Hey chasps,

I'm posing a few Q.'s here about my new bike because it seems a few of you guys have a bit of background with bikes, plus after trying the Australian HD riders forum, I'm underwhelmed with the general response. In fact, the whole level of dialouge there suggests somewhat limited intellectual horizons. Sadly, some of those guys can barely string 2 words together, let alone spell.
Now, I do recognise most of you won't have had bikes, but some of you will, and a few will have had Harley Davidsons. Those last few are who I am specifically addressing.

The bike is a 2010 HD XR1200. It's almost new, just 900 kms. Say 600 miles. Barely run in really. However, having always had Japanese fours, and having had the last one, a Yamaha XJ650 continuously registered and on the road for 22 years, I am far from current with HD's.

What I am wondering is regarding motor and gearbox oils for it. The owners manual recommends HD synthetic 20-50W for the bike's engine in my general climatic temperature range of 40-100F here in southern Australia. Well, what else would a motor vehicle manufacturer recommend but its own expensive oil brand? Last I checked 5 litres of synthetic oil at an auto accessories and parts store, you could pay anything up to $120 for it. I suspect the HD engine isn't quite that exotic or particular in its lubrication requirements. It's basically a warmed over Sportster motor and that's all. Buell cams, compression ratio of 10:1, up from the standard Sportster's 9.7:1, EFI via a cold air "scoop", and an oil cooler. Hp is claimed to be 90 from 1200cc, so the specific output is pretty modest by todays sportbike standards. To be precise, it's yeilding 75hp per litre at the crank, versus, say 170hp/litre for the current Yamaha R1, maybe 180hp/litre from the current Suzuki GSXR1000, and the new ZX10 Kawasaki is claiming 195hp from its 1L engine. All the Japanese bikes are of course DOHC mutivalve engines with redlines of 12-14000rpm. My XR's is 7000, and is of course a pushrod 2V motor, no OHC or camchains. I don't know yet if it's a roller bearing (high oil pressure required) or plain bearing (low oil pressure adequate) bottom end, but maybe you guys do.

To the gearbox. Engine + gearbox although of unitary construction sharing the cases, have different oils, which is new to me. It is a constant mesh design like Jap bikes, so no riding issues, in fact it's a barrel of laughs to ride and despite the output figures goes quite hard, will pull 2 up easily and actually feels and sounds like a real hooligans bike. I'm going to have to be very careful.
So given the output and that it's purely a recreational toy, no racing, shouldn't regular hypoid 80-90W be okay? Is there anything particular Harley characteristics which really do mean you should go with the expensive exotic gearbox oil?

I look forward to your articulate responses. If you can spell them right, all the better.

Cheers,

John