Changed to 19t front at approx. 3500km. Speedo has been spot-on with GPS since.
ODO reading was 5% low compared to GPS log ever since.
The trip/fuel mileage/fuel to go were affected as well.
Triumph centerstand and heated grips, Givi V47 and TRK52 topcase, Givi ST603 tanklock tankbag, Evotech radiator and oil cooler guard, Evotech crash bobbins, ExtendaFenda, Pyramid hugger extension, Puig Screen with spoiler, Zumo 396 with Zumolock holder on RAM mount, Remus can, GIVI PLR6404 pannier rack for GIVI Trekker Black 33/46/52ltr panniers, Triumph gel seat, Triumph rear mudguard extender, Osco chain oiler