Clincher rim

[bm0p700f]

I have not been able to inflate tyre beyond 50 psi safely on hookless rims. You can see the tyre moving up ready to blowout at 60 psi. Great if you want to use a wide 35mm tyre hopleless for a 23/25mm tyre.

Stiffness of the rim is more related to its shaped than the type of aluminium used. That is a shallow rim with both walls very close together hense the short eyelets. All such clincher rims are not very stiff and bensift from a thick spoke. I would use sapim strong single butted 2.3/2.0mm spokes and that would make a stable wheel.

 

[stefthehat]

Re: concave rims

Agree about shape ultimately controlling structural integrity, just more of a comment on memories of them being a softer alloy,your Psi problems make me wonder if they arnt original wheels and more of a concave for 'roadsters',Scirroco originally had pretty narrow 'racing' tyres, I know you like shape of rims but seems a waste of lovely Sapims, sorry

 

[Cefnbikie]

Back in the 1960s and 70s I used a variety of both steel and aluminium alloy 27 x 1 1/4 rims, and none had the modern bead retainer. I used mainly Dunlop Road Racing tyres, and later Michelin Sports, pumped up as hard as I could get them with a hand pump, and I did not have any trouble with the tyre lifting off the rim. Next year I shall be rebuilding some 27 x 1 1/4 wheels from parts in my loft for my RO Harrison rebuild, but I will be much more cautious, and only inflate to 60 - 65psi.

 

[t47b]

Re:

I have a pair of hookless rim weinmann 700c rims dated late 60's ( you can have them for free to practice on if you like)

I think you will need lower pressure rated tyres rather than rely on lowering the pressure of higher pressure tyres to be safe.

 

[Cefnbikie]

I have a pair of hookless rim weinmann 700c rims dated late 60's ( you can have them for free to practice on if you like)

I think you will need lower pressure rated tyres rather than rely on lowering the pressure of higher pressure tyres to be safe.

Many thanks for the offer. My RO Harrison, however, was built for 27 inch wheels, plus mudguard clearance. The 27 inch wheels are slightly larger diameter than 700c, so I would like to use the 27 x 1 1/4 wheels that I have. I used 700c sprints with the ROH back in the 60s, which performed very well, but didn’t look correct. Thanks for your suggestion on tyres. When I use my 27 inch wheels I will probably use tyres similar to the Schwalbe 159, which has a recommended pressure range of between 50 and 85psi, rather than using, and under-inflating, a tyre like the Continental Gatoskin (120psi max pressure)

 

[BobToo]

What is different about tyres that are meant for hookless rims?

 

[t47b]

Re:

What is different about tyres that are meant for hookless rims?

Tyres have to be the wired variety and suitable for max inflation below 60psi I don't think that tyre beads have changed only rims.

 

[mrcpea]

Many thanks for all your input.
The tyres I removed were shot to bits, and VERY narrow (3/4")
I'm not sure if the tyres removed were original or not.
Don't I will use the rims as I want a higher pressure.
I may yet clean them up a bit and give them away free to someone on here if they can collect from Ely, UK.
I think they're a lovely looking rim.
Any takers?

 

[mrcpea]

Re: concave rims

Also can't see for def from photo and my memory not good as casting it back 25yrs ago,i think it's not box section rim just the bed with that eyelet,but yes pretty rims also from memory Sirroco I think might of had nice frame but forks normal steel so ride quality might benifit from a cheap upgrade in future

Steve,
Frame is reynolds 501, not sure on fork material.

 

[t47b]

Re:

I may yet clean them up a bit and give them away free to someone on here if they can collect from Ely, UK.
I think they're a lovely looking rim.
Any takers?

Oi! Stop trying to muscle in on my free rims market, I asked first