Originally Posted by
QuietPaul
The shop is now saying they can’t fix it, and either the brakes need to bed in a bit more (I have ridden about 100 to 150 miles so find that a bit hard to believe), or even that it’s a characteristic of the bike, and they have suggested I should swap it for a different bike, which seems crazy to me.
Bedding brakes isn't hard, but it's unlikely to happen just riding around (unless you have steep hills). Before starting, clean the rotor with isopropanol.
Simple procedure I use:
1) Ride for ~60s, modest effort (100-150W), while dragging the brake to keep speed <10 mph. This gets some initial heat in the rotor.
2) Quickly accelerate to 15+ mph. Hard brake to near stop. (Repeat 3x)
This is where the bedding really happens. The brakes get nice and hot and firmly bed in.
At that point, just ride around normally, making a few modest effort stops to evaluate things.