Originally Posted by
sam_cyclist
I test rode a road bike with mechanical discs a few weeks ago. The brakes literally would not stop at all. I grabbed both levers and squeezed them as hard as I could just to slow the bike down. They were incredibly weak stoppers. I WALKED the bike back to the shop.
The employee gave me some lame excuse about the brakes not having been broken in. I feel sorry for anyone who bought that bike.
In all likelihood, that was the actual reason the brakes were so ineffective when you rode the bike. Disc brakes do need to be broken in before they work properly. A series of several hard applications of the brakes allows the pad material to integrate with the disc surface, making the brakes work properly and avoiding squeal. It was a lame excuse in the sense that the shop should have done the break-in process before putting the bike in the showroom, but not in the sense that it wasn't true.
I have done this process on dozens of bikes I built up and sometimes the difference between the first braking and the tenth braking is incredible.