Originally Posted by tashi

On setback posts: Ideally, the front of your kneecap should be directly above the pedal axle when your foot is foreward in the 3 'o clock position. Where your kneecap winds up is related to cleap position (if applicable), crankarm length, seat tube angle, seatpost layback, and fore-aft saddle position (on the rails). It's quite likely that if the bike is a little small for you that your knee is a little too foreward of where it should be, so you can go with a layback (or setback) post and you'll get better pedaling geometry and gain reach at the same time.

I would suggest prioritizing getting your pedaling geometry right first, and then the reach. Your comfort will be compromised by the wrong reach, but with the wrong fit for your legs you not only can be uncomfortable but compromise your speed and leave you at risk for injury as well.

Your clothes are your deal, but clipless pedals will allow for proper foot positioning and a helmet will help you avoid serious head injury. If you're riding alot the risk of this is real, so my recommendation is to sacrifice style for safety. A head injury is NOTHING like breaking a bone.