Innertube problems?

[FOAD]

Both a friend and I recently purchased Cube bikes, which are fitted with the same tyres and tubes. We are both on the heavy side. Our tyres are 700 x 23 on road bikes.

I pump my tyres to 120 PSI for every ride, but even after a short trip (12 miles is the shortest I have done), the tyres have gone down by about 20 PSI front and back. My friend has exacly the same problem.

A third friend who bought a Cube at the same time (C2W) is much lighter and isn't suffering from this issue at all.

Is it possible that the innertubes are just poor and can't handle the extra pressure of the weight as well and leak through the vaklve until they find an equlibrium (ie. 100 PSI in this case), or is this a common thing for heavy guys on road tyres?

 

[Alves]

Not too uncommon and may reflect your pump and technique for disengaging the pump head from the valve causing a minor leak.
Also, when you pump up a tyre the air will heat up and when the tyre cools again, a certain amount of pressure will be "lost" as a result.
I usually lose about 10 or 20 psi per week in my high pressure tyres and I suppose a similar but unmeasurable amount in my MTB and Brompton which run on much lower pressures.

 

[tyred]

My road bike tyres usually lose about 10 -20 psi in the average week as well. I guess this must be normal but I wouldn't have thought it should drop by that much every ride. What type of valves have you got and what type of pump/pressure guage have you got. The accuracy of pressure guages vary wildly. Maybe you're just not getting consistant readings from the one you're using. Do you have problems removing the pump/nozzle from the valve after pumping it up and hear air hissing out?

Tyre pressure does vary with temperature but after a ride the tyres should be warmer and therefore higher pressure.

 

[gaz]

I have a similar problem, i run on 700c 28's at present, and the recomended pressure is 80psi for my inner tube, and pump it to 75psi with an electronic pump. but even after a shot ride i look down whilst on the bike and the pressure of my weight on the tyres is making it bulge out and gives a larger contact area. I don't feel it's my weight as i'm between 12 - 13.5 stone.

 

[FOAD]

The valves seem fine (presta) and I have a Topeak floor pump. The loss of pressure is very obvious just to the squeeze so it's not a guage issue.

I may just try putting new tubes in and seeing whether it make a difference.

 

[Mr Pig]

I bought a couple of Halfords tubes for my son's bike last year, they were in the bargain bin. Both tubes lost air rapidly and I swapped them for older tubes I had in the house which have been fine ever since.

 

[Tynan]

got a halfords tube in the back after an unscheduled stop and push, it did feel cheap but it's been fine

 

[MadoneRider1991]

i loose around 20 psi a week too

 

[Steve Austin]

Could have a lot to do with ow accurate your pressure gauge is

 

[gaz]

just measured my two tires, both which i pumped to a little over 70 psi on tuesday, and tonight they were both in the low 50's... both running new inner tubes..

 

[Mr Pig]

I have four Continental tubes in my two sets of wheels and none of them every seem to loose air. I guess them must but it's certainly not much.

 

[BIGSESAL]

I think its just one of those things. Check them weekly or before you go for a long ride.

 

[MacB]

As I've recently discovered the PSI will have an impact on the distance your computer records. I set the comp up with the standard circumference for my tyre/wheel size. I accepted that this wouldn't be precise but only wanted to log progress. To get more accurate you'd need to take a rolling measure with your weight on the bike.

What surprised me was the difference upping the PSI made, I went from approx 50 PSI to about 75 PSI. With all else being equal this was making approx 0.2 miles difference over 20 miles. Having now ridden 160 miles, over 4 days, since upping the pressure, the distance logged is creeping up slightly. This would indicate there is air loss but, at the rate it's moving, a rough calc would indicate it would take 10-14 days to drop by 20 PSI.

Short answer, 20 PSI loss on one ride, or one day, seems dramatic, I'm no lightweight either.

 

[ASC1951]

All tubes lose pressure gradually, more so if they are ridden. Latex tubes, for instance, lose enough to have to reinflate almost daily. I use £3.99 tubes, nothing fancy, and find they will hold 110 psi for a couple of weeks unridden; on holiday in the summer I have to top them every four days or so.

20 psi on a ride is a lot. Another batch will probably be better.

 

[mickle]

You are suffering from cheap far-eastern OEM porous tubes, replace them with decent aftermarket ones from the likes of Schwalbe, Continental, Vredestein, Specialized, Panaracer, Bontrager, etc.