Hi All.

my front pads are wearing slightly unevenly on both calipers.

Both sets are chamfered  towards the rear of the caliper .

ie, the first part of the pad to come into contact with the disc in normal forward wheel rotation

All four pistons move and retract freely.

All the pads are wearing evenly across the pad surface and braking is good.

Is this the result of using floating discs ?

Bob

It's difficult to see if there's described uneven wear from the piccies you've posted, but you state that they are wearing evenly across the pad surface. Some manufacturers chamfer their pads from new. 

For peace of mind the first thing I'd do is to remove the pad retaining pins and clip from both sides and 'shine' them a bit, also deburring the holes in the pads so that the pads can move freely through their intended range of travel as the pistons press against them and retract. There was a bloke several years ago in the UK selling stainless steel pins for Brembos and I bought a set and used them successfully. There also might be a slight hang up in one or more of the pistons in use over the road that isn't readily noticeable in situ. A good bleed and refill might eliminate debris caught behind the pistons. It's a hard life inside.

I have personally never experienced uneven wear on pads that could be attributed to floating discs.

I see that all the time. I don't worry about it.

Sticky pins meaning the pads don't quite hand and move freely on them as they should but they won't ever move so freely the wear is totally even unless you only ride in some nice 20c plus location and never ever get them wet.

For the rest of us road crap, moisture, rust and build up are the order of the day .....all you can do is clean them up regularly but you won't prevent it happening. I pull the brake pads out regularly and check them and keep spare sets of cleaned up pins so I can swap them quickly.

All my guides are stainless, and the whole system was completely overhauled a couple of years ago.

Just a bit odd that the wear is the same for both sides..

I regularly change the fluid and clean the pads, especially during the winter.

Pad free movement is checked on the pins and against the caliper body.

Seen this on cars when the carrier is stuck on one side.

I will monitor pad wear the next time  I change them .

bob