Originally Posted by
Niteshooter
Yes, sorry to necro an old post as I was looking at the comments about 750 and 610's. I have just such a setup on my old CCM frame which originally had 27" wheels but was swapped to 700c. Granted I switched things around and have the 610 in back and the 750 up front.
The reason that many companies positioned rear brake bridges to require longer calipers was to reduce wheel lockup with inexperienced riders who typically applied equal pressure to both levers. Under normal braking the rear wheel becomes unweighted, increasing its tendency to skid. Longer brake arms flex more, reducing this tendency. Most modern brakes are designed with equal length arms, but the rear calipers are often designed with thinner arm sections, to make them flex more.