mtb tube exploded at 50psi

delllat

had my mtb tyres fairly hard at about 40psi but decided to max them out for more speed on city roads

on the side wall it says 40-65psi so i go into the petrol station,start pumping it up with the airline and it exploded with an incedible bang at around 50 psi

my ears are stil ringing,i was using a raleigh mtb and the tubes,wheels and tyres were original and almost new

are the tubes not rated to take as much air as the tyres?

can i ask for a replacement from raleigh or the reseller?

has anyone ever seen anything like this before?

72hundred

I've heard it mentioned that the gauges at the stations aren't that accurate. Therefore what looked like 50psi could have been 75psi.
Or you could have just got a defective tyre.

72oo

Hermy

I think the problem is the amount of '50psi' the garage pump puts into your bike tyre. Garage pumps are set up to fill car tyres which require a much larger volume of air regardless of psi.
A track pump is generally recommended.

Explosive_Cornflake

Reminds me of the part in Fear And Loathing in Las Vegas.
+1 on what was said below.If using a garage pump, go by feel, not by the guage. They're woefully inadequate,especially at high pressures.

Danbo!

Hermy wrote: »

I think the problem is the amount of '50psi' the garage pump puts into your bike tyre. Garage pumps are set up to fill car tyres which require a much larger volume of air regardless of psi.

Psi is Psi no matter what the volume. Garage pumps are setup to blow air, volume doesnt matter. The smaller the tyre, the greater the psi - road bike=110psi, car=30-35psi, tractor wheel=about 5psi.

As mentioned above, the air lines in petrol stations have to be re-calibrated in scotland, so no one ever bothers doing it.

Hermy wrote: »

A track pump is generally recommended.

+1

kenmc

noblestee wrote: »

Psi is Psi no matter what the volume. Garage pumps are setup to blow air, volume doesnt matter. The smaller the tyre, the greater the psi - road bike=110psi, car=30-35psi, tractor wheel=about 5psi.

True, but the smaller the volume of the tyre, the quicker the pressure will increase, so a small percentage change in the volume of air dispensed will lead to a relatively large percentage increase in the PSI of a bike tyre compared to a car tyre. And that's *before* you even take into account the accuracy of the guage.

blorg

You can pump up safely in petrol stations (I do it all the time) but you MUST ignore the gauge entirely and just do it by tyre feel (squeeze test.) Use short bursts; as others have said they are designed to move a large volume of air.

If you want/need accurate pressure, get a track pump as others have said (I have a Joe Blow Sprint which is really great.)