I would say when it gets above 140 degrees C. is no good.
If its for a short time, no problem.

Below 105c. is normal there abouts. (230 fahrient is good).

If your using syth. oil the figures will be lower & vice versa.

With SIN 25 I get around 80C.s

shadowhand,

What is the ambient temp when you get 80C?

What brand of oil are you using?

I am currently on 900klms (08 Fatboy) using genuine HD mineral oil at 30C plus I get 240 to 250C...thats in suburb riding though.

I plan on changing to syn oil at 1500 service...is this to early to use syn oil.

The ambient temp for the 80C result was 25 degrees C.

The brand is Penrite SIN 25 (available at Repco).  This is the only other sythetic oil I've found that works for the V-twin. Its around $74 for 5Ls too.

The temps. you are getting are normal with the H-D oil & are fine for the engine.

1500 KMs should be OK too change to synthetic oil.  I changed mine at 4000Kms to synt..

The 80c figure I got was consistant for highway riding at 110KM/hr for 110KMs about five times.  The lowest temp would of being around 19C.s

I reckon for winter use that the 60 weight is to thick to lube the engine properly.

Penrite, Mobile 1, Amsoil

There are different opinions on which oil is best, the most popular I have read and seen around is Mobile 1.

It all comes to personal opinion at the end.

Although I'm sure they are all good oils.

Cheer

WC

When it comes to synthetic oil; I reckon there all very similar the cheaper ones work almost nearly as good as the the more expensive.

The Mobil 1 is the best, (I reckon) because it's specifically designed for the Harley V-twin.

The only sure way to know which is better or more cost efficent is to get all the oils tested in a lab, like they do in racing.