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Unnerving experience - tyre pressure loss

askgeez

Well-known member
Joined
5 Apr 2015
Messages
1,660
I had four new michelin Supersports fitted Friday morning.
Local independent place , well regarded and used them before
I drove the few miles back home and put car away

Saturday , drive the 100 miles to drop car off at Centergravity for work next week. Chris notices rear offside tyre, looks low. It's dropped to 10psi

First thought is I've had a lucky escape as I have been doing motorway speed :cop: "Enjoyed" a few dual carriageways and roundabouts

Second thought is have a knackered a brand new £250 tyre?
Impossible to say at what point of journey it got that low.
Obviously hoping that constant speed kept some heat in tyre and maybe above the 20psi minimum.

My alloys are factory fresh as far as I can see , not old enough to be porous and previous tyres held pressure. quick scan and didn't see a nail etc

Crossed fingers it's a crappy valve

Anyone recommend an aftermarket TPMS??
 
There are 3 possible issues with new valves that can lead to this:

1. Tiny sharp swarf from production on the thread of the valve core, or local contamination from a bit of grit etc, stops it from being fully tight

2. To inflate the tyre its quicker to do without the valve core, usually a higher psi is used to 'bead' the tyre, eg 50psi. Once this is done, the valve core is inserted but the air is rushing out at high velocity. In some conditions the air is sub zero temp and tiny ice particles can stop the core being tightened.

3. Valve core just not tightened enough, operator error.
 
Update

It wasn't the valve, but a new sharp small galvanised woodscrew, right in the middle of the tyre.

Must be some kind of record, tyre on less than 24 hours and inside 110 miles of use :frustrated: :frustrated:

Very annoying ... Was feeling happy that I had 4 new tyres , no repairs to be concerned about

CG have had it repaired for me , and it is best kind of repair and I shouldn't be concerned that it affects speed rating.

Thanks Chris (Exel) for comments and others for recommendations of TPMS
 

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