I've seen were marked 55psi and
even 60psi on some racing bikes, its doubtful they would specify bicycle
tyre pressures that a bicycle hand pump couldn't produce.

[John Smith]

Post by ian field

Post by michael adams

Post by ian field
Why do bicycle tyres with "Inflate to 50psi" stamped on the sidewall burst
at just a tad over 40psi?
TIA.

Surely it's inner-tubes that burst, not tyres ?

So how do you suppose the inner tube managed to escape?!

Post by michael adams
Given their construction and means of attachment to the rim I imagine
it would be impossible to "burst" a tyre casing simply by use of a handpump.

It was a 12V tyre pump with a pressure gauge - on motor vehicle tyres I
always double check with a digital gauge so I know the gauge on the pump is
close enough.
This bicycle had tyres marked "inflate to 50psi" stamped on the sidewall (it
burst just over 40psi) some bicycle tyres I've seen were marked 55psi and
even 60psi on some racing bikes, its doubtful they would specify bicycle
tyre pressures that a bicycle hand pump couldn't produce.

Your gauge or the tyre was faulty. i.e it had a tear in it.

The tyres on my own bike - Vredstein Ricorso 23*622's (£8.50 cheapos) have a
maximum pressure of 130 psi. 9.0 BAR

http://www.glorycycles.com/vrriroti1.html

I don't know where you got that 60psi figure from.


michael adams

...

[terry]

Post by ian field
Why do bicycle tyres with "Inflate to 50psi" stamped on the sidewall burst
at just a tad over 40psi?
TIA.

What 'all' bicycle tyres??????
Or is this a case of 'one' tyre bursting on 'one' occasion?
60 lbs (approx 4 bar) or somewhat higher sounds familiar from my
bicycling days over 50 years ago.
And quite achievable with a bicycle hand pump; which would get quite
warm while pumping!
Also is the gauge accurate?
Sounds fishy! Maybe the inner tube was caught or ripped etc. or the
tyre itself was damaged, with perhaps a defective sidewall?

[ian field]

Post by ian field
Why do bicycle tyres with "Inflate to 50psi" stamped on the sidewall burst
at just a tad over 40psi?
TIA.

What 'all' bicycle tyres??????
Or is this a case of 'one' tyre bursting on 'one' occasion?
60 lbs (approx 4 bar) or somewhat higher sounds familiar from my
bicycling days over 50 years ago.
And quite achievable with a bicycle hand pump; which would get quite
warm while pumping!
Also is the gauge accurate?
Sounds fishy! Maybe the inner tube was caught or ripped etc. or the
tyre itself was damaged, with perhaps a defective sidewall?

Evidently the sidewall must have been defective but the tyre wasn't all that
old.

I was using a 12V pump with built in gauge - The pump has been in use for
quite a while and I always double check with a digital gauge so I know the
one on the pump was close enough. The tyre had "Inflate to 50psi" embossed
on the sidewall, it burst just as the pointer crossed the 40psi mark - in
fact I had planned to stop at 40psi and the tyre burst almost simultaneous
to me hitting the off switch.

[terry]

Post by terry

Post by ian field
Why do bicycle tyres with "Inflate to 50psi" stamped on the sidewall burst
at just a tad over 40psi?
TIA.

What 'all' bicycle tyres??????
Or is this a case of 'one' tyre bursting on 'one' occasion?
60 lbs (approx 4 bar) or somewhat higher sounds familiar from my
bicycling days over 50 years ago.
And quite achievable with a bicycle hand pump; which would get quite
warm while pumping!
Also is the gauge accurate?
Sounds fishy! Maybe the inner tube was caught or ripped etc. or the
tyre itself was damaged, with perhaps a defective sidewall?
Evidently the sidewall must have been defective but the tyre wasn't all that
old.
I was using a 12V pump with built in gauge - The pump has been in use for
quite a while and I always double check with a digital gauge so I know the
one on the pump was close enough. The tyre had "Inflate to 50psi" embossed
on the sidewall, it burst just as the pointer crossed the 40psi mark - in
fact I had planned to stop at 40psi and the tyre burst almost simultaneous
to me hitting the off switch.

So it was one particular tyre. Then?

That is to say not 'all' tyres?

Therefore an assumption would be that it was one individual case of a
defective or damaged item. That failed at 40psi. One could expect that
if 50 was the recommended it should be quite safe to go to 80 or even
100? I seem to recall 70 psi was quite typical on the small 1.25"
Dunlops we used back then.

We have snow now; but unti recetly young lads bicycle on bikes common
around here and their tyres are given a real beating by all the
jumping and cross country they do. While most of the tyres seem to be
made in China tyre problems are not a significant problem!