PVD 650B
Contents
650B
A standard 26x2.2" wheel has a diameter of approximately 670mm. A 650B wheel with on of Pacenti's tires has a diameter of approximately 702mm. A 4.7% increase in diameter. A 29x2.2 wheel diameter is about 736mm, a 9.8% increase in diameter. 29" wheels are really to big for all around riding, the 650B may be an improvement. Only testing can say.
2x9 or 3x9
I like 2x9 gearing. It works well enough for all around riding, but makes me hit the pedals a little harder and more efficiently in general.
One real key to doing a nice 2x9 configuraion is by using a 130mm rear hub. Disc versions of these hubs are just starting to become available.
On a 26" bike, I've tended to run a 2x9 with 39-26 up front and an 11-32 cassette in the rear. This translates to a range of developement between 294.1 and 67.4 inches.
On a 650B bike, this gearing would be corrected to 36-24 up front with the same 11-32 cassette. The development range here would be 284.2 and 65.1 inches, a little wider which may be better and better front shifting. If 284.2 is too low, a 38 tooth ring could be used to increase maximum development to 299.9 inches.
Now the problem is chainrings. 104mm 4 bolt is the most popular choice for MTB.
