Repeatedly deflating 700c inner-tubes.

[TheCyclingRooster]

Hi to you all out there. For some time now I have been aware that the inner-tubes on my bikes and those on the bike that Ms Cycling Rooster has are also constantly in need of re-inflating. It is extremely annoying and even though I have a Track Pump it leaves me needing a Mars Bar to top up my energy levels again.
I then have to stay out longer to burn off the calories.

The tubes are not punctured or indeed show no signs of being porous when submerged in water and they are Butyl inner tubes - which I understood were better than the older style 'thick black condom rubber' ones.

Another thing that has occurred several times is the Presta Valve leaking at the position of the seat/reinforced area albeit the rim tape is in position and there are no burrs on the rim valve holes.
I inflate the tyres having first ensured that the valve is at right angles to the rims and then take the security ring/lock-ring to just touch the rims and therefore not pulling down on the tubes.

 

[G3CWI]

Buy better tubes?

All tubes leak air to some extent and the very act of checking the pressure in a tube releases some air. What loss are you finding?


...the bike seat in your avatar looks incredibly low...

 

[TheCyclingRooster]

Hi G3CWI. I don't buy cheap tubes - or at least I thought that Conti tubes were not cheap. The pressure loss is circa 20psi and sufficient that there would be a risk of 'Pinch Punctures' and rim damage on some of our crappy roads.

Yes my seat height does look low but the mechanics of it are - that I stand at 4' 10" and have a 23" inside leg,the bike is a 50cm ( 19.75" ) Bianchi Via Nirone7 Alu Carbon on Campagnolo Veloce and fitted with 140mm Thorn Cranks with triple Stronglight rings .
I also have a 52cm Scott S50 FB Road Hybrid and it was was asked "did I feel dizzy so high-up" ? At 69 in 8days time - I am past thumping the idiots - I just smirk.
The shorter cranks were necessary because of limited bend at the knee after Total Left Knee replacement in November 2007. My short lower limbs do not help and more-so when climbing stairs because of the kicking of the fronts of the steps.
Stand-over height has always been an issue and non more-so than when I used to ride my Hetchins Vibrant Triangle Track Frame on Fixed Wheel. I became an expert at traffic light - Track Stands.

My ideal frame-size would be a 48cm horizontal top-tube example but there are few about and especially decent lightweight ones. I just might blow my whole years pension and contact David Millar in Preston for a bespoke Hetchins Vibrant Triangle frame

 

[youngoldbloke]

I've had problems with Conti tubes, especially failure where the valve joins the main tube, and often not apparent (even under water) until the valve is flexed. In one case the tyre was absolutely flat, yet I was able to reinflate the tube and it held pressure until another complete deflation some time later. Could be a bad batch. I now use Michelin butyl tubes, (and latex tubes on the 'best' bike - they lose 10-20 psi overnight - but I'm happy with that, given their qualities). Joe Blow pump may make life easier for you, have no problem getting up to 120psi.

 

[TheCyclingRooster]

I've had problems with Conti tubes, especially failure where the valve joins the main tube, and often not apparent (even under water) until the valve is flexed. In one case the tyre was absolutely flat, yet I was able to reinflate the tube and it held pressure until another complete deflation some time later. Could be a bad batch. I now use Michelin butyl tubes, (and latex tubes on the 'best' bike - they lose 10-20 psi overnight - but I'm happy with that, given their qualities). Joe Blow pump may make life easier for you, have no problem getting up to 120psi.

Hi youngoldbloke. I certainly you are not a later-life yob!!!!!!!!!!!
Yes I also found that the Michelin tubes were better performers albeit they did loose pressure.
I actually have a BETO Track Pump that will deliver 120psi but I usually only go to circa 110psi as I only weigh 68kgs and at 4'10" tall I would like to drop about 12kgs and get back to where I was before I had my knee replaced and was forced into retirement in 2007.

 

[User6179]

Conti valve cores are usually loose ime so tightening them up might reduce the deflations .

 

[MikeW-71]

I use Conti tubes too and after a day or two, they'll have lost about 10psi, it's just a fact of life for high pressure tubes I fear

 

[Robeh]

halfords tubes do the job