Tube losing pressure, normal or time to get better ones?

[Irishrich]

My new bike came with Ultremo ZX tyres and as yet I haven't had the need to change the tubes so have been using the new tubes since I got the bike about 2 months ago. The problem is that both tubes are losing pressure at slightly different rates but the rear tyre lost 40 psi in one day. I always pump them up to 120 psi before rides and only noticed the major pressure loss after I hadn't ridden for a week and noticed the rear one was down to 30psi so it had lost 90 psi in one week. I pumped them up last night and checked both tonight, rear was down to 80 psi and front was 90 psi. Been searching online and there are a few possibilities such as latex tubes losing pressure quicker but wondered if this was normal for these types of tubes and to just stick with them by pumping them up before each ride? Have a long club ride on Sunday and am worried they might lose too much pressure over the course of the ride.

 

[Mickthemove]

According to my track pump, my tubes loose about 30/40 psi over a week! never really more but sometimes less,odd but i just live with it and as long as they are up to pressure before i go out, i have had no probs

 

[Dusty Bin]

If the tubes are latex, then pressure loss is not unusual - although 40psi in a day is a fair whack, tbh. If in doubt, put a couple of new tubes in..

 

[T.M.H.N.E.T]

I've found tubes in my new bikes this year somewhat lacking., so I ditched them soon after purchase.

No explanation to offer, but I haven't noticed any significant pressure drops since

 

[Irishrich]

Cheers, looks like I need to replace both tubes just to be safe. I don't like the thought of them deflating while on a ride.

 

[Ern1e]

Cheers, looks like I need to replace both tubes just to be safe. I don't like the thought of them deflating while on a ride.

Hi would I be correct in thinking you have checked the valves for air loss after infalation,if so then most certainly replace them 40 psi loss in a day is not good and I to would not like the thought of them failing whilst riding at any speed and also whilst you are out getting replacments for the but an extra for a spare.

 

[Irishrich]

Valves seem fine so must be the tube itself. Front one seems to be holding pressure better but the rear is rubbish so will replace it at the least.

 

[the_mikey]

I had that problem a week ago, checked the tyre/tube and found a thorn in the tyre which was also penetrating the tube, it was the only thing stopping the air from escaping!

 

[Ern1e]

Valves seem fine so must be the tube itself. Front one seems to be holding pressure better but the rear is rubbish so will replace it at the least.

So it would appear these modern tubes (oh my god I sound like my father lol) do not seem to good ! I always try and use the Michelin air stop tubes if I can find them and if not well the best the shop has if needs must.

 

[Irishrich]

Went into my LBS where I bought the bike. The owner said the lightest tubes tend to be very porous and leak air but not at the rate mine were losing pressure. he said a race tube can lose 40 psi in a week whereas I was losing 40 psi in a day so I bought 2 new tubes and replaced the rear one which was losing far more pressure than the front one. He said there was very little difference in tube quality in the standard tubes so I bought a couple of his basic ones and fitted one earlier. I'm out on a club run tomorrow so will check the pressure before the ride and see if the problem is gone which I expect it will be.

 

[Linford]

My valve was the cause of the air loss last week on my front wheel.

 

[ColinJ]

Valves seem fine so must be the tube itself. Front one seems to be holding pressure better but the rear is rubbish so will replace it at the least.

You are making sure you screw the knurled bits on the valves tight after taking the pump off, aren't you?

Another possibility is slow punctures. I had punctures which take anywhere from 1 second to 1 week to deflate my tyres.

 

[Davidc]

Dirt in the valves can cause air loss.

40 psi over a week, yes, but in a day seems wrong.

Not the lightest, but I've found Schwalbe tubes good, Continental variable, and the basic ones from an LBS perfectly adequate.

 

[Irishrich]

You are making sure you screw the knurled bits on the valves tight after taking the pump off, aren't you?

Another possibility is slow punctures. I had punctures which take anywhere from 1 second to 1 week to deflate my tyres.

Yeah Colin, I am pretty meticulous about checking things before each ride and I always screw the valve tight after pumping the tyre. The tubes never fully deflated after one week of no use but the rear one went down to 30psi and stayed there which doesnt seem like a slow puncture as it wouldnt hold pressure surely if was a puncture?

 

[ColinJ]

The tubes never fully deflated after one week of no use but the rear one went down to 30psi and stayed there which doesnt seem like a slow puncture as it wouldnt hold pressure surely if was a puncture?

If the hole in the tube is really tiny, it can take a certain minimum amount of pressure to get the air to leak out.

I had a tube with a slow puncture that only leaked down to about 40 PSI (confirmed by holding it under water) and then it stopped!