Hi, just realised im overdue on the oil change, using Castrol GPS at the minute, which is semi synth from what I remember. What are your opinions on going fully synth? My type of riding is mainly commuting with a short period of days out.

dave

clutch can slip with fully synth so stick to mineral or semi synth

Yes, I have been reading around and that does seem to be the opinion. So next question must be if it causes clutch slip, what sort of bike is fully synth for? Reading the Castrol site it just says wet & dry clutch, sports bikes, race replicas etc so Im non the wiser.. Anyone actually using fully Synth can shed some light?

i run fully in my 29 clutch is fine cams and vales are like new

I ran mine on S rated mineral for 6 years or 20k full throttle until my supplier changed brands and now run semi. Been running semi for around 10 years all on same 400
Its recomwended for my ZX6 and R6 too.
If you want to use fully synth, then do.
Its the same as the ZX rated tyre debate on 400's and grip levels and feedback. You will never convince those that have ZR rated tyres that they would be better off with H rated 090's.

fully sync doesnt cause clutch slip... ive been using castrol r1 racing full sync oil for years in my race nc29, with no probs.
col

Full will highlight problems with your clutch about 5000 miles sooner than semi.
That's not a bad thing.

I run Motul Full Synth 7100 10W40. All fine and never get any issue.

Well as it happens went to my local Halfords for my usual GPS and unbelievably they only had Fully.. So tempting fate, much humming and arring and being very curious I bought 4ltr Castrol R1, now to see if Ive wasted my money and buggered my clutch, will report any strange goings on.

I been running Motul 2092 5w30 in my race bike with no issues for a season.

Only recently found out it is unobtainium, it fell out of a mates garage via the back of a truck at the Island Moto GP a couple of years back.