So your after a nice retro bike, you know you want one.
…but it is truly a minefield if you don’t know what your looking for. Not only does quality vary massively but also bikes over 20 years+ often have a dubious and unknown history. With a few pointers from this guide you should be able to find yourself a nice frame.
This week I’m going to cover the differences between modern frames and frames of 20+ years old.
The first thing to remember when buying any old frame is that although bikes essentially look the same, things have changed quite a bit in the last 20 years. If your planning on fitting period equipment, then its no big deal. On the other hand if your wanting a retro bike with modern equipment then you need to be careful what frames you look at.
The first thing to bear in mind is what wheels the frame was originally built for. Depending on the age and the purpose of the frame it may have been built for 27 x 1 1/4 wheels. Unlike the 700c wheel that your probably used to on your modern bike, 27″ wheels are basically an obsolete size. 27″ rims are also slightly bigger diameter than 700c rims which means it will be hard to find modern brakes which are deep enough. Finding a frame that was made for 700c wheels doesn’t always get you out of trouble either.
The best rule of thumb is to measure from the brake mounting hole to the center of the axle, and it should be around 365mm or less. The forks are most important, because if the measurement on the forks is too high then there is nothing you can do really and you will struggle to get brakes that are deep enough to work.
Frames have been built with diferent axle spacings over the years to fit anything from track hubs, to 5 speed screw on hubs and right up to current 10 and 11 speed hubs. Modern road wheels need 130mm between the rear dropouts. If the frame has anything less than 130, it will need to be opened up if you intend fitting a modern wheel.
Another little, often forgotten detail is fork column length. Generally if your talking about older frames, they will have been designed for a threaded headset and quill stem. Now, all headsets are not the same. The amount of space the headset needs above and below the head tube is called stack. Modern headsets tend to need more than older ones, so you can end up with a for column that isn’t long enough to fit a modern headset. Again it’s not the end of the world but having a new fork column fitted is another cost to add to your build.
Aside from the wheel size problems that I mentioned earlier, modern caliper brakes all fit with a hidden allen key nut, where as older brakes fitted with a normal nut. Now it doesn’t sound like much of difference but the frames brake bridge and fork crown are slightly different.
Courtesy of Paul Gibson @ vintagelightweights.southcraven.co.uk