Wednesday, March 09, 2005

I love steel frames

So I bought the hub and started looking on e-bay for a frame. I wanted a used steel frame. I don’t like aluminum frames because they’re too stiff. Steel gives, and riding a steel bike is comfortable. Steel bikes are also prettier. Steel bikes also last longer.

I'm all for choice in bikes. I respect the bike you want to ride. But I don't think anybody really wants to ride an aluminum bike. Yet most people do. I also don't think anybody should ride a bike with a chain guard. Or Fenders. Those are my rules. Everything else is up to you. (but I should point out that my main bike doesn't have a chain guard. Shame on me.)

But aluminum frames are all the rage (at least in America). Bike manufactures are happy to make aluminum because they sell and they can be made with robots welding. Steel is thinner and a good steel frame still needs a caring professional to put it together. A good new frame, such as they sell at Rivendell (if you like bikes, subscribe to their Reader--Each issue is a classic) costs $1,000 to $2,000.

So I wanted a steel frame with a horizontal drop out (vertical drop outs need a derailleur) and eyelets for a rear rack. The size had to be no bigger than 55cm (measuring the seat post tube from the center of the bottom bracket to the center of the top tube). Zora’s current frame is 55.5cm. My bike is 54cm.

On the new frame, a headset is also a plus, because installing a headset requires a special tool I don’t have.

And the frame has to have drop-out at least 130mm apart (O.L.D. measurement). Many older frames are smaller. Here's the thing about bikes: there are lost of measurements. And there is no single standard. Italians use one system. French another. British a third. And this is just for road bikes. But there is some general US/Continental/Japanese agreement. The rear drop outs are where the wheel goes. The hub I'm going to use has a length of 132. No old frame uses this. But steel can be bent ("cold set" is the proper term) to the new size. This is all stuff I'm learning.

I am also thinking that I will build 26" wheels. Why 26" wheels? Most wheels are 27". Well, there’s a small but dedicated following to a special size of 26" wheels. Here's one. I love the section titled, "Why would someone devote a website to an obscure tire size?" I don't know the answer, but I'm glad he did. And I learned that 650B wheels are still the standard in Sweden. So there. And another, a group in France. It’s also a size used in France. I feel so international.

You see, all 26" wheels are not the same size. Sheldon Brown tells us there are, count 'em, six different sizes of 26-inch wheels. Wheel sizes are really screwed up. In the old days, wheels were measured by the outside diameter of the tire. This is what the inch size refers to.

Of course then there's metric. In general, and only approximately, 27" = 700mm = road bike; 26" = mountain bike. These approximation are fine when you're buying a tube, which can stretch. But these approximations do matter when you're buying a tire, because it has to fit exactly.

The only real way (and the only way to match a tire with a wheel) is to use the ISO measurement. ISO stands for International Organization for Standardization. Guess what they do? Yep. ISO is the diameter of the bead (inner part of the tire, where rubber hits metal). It is in millimeters. Tubes are not sold in ISO. But tires have the ISO printed on them.

So these wheels, known as 650B, have an ISO of 584mm. They are smaller than road wheel (630mm) and bigger than a mountain bike wheel (559mm). Why not just use a mountain bike wheel? Cause I like to be different. No, that might be true, but it's not why. I don't want a small wheel, I just want fender clearance. A road frame with standard road wheels doesn’t have clearance between the wheel and the brakes. These will. And what the hell, if I'm building a custom bike, I minus-well make it special. And 650B wheels can also hold narrow tires, which is good for any bike that isn't riding off-road.

Why not just buy a bike? Well, for starters, there is no steel bike with the Shimano internal-shifting hub. And I want fenders. And I want a chain guard. And these things aren't standard. And it’s surprisingly impossible to just slap such things on a bike that isn’t made to take them. And new bikes are thief magnets. And by building a bike, I'll know the bike inside and out. Not only do I learn, but it will be easier to fix when something goes wrong. And because I'm building a good bike, things will rarely go wrong.

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