KNOW YOUR CHAINS
When it comes to unleashing a motor’s power, a chain provides that essential link to the rear wheel. Tech guru Neil was on hand to tell us more…
FB: What is a chain and how does it work?
NC: Fundamentally, a chain’s there to provide that vital link between the engine and the rear wheel in the most effective way. It transmits energy through a succession of roller bearings from the front sprocket to the rear sprocket, propelling the bike in a forward motion.
FB: What different types of chains are there?
NC: There are four main types of chains; standard non O-ring, O-ring, X-ring and W-ring. The main difference between all four groups of chains is the addition of rubber, for lubrication purposes. Conventional chains require regular lubrication while O-ring, X-ring and W- ring chains contain factory packed grease, to lubricate the roller bearings.
It’s virtually impossible to access the area contained by the rubber, which can be both a good and bad thing. It means the bearings will remain protected from dirt and lubricated all the time the rubber’s integrity holds, but when it fails or the factory packed grease runs out, it will also spell the end of the chain’s life, because you’ll struggle to get lubricant in behind the rubber.
Typically, an O-ring chain saps 3-5% of the power put through it and for this reason, manufacturers developed the X-ring chain. The theory behind retaining lubricant is the same, although the point of contact from the rubber is substantially less. This lessens the resistance and improves the power put through the chain. In turn, the W-ring chain was developed to further reduce the power lost by the X-ring chain, while ensuring the chain’s lubrication.
FB: Why is correct chain tension so crucial?
NC: Chains work to certain tolerances. By over-tightening a chain, you can exceed those said tolerances; compromising the integrity of the chain. If you have a chain which is too tight, there is a possibility you will overcome the bearing pressure between the pin and the bush, which will turn the pin in the outer plate.
Once that’s turned, you’ve lost your pressed fit, the hole elongates and you have a failure where the plate will break. A chain which is too slack is unlikely to jump off your sprockets, but it is likely to damage your bike’s swingarm as it comes into contact with it.
Typically, a chain’s tension should represent 1% of the sprockets’ centre distances. You can work this out by measuring from the centre point of the front sprocket to the centre point of the rear sprocket. One percent of that figure is the distance of acceptable chain movement.
FB: What’s the best way to lubricate a chain?
NC: People say the best way to lubricate a standard chain is to remove it from the bike, give it a good clean in paraffin and boil it in genuine chain wax. It’s not the quickest or easiest of jobs, but it’s the method implemented
by the chain manufacturers, because it works. For all sealed types of chains like O-rings, etc. the practice would be pointless, because you’d never be able to get in behind the O-rings, to access the bearings which need lubricating. In fact, spraying O-ring chains with chain lube has very little effect, other than to create a buffer between the sprocket and the chain; reducing the noise created.
If you choose to lubricate your chain with a sprayed product, it’s essential to apply the lubricant sparingly, aiming it on the inside run of the chain on the sprocket, so the lube throws out onto the chain.
FB: Why do chains have different pitches?
NC: Chain pitches are often determined by the power of the machine they’re going to be fitted to. Manufacturers will create chains with specific tolerances to cope with the torque which is set to be transmitted through them.
If you had a single universal pitch, the chain may be inadequate for some bikes’ power, while it might overwhelm some smaller machines’ engines, because the physical weight and size of the chain is creating too much resistance for the bike’s output. Chains need to be efficient. They’re there to transfer power from the engine to the wheel, consciously sapping as little power as possible from the original figure.
FB: What are tight spots and how do they develop?
NC: Tight spots are areas of the chain which don’t move as freely as the rest of the links. It’s important to identify them, especially when it comes to adjusting your chain’s tension. You should always adjust a chain from the tight spot, to prevent over tightening.
There are two common causes for tight spots; over tight bearings and rust. Through lubrication and manipulation, rusted tight spots can be improved. However, tight spots on an O-ring chain often serve to demonstrate that the grease behind the O-ring seal has run out, indicating that the chain is in need of replacing.
FB: What makes a good chain?
NC: A good chain maker! And good quality components. The best chains are often made from high-grade steel, chromised pins and deep drawn rollers. The production process is massively important too. The way in which a chain is put together and crafted will often determine its life.
SPRAYING O-RING CHAINS WITH CHAIN LUBE HAS VERY LITTLE EFFECT.