My question is, why does shift feel deteriorate so soon on a shared sump motorcycle where the engine and transmission share the same oil? Ill get a little specific with my example. I've got a Honda 2007 CBR600RR, and ive just passed 48,000 miles on this motorcycle, runs great, no consumption that im aware of. No matter what brand 10w40 JASO2 spec oil i use, gear shifter feel greatly deteriorates after 1500 miles and begins feeling super notchy, with the first gear through neutral upshift into second being the most harsh with 2-6 still a little notchy but not as bad. For that reason, ive made a habit of changing the oil every 2000 miles. And with fresh oil, the gear changes are as smooth as butter again. Now ive used all the name brands in 10w40 weight, Amsoil Metric, Castrol Power 1, Motul 300v, Rotella T6 etc. And no matter what brand, at around that 1500 mile mark, the shifty gets notchy. Now ive read many UOA's on the oils im using and it seems they stay in grade well past 2000 miles. So whats happening with the oil that's causing this notchy feeling?
I should add I use this bike to commute to work yearly, 20-25 minute ride each way to and from work with the coolant temps reading between 165F(thermostat) and 205F when the rad fan kicks on so i certainly feel the oil is getting properly heated up to burn off the moisture.
I should add I use this bike to commute to work yearly, 20-25 minute ride each way to and from work with the coolant temps reading between 165F(thermostat) and 205F when the rad fan kicks on so i certainly feel the oil is getting properly heated up to burn off the moisture.