Losing pressure thread

Seems a common complaint and I wonder if anybody has painted the internal of the rims with a rubber paint like rim sealant to compensate for the sometimes porous nature of alloy rims?.
Is the pre- puncture gunk you hear so much about any good even if it is not appreciated by tyre fitters?.

Is it definatly your rims that are causing the problem?. Have to checked the valve?.

Yes----valve seat,valve and tyres all ok. Wheels and tyres have been submerged and can't find an air loss so I am suspecting slightly porous rims. To be honest I check the tyre pressures every time I use the bike and I know that if I am away for 48hours they will only drop by 2lbs psi max. The problem is such that I can live with it rather than remove the wheels and tyres.
I was only asking if anybody had done anything along the lines of painting the internals of the rims so that when I have my next set of tyres fitted I could try it if somebody else has already and it eliminates the problem

[dyzio]

My previous set was loosing air, about 5psi/2days. Turned out to be a dodgy valve.

Are valves supposed to be changed with every tyre change?

I had my front valve replaced due to it leaking noticeably, but now my front goes down at about 1psi/day.

The back tyre however, holds pressure no problem for weeks. I do suspect the front is due to the porosity of the metal, might try to seal it sometime.

Originally Posted by Dicky Ticker

Seems a common complaint and I wonder if anybody has painted the internal of the rims with a rubber paint like rim sealant to compensate for the sometimes porous nature of alloy rims?.
Is the pre- puncture gunk you hear so much about any good even if it is not appreciated by tyre fitters?.

This is good stuff we use it at work, gives a good seal and slows down corrosion.



Remove the tyre and get rid of the rim corrosion using a wire brush, then paint this onto the rim where the bead will sit.

Originally Posted by dyzio

My previous set was loosing air, about 5psi/2days. Turned out to be a dodgy valve.

Are valves supposed to be changed with every tyre change?

Yeah we always do when we change a tyre/repair a puncture, unless it's a metal valve then quite often we will leave them in, unless it's corroded/leaking.

[timwilky]

in another thread I posted

My brothers Mille had strange pressure loss, never in the garage. Only on the road.

Turns out to be dodgy valve cores, sod all spring in them as the pressure should maintain the seal, but in use it didn't. Changed the cores and the problem went away.

The guy over the road had even dodgier pressure problems on his race blade. Turned out his £800 carbon wheel was porous.

Sounds like your issue may be similar to my brothers valve core issue. Nip down to quickfit etc and scrounge a couple of cores (assuming you have the tool to unscrew cores at your age)

"Assuming you have the tool to unscrew cores at your age"--EXCUSE ME
not so young yourself--1/2century= 5 decades Your as bad as Sid S when I was moaning about adjusting back brake rods.

Why is that, have they stopped fitting the bit of rubber on the valve?

I have already changed the cores and tried HP dust caps but still have the same problem. Like I previously stated I can live with it till the next tyre change comes around.

I'm glad I found this thread when I did.

I went to inflate my rear tyre yesterday...12 psi!! Down from 36. The front was only down from 33 to 31.

In my haste - I'm booked in tomorrow at 8.30am for two new Avon Storm 2 to see if this cures the problems, but it seems it may not be that simple?

I'm worried that a) I'll need to attempt to scrub them in in the wet on the way to the AR and b) two brand new tyres may not solve this problem!

The old tyres have been on since about April and covered about 4,000-5,000 miles. Any ideas?

buy a new bike, simples