Clincher rim

[mrcpea]

Acquired a Raleigh Sirocco for a good price form the Bay. It all works, but am going to rebuild the wheels.
The rims are nothing special, but have a nice concave profile that I like, and the braking surface is hardily worn at all.

The inside if the rim wall is dead straight, with nothing to hold the tyre bead in, so was wondering if these would be really suitable to use at high pressure? Not seen this before on alloy rims.
Anyone have any advice?

Cheers,

Richard

 

[Midlife]

Looks like a Weinmann concave for HP tyres not more modern clinchers. Does it have 27 x 1/4 stamped on it?

Shaun

 

[Martin Rattler]

Re:

I have got a couple of pairs of these and they are fine in normal use although I limit the tyre pressures to about 70 psi. I had a front blow out on my RO Harrison earlier in the year when running at 100 psi; judging by the smear of rubber on the inside of the fork, the inner tube squeezed itself out and popped. I didn't have any further problems once I reduced the pressures.

 

[mrcpea]

Looks like a Weinmann concave for HP tyres not more modern clinchers. Does it have 27 x 1/4 stamped on it?

Shaun

Hi Shaun,

It's a 700c, and your right it's a weinmann.

 

[mrcpea]

Re: Re:

I have got a couple of pairs of these and they are fine in normal use although I limit the tyre pressures to about 70 psi. I had a front blow out on my RO Harrison earlier in the year when running at 100 psi; judging by the smear of rubber on the inside of the fork, the inner tube squeezed itself out and popped. I didn't have any further problems once I reduced the pressures.

Many thanks Martin, great advice

 

[torqueless]

Re:

IME it might be advisable to keep the spoke-tension down as well if you are rebuilding these- I watched a rear one I had just built pretzelise itself spontaneously. I guess I was incredibly lucky to a) witness it, and b) not be riding it when it happened. It straightened out again without any coercion whatsoever when I released the spoke tension. That was the narrow (20mm?) version of this rim, and they were probably quite worn as well. Yours might be a bit sturdier.

So I'm prejudiced to view this rim-design with suspicion. I can't imagine something like that happening with a box-section rim, even with wheelbuilding skills as primitive as mine..

 

[stefthehat]

Re: concave rims

All previous comments very valid rode these back in the day,rim had no eyelets hence spoke tension could allow nipples to pull through and rim bed shallow hence tyres could pop off,in all my recent retro builds ive put time and money into the wheel builds and paid off in reliability and ride quality Weinmanns were etc were to hit a pricepoint over the obv much better Mavic,ambrosio's and Wolbers of the day

 

[Midlife]

Those rims look like they have eyelets?

Shaun

 

[stefthehat]

Re: concave rims

Sorry just looked at photos,but comments still hold, the concave bit obv was meant for stiffness but compared to Mavics etc seemed in use a softer alloy, def a softer rim,kept getting them trued up but was a continual job, going back to tyre pressures all good modern tyres are meant for fairly high pressures so you owe it to yourself to go for good wheels, ive been v v surprised recently buying for my students retro projects how cheap and good quality wheels have been on the bay under the various sections

 

[stefthehat]

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