That doesn’t prove what you think it proves. The lady in my life is 1.52 m tall. Her bikes are a Specialized Vita that is a 36x39 (seat tube X top tube) and a Terry Symmetry that is 40x50. 5cm of top tube length is a lot of top tube length. Look at your Alan chart. 5 cm of top tube length is the difference between a 48cm bike and a 60 or, on that chart, 12 sizes larger or 10cm larger. I ride a 58cm bike and wouldn’t want to ride a bike that had a top tube for a 68cm bike.

There’s also the problem of the 50cm seat tube. Would you ride a bike that had that radically sloping top tube…sloping top tubes aren’t new, by the way…with a seat post that is from 10cm to 14 cm taller than it needs to be? For my example, that would have a seat tube that is 68 to 72 cm long. It would look just as wrong as that bike looks.

We’ve gone through a dozen or more bikes over the last 40 years trying to find an off-the-shelf bike (couldn’t afford custom) that fit her. I can walk into any shop in the world, point to a bike in my size and walk out with it without riding while knowing that it will fit and have been able to do that for all of the 40 years I’ve been riding. My wife cannot. We have had to hunt far and wide and make many modifications to get bikes that finally fit.

DSCN1059 by Stuart Black, on Flickr



The lady actually enjoys riding both of these because the front end is actually in her current zip code rather than in the next county over.