kek

With new 11-30 Dura-Ace cassette on pros bike we can see new front chainring configuration:
46/36 (11/28) now replaced by 46/39 (11/30) - Toon Aerts example - .

Lower ratio 36/28=1.286 now replaced by 39/30=1.300 which is just 1.1% harder
Front chainring jump 46/36=27.8% now replaced by lower 46/39=17.9% jump

11-12-13-14-15-17-19-21-23-25-28 - old cassette with jumps - 9% 8% 8% 7% 13% 12% 11% 10% 9% 12%
11-12-13-14-15-17-19-21-24-27-30 - new cassette with jumps- 9% 8% 8% 7% 13% 12% 11% 14% 13% 11%

Now front jump equals 2 rear jump instead of 3 - it makes possible to do smooth synchroshifting with Di2

fietsbob

They probably change gearing every week according to the course they are racing around..

How many CX races have you gone to watch?