Thursday, August 23, 2012

Chain and Sprocket Service

Written by: RoadRUNNER Motorcycle Touring & Travel

Chains are simple and effective, but need regular maintenance. A neglected chain may severely damage the engine case, or wrap up in the wheel and sprocket, locking the rear wheel. The two major types of chain designs are O-ring chains and non-O-ring chains. O-ring chains employ rubber O-rings between their side plates to retain lubricants. These usually last much longer, but although internally lubricated, O-rings need to be kept clean and side plates require lubrication and rust protection.

Lube it or Lose It!
Good guidelines for O-ring chains suggest that street riders should lube about every 500 miles. If you ride in heavy dust, rain, or other extreme conditions, or have a non-O-ring chain, the interval should be even shorter. Also, be sure to lube the chain after washing the bike to prevent rust.

If the chain is dirty, avoid harsh or flammable solvents such as gasoline, which can ruin the O-rings or cause a fire. Instead, spray the chain with a cleaner like PJ1 Super Cleaner or WD-40. A Simple Solutions Grunge Brush cleans well, or an old toothbrush and rag will do.

There are many lubes available, and you may need to experiment to find a favorite. I’ve found waxes work best for me. Lube the chain while it’s still warm after riding, but never with the engine running. Engage neutral and use the centerstand (if equipped) turning the wheel by hand, or roll the bike. Apply the lube evenly. Automatic chain oilers are also available, which make it easier to keep chains lubed.

Chain Adjustment
Owner’s and shop manuals provide slack measurements and adjusting procedures. If you don’t have a manual, gauge about 1 to 1.5 inches of vertical slack, measured midway between sprockets. Too loose and the chain may grind at the swingarm and even jump the sprockets. Too tight and the chain may damage the countershaft and bearings, and even snap. Generally to adjust the chain, you remove the cotter pin and loosen the axle nut, then turn the adjusting bolts until the proper slack is achieved. Worn chains develop loose and tight portions, and slack varies, so it’s critical to check slack as you rotate the wheel and set it when the chain is at its tightest point. Recheck slack after tightening because it may change.

Most double-sided swingarms have alignment marks, but besides using markings, there are several ways to measure axle alignment. Motion Pro makes a chain alignment tool. Or you can also use a tape measure and measure from the centerline of the axle to the centerline of the swingarm pivot bolt on each side. Another method is to wrap a long piece of string around the front tire (set straight) and pull the string back on both sides toward the rear wheel, near and parallel to the floor. If the wheel is crooked, it will be quite obvious.

Time for Replacement?
As sprockets wear, the teeth develop sharper points and eventually become hook shaped. Pull straight back on the chain in the middle of the rear sprocket. If the chain pulls out so much that you can see the sprocket teeth, you’ll know it’s worn. If the chain resists pulling away from the sprocket, it isn’t worn out yet. Changing the rear sprocket requires rear-wheel removal, while changing a front sprocket usually involves removing the sprocket cover. Once the rear wheel is off you can change the rear sprocket. It may pull off with the damper hub, but you’ll have to unbolt the sprocket from its mounting. Install the new sprocket and tighten securely. Put the sprocket assembly back on the wheel and put the rear axle in. Follow the procedures in a shop manual if needed.

Many motorcycles come with continuous chains that are riveted together, whereas replacement chains are available with or without master links. Generally, because they’re stronger, high-horsepower bikes only come with riveted links, which may make it necessary to remove the swingarm for replacement. If you work on chains a lot, consider purchasing a chain breaking/riveting tool from a motorcycle shop or online; Emgo, Motion Pro, and RK Chain all make them. Otherwise, have a shop do the work.

To replace a master-link chain, remove the old link and connect the end of the new chain with the old one, using a new link. Loosen the rear axle to allow slack. Then pull the new chain past the countershaft sprocket. Pull and guide the new chain using the old one until both ends meet each other on the upper rear portion of the rear sprocket. Insert the master link through both new ends, and install the clip, or carefully rivet the new chain together. Follow the instructions that come with the tool. Or find a description online at www.canyonchasers.net/shop/generic/chain-rplc.php.

Chain Oilers
Hawke Oiler: www.hawkeoiler.com
Scottoiler & Acumen CL10 Electronic Chain Oiler: www.riderstation.com

Chains and Sprockets
Bike Bandit (888) 339-3888, www.bikebandit.com
Motorcycle Superstore (877) 668-6872, www.motorcycle-superstore.com