Alternative to Andra 30 rims

[Andyb1]

‘Perhaps when you decide to retire the Rudge wheels, you could pressurize fat tyres on them progressively until they split the rims and let us know.’

The bike has Araya rims, about 15mm or 17mm id I would guess, and stamped on them is 26 x 1.50 as the tyre size to use.   The old 1.50 tyres have a MAX pressure rating of 40psi - incredibly low compared with a modern tyre of that size - and it makes me wonder how much pressure the rims were designed for.  Particularly after reading Martinf’s post.   I have a pair of little used 1.50 Marathon plus tyres on their way to me which have a minimum pressure of 55psi so might not have been the best choice!

[mickeg]

...
I did once destroy a new rim by inflating a 50 mm wide tyre to about 80 PSI. My idea was to use overpressure to properly seat the tyre beads on the rim. Doing that also destroyed the inner tube, but the tyre survived. ...

Thorn recommendations for maximum pressure in a rim have changed over time.  Last time I saw some numbers, I thought that the recommendations were a bit too conservative, but rims can be weaker than tires, especially if the rim has had brake wear and if the rims are corroded.

I wish all rims came with labels on them with that data.  My (now twenty plus years old) Mavic A719 rims did, photo attached.

I think I have put up to 60 psi in a 50mm tire, but not more than that.  I might have put 80 psi into a 40mm wide tire on the rear wheel of a touring bike with a heavy load, that was a really solid rim that was designed for touring, the now discontinued Salsa Gordo rim that I have on my Sherpa.

I think I have put 50 psi into a 57mm wide rear tire with a heavy load, that would have been the Andra 30.

I did a quick google search, found this:
https://thorncyclesforum.co.uk/index.php?topic=13100.0

And I posted this a decade ago:
https://thorncyclesforum.co.uk/index.php?topic=11833.0

[Andre Jute]

ERTRO and Schwalbe are in effect saying, If you choose rims that are narrower than 40 percent of the width of your tyres, you'll have to inflate to a higher pressure to keep your tyres on the rims, which could lead to a catastrophic failure of the rim.

I did once destroy a new rim by inflating a 50 mm wide tyre to about 80 PSI. My idea was to use overpressure to properly seat the tyre beads on the rim. Doing that also destroyed the inner tube, but the tyre survived.

QED.

If it is necessary, I now use Schwalbe seating liquid (or washing-up liquid) to seat tyres properly on the rim.

I wish I had that advice when I fitted Schwalbe Marathon Plus tyres.