Keeping the chain on your motorcycle correctly adjusted for tension isn’t just a vital safety check you need to carry out, it will also assist with fuel economy and the wear and tear on the chain and sprockets.
There are a few different ways to carry out the checking and adjustment process and this can change between different manufacturers and the different engineering used on the motorcycle.
If you’re in any doubt about how to do this, either ask for someone experienced to show how it’s done or ask for help from your dealer or local motorcycle shop. You may also find some useful videos on YouTube of others working on your particular make and model of motorcycle.
In light of this, it’s vital you check the manufacturer instructions and the owner’s handbook to see how you carry out the check and adjustment for your own bike. Many bikes these days have a sticker on the swingarm giving a chain tension measurement, although this can get worn off on older bikes.
Keeping a chain clean and lubricated correctly will not only extend the life of the chain and sprockets but will also reduce the amount of times you need to adjust the tension. No matter how well you maintain your chain over its lifetime, as it gets older and closer to needing to be replaced the frequency of needing to tighten the chain will inevitably increase.
VITAL SAFETY TIP: DO NOT EVER CARRY OUT ANY CHAIN MAINTENANCE WITH THE BIKE ON A PADDOCK STAND AND THE ENGINE RUNNING AND IN GEAR, AS IT IS VERY EASY TO GET FINGERS TRAPPED AND INJURED IN THE CHAIN AND SPROCKETS.
How to measure chain tension
Check if your bike needs to have the chain tension measured while on a centre or sidestand. Some bikes (on rare occasions) need the chain checked while on a sidestand, and if this is the case it will be stated in the owner’s manual. Having a rear paddock stand isn’t essential but it can make life easier.
Put the bike in neutral and keep the motor switched off.
While the chain is cold (and not straight after a ride when it will be hot), measuring the tension can be done by pushing up on the chain in the midway point between the front and rear sprockets. Rotate the rear wheel and carry out this check in multiple places to find out where the tightest part of the chain is.
To get the most accurate measurement, use a ruler or tape measure and look across at the top of the chain links to line-up with the tape or ruler. Push up on the chain to check the movement. Rotate the wheel and check in few places. You need to measure the tension where the tightest part of the chain is and adjust from there.
If you do it for a looser part of the chain (where there is more movement upwards) when you tighten it all back up again the chain will be too tight and that’s as bad as it being too loose!
There will come a point where the tightest part of the chain will be significantly different to the loosest. At this point you may have to accept it’s time for a new chain and sprockets!
Lock nuts
Using a spanner to keep the adjuster in place against the swingarm recess, you will need to loosen the lock-nut holding in the rear wheel.
At this point you will also need to crack the axle nut loose a little too. It only needs to be loosened to the point where it will allow the chain adjusters each side to move. Don’t undo the axle nut too much or it becomes easy to accidently knock the rear wheel out of alignment.
Be sure to make the same adjustments to both sides to keep the wheel aligned. You can measure the adjustment made with the ruler from the edge of the swingarm recess.
Start the adjustment with small turns of the chain adjuster nut. If you go crazy straight away it will only add time to the task as you may well need to go back and start again. A quarter of a turn and then a check of the tension at the tightest point will be a good progressive start.
Once you are happy with the tension and it’s within the manufacturer recommended setting, tighten up the axle nut which will prevent the adjuster moving any further when you tighten up the lock-nut again.
At this point the adjuster nuts will need to be gently tightened against the swingarm. The lock-nuts can then be tightened.
The axle nut MUST be set to the correct torque setting and then checked again after your first ride.
Unless you are completely confident the graduated marks on the swingarm are completely accurate it may be necessary to check the alignment of your rear wheel. There are various methods to be found online to show you how to do this.
What about concentric adjusters?
There is another type of chain adjustment type that differs and this is the concentric type; normally only fitted to motorcycles with single-sided swingarms.
Normally these have a pinch-bolt closure system on the end of the swingarm which you loosen before rotating the concentric adjuster to tighten the chain using the check and test technique outlined above. There are differences between manufacturers so, as previously mentioned, check the manual for the right information.
