Boston Trevor said it well.. USE A FRONT BRAKE! I don't like using them but when your knees start to go..they GO!
get a fork with a drilled hole and use a front brake.
S/F,
CEYA!
Originally Posted by bostontrevor
It also just sort of depends on how you ride. You may be pushing a low gear, but if you always skid, skid, or rapidly decel, that can be rough on your knees. On the other hand, you may be pushing a 100" but if you gradually work up to speed and never have to climb, that can be completely benign.
Me, I run 47/16 and 42/16. I have a front brake and I don't mind using it, so the higher gear is really worse for me (there's one particular spot in my commute where I really hammer it and I know it's bad for me, I can feel the knee strain). YMMV.