Moto Garage - Dyno Tuning, Servicing, Race Prep. Ph: (02) 6162 2031
Chains and Sprockets
Chains and sprockets are some of the least understood yet most important parts on motorcycles. For those of you with shaft or belt drives, this topic isn't for you
I will add pictures from my library of photos but we'll start with the text version and I'll update it as I get high-quality pictures of each part.
One piece of maintenance a lot of people forget is to lubricate their chain. It isn't difficult nor is it that time-consuming, but it is important. Depending on the usage, recommendations are between every tank of fuel (200-300km) or every 500ish km (every couple of weeks, or a big ride). If you ride in the wet, it can be useful to do it more often. If you ride in dusty conditions, more lubrication can help a lot here.
Lubing the chain is not difficult - you just need to find a way to get your lubricant of choice on the inside of the chain, as in, the side that contacts the sprockets. The most important part to lubricate is the rollers on the inside of each of the 'side links'.
Hard to see in these pictures (I use a clear chain lube), but, it's important to lube the chain...
... then wipe the lubricant off.
You don't need very much chain lube on there and this reduces fling once it's penetrated into the chain a bit.
The choice of lubricant depends on the type of chain that you have and the type of riding you do (see chain types below for description of the different chain types).
Lubricants can come in a few varieties, such as fairly plain oils you drip onto the chain, grease you soak into some chains, lubricant in an aerosol bottle (the most common variety) or chain waxes.
If you have a chain with o-rings (or some other fancy variant of o-rings), then you need to use a lubricant that is safe for o-rings. Most things you can buy in stores is, but it can be worth checking.
If you have a non o-ring chain, you can use anything (including stuff suitable for o-ringed chains).
The best time to lubricate your chain is when it is warm after a ride. A short spin around the block can be enough to warm it up, but straight after a decent ride is better. The heat helps the lubricant soak into the chain, reducing 'fling' so your bike's tail and back wheel remains cleaner for longer.
You can purchase automatic chain lube devices. A popular brand is the ScottOiler, though other brands also exist. These drip lubrication (usually a relatively thick oil like gear oil, or possibly automatic transmission fluid) onto the chain. This keeps the chain lubricated and clean, though with the downside of more lubricant 'fling', dirtying the back of the bike and often the wheel of the bike.
The flipside to lubrication is cleaning your chain. This is perhaps slightly less crucial, though a dirty and gritty chain will prematurely wear your sprockets out. Here's an example of an excessively thorough cleaning; you can get away with not going this far .
It is much easier to have your bike on a rear stand/race stand/paddock stand/centrestand. If you can't do that, it's just a bit more tedious; clean a bit of the chain, roll it forwards a bit, clean a bit more etc etc.
Up close, we can see just how filthy this chain is. I've been lazy but it does make it more obvious as to where it has been cleaned.
My chain cleaner of choice - kerosene. Motorbike specific chain cleaners are sometimes the best bet as they work best with most of the commercially available chain lubricants out there. WD40 (chemically not too dissimilar to kerosene) is also ok, though less recommended. In any case, it's useful to make sure that the cleaner you want to use is safe for use with o-rings (if you have an o-ring chain: the vast majority of motorbikes sold in the last 30 years do, though). When in doubt, assume it isn't . Petroleum based degreasers are also acceptable too, as are (usually) biodegradeable degreasers. Acetone, brake cleaner, carburettor cleaner and a lot of other chemicals ARE NOT.
To clean it, use a soft bristled brush (e.g. nylon) to scrub away. Toothbrushes work, but better are the multiple sided brushes designed for chains.
The thing to bear in mind is you really want to clean the inside run of the chain, that is, where it contacts the sprockets. Lots of grime there can accelerate wear of the sprockets, which then accelerates wear of the chain.
It is usually pretty apparent where you have cleaned.
Clean inside and outside runs of the chain (I have also scrubbed the rear sprocket at this point to get rid of grime on it, too).
An often neglected spot is behind the front cover. I don't clean behind here every time I clean the chain, but I do every few times. The amount of times this is cleaned is proportional to the ease of removal; on the Monster here it's very simple (2 allen bolts, no need to remove the clutch slave cylinder). On other bikes, it's so difficult it's something only done when the chain and sprockets are replaced.
Gunk buildup behind the front sprocket cover.
It is really hard to clean behind the chain with the sprocket still on, and I didn't feel like removing it. Here I'm using some non-caustic and organic based degreaser: non-caustic is important as to not eat into the engine cases. Non-caustic degreaser is what you want to use on motorbikes in general.
Hosed off and scrubbed.
With all that done you then lubricate your chain. Although lubricant soaks into the chain better if the chain is hot, which is best done straight after riding, I prefer not to ride for a few minutes on a complete unlubricated chain. So I tend to lubricate it, wipe off excess, ride it for a few minutes, come back, add some more lube then wipe it off again. Possibly overly anal but anecdotally it helps chain life.
Keeping your chain in correct tension is important. Too tight and you can ruin the output bearing in your gearbox - expensive to replace. Too loose, and the chain can slap against the swingarm, make it more difficult to correctly change gears, or in a worst-case scenario, come off the sprockets and stop the bike riding at all.
There are as many tensioning mechanisms as there are motorcycles, though in general they fall into three categories:
* Plates with bolts on it
* 'Eccentric' adjusters on each side of the swingarm
* Eccentric adjusters for single-sided swingarm bikes.
The last two are quite different despite their names being similar. Your owners manual hopefully tells you what to do, but I will endeavour to get some pictures to make the differences clearer.
All achieve tension by moving the rear axle backwards (to tighten the tension) or forwards (to loosen the tension).
You measure tension on the bottom run of the chain, halfway along. You look at how much the chain can move up and down: usually, you want to aim for a total vertical movement of about 20-30mm. It does depend on the bike, and usually is specified in your owners manual. Bikes with longer travel suspension, such as dirtbikes, need a slacker chain and bikes with short travel suspension require tighter chains, in general. This is because the chain tension changes as the suspension moves up and down.
Within reason (i.e. the chain cannot be pulled all the way off the rear sprocket), it is usually better to run the chain looser rather than tighter. If you notice you're miss-shifting and finding false neutrals quite often, then that's a signal you need a tighter chain - the load from the chain helps the bike engage gears as you shift. On the other hand, too tight a chain is generally associated with a general feeling of tightness and a bit of a whirring noise/grinding feeling as you drive - that's the gearbox output bearing being pulled and pushed by the chain.
Keeping everything in line
One of the tricks to correctly tensioning your chain is to keep the sprockets aligned to each other. There are often marks on swingarms to make sure each side is adjusted the same amount, though lining them up can be a pain.
A simple solution is to use something straight, like a metal ruler, and place it along the sprocket. If it points 'out' from the inside of the chain run, then the sprocket side is too far back, conversely, if it points 'in', then the side opposite the sprocket is adjusted too far back.
You can also 'stringline' the bike, which is how you check the wheel alignment. If everything is installed correctly and the bike's frame is straight, then the chain will be correctly aligned when the wheels are correctly aligned.
Stringlining is more accurate than using a straight-edge down the sprocket to get the wheels in alignment, though if the wheel alignment doesn't line up with the sprockets being inline, then your frame is bent.
This is not something you have to worry about on single-sided swingarm bikes: their chain alignment is set by the position of the swingarm and cannot be adjusted without either replacing shims in the swingarm pivot, changing the way the sprocket is mounted or by having an accident significant enough to bend the frame.
Working out when to replace the chain and/or sprockets
(Generally you do both together so a stretched chain doesn't ruin new sprockets, or old sprockets don't more rapdily stretch a new chain.)
Although each link in a chain doesn't elongate, the pins and the rollers elongate and that lengthens the chain.
Technically, a chain is due for replacement when it is 1% longer than new. In the case of most modern motorcyles with about 100 links in their chains, this is practically like being a single link longer than it was when installed (see below for link lengths).
You can also measure the length of the links to work out if it's worn out. As an example, measure 15 links on a 520 chain. This should measure 15 * 5/8" in length - 75/8" or 238.1mm. If it's longer than 240.5 mm (101% of the expected length), then the chain is stretched by more than 1%.
12 links measures 191.07 mm on my Vernier calipers.
Remember to measure from the same side of the pin each time, and it's the number of pins after where you started measuring that is the number of links you've measured!
525 chain means each link is 5/8" long, so 12 links should be 12 links * 5/8" per link * 25.4mm per inch => 190.5 mm.
191.07 / 190.5 * 100% = 100.2% longer than standard, so I've got a bit more use before it is too elongated for use.
A far simpler test is if you run out of adjustment - if you need to move your axle too far back to get correct tension, then your chain is worn out.
Another rule of thumb is if you can lift up a link on the rear sprocket and see a complete tooth, then your chain is also worn out.
Another time to replace your chain is if you notice things like o-rings missing, or there are lots of 'tight' links - these are links which don't bend easily.
You can also work out if you need to change sprockets if your teeth on your sprocket are 'hooked', are much smaller than they were new, or are narrower than they were new.
Chains come in two 'varieties' - normal, and 'o-ring'. A 'normal' chain is just one which doesn't have o-rings . Manufacturers like to use different and fancy names for o-rings, like X rings, XW rings etc - these are all fancy shaped o-rings.
The difference comes in that o-ring chains use o-rings to seal lubricating grease inside the links. This extends the life of the chain, also increasing it's strength for a given mass of chain. This comes at the expense of making the chain more expensive and requiring a little bit more care to install and also increases friction. Slightly more care also needs to be taken in cleaning. Cleaning fluids which are 'o-ring safe' need to be used so they do not make the o-rings perish and stop sealing the grease, and you need to use a brush with soft enough bristles so as not to damage the o-rings.
The vast majority of motorcycles available today use an o-ring chain.
Master link types
There are two main master links types used to hold chains together: the clip link, and the rivet link. The clip link is where you press the side plates on and use a little clip on the outside plate to stop it coming off. This can be installed without any extra tools, though it's imperative to press the plates on straight and true so you don't tear o-rings. The other type is the rivet link, which is where you use a chain riveting tool to 'flare' the ends of the link pins a little, which stops the side of the chain coming off.
The main advantages of the clip link is that it is removeable and you don't need special tools to install them. On the flipside, they can be less strong and the clips can come off (unless you silicon or safety-wire them on).
Rivet links, on the other hand, are not removable (don't use a chain breaker on one!) and do require special tools to fit. They are stronger and less likely to fail if installed correctly.
These days it's becoming more common to get rivet links with chains. For this reason, it's handy to buy a chain tool which can both break and rivet chains.
Sprockets are usually made from two materials: steel, and an aluminium alloy. Steel sprockets will last longer, but they are heavier. Aluminium alloy sprockets will last less time, but they are much lighter. The longest lasting alloy sprockets will be 'hard anodised'. This is not in reference to 'anodising' in the sense of dying the oxide coating on the aluminium sprocket, but a process by which a hard and thick layer of aluminium oxide is built up on the surface of the sprocket, improving lifespan.
Some aftermarket manufacturers will offer sprockets which are alloy in the centre and steel on the outer. This reduces mass, though thanks to the fun of physics it has significantly less effect than an all-alloy sprocket: rotating mass is much more significant on the outside compared to the inside.
In terms of mass and a practical example, a 46 tooth rear sprocket for a 1990 RGV250 has a mass of 960g in steel (JT branded), and as little as 280g in alloy (Renthal branded). Front sprockets have much less of a mass difference.
Lifespan of chains and sprockets can vary quite significantly. Modern sportsbikes may ruin chains and sprockets in 20-30,000 km even in normal usage and with normal levels of lubrication. Less lubrication will shorten this lifespan as will harder riding, more lubrication (especially automatic lubrication) or easier riding will lengthen it.
Not all sprockets are created equal, either. Original equipment (OEM) sprockets may last longer than aftermarket sprockets, even if they are both steel. The difference comes down to the heat treatment of the steel and also the strength of the steel used.
Nylon sprockets were available for lower-powered bikes in the 70s and 80s, though these have fallen out of favour as they wear out very rapidly and do not cope with even tiny power levels.
Chain and sprocket sizing
Chains (and sprockets to suit) are sized using a specific system, which is related to 8ths of an inch. Common chain sizes are 520, 525 and 530, though you may also see reference to 420 and 428, plus 630 on some older big bikes.
The first of these three numbers is the length ('chain pitch') of each link in eights of an inch:
4xx chain: link length of 4/8" (1/2"), or 12.7mm.
5xx chain: link length of 5/8", or 15.88mm.
6xx chain: link length of 6/8" (3/4"), or 19.05mm.
The vast majority of motorcycles run a 5xx pitch chain. Postie bikes and some smaller mx bikes run a 4xx chain, and some of the older bikes did run 6xx chains (e.g. Kawasaki GPz750 turbo).
The second and third number, divded by 10, is the width of the chain in eights of an inch.
x20 chain: link width of 2.0/8" (1/4"), or 6.35mm.
x25 chain: link width of 2.5/8", or 7.94mm.
x28 chain: link width of 2.8/8", or 8.89mm.
x30 chain: link width of 3.0/8", or 9.53mm.
Generally, larger bikes will run wider chains and smaller bikes will run narrower chains. Sportier bikes will run narrower chains to make the chain and sprockets lighter. Some people will do a '520 conversion' - this is where you run a 520 chain on something that was designed for a larger chain. The downside to this is a shorter chain lifespan, but the upside is potentially lighter chain and sprockets, which speeds up acceleration.
Affect on gearing
I'll discuss motorbike gearing in another article, but in general:
* Less teeth on the front makes the bike accelerate faster, with a lower top speed.
* More teeth on the front makes the bike accelerate slower, with a higher top speed.
* More teeth on the rear makes the bike accelerate faster, with a lower top speed.
* Less teeth on the rear makes the bike accelerate slower, with a higher top speed.
Because there are many more teeth on the rear than the front sprocket, one tooth changed on the rear has much less effect than one tooth changed on the front. The specific difference depends on the ratio of the two (e.g. 15 front / 46 rear) but in general it's about 3:1 - so for the same change as one tooth different at the front you need to change 3 teeth on the back.
Front sprockets are cheaper than rear sprockets, so for changing gearing - say for more acceleration - it can be cheaper to get a couple of front sprockets.
Changing the number of teeth does change the length of the chain. Up or down a tooth on a front sprocket isn't too bad, but adding 3 teeth to the back means a much longer chain is required. When replacing chain and sprockets and changing the gearing, you will need to make sure you install the chain to the right point. Changing length by 1 link is actually quite hard (since chains are one inside link and one outside link), so compromises have to made.
The key thing to bear in mind here is if you have the axle forwards compared to where it was meant to be with a new chain then the bike will steer faster / be more nervous. Alternatively, if the axle is further back then the bike will steer slower / be more stable.
Changing chain and sprocket
If you want to change your chain and sprocket, there's a few things to bear in mind. This is the order I like to do it in. Most of the photos in this are from me changing the chain and sprockets on a 2009 Ninja 250R (EX250J).
1. Take off things you need to
Examples here are chain guards, fairings and covers to get into the front sprocket area. Other stuff might need to come off, too, depending on your model.
The front sprocket cover usually has to come off, and most of the time this also means the gear lever mechanism has to come off.
The gear lever mechanism comes off easily, one bolt. Just note that with most gear change splines, the bolt has to be completely removed and not just loosened to let the mechanism come off the shaft.
The inside of front sprocket covers is universally covered in crap. Make sure you clean all this off before you put it back on!
2. With the chain correctly tensioned still, undo the front sprocket.
There are three main ways of attaching front sprockets:
* Plates with a couple of tiny bolts
* Big arsed nuts and bolts
The last option may be done up to significant torque. Rattle guns are handy here, as are big pieces of pipe and long breaker bars. A handy way to hold the rear wheel from spinning is to put a piece of wood in so it holds against the swingarm - MAKE SURE YOU WON'T PINCH BRAKE LINES ETC DOING THIS THOUGH! A lot of success can be had with a helper holding the rear brake on hard, but it depends how tight the nut is on.
The other two options are quite easy.
On this Ninja, the front sprocket nut is retained by a deformed washer and a big arsed nut.
Using a hammer and a blunt chisel, or a screwdriver, you simply fold the washer away from the nut. Generally you replace these after you have used them once but I forgot to order one and I really needed to do the chain and sprockets, so I'll risk death and reuse it. If you are going to reuse one, you don't fold the same bit back over. It's more likely to break then, and once it breaks it is no longer retaining the nut.
Big nuts need big bars. The penetrene and the reducteur are two things used to try to make it easier. This particular nut required a lot of pipe as well as heating the nut to get it to budge. It just laughed at a rattle gun. Some are easier than others.
Once the nut is loose then it is pretty simple to get off.
Just like the front sprocket cover, the area behind front sprockets is universally a grime magnet.
At the same time, it can sometimes be easier to loosen the rear sprocket nuts while the original chain is all hooked up and tensioned.
On this bike, the sprocket is held on by nuts which connect to studs in the sprocket carrier. Pretty simple to undo, just hold the rear brake on and undo each nut in succession. They don't need to come all the way off, just loosened enough to make it easier to pull it apart later.
3. Break the chain.
To break the chain using the RK tool I refer to at the bottom, you first have to screw the breaking pin into the large bolt on the side of the chain tool. You need to lubricate the threads on the breaker pin, or else you risk damaging the tool. You also don't fully screw the breaker pin down; you screw it down so the tip is almost at the conical part of the large bolt.
This is NOT how you want to set it up, but I did this so you can see where the chain breaker pin pokes through. The idea is that as it presses onto the pin of the chain, it twists and rotates which removes the 'stakes' on the side of the pin, allowing it to go through the side plates of the chain.
The four 'flat' sides on the pins are the stakes. They form little lips that hold the pin from going through the side plates of the chain.
The chain tool in position. You start by positioning the rear bushing over the far end of the pin you're going to break the chain at.
The large bolt is tightened until the face of it lightly touches the side plate. You do not need to have this part super tight - in fact, if you put pressure on the side plates, you make it harder to push the pin through. Your aim, as I said, is to roll the end of the pin using pressure in the middle of the pin, not force one side of the chain through the other.
To make sure you don't inadvertantly tighten the tool against the chain, a 17mm spanner goes onto the large nut. The chain breaker pin is spun with a 14mm socket or spanner - not shown here. Some force is needed for the first one or two turns. If it feels really tight, make sure you have the tool centred on the pin - pushing off centre is usually how people break the pins in chain breakers.
The pin coming out the back of the chain tool. Easy. Just before it comes out of the chain, you get extra resistance as you push the stakes through the far side plate of the chain. This is normal to feel.
With the pin out of the way, the chain simply separates.
In this photo, you can just make out the lighter area on the inner plate where the o-ring sat.
Some race chains have really strong pins, in which case you grind the head of the pin off first, then push the pin out. For most chains this is not necessary.
If you are going to grind the head of a pin off, make sure you direct the sparks away from the bike. With lots of sticky chain lube around, it's easy to end up with a heap of metal shavings stuck in the chain lube, or even get nice metal shavings in stuff like wheel bearings, where it causes heaps of wear.
I generally prefer to use a chain breaker. It doesn't take me any longer than using an angle grinder safely and I have a chain tool out to do the rest of the chain anyway. My RK tool has now done about 15 chains and shows no signs of wear or damage. Cheap ones might not last as long.
4. Remove the rear wheel (dual-sided swingarms), undo the sprocket nut (single-sided swingarm)
Removing the rear wheel is a topic in itself, but I've got some photos here that explain it to help.
Lots of motorbikes use castellated nuts (named as they resemble a castle: in Britain, they are called castle nuts for that reason) and they have split pins through the nut. This means the nut can't come loose: also means you have to remove the split pin before you undo the nut. Not hard, but something you have to remember to do. Some people replace them with reuseable spring/R clips to make it easier. You don't reuse split pins, so remember to have a new one handy for when you put it back together.
Straighten that split pin!
Big bar and get that rear axle nut undone.
Holding up a rear wheel takes a bit of practise. I find I can get two feet under there and position them to take the weight of the wheel. You don't need to lift it up, you want it neither up nor down, that way the axle goes through easily.
Rear axle mostly out. If the axle has been greased and looked after, and isn't a hollow Ducati axle that's no longer straight, it's very easy to pull them out. Light taps with a plastic mallet or soft drift might be required for more stubborn axles.
Often people hit the axle with large hammers because they find them hard to get out, but that's because they aren't holding the rear wheel up correctly. Lots of people lift the rear wheel up too high, which is just as bad as not supporting the rear wheel at all.
The rear wheel is off! If you pull on the sprocket, it and the carrier it sits on comes off from the wheel, exposing the...
... cush drive rubbers. These are called cush drive rubbers as they are made of rubber and cushion the little jerks of the motorbikes drivetrain. You want to inspect these for cracks and other signs of wear. It is also a great time to inspect the rear wheel bearings - you want to make sure they don't have any play (i.e. the centre can't wiggle) and they have a nice smooth, quiet motion when you spin the middle with your finger.
5. Remove the rear sprocket from the rear hub/carrier
This part is so simple I didn't take a photo - needless to say, you finish taking off the nuts and lift the sprocket off.
New and old sprocket. New is in black, the teeth underneath are of the old sprocket. Although they sort of look ok here, they are starting to hook, i.e. they're slanting one way. They're also a fair bit smaller than a new set of teeth, and show wear on both front and back sides, too.
6. Bolt up the new rear sprocket, reinstall the rear sprocket.
Again, this is pretty easy. Sprocket goes on, nuts go on. Here's some handy hints, though.
With the nuts loosely tightened, we need some way of holding the sprocket steady. Note these nuts have little metal tabs at their tops - this helps them to stay on the sprocket carrier. This means no loctite is needed to hold them. If you were going to use loctite, you need to use an oil safe one: loctite 243(the blue loctite in a bottle) or 248 (blue loctite in a glue stick style thing) is what you want.
Make sure you put all spacers back into the carrier. This is a spacer that sits between the sprocket carrier bearing and the wheel bearings themselves. Forget this, and you'll have a not-fun crash down the road.
Sprocket and carrier back on the wheel. Note the nuts are still loose, that's because the rear wheel provides an easy way to tighten them up.
Standing the wheel up and sitting on it works perfectly to hold everything still and torque them up to the recommended settings. For this bike, it's about 50 Nm for these nuts.
The rear wheel is now ready to go back in. In order to do that, you need to line up the chain adjusters.
Most mortorbikes have provision for a total of 30mm of movement of the rear axle to allow for chain tension requirements. This amount might seem random but let's have a diversion to think about chain tension. Chains are worn out when they are elongated by about 1% - this elongation comes from deformation of the pins and their bushings, not stretching of the side plates, by the way. Anyway, most motorbike chains use about 100 links or so - in this case, 106 is standard chain length. So, 1% is roughly 1 link total elongation.
Now, with the factory chain pitch (e.g. 5xx) and factory number of sprocket teeth, the correct tension with a new chain is generally with the axle in the middle of the adjusters. I have the photo above set up at the farthest forward area as I am changing the number of sprocket teeth - I am overall adding teeth. Because you can only change the length of chains by 2 links at a time, this means sometimes you end up with a combination of teeth that means you need the axle forwards by a link, as you would be too tight if you had a chain that was one link too short, and too loose if you went 1 tooth too long.
In any case, if you start at the start of the chain adjusters, your chain is worn out when you get to the middle, NOT when you get to the end. Likewise, if you start at the middle of the chain adjusters, then your chain is worn out when you reach the end or thereabouts. Actually, if you do the maths, it's worn out before you reach that point, but it'll do for simplicity.
Before reinstalling the rear axle, give it a really light bit of grease. Helps to get it through the bearings and makes future removal simpler.
With double-sided swingarm bikes, there are two areas that are hard to line up. The first is the spacer that sits against the rear brake assembly.
The other area is getting the rear brake over the rear sprocket and all sitting happily.
There's no real secret to getting this right and making it easy. Holding the wheel just so with your feet helps, as does a touch of grease to make the spacers stick to the bearings and not fall out every 2 seconds.
Once you get it all lined up it's pretty simple, you just push the axle through.
7. Install the new front sprocket.
With aftermarket sprockets, one of the biggest things is to make sure they have the right offset.
In this case, the lip goes towards the engine. You're looking at the backs of the sprockets here. The rubber black bit on the stock worn out sprocket on the left is just a thing there for noise suppression, it doesn't matter that the new sprocket doesn't have this.
Mostly clean area behind the front sprocket. I did clean it more after this photo, though things always look dirtier in photos than real life.
Washer goes on.
You won't be tensioning this up until the chain is correctly joined with the new master link, BUT DON'T FORGET TO DO THIS. Not doing your front sprocket up tight is pretty unfunny.
8. Feed in the new chain, cut to length (if you know what length it needs to be).
Chain usually comes in awesome greaseproof paper. This is a DID x-ring chain, though I hate calling them by their stupid names for the sealing rings, so I just call them all o-ring chains.
There's no real trick to feeding the chain in. If you're not replacing the sprockets, you can wire the new end to the old chain and pull it through that way. Alternatively, you just have to do it and pull it through. Make sure you don't get any grit on your pretty new chain and sprockets, though, so don't drop it on the floor and make sure you cleaned all the things like the chain rubbing plate on the top of the swingarm etc.
9. Verify the chain will be roughly at the right tension with the rear axle in the right spot.
If you have changed gearing, here's where you work out how long a chain you need, and cut it to suit. Remember you join up two inner links!
Here's me verifying the exact length. Although lifted is an outer plate, you'll see that breaking it at this pin leaves me with two inner links - the original end of the chain as supplied, plus the one hiding underneath the side plate that marks the start of the bit I've lifted up.
Breaking the new chain.
10. Fit your new master link, remembering to put some grease on the pins and then fit the outside o-rings if it's an o-ring chain.
This is the contents of the packet that contains the master link. This is a clip type master link. The general principles, other than the final connection, is the same as for a rivet link.
Two o-rings go on the link. Liberally coat each pin with grease from the little packet that is supplied with the chain. This grease is what is sealed in by the o-rings and helps to keep the pins and bushings nice and lubricated.
Push the link through from the back side of the chain.
Put the other two o-rings on the area on the front side of the chain.
Sit the front plate on.
11. Secure the new master link.
Now you need to press the front plate on gently to seat the o-rings properly. Some people do this with pliers, but I do it with the chain tool because it does a better job of pressing the plate on straight.
The chain tool comes with two pressing fittings. One is for rivet links, and the other is for clip links. They're easy to tell apart, the one for rivet links is not as deep because the pins in rivet links aren't as long.
You then get it all nicely sitting on the chain...
...By screwing the big bolt in, you press the plate on.
Do a quick check from the back to make sure you haven't pressed the plate on too hard and squeezed the o-rings. Can't tell from this angle, but in real life it was easy to verify all 4 were sitting nicely.
The clip sits on this way to begin with. The closed end is 'forwards' when you consider the direction of rotation.
A pair of needle nosed pliers is used to push the clip on.
Clip all seated properly.
12. Correctly tension chain, making sure that everything is correctly in line.
This is my metal ruler trick for checking tension. With the ruler sitting flush with the sprocket, you look at which way the end is pointing.
Inside edge is just inside the outermost plate = perfect. If it was pointing inwards, then the right-hand side axle adjuster is too far back. Likewise, if it was pointing outwards, the left-hand axle adjuster is too far back.
With castelated nuts, you do them up to the correct torque. If you can't poke a split pin through the holes in the axle, you then tighten it up the least amount needed to make it so you can poke a split pin through the hole. Yes, I am aware the back locknuts on the chain adjusters are not done up. I'll have them done up in a minute. Tightening the axle first means that the whole lot can't move when I tighten up the locknuts.
New split pin through and bent back.
13. Refit everything else, go for a ride.
One of the things you have to do now the chain is tensioned is to tighten the front sprocket nut up to correct torque.
In this case, it's really tight and they want you to grease the threads as well. With that done, the washer is folded over to hold it all in place.
Then you refit the sprocket cover etc and go off for a ride around the bloke and see how the new chain and sprockets feel.
Example of a chain tool
The chain tool I use is the RK UTC 4060 chain tool.
The biggest piece is the chain tool itself. At the bottom is the chain breaking pin - it screws into the big bolt part on the top side of the chain tool. The two plates are used to press the side plates for each of the types of master links (either clip or rivets). The other three parts are the bits needed to rivet and break chains.
It's not the cheapest but it works, and it can also have individual parts replaced as necessary. It can break chains up to 6xx, and join chains up to 5xx sized using both rivet and clip links.
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