Originally Posted by
Paramount1973
Not that Steve PGN10 was suggesting converting a 700c bike to 26" but just to run some numbers, the conversion of a 700c bike to 650b involves a 19mm drop, (622-584)/2. That is doable with long reach caliper brakes or perhaps a brake bridge, a la Sheldon Brown. Conversion of a 700c to 26" involves a 31.5mm drop. Add 4mm for a 27" wheel to a 26" wheel - 35.5mm, (630-559)/2. Even if you found a caliper brake with a reach like that, you would be at a mechanical disadvantage compared to a shorter reach brake. This leaves you with a fugly brake bridge or disk brakes (or a coaster brake).
Thanks for running the numbers. When I posted I was confused about the actual size differences.
Originally Posted by
Paramount1973
So, it would be a lot easier to just take a 26" bike and run 650b type tires on it. Conversion to a drop bar tourer is just a matter of finding the right frame and using drop handlebars, etc.,
whole thread on it here. The only problem with converting a mountain bike to a 650b-like tourer is the beefier and heavier frames on many vintage MTB bikes. With the
right tires, though, this looks to me like an option versus a 650b bike.
My deeper dive into learning about 650B conversions started when I was trying to get a MTB ready for a backup commuter for the winter. I had bought some Zefal fenders last year that gave unsatisfactory results when used with 26x2.1 tires. This got me to thinking about using some narrower slicks, and a google search of 26x1.75 (picked at random for a width) turned up the Compass tires that are being made on the same molds as the Paselas. What with superstorm Sandy bearing down on us, and a lot of hours at home, I spent those hours reading about 650B. Looking at the 26x1.75 Paselas, it was hard for me to wrap my mind around conversions when it seemed dead simple to use a tire like the Paselas on a MTB and get the goodness of balloon tires. This does not take into consideration those who prefer a road bike with balloon tires, but I don't know what that buys you in comparison with a MTB with balloon tires. I would find it interesting to hear from someone who has run 26" balloon tires on a MTB, 650B on a MTB, and 650B on a road bike and can give objective comparisons between them.
For the record, I'm going with the Paselas.