QuestionI own a 2003 Honda Shadow VT750 and the chain always seem to be too loose. I need to learn how to make the adjustment myself. I tried to loosen the nuts but they were too tight. Is the thread a normal right hand thread or is it a left hand thread? Is it difficult to adjust the rear brake if I ever do manage to adjust the chain?
AnswerTony, sorry about the delay...holiday weekend and all.
Neither of these jobs is particularly tricky, but the first time is always the hardest.
You should get a shop manual with instructions to do this stuff, as all bikes are a little different. One book I like in particular is Evan Brasfield's "101 Sportbike Performance Projects." It's a general book, and even though it's techically about sportbikes, the instructions can be used on most any bike. I recommend it to metric cruiser riders all the time. I edited the book and pulled some information from it (see below) to try to help.
To adjust the chain, you must loosen the rear axle. Because so much weight and so much power rides on that bolt, it's on pretty tight, probably 70-90 foot-pounds. It should be threaded normally, but I imagine you'll need a pretty heavy-duty breaker. (The stock tool kit should have what you need, though you may need an extension of some sort for leverage.) You don't have to remove the axle, just loosen it enough so the wheel can move with the adjusters.
When your chain is cold, measure the slack halfway between the sprockets by moving the chain up and down. Press down on the chain slightly to make sure it is at its lowest point. To get an accurate reading, hold a tape measure in front of the chain and look across the top of the links. Adjust your line of sight until the tops of both sides of the chain line up––your eyes will be perpendicular to the chain, and parallel with the top of the links. Then move the tape measure so that one of the inch markings aligns with the top of the chain. Now, press the chain up until it is tight, and bringing your vision up to align the top of the chain again, note the measurement. A little math will tell you if you need to make any adjustments. Since chains don't wear evenly, check the slack measurement in a couple of places. If you need to adjust the chain, set the chain tension to accommodate the tightest point. Also, if the chain is dramatically tighter in one place, consider replacing it.
Before you get down to the nitty-gritty of adjusting the chain, take a look at the chain and sprockets. The most common causes of premature chain wear are an out-of-alignment rear wheel or worn sprockets. Look closely at the sprockets. Are the sides of the teeth worn? If so, expect to find a matching wear pattern on the inside of the chain. Do the teeth of the sprockets look like cresting waves? Why don't you ride down to your local shop and buy a new chain and sprocket set? You'll just be wasting your time adjusting an old, worn out one.
For bikes with lock nuts on their chain adjusters, hold the adjuster in place with a wrench while loosening the lock nut. Loosen the axle nut just enough to enable the chain adjusters to move it. If the axle nut is loosened too much, you can accidentally knock the rear wheel out of alignment. For now, assume that your wheel is properly aligned and make the same adjustments to both chain adjusters. With the exception of eccentric adjusters, you can only move the axle away from the counter shaft sprocket via the adjusters. So, don't get carried away or you'll have to start all over from scratch. Small adjustments of a quarter turn (or less if your chain is only slightly loose) are the safest bet. Measure the slack after every change. When the chain is within factory specifications (usually around 1.2-1.5 inches), tighten the axle nut to keep it from slipping. If you go too far and the chain becomes too tight, loosen the chain adjusters two full turns and use a rubber mallet or dead-blow hammer to knock the rear wheel forward against the adjusters and begin again.
When the chain has the proper amount of slack, torque the axle nut. Next, tighten each adjuster about one eighth of a turn against the axle. Hold the adjuster in position and set the lock nuts.
The last step in any chain adjustment is making sure the rear wheel is properly aligned. Don't trust the stamped marks on your bike's swingarm, unless you've verified they are correct by checking the rear wheel alignment several times. A variety of methods of checking the wheel's alignment are available through the aftermarket, but the least expensive and, possibly, the easiest is the “string method.”
Take a piece of string a little more than twice the length of the bike, find the center and wrap it once around the forward edge of the front tire just below the front discs. Take each end of the string down opposite sides of the bike. Lie down on your stomach, pulling the strings taut so that they both lightly touch the leading edge of the rear tire. Since the rear wheel is wider than the front, the strings will leave a slight gap as it passes the rear edge of the front tire. Your assistant should make sure that the front wheel is straight by checking the gap on both sides. Now, keeping your hands steady with the string only lightly touching the rear tire, compare the gaps between the strings and the rear edge of the rear tire. If they are not equivalent, the adjuster on the side that has the smaller gap will need to be tightened slightly. Finally, measure the slack one last time. You'd be surprised how often something tightens up. Don't forget to put a new cotter pin through the axle nut.
If you don't have an assistant, a simpler but less precise method for checking rear wheel alignment is to spin the rear wheel a few times and watch that the sprocket stays aligned in the center of the chain. If it rubs against one side or the other, the wheel is out of alignment. Get someone to help you perform the “String Method.”
The rear brake is not difficult to adjust. If memory serves, it's just a matter of turning the bolt this way or that to adjust the pedal height.
Pat
