I have read tutorials, and I have seen photographs, and I have listened to stories of individuals that have devised, highly accurate and elaborate ways to align their rear wheel and chain with their, front countersprocket. This is well-and-good for a "clinical setting", like a garage, or other home setting, but what do you do when you are out on the road and need to make an adjustment?
Before I left on last weekend's trip into Québec, (I'm working on the photos.........I just came across these that I wanted to share separately), I installed new, rear brake pads. My method of doing this job has been to, drop the rear wheel off of the bike. When changing rear pads, I have always made it a point to do chain maintenance as well, (cleaning the chain and cleaning the chain guide.). That is why I drop the rear wheel. (However, I have since learned that, if I don't want or need to, I can change the rear pads without removing the rear wheel. Thanks, Frostypuck!).
By the end of my first day of riding up to La Tuque, I noticed a vibration in my left footpeg. I knew that it was chain related. I figured that in my rush to get the brake pads installed, I either, didn't get the rear wheel aligned quite right, or did not apply enough tension to one of the adjusters; allowing the axle to slip forward a little.
By the time I got to Rivière-Éternité, (Saguenay), the vibration was bugging me. Because I could not get into my campsite until 3:00pm, or until the current campers left the site I had paid for, I decided to fix the problem.
I set my bike up on its centerstand. I loosened the nut from the rear axle and then loosened both adjusters. I then "tunked" the wheel forward with the palm of my hand, to loosen things up a bit. I then began to tighten the adjusters to bring the rear wheel aft and to tighten the chain, (To where I personally like the slack to be.). When I was close to where I liked the chain tension, I fine tuned the alignment.
Here's how I do that while on the road:
Using a 3 x 5 index card, (I carry a few of them in my tankbag for taking and leaving notes), I butted one end of the card up against the back end of the left axle plate. Using a pen, I made a mark on the index card where the end of the swingarm meets the adjuster cap.
I then transferred the mark to the other side of the card. I then butted the card up against the right axle plate. I don't know if you can see in the below photograph, but the mark I made on the left side, does not match the right side.
I adjusted the right side to match the left side, and then tightened up the axle bolt.
The vibration was gone for the rest of the trip.
This is what I believe; I believe that the length of both "arms" of the swingarm are very accurately machined at the factory. I believe that the swingarm is mounted very accurately to the bike frame. I have had no problems using this method of alignment over the latter part of last season and all of this season. The only change I make when I am at home is, I use a tape measure instead of an index card. But, really anything will work that can provide you with a "left to right" comparative measurement.
Just trying to keep things simple.