I'm a machinist and toolmaker these last 37 years. Been riding since '65, nonstop since '74. A chain drive is the most efficient way to transfer power on a motorcycle than any other method used today. And, like almost all the power transfer mechanisms that I've worked on over the years, it must be aligned properly and lubricated. That brings us to the topic question above. A FSSNOC rally smells like Gear Oil. I used to be a devoted follower of PJ-1 Blue, until Jack Robinson showed me The Way.
LUBRICATION Lubing an O-ring chain mostly keeps the O-rings moist; prevents drying out and flying off. They're lubed at assembly. Lubing does lube the rollers, making the chain run smoother and quieter. Unlike PJ-1, gear oil (I use 85-140wt) drips on the ground when applied. BUT the drops are nasty and black-looking, indicating that there's flushing action taking place; the black nasty on the ground is no longer in my chain! The last two Tsubaki Omegas I used, went around 20,000 miles each: 80%road, 20%dirt. I'm not out spitting roost every weekend like Gino or Fred, so I'd defer to them how good it works in dirt, if they ever use it. Gear oil tends to build up around the c/shaft sprocket, and it makes a mess out of your rear rim and license plate. Small enough price to pay for that much wear: I can pay for a bunch of car washes with what I save out of my chain budget.
INSTALLATION AND ALIGNMENT Best to replace the chain and both sprockets as a set. I use a 39T aluminum rear, which I'll discuss later; the lube I use protects the rear sprocket to the extent that it lasts as long as the front, and the chain. I'm not throwing away a still-good chain because the rear sprocket is toast. Running a new chain on old sprockets, or an old chain on new sprockets, is like stepping over a dollar to pick up a nickel.
When I get a fresh final drive installed, I leave the bike on the centerstand, and crank the axle adjuster nuts in until the bottom run of chain is almost taut. Then I grabd a mirror and settle down on a low stool at the rear tire, and try to get an image of the rear sprocket edge-on. I sight along the bottom run of chain, and adjust the axle nuts until the chain run comes straight onto the sprocket. Then I back off the adjuster nuts maybe four turns each, and tap the axle foreward with a dowel or a hammer handle until it seats. I don't rely on the index marks on the swingarm: I've seen some that make me think there's a worker somewhere at KHI, putting in those marks with a yardstick and a cold chisel. Next I back the monoshock preload off to click one. I sit on the bike to sack down the suspension (not hard @ 290lbs) and feel the bottom run of chain for slack. What I'm shooting for is between 1/2 inch and 1 inch. I roll forward about a foot, and check again. I tighten the axle bolt and pin it. I then go on a short ride to see if everything's OK, before I return the preload to where it was.
Two good ways to check the chain on a ride. With a buddy, trade chain checks. If his is fluttering, it's probably too tight. If it's rolling in waves (like the ocean, or 95% of the Hogley chains you'll see), it's too loose. The bottom run should show no motion, like he's standing still. Same with yours. When I'm alone, early or late in the day when the sun angle is low, I try to catch my shadow on the concrete barriers on overcrossings. That's also a good place to listen: they reflect the sound back to my ear; if the chain's buzzing or ringing, it's probably thirsty. Most of the time that sound falls below the wind noise inside my helmet.
ADJUSTMENT As time goes along, repeat the above, minus the alignment procedure. Be sure you turn each adjuster nut in the same amout. Try to avoid adjusting a dry chain; when you lube it, it'll tighten up, and you'll have to start over. This is becaise the rollers are then rolling on a thin film of oil, where they were dry before. On long dirt rides, I lube my chain every day, after I've shot off all the red dust (that's a clue) with a hose or in a car wash. On a road trip, I lube at least every other tankful.
I made several day rides when Mo and Mikey came up. Mike's Tour Glide was belt-, but Mo's Low Rider was chain. We pulled into the Denny's parking lot in Cedar City, and I gave the PJ-1 to Mo. Mike got on the LR, and gave me a sly grin. He started across the parking lot with Mo applying the lube (no centerstand on his bike), and Mike started going a little faster, and faster. Pretty soon Mo was running trying to keep up. I looked in the window, and everybody around the salad bar was howling. Mo laid a trail of chain lube the full length of the parking lot :-D
I use an aluminum 39T rear. With the stock 15T front, that brings the revs down very near 4000 RPM @ 70 MPH with fresh tires. I can change to the 13T front in about 30 min, for dirt stuff. Why all the odd numbers, you ask? Car clubbers during the 50's knew the rear end ratios were ALWAYS wierd: 4:11, 4:33, 4:51. Rear end spur and ring gears have odd numbers of teeth: creates what is called the Hunting Tooth Effect. Each tooth meshes with EVERY other tooth differently over time, spreading out the wear. If you run an even-numbered sprocket, especially on front, you'll soon notice that the wear from the chain's inner sideplates never moves. Some hard grit or a cracked roller punishes the same tooth or gullet every time around. Same with a broken sprocket tooth on the chain. I change the sets out long before the rear sprocket becomes a candidate for The Missing Link trophy. You'll understand that last if you come to Moab in June.
I've probably left something out, or provoked criticism from some of the bretherin... Notwithstanding differences of opinion, it is my policy to avoid giving out damaging advice, especially to the newbies coming along all the time. Lots easier to edit the printed word, than replace a part (both motorcycle and body) produced by bad or incomplete recommendations.
