I'm planning on doing a bit of traveling this summer on my 1997 HD sportster 1200 xlh and i was concerned about having a quality oil at my disposal, or at least what i've been using (valvoline 20w-50 full synthetic engine, spectro primary), I may not be able to get what i'm using now everywhere so I was wondering if anyone else here uses a synthetic gear oil in their primary or if you could even get away with doing it for the life of the engine. I've done some searching on this site and have yet to find any definitive answers. Also i was thinking about switching to mobil 1 synthetic 15w-50 for the engine, would it be an alright switch from 20w-50? can i use it in the primary as well?

The November issue of American Iron had a great article about choosing the right oil for your bike, written by Donny Peterson. (The cover of the Mag has the words "Bumpstick Power")

from Am Iron article:
"Do I use HD synthetic oil? No, I don't. I prefer Mobil 1 15w50 automotive oil. I use a lighter grade oil in the primary and heavier synthetic in the transmission... I cannot see how a 20W50 synthetic oil, like HD's SYN3 is adequate for transmission lubrication. In my opinion, the shearing forces of the transmission gears will chop up the molecules, destroying the lubricity of SYN3, or any other 20W50 oil for that matter..."

Donny Peterson, pg 38 of American Iron November 2005 Issue

I know this doesn't answer all yor questions, but the article is worth reading if you can find it.

Here is an old post of mine.

========
For wet clutches some folks say to be careful with oils
tha contain Molybdenum, or “moly”, that is one difference between
some MC oils and auto oils. Most MC oils like Mobil1 MX4T (20w-50) ,
Amsoil MC as well as all HD oils and SportTrans fluid contain zero Moly.
That is why they say it safe for the primary with wet clutch.

Some other oils may or may not contain moly.

Of course I know of riders that use Mobil1 15w-50 (auto, gold cap)
in the trans with no problems either. While Mobil1 gold cap does
contain some moly it's a fairly low amount compared to other
brands and maybe that's why they have not had any problems.

Me?
Gold cap in engine, sometimes 20w-50 oils but always syn.
Sport trans in primary, it works for me and cost about the same as
the gold cap ~$5.
http://www.xlforum.net/vbportal/forums/images/buttons/orange/quote.gif (http://www.xlforum.net/vbportal/forums/newreply.php?do=newreply&p=185226)

I plan on trying 70-90 Mobil 1 gear lube after warranty. I like the idea of the extreme pressure additives (sulphur) and it should be fine with the clutch.

Kim

The November issue of American Iron had a great article about choosing the right oil for your bike, written by Donny Peterson. (The cover of the Mag has the words "Bumpstick Power") ...

If you cannot find the mag, all of Donny Pererson's AIM articles are on his website: http://www.heavydutycycles.com They are in the more rough, unedited form as he submitted them for publication.

I have been running Mobil 1 15W-50 Syn in the enigne on my 2000 since it's second oil change. You can buy this from any Wal-Mart, and dang near every auto parts store. I have tried HD SE Syn3 in the enigne and was not as happy with this as the Mobil 1. Tried the Syn3 in the trans and was pleasantly surprised....but not enough so as to spend the extra couple of bucks over the SportTrans Fluid. There are HD dealers all over the country and you should be able to pick up SportTrans at one of them while touring the country. IF you stop in your local dealer and pick up one of their maps, it'll show all the dealers in each state.

So it's Mobil 1 15W-50 in the engine and Sporttrans in the trans for me:)

excellent, thanks for all the info guys, i'll probably make the switch from valvoline full synth 20w-50 to mobil1 15w-50 and try a 75w-90 synthetic gear oil (probably mobil1 if they do carry it at most wally worlds) without much moly in the tranny. I just downloaded and read "Oil and the Modern Harley-Davidson Motorcycle" Oil study by Lee C. Bussy from september 9, 2005. It was posted up on the forum somewhere and its got a lot of good info. definately worth checking out, now all i need is some good weather haha.