Tyre / rim problems :(

[fiveSixteenths]

Evening all
Tyre popping off the rim question here
Happened twice now
First time I thought it was the cheapo tyre, so binned that and changed to Schwalbe ones, new tube, new rim tape
Happened again, tube and tyre seem fine
No apparent distortion to the rim wall, clincher edge seems uniform around the inner wall
Rims are Weinmann 27x1 1/4, probably 1970’s-era, tyres at a modest 55/60psi
Have been tipped the max pressure might only be 45psi as maybe they not ‘high pressure’ rims?
Any thoughts welcome

 

[bikeworkshop]

Are the rims "hook beaded"?
There will be a bead all the way round the rim - see pic right:

If its an unbeaded rim, it's harder to get a stable fit, especially at lower pressure.
Modern tubed tyres, especially for 27x 1 1/4 aren't designed for hookless rims.

Sometimes you get a loose fit on a beaded rim - but schwalbes are usually quite tight.

All I can suggest is manipulating the tyre at low pressure to be nice and even around the rim, and keep an eye on it as you inflate it bit by bit.

 

[jim haseltine]

We used to run Weinmanns much higher than that, more like 70-80psi. Tyres were the thing though, Michelin and Barums were great, gum wall Hutchinson were awful and would pop off just about any rim at really low pressures. I don't know how modern folding bead tyres would work on Weinmanns.

 

[fiveSixteenths]

Are the rims "hook beaded"?
There will be a bead all the way round the rim - see pic right:
View attachment 873557
If its an unbeaded rim, it's harder to get a stable fit, especially at lower pressure.
Modern tubed tyres, especially for 27x 1 1/4 aren't designed for hookless rims.

Sometimes you get a loose fit on a beaded rim - but schwalbes are usually quite tight.

All I can suggest is manipulating the tyre at low pressure to be nice and even around the rim, and keep an eye on it as you inflate it bit by bit.

Will go into the garage in a bit to check but I think they’re hookless
So I think I might end up getting a pair of better rims and rebuild the lovely early Record hubs onto something that won’t die when I’m miles from home

 

[fiveSixteenths]

We used to run Weinmanns much higher than that, more like 70-80psi. Tyres were the thing though, Michelin and Barums were great, gum wall Hutchinson were awful and would pop off just about any rim at really low pressures. I don't know how modern folding bead tyres would work on Weinmanns.

The Schwable’s are gum walls
Might try bunging on another tyre type, hitting it up to 80psi and seeing if it’ll go bang lol

 

[fiveSixteenths]

Are the rims "hook beaded"?
There will be a bead all the way round the rim - see pic right:
View attachment 873557
If its an unbeaded rim, it's harder to get a stable fit, especially at lower pressure.
Modern tubed tyres, especially for 27x 1 1/4 aren't designed for hookless rims.

Sometimes you get a loose fit on a beaded rim - but schwalbes are usually quite tight.

All I can suggest is manipulating the tyre at low pressure to be nice and even around the rim, and keep an eye on it as you inflate it bit by bit.

Yep, hook-free

 

[fiveSixteenths]

And thanks very much both : )

 

[Takingabreak]

michelin world tour tyres?

 

[fiveSixteenths]

michelin world tour tyres?

Ah, will look those up now

 

[bikeworkshop]

Probably helps if the rims and tyres are clean and dry, and maybe rub the inside of the rims with some wet&dry if they look a bit polished.
You could even paint something on there to increase adhesion.

I don't think anyone's made a tyre specifically to fit a 630 hookless rim since the 70s