It’s time to talk about chain tension! When you buy your first motorcycle, you may not realise what kind of maintenance you should be performing to prolong its life and make your bike safer to ride. Checking your bikes chain tension is one of the most critical upkeep jobs you should be doing and you should be learning to do it right.
Why should I check my chain tension?
Making sure you’re running the correct chain tension not only prolongs the life of your chain and sprockets but drastically increases rear wheel horsepower and makes the bike a lot smoother to ride. In severe cases of incorrect tension, they can fail and either brake cases, gearboxes and other parts of the motorcycle, they can cause the rear wheel to lock up at speed or they can even become dangerous projectiles. Nobody needs this kind of drama in their life, especially not when you have a cold beer in the fridge at home calling your name after a long day at work.
How often should I check my chain tension?
You should be checking your chain for correct tension every 800kms or twice a month if you ride often. It may seem tedious but it really doesn’t take long to quickly check and could save you a lot of time down the road. You should also be washing your chain and lubricating it every 300-500 kms and looking for visible signs of wear such as stuck links, damaged rollers, loose pins, and rust. You can check out me trying to conquer my camera shyness and learn how to wash your motorcycle chain all in one video RIGHT HERE! If there is excessive wear on the chain then you will need to replace it. Don’t forget to also check your sprockets, chain sliders and guides for wear and replace them if needed.
What is the correct tension for my chain?
Once again, your owner’s manual will be your best friend. In some cases, there may be a sticker on the swing arm that will give you some indication of what your tension should be. When it comes to dirt bikes I like to use the “three finger” method which will be explained below. You have all the tools you need, it’s simple and it’s a good quick method you can use before each ride, which means you’ll be more likely to check your tension more often and in a world where convenience is king, it’s good to make things as simple as possible.
How do I check my chain tension?
There’s a lot of different ways to do this, some people prefer to put the bikes on stands, some people prefer to use more accurate methods, we’re all a bit different. I personally don’t think you need to be ‘to the millimetre’ accurate when it comes to chain tension but I understand there are perfectionists out there and in that case, get out your rulers. I personally check my chain tension like the following, have never had a problem, was taught by a mechanic and have spoken to other mechanics in the industry who also believe this is the best way to go about it.
1. Turn the engine off and make sure the bike is in neutral. Either get the person who rides the bike to sit on it or if you don’t have help, stand on the opposite side of the bike and put your weight on it so that the suspension is compressed as it would be if you were sitting on the bike.
2. Pick a point in the middle of the chain between the front and rear sprockets, usually just behind the front chain guide and pull the chain up to check the ‘chain slack’ by sticking two to three fingers upright between the swingarm and the chain. The chain should be tight across your fingers. There should be roughly an inch to an inch and a half of play from its lowest point to its highest point. Dirt bikes can have a little more. Road bikes have a little less. But all in all about 2-3 fingers.
3. Roll the bike forward and check the chain slack again using a different point in the chain as they don’t always wear evenly. You want to check the chain in several places and the slack should remain fairly constant, otherwise some links may be kinked and binding. Lubricating the chain will often eliminate this. You should also check your sprockets for wear as the teeth can give you more information as to what’s happening down there. Worn teeth, wave shaped teeth or sharp teeth can all be indicators of a chain that hasn’t been adjusted properly.
How do you adjust a chain if the tension is not right?
1. Loosen the rear axle nut
2. Loosen the adjuster nuts and turn the chain adjuster bolts counter clockwise to decrease slack or clockwise to increase slack
3. Make sure the adjustment is made evenly by lining up the axle index marks with the edge of the axle block (or some bikes have a reference notch in the axle block) and make sure it is the same on BOTH sides.
4. Tighten the rear axle nut enough so that it is unable to move.
5. Recheck chain slack and adjust as necessary
6. Turn the adjusting bolt counter clockwise until it touches the axle plates lightly. Then tighten the chain adjuster lock nut to the specified torque listed in your owners manual while holding the adjusting bolt with a wrench.
7. DON’T FORGET!! Tighten the rear axle nut to the specified torque listed in your owners manual
WHY? If you don’t your rear wheel will come lose and start falling off. It’s like riding on slick oil.
8. Recheck the index markers are still sitting at the same spot on both sides.
WHY? You want your wheel facing forwards… not sideways.