[Alexander Johnston]

Three characteristics of Space Frame Moultons are small wheels, unisex design and high pressure tyres.
Regarding the latter I run my TSR 30 at about 100psi on the back and about 80psi on the front. I might ride it once every two or three weeks.
Should I take the edge of the tyre pressure between rides in order to protect the tube/valve?
This used to be “common practice” years ago but perhaps it’s no longer necessary with modern tubes and valves.
On the other hand the tyre pressures recommended for a Space Frame Moulton are higher than most bikes.
From an “easy life” viewpoint I’d rather leave it if there are negligible savings from letting a bit of air out.

[david james]

i think uv light degrades tyres more than anything, good idea to cover them up if near a window etc

[Werner]

Alexander,
would be interesting to know which tyres you use and where you found the recommendation for higher pressures? How much higher?
This is relating to the space frame Moultons or to smaller wheels in general?

I never heard about the practice to take the edge of the tyre pressure, but that may be my failure 😉
anyway my tyres have a pressure loss over time… here is a comparison of air retention:
http://www.schwalbe.com/en/schlauch.html
in 14 days you may lose about 10 psi.

[Alexander Johnston]

Hi Werner
If you click Dr Alex Moulton above and play the video you will see Alex talking about the development of the Moulton bicycle and the emergence of the “definitive form” (the F frame) which among other things had high pressure tyres (07.25 minutes).
Of course what was meant by high pressure then may not be what would be meant by high pressure today.
“in 14 days you may lose about 10 psi”.
I’ve noticed that as well. I give my tyres a few extra pumps before riding if I haven’t ridden the bike for a week or so.
Have you any idea where the 10 psi goes?
Does it leak through the valve or mysteriously disappear through the tube and tyre?
Or does air under high pressure naturally return to “normal” due to some law of physics?

[Author]

Posts