Published by the:
New Zealand Motorcycle Safety Consultants.
P O Box 26-036,
Email address: email@example.com Phone 64-4-478-5024
CARING FOR YOUR CHAIN
Motorcycles have changed a lot, in even the past five years. And while the motorcycles of 20 years ago are similar to those available today, there is a world of difference. The same can be said of chains. Even though the chains still look very much the same, the improvements in the technology of chains are immense.
The power that modern big sportsbikes make is more than that made by the GP bikes of the late seventies. They made just over 110-120 HP and used a 530-size chain weighing about 2.5 lb. per yard. Today, some bikes produce close to 200 HP but manage with a 520-size chain that weights only 2.3 lb. per yard. That's no mean feat. All those internal improvements in materials and technology are simply not visible to the naked eye.
The ability to handle sheer horsepower is not the only thing when it comes to the requirements for a reliable chain though. A harsh riding style on a smaller bike can place as much demand on a chain as a huge power output.
Manufacturers are always looking for a better way to transfer power. But is there an option to the classic roller chain?
The toothed rubber belt seemed to be a nice alternative at first. It has even been raced. But it is not the answer.
A toothed belt's power limit is directly related to its width. While a belt drive might be fine for a stock 60HP (or 90HP) Harley Davidson, where the use of belt drive is common, to cater for high power outputs a drive belt would have to be so big the whole bike would have to be widened to allow the belt to be fitted. Also, unlike chains, drive belts are not adjustable.
So, for the foreseeable future, chains seem the best option.
The last big leap forward in chain development came in the 1980s with the mass introduction of the O-ring sealed chain. Those little rubber rings in the chain solved the chain maker's biggest headache for many years - loss of lubricant from between the moving parts of the chain. The load bearing pins and bushings that allow a chain to bend over a sprocket have precious little oil to keep them happy, without adding the oil-removing high centrifugal forces that occur when the chain turns around the drive sprocket.
By far the main reason for chain wear is the loss of this lubricant. With the O-ring chain. the oil is kept inside the chain and the important bearing pins and bushing stayed lubricated for long periods.
The lubricant sealed into a modern O-ring chain is not ordinary oil. It contains synthetic additives that help it withstand the enormous loads that may be imposed on the chain, such as during a first-gear burn-out! There are no friction-reducing additives in the chain's lubricant since friction is not a problem as long as the lubricant is present and strong enough to keep the various metal pieces from touching and wearing. The moment that oil is not there, wear escalates.
If you care for your bikes chain by keeping it adjusted and oiled at 350 mile intervals, even the cheapest chain without O-rings will last a surprising amount of time.
When did you last carry out a maintenance session on your bikes chain?
Oiling Your Chain
While heavy gear oil applied with a brush is an excellent lubricant for a chain, this is a messy proposition and best only when the chain can be left to drip away the excess overnight.
Most riders spray on chain lube, but you must wait the required 20 minutes to let the solvents in the spray evaporate and leave the thicker lubricant on the chain, rather than on the tyre's sidewall! But, it pays to remember that most chain sprays and lubricants contain a tactifying agent to help the lubricant stick to the chain. However, this also helps the grit and grime to stick, and this contamination can grind up the O-Rings. So, use chain spray sparingly.
Many chain sprays also contain caustic and corrosive solvents and detergents. Be careful which spray you use and try to avoid the O-Rings when lubricating the chain.
Grease sold as chain grease is actually not particularly efficient. It cannot get into the tight clearances between the moving parts of a non O-ring chain and the most good it can ever do on these chains is keep the chain's side plates from rusting in the winter.
One of the best lubricants for O-ring chains is said to be diesel oil. This can be brushed onto the chain with a stiff brush to both clean the chain and leave a layer of protective oil on the chain to stop it rusting, which is the main task for externally applied oil on an O-ring chain, since these chains have their important lubricating oil sealed in.
Be careful not to damage the O-Rings.
DO NOT STEAM CLEAN THE CHAIN.
DO NOT USE HIGH PRESSURE SOLVENTS.
DO NOT USE A COARSE BRUSH OR CAUSTIC SOLVENTS.
All of these will damage the O-Rings.
The main enemy of chain oil is high running temperatures. Ideally, the running temperature of a chain should not exceed 160 degrees Fahrenheit (70 degrees Celsius). Above that, chain lubricant starts to thin, and with it comes the chances of it seeping out past the O-rings. Eventually the film strength drops.
Chain adjustment, or rather maladjustment, is the main culprit when it comes to ruining chains. An over-tightened chain is a far worse than a loose one and it is very easy to over-tighten a chain if the chain is adjusted at the chains loose spot. Then, when the wheel turns and reaches the chain tight spot, the chain is very tight indeed at that point.
Another problem is suspension bottoming on a bike with a tight chain. As we all know, suspension movement increases chain tension and, when the suspension bottoms, a chain that is fairly tight at standstill becomes impossibly tight. These added and unnecessary tensile loads will exceed the chain's capacity and the increased friction will lift the chain's temperature sky-high.
A new chain that is too tight can be ruined in no time at all. A good way to check chain tension is to ask two of your biggest friends to sit on the bike, thus compressing the rear suspension to the point where the wheel spindle, swing-arm bearing bolt and the front chain-sprocket centreline are all in line. That is the point of maximum chain tension.
Or you can compress the bike's rear end with a ratcheting tie down. With the suspension bottomed, free up and down movement at the middle of the chain's bottom run should be about half an inch (13 mm).
A loose, dragging-on-the-road chain is bad news too. A loose chain will rub on many static parts of the bike such as the swing arm rubber buffer and frame spacers, being damaged as well as damaging those parts. Also, with the chain's ability to saw through anything in its path, the added friction will again raise the chains temperatures and increase wear.
With a loose chain, the sprockets suffer. A loose chain "rides up" into the higher and weaker areas of the sprocket teeth, slowly bending them into a wicked hooked shape. Once the sprocket is worn like this, both the chain and the sprockets must be replaced. If you use the old chain on new sprockets, the old chain will ruin the new sprockets. If you use a new chain on the old, hooked sprockets, the sprockets will ruin the new chain.
An important ingredient for proper chain tensioning is a straight and true running rear wheel. A cockeyed, sideways rear wheel will place uneven stress on the chain, making one side of it work harder than the other. Thats bad. You can check for a miss-aligned rear wheel by sighting along the chain's top run, back to front. A badly miss-aligned rear wheel will show as a notable kink in the chain's run line. For more exact results you can pick two eight foot (2.5 metres) straight-edged wood boards and place each on either side of the bike, about 4" (100mm) above the ground. On a properly aligned wheel, the edges should touch the rear tire sidewall and leave equal gaps on both sides of the front tire. If the rear wheel is out of line, adjust your chain tensioner accordingly. Of course, race teams mechanics don't crawl on the floor with wood planks. They use a compass with two, long sharpened points to compare the distance between the swing arm bearing pivot and the rear wheel spindle on each side of the bike. On a bike where the exhaust doesnt get in the way, a measuring tape is just as effective.
Even after checking the straightness of the rear wheel, it is worth checking that the chain runs evenly, centred on the rear sprocket. A 1mm washer missing somewhere may cause one side of the sprocket to make contact with the chain. Another clue to this is, after a bit of use, one side of the rear sprocket will get shiny near the teeth. This means that the front and rear sprockets are not properly aligned. A few shims or washers here or there can cure this.
The 500 pieces or more that make up a chain lead a very unglamorous life. The failure of just one of them leaves you with an immobile bike. Chain care, unlike the maintenance of some modern multi-cylinder bikes is easy to do and not hard on the body, soul or pocketbook. It is definitely worth doing.
A LITTLE VERSE
Haiku is a Japanese form of poetry,
Three lines, which must say all, and yet.
Some still feel hungry
First engine rattle, then silence.
Many thousand dollar motorcycle
Becomes a sculpture.
A LITTLE ON THE LIGHT SIDE
My friend bought a new bike.
He called and said, "There is water in the carburettor."
I said, "Where's the bike?"
He said, "In the lake."
RIDING SKILLS TIP
Something that worries many riders is, when travelling in an adjacent lane to a car, they have to move through its blind spot to overtake.
They are left with a choice - to edge past relatively slowly and spend a lot of time in the car drivers blind spot in the process or move quickly past the car. The disadvantage with the first is obvious but, in the second case, the rider is moving rapidly away from a position the may driver knows hes in and then appearing in another position.
The worry of many riders is that, if the driver is not 100% on the ball he/she could miss the riders movement and change lanes thinking the way was clear.
When you think about it, however, the best answer is to move assertively past the car. The longer you are out of sight of the car driver, the more likely he is to forget you were there. You also decrease the time you are in a vulnerable place and if you move to the front quickly, keeping as much air space between you and him there isn't much time for the driver him to move far enough to enter your path of travel.
There's also the probability thing. It's unusual for a car to change lanes for no reason. There is usually a reason for their move, including:
- the other lane is moving faster
- ahead in their lane is a turning vehicle that will block their path
- their lane is becoming a turn-only or merge lane
- they want to change lanes to turn or exit the road.
For the first situation to occur, you have to be in a faster-moving lane than another lane. Further, if you are positioned on the lane away from the slower moving lane with a clear space in front of you, the driver in the slower moving lane is more likely to "push" his way out into what looks, to him, like a gap. Even so, the chances are that driver will indicate (not always, but usually) before moving. Thus, if you see indicators flashing towards your lane ahead, get ready! Someone is about to try it.
Car drivers are generally quite predictable. Just like bike riders, the people driving them are selfish, tending to be focused mostly on getting where they are going as soon as they can. Thus, you interpret driver behaviour and likely responses on that basis.
Sometimes, as with all humans, one driver is more selfish than normal. You can spot them fairly easily - they stand out. They move suddenly, and keep pushing. The best way to manage these people is to simply stay out of their way, expect them to behave in a selfish way, and know that sooner or later these people will, with a loud crash, meet another driver equally selfish.
A TRUE STORY
Picture the scene:
A 1988 Kawasaki Ninja is coming around a right hander in a suburban area a little too hot on the gas.
On the road is some fresh gravel.
Since it is night time and the rider is in a new housing development where there are few house lights, there is not a lot of ambient light!
The rider notices that the curb is not particularly high or steep so he thinks its a minor matter to just run wide into the "grass" and recover, rather than risk a hard drop
on the asphalt.
Meanwhile Rider #2, Rider #1s riding buddy, is hot on Rider #1s trail - but not so hot that he too is at risk of running of the road.
Suddenly, as it runs onto the grass, the rear tyre of Rider # 1s bike hits a beer bottle in the grass with its rear tire and sends it squirting out at an amazing speed inches in front of Rider #2s face.
Rider 2 goes for the brakes - hard!
By now, Rider #1 is discovering that the owner of the new house whose "lawn" he is cutting up has recently turned over the soil to sew some new grass. The home owner has also been watering freely in hopes of having the greenest lawn on earth.
The result is that Rider #1s rear tyre is spewing out a wide spray and tall rooster tail of mud and sending it flying 6 metres into the air. The whole lot is then splashing back all over Rider #2 who now is finding it difficult to see through a mud covered visor, while attempting to make it the rest of the way around the corner.
Meanwhile, the home owner, who had come out to clear his mailbox, is going ballistic at Rider #1.
With a last spurt of mud and water and an exciting slide, the bike re-enters the sealed roadway. Then, in a miracle, the two bikes make it around the corner.
Both recover and learn that in the dark all the hazards are still there, you just cant see them.
Addendum To May 99 NZMSC Riding Skills Newsletter.
This addendum is to answer a couple of questions that have been raised with
us about the article on chains:
Q: When should you clean the chain?
Ans: If the chain is not too dirty, the operation of the lubrication on
the chain is normally sufficient to clean the chain. If you encounter
unusual conditions; such as mud, sand, or wet asphalt at roadworks; the
accumulated deposits on the chain may require the chain to be cleaned.
Q: Is there anything easier to get than diesel oil that we can use to clean
Ans: Yes. You can use kerosene, which is available in some supermarkets.
However, you MUST oil the chain again afterwards.
Q: Chain spray is so easy to use. Is it a definite "No, No" to use chain
Ans: Chain spray is fine as long as it is of a type that is safe to use on
(check the container or ask where you buy it) and use it according to the
Q: You say to use a stiff brush to clean the chain but I've heard that a
hard brush will
damage the O-rings if used to clean the chain.
Ans: It's true that a hard brush may damage the O-rings. That's why we
said "stiff" brush, but I guess we should have explained things better.
Q: Does an O-ring chain actually need any lubrication if we don't mind
having a rusty chain.
Ans: Yes. Lubrication of an O-ring chain will do several things including
prevent the chain from rusting, lubricate between the bushings and the
rollers, and help keep the chain clean.
We take a look at a famous quote from a famous person and make a minor gentle adaptation to show you how this famous quote would have ended up if the author had been motorcyclist:
Every motorcyclist over 40 is a scoundrel.
(Please note Ulysses members)
George Bernard Shaw 1856 - 1950
Anglo-Irish dramatist, critic, novelist, social reformer, and wit.
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