Tyres kep losing pressue

gaved

Hello...!!

Can anyone please help me,
After a couple of days, the pressures in both tyres have dropped considrably, 20-30 psi ish. Is this a normal occurance for road tubes..? I don't get this with my MTB tyres can anyone please help?? Am I doing a proper newbie simple mistake...

Many thanks

mattward1979

are they new tyres? I had the same problem when I put brand new ones on as Im imagining they go through a period of bedding in, with the walls expanding slightly cause a pressure drop.... Might be totally wrong though!

desweller

Unless you're using latex inner tubes, you have a slow puncture or a leaking valve.

vorsprung

My tyres take a week to drop from 100psi(7 bar) to 80psi(5.5 bar)
Perhaps if you have them pumped up harder than this they might loose more
The weather seems to effect the pressure a little too
But a 20 psi drop in a couple of days doesn't seem right

ex-pat scot

Leaking valve (probably).
Slow puncture (possibly)

CiB

Do you tighten the valve screw tops up? If you don't have two punctures, that's the likeliest cause.

Apologies if you're already 'very aware of this thanks very much for asking'.

tri-sexual

check tyres for foreign objects
check rim tape
check condition of the wheels
check tubes and the valve, make sure that screw cap is tight

night_porter

+1 for closing/tightening the valves

But if you do have 2 punctures at the same time don't waste your money by doing the lottery coz you are really really unlucky...

Mike67

Not just the valve nut, but the valve body itself might be loose.

I had some new (Presta) Conti inners where the valve nut was tight yet I still lost air.

Turned out the valve body itself wasn't fully tight and leaking. I needed to loosen off the valve nut fully then tighten the body home to stop the leak.

Not all tubes have removeable valve bodies though, but worth a check.

fnb1

cold be leaky vaves as others have said, try a little , like one drop , of oil into the top of the open (unscrewed) valve (wheels obvioulsy positioned so valve nearest ground so oil runs into the valve, then screw valeve down tightly. Sometime the seal can be a bit dry or just poorly maufactured so a little lube eases the joint. Other wise slow puncture, crap tubes or perhaps very good tubes, e.g Latex, latex is a little more leaky than butyl but gives a smoother ride and is a little lighter.

You will nitice pressure drops sooner than MTB as the pressure is higher.

desweller

vorsprung wrote:

My tyres take a week to drop from 100psi(7 bar) to 80psi(5.5 bar)
Perhaps if you have them pumped up harder than this they might loose more
The weather seems to effect the pressure a little too
But a 20 psi drop in a couple of days doesn't seem right

You are of course aware that, when you attach your pump, the air in the tyre enters the pump tube, causing the gauge to read a lower pressure than the tube was actually at?

Not wishing to teach anyone's grandmother about removal of egg internals, of course.

Berk Bonebonce

Latex inner tubes deflate by themselves. You need to pump them up everyday.

Butyl inner tubes keep the pressure a lot better.

gaved

Cool,

Thanks very much for all of the replies, I will be trying all of these out

Another trick picked up.....

Bunneh

tri-sexual wrote:

check tyres for foreign objects

Bloody foreign objects coming to our cycle tyres and puncturing our tubes!

To the Daily Mail Cave, Batman!