Brompton tyres don't stay at high pressure for long

[pintofale]

Hello everyone, new user here just wanting a bit of advice.

I have a Brompton which I have been riding infrequently for ten years or so. I have Schwalbe tyres and tubes, but I always find them down on pressure when I come to use the bike (sometimes after a few weeks), and have to top them up (which I do by judgement, not to a specific pressure). I am quite hefty (107kg) so I do run them at high pressure, perhaps over spec (I inflate them till they hold shape when I am sitting on the bike), but I have not had this problem with other bikes. Can anyone suggest a different tube option which might hold the pressure better? Perhaps the problem is that my weight is all on the back wheel which is small, whereas on another bike the weight is spread over two larger wheels...

EDIT: Just wondered if trying a presta valve instead of the car type would be worthwhile??

 

[pintofale]

Yes I have plastic valve caps which came with the tubes, which have always been on, so no dusty valves. I have never used slime either. The valves should be good - I have also changed the tubes (for the same type, Schwalbe) and the problem remains.

 

[srw]

They just don't hold pressure well. Get a track pump with a gauge and pump regularly. It takes a couple of minutes.

 

[the snail]

Schwalbe tubes hold pressure well IME (the heavier ones not lightweight), I'm more surprised that you find any tube will hold pressure over several weeks, I'd expect to top them up every couple of weeks. My only suggestion is to buy a track pump with guage, so you can easily pump up to a consistent pressure.

 

[pintofale]

I have two more bikes which I don't use very often, one has not been used for over a year and the tyres are still hard on that. I also have a Land Rover which weighs over a ton and half which I drive regularly and I haven't had to pump the tyres up for months, so I don't accept that they "just leak".
I can't see any other brand apart from Schwalbe which supplies Brompton tyres so I think my only option is to try the prestex-valved ones and see if they are any better.

Thanks for the replies!

 

[annedonnelly]

I have no problem with Schwalbe tubes on my Brompton - though I'm not as heavy as you. If you haven't got a gauge then perhaps you're not pumping them up as hard as you think.

I had Presta valves on the Brompton for a while & hated them - plus the hole in the rim is cut out for Schraeder so it's not ideal putting slimmer Presta valves in.

 

[Cycleops]

I would have thought most inner tubes loose pressure after a few weeks, c'est normal.

 

[Ian H]

After a few weeks I'd be surprised if I didn't need to pump up the tyres.

 

[GrumpyGregry]

have to pump my kojaks weekly.

 

[pintofale]

Anyone using solid rubber tyres? I remember a work colleague of mine many years ago had a folding bike in the office which ran on them. Found some reviews of Tannus tyres which were not encouraging!

 

[annedonnelly]

You can get little adapters to fill the gap around a Presta valve in a Schrader hole.

That might be worth doing if I actually liked the Prestas

 

[GrumpyGregry]

Is this a euphemism?

Only in other people's worlds...

 

[oldwheels]

I heard of someone who had to pump up his Brompton tyres oftener than he liked. He discovered that checking the tyre pressure lost a bit of air every time he did it so the tyres went down fairly quickly due to this air loss. Certainly I find that attaching the pump loses quite a bit of pressure from the small volume high pressure tubes. I have now developed a system of checking the pressure by feel ( as we always did years ago anyway ) and only inflating when it seems necessary. I know this sounds a bit odd but it seems to work for me. I also slightly over inflate to compensate for the slight air loss when removing the pump head. In any case pressure gauges are notoriously inaccurate so feel is probably ok for a rough indication.

 

[CanucksTraveller]

It's normal to need to put air in tyres, bike tubes are pretty porous. Higher pressure tyres more so, but they all need some air fairly often.
Find the pressure rating, get a track pump with pressure gauge, and pump them up to the proper pressure. In a couple of weeks, do them again if needed. I suspect you're not reaching the right pressure, "feel" with fingers is not always close to accurate.

Pumping tyres up is fairly normal, routine cycling stuff, just see it as part of ongoing maintenance.

 

[NotAnother Cyclist]

I pump mine up once every week or two (I keep them at 110psi)