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My 2010 aluminum frame may be toast (stripped bottom bracket) and I was considering getting an older chro-mo frame and transferring the components to it. It's a racing/sport style with drop bars and 24 speeds. I'm an beginner/hobbyist bike mechanic, I have the basic tools and can take a bike apart and put it back together (given enough time ;)).

If I remember correctly some time in the past road wheels were commonly 27". When did they switch to 700mm being the common size?

(I ride for leisure and exercise about 50 miles/week.)

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I think the switch from 27" to 700C happened about 1990. – Daniel R Hicks Nov 5 '12 at 4:10
One thing to keep in mind is that manufacturers "turn over" bike design roughly every 15 years. Yes, some of it is "improvement", but much is simply to create incompatibility and force you to buy a new bike when you can't get parts for the old one. – Daniel R Hicks Nov 5 '12 at 12:16
up vote 6 down vote accepted

It is possible to make the switch, but there are a few components that probably won't be an even swap. This will depend on the vintage of the frame you're planning on using (and it really should be steel as aluminum doesn't age gracefully). Since I have a steel 1992 Bridgestone RB-T, I'll use it as an example.

The headset on your bike is most certainly 1 1/8" threadless, while the headset on an older bike will be 1" threaded. You will have to use a threaded fork and a quill stem. You may find it tricky to locate a quill stem to fit your handlebars if they have a larger clamp diameter (older bikes commonly use 25.4mm and 26.0mm bars).

Wheel size won't be an issue. 27" wheels have an ISO diameter of 630mm while 700c wheels have an ISO diameter of 622mm (4mm smaller at the rim). You'll want to make sure that your brake calipers reach the rim squarely, but that will depend on the frame. It really shouldn't be an issue unless you decide to run 650b wheels (which have many virtues).

A bigger problem may be fitting your rear wheel in the frame. Presumably your rear hub as an O.L.D. of 130mm (i.e. 130mm wide). Most older frames (such as mine) have 126mm dropout spacing to accomodate 6 or 7 speed freewheels. There are resources on re-spacing your dropouts by bending the stays (this is only possible on steel frame bikes.) Alternatively, you could buy a freewheel rear wheel, but then you'd have to futz with your indexed drivetrain and that's no fun.

You'll want to make sure that you use the bottom bracket length specified for your crankset which may require removing the old bb components from your new(old) frame. With the right tools it shouldn't be difficult.

Those few things will be your bigger obstacles. There may be one or two other small things, but they'll be easy to work around. If you're serious about this, also consider that there are a great many steel frames from the 80s that are worth the effort.

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Keep in mind that the seat tube may be a different diameter, meaning the front derailer won't fit without shimming. – Daniel R Hicks Nov 5 '12 at 4:36
Appreciate the answers but project aborted. I had a line on a Serotta frame that was just my size at a good price. Turns out it was an aluminum frame, and although is has the Serotta Colorado name on it it was really made by a non-Serotta factory. Not nearly appealing to me as a steel frame. Thanks anyway! – obelia Nov 6 '12 at 0:24

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