Some info:

If the gear jump out of 4 gear then you have to change 642 (5933) and 654 (5954) then you change this, it some time can be a good idea also to change 2 gear 621 (4964) or 624 (4080)

If the gear jump out of 3 gear then you have to change 632 (5924) and 663 (5976) then you change this, it some time can be a good idea also to change 1 gear 611 (4949) or 613 (5904) or 615 (4944)

If the gear jump out of 2 gear then you have to change 621 (4964) or 624 (4080) and 653 (5954)

If the gear jump out of 1 gear then you have to change 611 (4949) or 613 (5904) or 615 (4944) and 663 (5976)

If the gear jump out of 5 gear then you have to change 542
(5910) and 554 (5940)

If the gear jump out of 6 gear then you have to change 542 (5910) and 564 (5966)

Most common gear there jump out is 3 and 4 gear because you
use that all the time in a races.

5 and 6 gear, normally last very long time.