Odd tyre issue

[GlynMo]

Hi all,
I'm down in Aragon for the GP and had a strange tyre problem on my Griff. Prior to the trip, no problem but as soon as I got up to motorway speeds the front tyres started to deflate, the left one losing half of its pressure in an hour. Made it here by stopping every 45 minutes to pump the tyres back up but no pressure loss overnight. The only thing I can think of is that centripetal force at high speeds is causing the seal to break but I've never come across it before. Ideas?

[Englishman]

I would suspect a nail as I’ve had similar symptoms a number of times.

Other off the wall thought is age of the tyres, are there any signs of cracking?

[Colin RedGriff]

It might be linked to tyre temperature. The heat of the tyres when running at motorway speeds causing additional pressure or opening up a fault in the tyre?

[bluezeeland]

Dependent on the amount of time the tyres are on > corrosion inside the rims ? I've put mine on nitrogen now iso air....

[Bluebottle]

GlynMo said:

Hi all,
I'm down in Aragon for the GP and had a strange tyre problem on my Griff. Prior to the trip, no problem but as soon as I got up to motorway speeds the front tyres started to deflate, the left one losing half of its pressure in an hour. Made it here by stopping every 45 minutes to pump the tyres back up but no pressure loss overnight. The only thing I can think of is that centripetal force at high speeds is causing the seal to break but I've never come across it before. Ideas?

I doubt it would be the seal on motorway driving as the is near zero lateral loading of the tyre, and tyre heat/pressure increase at high speed will just push the tyre wall harder against the wheel rim ??.
Usual suspects are;
Tyre wall damage or cracking with age,
Foreign object still stuck in tyre plugging hole at low speed/pressure
Faulty valve or dirt in the valve
Damaged/buckled wheel rim
Porous or cracked alloy.
When you're parked up, I would over inflate to say 35-40 psi and listen for escaping air, if not then leave over night and see if it losses pressure over time at this increased psi, If the latter is the result I'm not sure it will help you any with diagnosis without putting a colour die into the tyre.

[GlynMo]

Rims and tyres are 2 years old and undamaged. I did the old spit test on the valves and no sign of a leak. Bit difficult to do it at motorway speeds though! I'll check the valve cores when this storm finishes.

ETA the left tyre did this a while ago but has been fine since as I've not been on a m'way for ages.

Edited by GlynMo on Friday 23 September 16:00

[bluezeeland]

Maybe the car just doesn't like Spain ? perhaps try to play some flamenco to it (not whilst driving !)

Which, if I'm honest, is another way of saying I don't know.....;)

[GlynMo]

Thread resurrection!

I'm no nearer to knowing what the problem is/was but a bottle of Slime in each tyre seems to have cured it. I haven't been on a motorway in the Griff since I raised this issue but the annual MotoGP trip is coming up and I really don't want to go in the daily barge!

[GlynMo]

Trip to Italy went well, the Griff didn't miss a beat and man, the Italians do appreciate a bit of style.

The tyre issue isn't completely cured, sad to say. The Slime has improved the problem no end, but there's still some deflation at higher speeds. I'm going to have the tyres removed and the rims and beads checked and the valves replaced as a last resort.

[griffdude]

What wheels are they?

[GlynMo]

griffdude said:

What wheels are they?

Compomotive M06s

[Speed 3]

Are you able to swap those tyres back onto the old wheels to see if the problem transfers or stops ?

Given the age of tyres and wheels I'd say its a bead/rim interface issue if you haven't picked up a nail given its happened on both sides. Were the wheels brand new or new to you but refurbed ?

[GlynMo]

Speed 3 said:

Are you able to swap those tyres back onto the old wheels to see if the problem transfers or stops ?

Given the age of tyres and wheels I'd say its a bead/rim interface issue if you haven't picked up a nail given its happened on both sides. Were the wheels brand new or new to you but refurbed ?

No, they're bigger than the originals.

Rims were brand new, and I watched the fitter fit the tyres and he did a good job so I don't believe any damage occurred. Hopefully, it's just 'one of those things' and refitting the tyres will cure the problem.