Our observations show chains and sprockets normally last between 10,000km to 40,000km, depending on the frequency of adjustments and the style of rider. A bike that gets used reasonably and is has a chain  that is lubed and adjusted regularly, (particularly after rain) will last longer than a chain that is not adjusted or lubed correctly. Good quality chains and sprockets are readily available and competitively priced.

The best advice in all cases is to look after your parts by regular checking and adjustments.

Adjusting your chain tension and lubricating the chain should be done every 1,000km, or according to manufacturer’s specifications. This very often goes overlooked and the result can be costly, i.e. new chain and sprockets every 10,000km, or sooner. The best way to adjust the chain is to lift the rear wheel up off the ground using a “race stand” or “paddock stand”, available at most motorcycle shops. Chain tension is the movement travel up and down (tension) on the lower length of chain (underneath your swing arm, see picture).

Always check tension from the lower chain.

Once the rear of the motorcycle is lifted up off the ground, it is important to check the current tension along many points throughout the chain. Measure the tension from one point, turn the rear wheel 90 degrees, then measure chain tension again, continue doing so until you have made at least 4 or 5 measurements. If the measurements change, and the tension varies, you may be in a position where your chain and sprockets need replacement.

If you’re determined to continue using a worn chain and sprocket (not recommended), rotate your wheel and find the point with the highest chain tension – then make your chain tension adjustment from that point.

If you have concerns about the condition of your chain, you must inspect the sprockets at the same time. Worn sprockets or sprockets loosing teeth can be very dangerous, (see image).

Spot the difference between the old and the new sprocket!

If the chain tension is consistently tight or loose, it will need to be altered. The following is a rough indication of what some major motorcycle manufacturers specify.
Road sports bike: 25mm-35mm
Road cruiser (125cc-400cc): 15mm-25mm
Road cruiser (500cc-1600cc) 30mm-40mm
Dirt bike (50cc – 150cc): 35mm-45mm
Dirt bike (250cc – 500cc): 25mm-35mm

The method of adjustment varies for every style of motorcycle. Check your owners manual for instruction. Depending on your bike, it can be difficult to determine if your chain and sprockets need replacing. If you think it might be that time, the easiest and safest way is to consult a qualified motorcycle mechanic.