I've gone back and forth between Vs and discs, changing fork/brake/cable/housing/wheel.
Didn't really notice it much after 10 minutes of riding. A proper disc fork is made from larger diameter tubing and/or thicker wall tubing, and is stiffer and heavier. I have a Kona P2 disc fork, and it seems too flexy to me - they did not use a larger tubing. Makes me wonder if it might prematurely fail near the steerer weld due to all that flexing. I've seen some awful injuries from faceplants, so this worries me some.
I have a nashbar/aprebic carbon mtb fork - it's actually stiffer than the Kona steel.
Also have a dimension/qbp/surly-ish x-cross disc fork. Stiffest and heaviest of all my disc forks.
Actually my favorite is a $38 tange steel fork - v or canti brake only. I have a couple of these.
To me, big problem has always been finding disc fork in the right a-t-c distance range. I want 385-395mm, but most are 420-450mm.
Went back to V brakes, did notice the loss of a pound or so when lifting bike to/from workstand. Good V brakes work just as good as disc in dry weather, and are quieter. I could never get my avid mechs to brake as quietly as my avid sd 7s - they always made a scrubbing noise, front or rear.
If I were riding in dirty conditions a lot, then I'd stick to disc brake to avoid rim wear.
You should go ahead and try it yourself. Get it out of the way. I think you'll find it doesn't matter that much. But you'll be wondering until you do it.
btw i'm running 26x1.35-1.75" tires - usually ritchey tom slicks or kenda kwest in low and hi pressure versions, if it matters.
Last edited by seeker333; 02-26-09 at 11:35 PM.