Doubt it, it's the nature of the gearbox that makes it clunk as you are physically making gears come together.
The oils are equally good lubricants when new. The fully synthetic breaks down more slowly. Motorcycle engines can be tough on their oil with high rpm and rather less stable cooling. At the oil change mileages most ‘pet’ bikes do there is little or no practical difference. ALWAYS remember the power of marketing. Marketing is usually defined as something like ‘mutually satisfying exchange based on perception of value’. In other words you pay more if you THINK something is better! .......doesn’t mean it is better or not enough to justify the price difference.
This is true, but if your clutch is dragging then the box is still going to be moving although you've pulled the clutch in, hence the clunk. I've experienced big differences in oils but I haven't tried Castrol, so I'll give it a go. Dropping into first is a firm clunk on mine, but on halford's own brand there was enough clutch drag to stall the engine, I'd have to leave it warm up a bit first to avoid an arse clenching crunch. Needless to say the oil was changed as soon as possible.
Oil thickness can make all the difference to clutch drag and gear operation. ATF works well in some manual car transmissions because its stickiness does not merely lubricate but helps synchromesh cones attract and self ‘clutch’ to near equal speeds as they engage.
I can't disagree with a word of this, particularly the marketing, where there is a market, there's a product, and we've all been seduced by the power of marketing...Ooooo shiny!! The higher rpm is a valid point, but that's another reason for keeping up with your oil changes. My old V8 idles at 600rpm, changes gear at 1750rpm and occasionally reaches the dizzy heights 2500rpm at which you'll be doing well over 80mph. The sheer loading on the oil is minimal in the V8 so mineral oil is fine. Our machines are, of course, a completely different application.
All sound theory, but of course bikes and cars are completely different designs. Cars typically use a dry clutch for greater power transmission, syncromesh gears because their quiet and baulk rings to slow the gears down to help there engagement. Bikes typically use a wet clutch, because we like to slip them and we would kill a dry clutch through constant slipping, and we don't need the extra power capacity of a dry clutch. Bikes use straight cut gears, and because the gears are so tiny they don't whine too much, although Harley Davidson got into trouble with excessive noise. Straight cut gears engage a lot more readily than helical cut gears, so they don't need baulk rings. And then some folk think you can use the same oil for both applications and get the same service life, error no. I could ramble on forever, but you've probably already fallen asleep
Just woke up.....NOT suggesting running your bike on ATF......just that viscosity is as important as lubricity!
