Going soft too quickly

[otherman]

The tyres on my bike lose their pressure in a couple of weeks, even though I put new tubes in it. Something very obvious occured to me today - maybe £2.50 tubes from the hardware shop are not the way to go. What does anyone know?

[Jimbo.]

Tyres, eh?

[itsnotarace]

Couple of weeks eh? My latex tubes lose 20 psi every 12 hours...

[MadDad]

Depending on how much pressure you have in your tyres it is usual to use PSI every few weeks. I run my road tyres at 140 at the moment, if I don't ride the bike every day it will easily lose 20 PSI over a week, if not more, regardless of the cost/brand of tubes.

Latex tubes are much worse, I used to have to top them up every ride - which is why I swapped back to good ole rubber!

[otherman]

Hmmm, maybe the question should be why my claude butler tyres stay up for months.

[MadDad]

OK - forgot to ask the obvious question, MTB or Road?!?!?

My MTB's stay at 30 or 40 PSI for months without any pressure loss, my CX bike normally runs at 60-80 (depending on tyres) and does not lose much, road bike runs at 140 and loses loads over the course of a couple of weeks!

[shouldbworking]

try a rubber band round... wait. nevermind.

[otherman]

MadDad said:

OK - forgot to ask the obvious question, MTB or Road?!?!?

My MTB's stay at 30 or 40 PSI for months without any pressure loss, my CX bike normally runs at 60-80 (depending on tyres) and does not lose much, road bike runs at 140 and loses loads over the course of a couple of weeks!

Actually we have three bikes and all are MTBish but with road treaded tyres fitted, on std 26x1.75 tubes and I'm only trying to hold 50 psi or so.

[MadDad]

In which case I would suggest that £2.50 tubes from the local hardware are not the way to go!

I have these on one of my MTB's; http://www.chainreactioncycles.com/Models.aspx?Mod...

And these on the other; http://www.chainreactioncycles.com/Models.aspx?Mod...

I usually run them at between 30-40PSI (depending on where I am riding), and they never lose pressure! Check the valve heads are properly sealed, I had a leaky one about a year ago, tiny bit of grease around the bottom of the valve stem and it stopped it.

[otherman]

So, I decided to try some different tubes and settled on these babies. When the package arrived I didn't realise what it was, I couldn't think of anything that big that I'd ordered. They are amazingly thick and consequently come in huge boxes compared to regular tubes.
I put them on this afternoon, which was a bit of a job in itself, and pumped them up to 65lbs. We shall see.