700c rim width measurement

I have a few 1970's Schwinn Continentals (one motorized) and lots of parts. I want to change the rear wheel to 700c. The old steel 27 x 1 1/4 wheels would be great, but:

* The rim tolerances suck; very hard to get them really true, especially vertically (radially?). They all seem to have pretty "lumpy" weld seams

* The tire beads don't sit in the rim properly because there's no lip on the rim flange like on modern rims

* Tire availability is low and getting worse. The only width I can ever find is 1 1/4 (they should be able to easily hold a wider tire) and the tread is too thin on the tires I find.

If they did make fatter tires, the clearance between the chain stays is so tight that I would have to modify my dropouts, but the other issues would still exist.

So...

I want to go to 700c on the rear. I've been to the Sheldon Brown (RIP) site to learn about tire/rim sizing methods. My "27 inch" rims are 630mm bead seat diameter. 700c rims are 622mm. So the slightly smaller diameter will work out just right for fitting a slightly fatter tire in my tight frame. My rims don't have any width markings, but they measure about 29mm wide. I also have a Univega with very skinny 700c rims that measure 22mm wide (no markings) with tires marked 622 x 28. My 27 x 1 1/4 (Schwinn) tires are labeled on the side 630 x 32. I would like thicker tires, maybe about 38.

But here's the real question, how are rim widths determined? My Univega rims are way too narrow for the size tire I would like to use. There must be a variety of options, but looking online, most wheels don't show a rim width specification. I called my local bike shop and they didn't have an answer either. He said he could order me a wheel (for "about 70 dollars") and "it should work". He did mention "road bike" as opposed to "hybrid".
So what's the deal? I know people here will give me a better answer than the LBS pros. If I order something online I want it to be correct. The ideal tire will have a thick but smooth tread (for my homemade friction drive - no nobbies), and will be about 38mm wide (1 1/2) maybe a bit wider.
And suggestions for online wheel/tire suppliers would be greatly appreciated. I've only ordered from Niagaracycle and Nashbar so far.

Thanks dudes.

PS, the "spring" weather here is killing me.

Zero replies. Thanks for the help.

I researched as best I could and bought a wheel online. When I opened the box, the rim was so narrow I couldn't believe it. Well, I can try a tire on it and see how it looks. First, let me put rim tape on... Whoa!! I want to line up the valve stem hole, but the hole is about just big enough to stick a golf tee into. I know nobody cares. Typing this is only going to be good for finger exercise.

Thanks for the responses, guys.

I knew there were Schrader and Presta valves. Probably more than 95% of bikes have Schraders, so why would a bike site sell a wheel with a presta hole without specifiying that?
My real gripe is the fact that so few wheels tell you the rim width. When I received the wheel, I saw a sticker on it that showed the ETRTO measurement of 622 x 14. That's 14 mm between the flanges that hold the tires bead. That's the rim width measurement I would have liked to have known about, but it's never specified in the ads.
If you look at the Niagaracycle site, they have the wheels in catagories of 700x20, 700x25, 700x35. What does the 20, 25, 35, mean? Mine was in the 700x25 catagory.
Tires have widths clearly labeled, but wheels are sold like they are trying to keep the specs a secret.

700c size basically means 622mm bead seat diameter, and is not just for road bikes. It includes things they call 29er, hybrid, cyclo-cross, touring, and whatever other retarded thing you can think of.
Since the wheel diameters are all 622, why can't they just give the rim width?

I definitely tried to research before ordering. Lots of Googling, Sheldon Brown, Wikipedia, Motorbicycling.com, Local bike shop, etc..

Thanks Whitmire for the jensonusa link. I got a little catalog/flyer from them before and they seemed to be quite pricey. I'm a cheepo!

I normally would not reply to anyone acting like this but I understand your frustration.

Click to expand...

I hope my mildly flippant post didn't provoke too much offence in sensitive forum members. Respect and forum etiquitte is important.

But, rim width measurement. That's what the thread is all about.

Whitmire's link is a perfect example. I've attached a screen cap of the ad:

They give info about the spokes, hub spacing, valve hole, rim depth...
But no rim width. They refer to the wheel with the terms city cruiser, commuter, hybrid, and in the specs it says wheel type: road.

"Road" generally means very skinny tires. "Hybrid" is getting closer to a mountain bike width, like 2 inch or so. This illustrates my point of the ridiculous naming convention with "non - 26 inch" wheels.

If you ordered that wheel from jensonusa, how narrow would the rim be?

There really should be more descriptive specifications. That's the whole point I'm trying to make.

Thanks for the replies.

It is truly frustrating when you can't find details in the ad or see the item in person.

I called customer service and brought up my issues with the wheel/ad.
What's the 700x25 mean?
"That's the ISO size."
But the rim is labled 700c 18/23. And the ETRTO meas. is 700x14. What does the 25 in the ad mean?
"I don't know."

At least I got customer service to say they don't know.
Then when I told them about the presta valve hole, they agreed to pay for me to ship it back. So I won't be out any money. But the return process is a pain. Email this and that. Download and print this and that.
When it's all over, I'll still need a wheel, but the learning experience is priceless, ain't it?

I still contend that 700c isn't necessarily a very skinny size. The rim I got sure was, but I've seen bikes with fairly wide tires and proportional rims. Dick's Sports had quite a few bikes with decently wide "hybrid" tires/wheels. (I wish they sold the wheels alone). Even Walmart had one or two 700c cheapo bikes.

Does everyone here pretty much use 26-inch?