Tyre-pressure loss

[oldrascal]

This is worrying.

I keep my GSA in a dry garage and, because I don't need it for commuting and the roads have been so crappy, I have an Optimate wired in - so no worries there.

But the lure of the road is too strong and I still want to get out now and again for a blast. As there are generally 7 or 10 days between outings, I decided to do the prudent thing and check the tyre pressures on the factory fit Battlewings. And that's where the problem arises.

The tyres have only done 3,000 miles but both times I have checked, about 4lbs to 5lbs or so of pressure drop has occured in each tyre. I can't imagine that both have picked up slow punctures so imagine that this type of tyre is prone to slow loss in cold weather.

Anyone got the same problem or is something going on that I had better find out about.

 

[Magwych]

What are you using to test the pressures?

 

[vilguy]

Are you measuring your tyres when they are bloody freezing in the garage and then pumping them up at the petrol station or something when they are warm?

Using the same gauge both checks?

Do they go down any more if left for longer?

Could be a slightly leaky valve , teeny tiny slow puncture. If you have a valve tool just check the valve is tight. And use a valve cap with an o ring in it.

If its still leaking, just bung some tyre sealant in it. Itll be fine.

 

[always 100]

Are you measuring your tyres when they are bloody freezing in the garage and then pumping them up at the petrol station or something when they are warm?

Using the same gauge both checks?

Do they go down any more if left for longer?

Could be a slightly leaky valve , teeny tiny slow puncture. If you have a valve tool just check the valve is tight. And use a valve cap with an o ring in it.

If its still leaking, just bung some tyre sealant in it. Itll be fine.

I would also make a solution of fairy liquid and water and put it in valve if valve is not leaking, squoosh solution around the rim or fill a bowl up with similair solution like you would for a push bike puncture just make sure you are up to the rim. If it's leaking and you take your time you'll find it

 

[squid]

I have a similar problem which I have found to be the seal around the base of the valve. Try and get plenty of water around all of the valve.

That will teach me not to change it when I did the tyre.

 

[oldrascal]

Thanks all for the quick replies.

I take the pressures with the bike cold in the garage and adjust the pressure with a foot pump. I can't see both tyres getting slow leaks simultaneously and of the same severity to give equal pressure loss in both tyres. So I am drawn to the tyre-valve scenario, but if this is right, how could it happen with the factory-fitted tyres?

More importantly, are the options getting both tyres refitted or using tyre sealant? And if I use tyre sealant, will it:

a) Do the job on sealing the porous valve?
b) Bugger up the works (rim) when it comes to a new set of tyres?

 

[always 100]

Have you got TPC???????

Have you tried the snoop trick arond the valve??

 

[t'other dave]

It's not uncommon for tyres that are stood to lose a few psi, use the washing up liquid water all over if you can't see anything bubble they will be ok. Don't bother with sealant goo.

Pinched from U.S GOV vehicle safty blarb


Tires lose air normally through the process of permeation. Changes in outdoor temperature can affect the rate at which your tires lose air. This change is more pronounced in hot weather. A tire may lose one or two pounds of air per month in cool weather and even more in warmer weather. Gradual air loss will increase the tire’s operating temperature. This can cause some of the components to separate, or damage the tire body in ways that create rapid or sudden air loss. Do not bleed air pressure when tires are hot. It is normal for pressure to build up as a result of driving

 

[littleredrooster]

Every GS that I have had has done this. They lose about 2psi in three weeks and always need inflating. I suspect (but can't prove) that it's porous castings because it happens with different makes of tyre.

 

[(RIP) ugg]

my front loses around 4,5 psi a week , i use the bike every day..

i just pump it up , but i suspect it might not have correctly seated on the rim, even tho ive done over 7000 miles on the tyres .

ugg