ThermionicScott 

"What? Why??"

I'm interested in getting my hands on one of the more difficult C&V clincher rims so that I can approach tire-mounting discussions with a bit more knowledge and empathy. Plus, I welcome the challenge.

Since this is just for my edification and wouldn't be going on a bike, I'm not looking to spend a lot, maybe a couple bucks plus shipping? An ugly, worn-out rim would actually be preferable, just as long as it's straight and not broken.

Whatcha got? I've heard similar things about some of the older Campy rims, so I'm open to suggestions. Bonus points if you have sworn that it must be a 27" rim.

Thanks!

clubman 

The problem with them, especially the anno'd Super Elite models, is they're good looking and bombproof. Hard to swap tires but also hard to just let go...

Ex Pres 

Ha Ha, I make sure those types go out on bikes I sell so they don't hang around and get used.

Another one I sent packing was the first generation DuraAce paired-spoke wheelset WH-7700. Rolled nice, looked cool (if you're in to that type), but I could not envision having to change a flat out on the road - I could barely do it at home.

Reynolds 

FWIW, I used those rims for years with 38 and 23 tires and never had any problems. A bit tight maybe, but doable with bare hands.

repechage

I was sent a set as protection for an expensive set of rims. So, essentially for free.
I bought a bike with 27" Superchamp Gentleman rims with the spokes too short, swapped over the rims.
Now I had 700c+ rims.
To be fair, with new kevlar bead tires, a pain, Big effort.
Super thin rim strip such as used with tubless helps.
With previously mounted tires, doable. Still an effort- two issues, the interior section is shallow, and the overall diameter dimension is a tad higher than other rims.

steelbikeguy

I'm using mine with some Veloflex Master 23mm tires. Very tight, at least initially.
If you are in central Illinois, swing by and I'll let you mount the tires of your choice on it.

It's kind of a shame that there isn't some easy way to precisely measure the diameter of a rim, especially when it's built up into a wheel.

Steve in Peoria

clubman 

Ahh, but those aren't the same rim. Wider, no eyelets and different profile. I'd like them. Interesting builds !

ThermionicScott 

'preciate it! I'll admit that mine isn't a very practical request.

Didn't/doesn't Ric Hjertberg have tools for that? I seem to recall a special tape measure for rims, and a two-piece wooden rack thing for tires... or am I thinking of someone else?

Or going mad?

repechage

Find one of those school classroom oversized slide rules they used to teach students how to use one with.

steelbikeguy

My first guess is that you'd want to be able to measure at least within 0.5mm to have a chance of quantifying the differences between rims. Heck, you'd need to measure the radius (or diameter) at a number of places around the rim, just to compensate for however out of round it might be.

However.... now that you mention Mr. Hjertberg... that does make me think about how a truing stand could be useful. If nothing else, it might allow measuring the difference between the rims of two built-up wheels (although you'd have to check that the axle diameters were essentially identical, or else compensate for this).

Ultimately, I'd think that you'd want a machinists table/bench and the associated measurement tools to properly quantify a rim's diameter or circumference.
In lieu of that.. I'd like to imagine that you could use a steel tape to measure the rim flange (a.k.a. sidewall) diameter, but I can't imagine a good way of keeping the tape on top of the flange. The accuracy would be pretty marginal too.

Steve in Peoria

steelbikeguy

I didn't see a in that message, so I'm not sure what the intent was. I'm pretty sure there's not a need to multiply or divide.

Steve in Peoria

(although I do find slide rules pretty neat... the San Diego Air and Space Museum has the slide rule that Reginald Mitchell used to design the Supermarine Spitfire....)

Reynolds 

You could make a fixture in the shape of a T with an old axle being the cross bar that measures exactly 311mm center of the axle to tip of vertical bar, put it on the truing stand and measure the distance to the "floor". This distance could be used as a reference for comparing other rims (but would work only with built wheels).

ThermionicScott 

Okay, this is gonna bug me now. What I think I remember seemed pretty well thought-out and accurate. The tire-measuring jig had two large D-shaped wooden blocks with grooves in them for the tire beads -- you'd slip the tire over both of them and then a turnbuckle or something would push them apart, and then you could add (twice) the distance between the two wooden halves to the known arc length of the bead grooves to arrive at the total circumference of the bead. Maybe Damon Rinard did it? I know there was a list of self-measured rims and tires at one time.

Best I can find for rims at the moment is Sheldon's article: https://www.sheldonbrown.com/rim-siz...#circumference The more refined method had a long steel tape with wooden handles on it for ease of use. It was reminiscent of an old-timey tree-cutting saw.

tiger1964 

I'm thinking my wife's measuring tape for sewing would be nowhere accurate enough. But, you would indeed have a better chance at accurately measuring the circumference than the diameter.

RustyJames 

Now that the WTB/ISO/for-sale string has varied wildly about measuring the OD of rims and its factor in tires being difficult to mount....

The talk of elaborate machinists tables, etc. are kind of silly. How about placing the rims side by side on a reasonably flat floor and placing a straight edge over the top? I have a set of those Elite 19s and i'll give that a go next to a current Mavic and report back.

repechage

Think scale, has the depth and length to measure a built wheel. So, only a half wink, from that a meter scale can get you the accurate measure.

squirtdad

I had those rim on a 84 torpado....did not have any problems mounting tires. IME it is specific Rim and Tire combos that are tough

RustyJames 

I just swapped tires from my Ambrosio Elite to a Mavic, tire is a Panaracer Pasela PT 700x25 and it was already mounted on the Ambrosio wheel. Short story - it was a bit trickier working with the Ambrosio but the bead on the tire didn’t make things easy. I agree that the wheel/tire combo is more relevant than just one or the other.

ThermionicScott 

I'd agree with that as well. It's all about the combo, as one engine builder puts it.

nlerner

My most difficult rim experience was when Sun decided to create a 650B/584mm version of the CR18. That was my first foray into 650B magic. The rims were likely 650D/587mm or some such, and I managed to break several valued tire levers in the process of trying to mount Col de la vie tires (about the best you could get at that time). I even tried putting the tires in the dryer to warm them up, talc, WD-40, you name it. The thought of getting a flat out on the road was a nightmare, but somehow those tires, after I eventually mounted them, likely with the use of a VAR tire lever, did stretch out a bit, and the occasions when I had flats were not a problem. As far as I know, Sun never again tried to produce those rims.

marius.suiram 

I have a set of Ambrosio Benelux, 27". I cannot see if any marks on hubs, skewers are Ofmega.
Are these quality wheels?
I put them on a old Gitane Hosteller. I don't want to waste them.