THE PROPER WAY TO REPLACE THAT WORN DRIVELINE
Story By Adam Booth
Photo By Adam Booth
Unless you plan on purchasing a new bike before the chain and sprockets wear out, a day will come when you have to get your hands slightly dirty and replace these components. It is an easy job if you approach it properly, but disastrous if you mess it up.
A. Are your chain and sprocket toast, roached and due for a swap? One way to tell is to pull the chain away from the rear sprocket. If it pulls out far and shows a lot of the tooth of the sprocket, you’re riding on borrowed time. Another sign it’s time to ditch the chain is if it moves side to side excessively. Does it push over into the knobbies of the rear tire? Yikes!
B. A good check method is to measure the pin distance using a chain stretch tool that tells you exactly how much it has stretched. You can also use a ruler. A 520 chain with a 5/8 inch or 15.875mm pitch should not measure more than 259mm when measuring center of pin to center of pin over 16 lengths (17 pins) on a non-O-ring chain. The maximum distance on an O-ring chain is 256.5mm. Also, keep an eye on the master link; it is the widest part of the chain and can wear faster due to friction against the chain guide and chain slider.
MANUFACTURER TORQUE RECOMMENDATIONS
HONDA: 23 LB-FT PLUS LOCTITE
KAWASAKI: 93 LB-FT
KTM: 44 LB-FT PLUS LOCTITE
SUZUKI: 26 LB-FT PLUS LOCTITE
YAMAHA: 54 LB-FT PLUS LOCTITE
Before you take the chain off, loosen the countershaft sprocket nut, especially if you don’t have an impact wrench. Push and hold the rear brake; this will hold the countershaft sprocket solid and you’ll be able to remove the nut. If your sprocket is held on by a circlip, put the socket away and use a pair of circlip pliers in the intended manner. You can always fall back on the “pry it off with a screwdriver” method, but it usually ends with a bent and destroyed circlip. Use the right tools, it won’t kill you. When you reinstall your new countershaft sprocket, tighten the bolt with the chain on so you can use the rear brake method again. Bikes with circlips recommend the use of silicone as a safety on the circlip.
The master link is one of the most important parts of the drivetrain. Lose it or install it improperly and bad things can happen. One way to remove it is to use a flat-blade screwdriver and push it off, but be careful, this technique can lead to screwdriver slippage, which usually results in blood from the hand in some way, shape or form. A safer way is to use a pair of pliers and squeeze it off as shown.
A little tip to save some skin when removing the sprocket nuts and bolts is to drape your old chain around the sprocket. If you happen to slip, then you’ll hit a chain and not a sharp sprocket tooth. Use the Allen wrench to hold the bolt and remove the nut; it will be easier than trying to turn the Allen bolt.
RECOMMENDED SPROCKET BOLT NUT TORQUE IS ABOUT 25 LB-FT. AGAIN, HOLD THE BOLT WITH THE ALLEN WRENCH AND DO THE TIGHTENING AT THE NUT. USE PROPER-FITTING TOOLS WHEN WORKING WITH SPROCKET BOLTS — THEY’RE ON TIGHT AND CAN EASILY ROUND OFF. IF YOU’RE AT ALL IN DOUBT ABOUT YOUR HARDWARE, INSTALL NEW BOLTS AND NUTS WITH YOUR NEW SPROCKET.
Don’t toss out the old chain just yet; use it to measure your new one, unless you’re going radically different on sprocket size (then you just have to check it on the bike).
Renthal recommends blue Loctite on the threads when reinstalling the nuts and bolts. We like to take it a step further and use just a small dab of grease on the flange of the bolt to reduce the metal-to-metal friction when torqueing the bolts down. You don’t want to get grease on the threads, just the surface area of the flange.
Of course, the proper way to take links out of a chain is with a chain tool like this. But not everyone has one on hand at all times...
The non-chain tool way is to grind down the pin and side plate a little and use a hammer and punch to get the pin out. Some mechanics grind down the pin a little even before using a chain tool just to make it press out a little easier.
As when removing the master link, using pliers to squeeze it on is the easiest method. Make sure it is installed with the opening toward the back of the bike when the master link is above the swingarm and heading toward the countershaft sprocket. If the opening of the master link is facing the direction of rotation, it can catch and rip off, resulting in what can only be described as a horrific no-no. Have fun riding!