Why are some trying to thicken their oil?

[TallPaul]

Good work cfromc. If I assume your bike is air cooled (probably not a good assumption these days, but in my day it was) then Redline is about the perfect oil for it. I talked to Dave at Redline and he definitely has no problem with mixing Redline grades or even putting some Redline into any other motor oil. Now when I asked Royal Purple about mixing a quart of their oil into regular oil, the first response was it would be okay, but was followed up by another person (presumably the other person's superior) saying they do not recommend mixing their oil, though I think they did say it would not cause harm.

 

[cfromc]

Yes, it is air-cooled and has about 1.1hp/cu. in., which I know is not earth-shattering but it is about 60% over stock. It does have a small oil cooler also. It is ridden hard every time it is taken out. I ran Amsoil 20W-50 Racing oil in it last year and the UOA was good, except for Cu which was a little high (still breaking in) but the engine seemed to make a lot of noise on the thin racing oil. This season I've only ridden it 3-4 times but I can easily notice the noise level has been reduced. Perhaps with straight 20W-60 it will get even better.