Owned one now for about three months.
So far I’ve had a 2.2 spez purgatory and currently a 2.3 spez slaughter on the back. Plenty of clearance below the seatstay bridge and ok clearance either side.
Bottom bracket – no problems with mine. Seem to recall the shop saying you needed to follow the niner instructions to the letter, but neither mine or the others they have built have had any problems.
Generally a very nice bike to ride – i was a little confused looking at the sizing of a medium compared to medium rallon and stumpjumper of previous but medium fits me well at 5’9″.
Its now my preferred bike for most my riding.
Bachebrothers, lye, Stourbridge have a silver model built up – think it’s a medium.