tcs

An intermediate size between 700C and mountain bike 26" makes a lot of sense from a frame geometry standpoint in the real world. Now, the traditional sizes of 650A and 650B are in fact just a few millimeters different - close enough that it's almost impossible to design a bike that couldn't use either, but just far enough apart that each requires their own unique bead seat diameter rims.

Like Mr. Kogswell alluded to above, the point of the recent 650B movement was the fact that it was so obscure. You pay for molds to build 650B tires, you "reintroduce" and promote the size and - voila - you are one of the very few sources of tires the owners must have. This is eactly what Rivendell and Bicycle Quarterly have both done, and what some other builders are now doing with the 650B mountain bike knobbies.

From a marketing standpoint, one could write just as much gilded prose about the grand popular cycling in England on 650As as has been written about the elite cycling in France on 650Bs. But there is no genius behind promoting the readily available 650A - any little botique shop (or Nashbar!) could import some of the many tires in current production in that size with no more effort than adding another line on their next invoice. Shoot, your customers could even go down to Walmart and buy a serviceable 650A.

Now, the dirty little secret of 650B: 650A is a very common tire size for wheelchairs. If the promoters of a modern implimentation of an intermediate bicycle wheel size had gotten behind 650A instead, wheelchair users could have benefited from a greater selection of good tires and lower prices. Post snippy little personal attacks if you want, but I'm sorry that benefitting the larger society wasn't important to the able bodied, highly mobile bike folks that made the 650B decision.

Best,
tcs