Fitted my custom 53mm one today, had to ream 0.5mm off the steerer bore to get it to fit over my carbon steerer but then again that is a bit tight on everything, fitted perfectly on alloy steerers. Very pleased indeed thanks @mdcc_tester
Some of that tightness could be from the steerer bung forcing the carbon tube to expand out a little. Looks great though. Acetone ftw! (EDIT just seen lasers)
Fitted my custom 53mm one today, had to ream 0.5mm off the steerer bore to get it to fit over my carbon steerer but then again that is a bit tight on everything, fitted perfectly on alloy steerers. Very pleased indeed thanks @mdcc_tester