View Full Version : Losing pressure thread
Dicky Ticker
04-08-10, 08:45 AM
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?.
SV650Racer
04-08-10, 08:58 AM
Is it definatly your rims that are causing the problem?. Have to checked the valve?.
Dicky Ticker
04-08-10, 11:29 AM
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
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.
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.
http://shop.advanceautoparts.com/wcsstore/CVWEB/staticproductimage//N3191/large/16910014_xse_14101_pri_larg.jpg
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.
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
04-08-10, 10:34 PM
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)
Dicky Ticker
05-08-10, 10:01 AM
"Assuming you have the tool to unscrew cores at your age"--EXCUSE ME:rolleyes:
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?
Not entirely helpful. No other ideas?
Spray soapy water around the valves, you'll see if they leak.
You're getting new tyres, maybe ask for new valves as well if you're worried. Tell tyre fitter to check if the rims look ok.
Take it easy on the ride down, especially if wet.
Weather says it's soaking coming over the bridge. Comedy value would be me turning up an hour after my group ride in.
I'll do that when I get in. Fairy liquid in water and smear around the valve?
Bap, will you have time to get a few heat cycles into the new tyres before you set off? A fast blast up the dual carriageway - stop for a coffee to let them cool back down - blast back down again. Repeat if you have the time. It might help a bit.
Yes - I think so. I'm booked in for half 8 tomorrow morning. M32 from Protyre to my house is about 4 miles. Can do that a few times. Meeting in Aust at noon.
However, weather isn't looking very good where I am. I.e. VERY wet. Should I be concerned?
I wouldn't be too worried - just treat them like cold tyres and be sensible with the throttle/brakes and gently increase lean angle until you've gained confidence in them. It's the first couple of heat cycles that "scrub" the tyre in. The rain won't help this but you'll still be able to get a decent amount of heat in them with a couple of quick runs.
Assuming your group run-in isn't going to be a knee-down hooligan fest then you'll keep up fine. Most of the problems will be in your head for the first few miles.
Dicky Ticker
05-08-10, 12:38 PM
Bap---get new valves fitted,not just the core, for the extra couple of quid it will cost
Rang Protyre on lunch. Man on the phone told me that when I arrive tomorrow I need to speak to Nick - who he assures me is the 'oracle' of motorcycle tyres, if there was such a thing.
The man on the other end of the phone assures me he will diagnose the problem and fix it, all in time for me to get some heat in the tyres and get to Aust for midday. Luckily, I have RichT's contact number, so if the said oracle cannot fix my tyres in time, I won't be left behind.
Thanks for your advice guys.
vBulletin® , Copyright ©2000-2025, Jelsoft Enterprises Ltd.