For me it's not a problem to have a 49 or 49.5. The bearing fit and there's no gap so, for me, it's the best and more durable solution. Better than a spacer.

The spacer don't work because it's too wide and compress the two rings of the bearing.

I tried with a 49x37x7 and it works. But I broke the Seat clamp

Hi, also purchased this frame raw carbon. Waiting for the good bearing top finish and let's go !