I have been seeing it a lot more lately; the questions about chains and sprockets. Which brand, which sizes and the whole bit. So I decided to do a thorough writeup, in hopes that it will eventually be stickied in the appropriate thread topic. I will attempt to give detailed and accurate info that will apply to all bikes, also covering different applications. Feel free to add, or correct things I may have missed, or mistaken.
Lets get it out of our heads that gearing is a fixed item. First of all one must realize that the sprockets are the " SECONDARY
" drive section of the bike and is made to be changed for two reasons.
1. To alter final drive ratio for whatever reason or application.
2. To replace worn parts.
That is really it. The chain and sprocket make up the the secondary drive system of the motorcycle and is the only drive system readily changeable for the two listed reasons above. Questions about what gearing is best, is completely irrelevant and pointless to ask. Only the rider knows what they want and need. The appropriate question to ask is what gearing will achieve " X " results.
To clear confusion about chain and sprocket sizes, one must understand that chains and sprockets are sized by " PITCH
". Pitch is the distance from roller to roller on a chain, or point to point on a sprocket. And lets also clear up that a sprocket is not a gear; it is a sprocket. A sprocket is sized just like a chain and will also be sized by pitch, which will match the like sized chain. You cannot mix and match different chain and sprocket pitches. The chain pitch must match the sprocket pitch.
Here is a demonstration of pitch:
The width of the different pitches is another attribute of chain size. Typically larger pitch chains and sprockets are wider and physically larger in size. The reason is that larger pitch chains and sprockets, are meant for larger loads and higher forces of energy. The most common sizes for sportbikes are 520, 525 and 530. The 520 pitch chain is usually an aftermarket choice for all sportbikes and a 530 pitch chain is usually stock on a 1000cc machine. Smaller displacement bikes may have a chain that is smaller than 520 since they are less powerful and can use a lighter duty chain. What must be understood though, is that the pitch of a chain and sprocket is usually decided by machine power and machine mass. The bigger the machine and the more power it creates the larger the pitch chain and sprocket will be needed to utilize the power. The common stock 600cc chain pitch is 525, but a 520 pitch is usually what replaces it.
There should be no question as to what pitch to use when you replace your chain and sprocket. The 520 options are vast and it is highly likely that there are some gearing options available for your bike. The 520 pitch has several advantages over the larger stock chain size on 600cc through 1000cc machines. Many 1000cc and 750cc owners change to the 520 pitch with great success, however shorter chain life should be expected. Some advantages and disadvantages of the smaller 520 pitch are noted here:
1. It will reduce unsprung weight. Nearly 8lbs of weight can be reduced.
2. It may have more gearing options for any given machine.
3. The loss of weight can improve bike performance minimally.
4. Even with stock gearing a 520 pitch may increase fuel mileage.
5. It has a shorter life expectancy on higher displacement machines.
Basically if you are looking to replace both your chain and sprockets the 520 pitch is the best choice. There are many gearing choices available and the gains acquired going from 530, or 525 to a 520 pitch chain are a no brainer.
Lets talk about gearing options. First we must understand the difference between " SHORTER
" and " TALLER
" gearing. Gearing shorter means that the gear ratio is higher and the engine will turn higher rpm's to acquire the same speed as a taller geared machine. A bike that is geared taller will have a lower gear ratio and the engine will turn fewer rpm's to acquire the same speed as a shorter geared machine. There are some other differences between gearing that must be noted:
1. Shorter gearing acquires lower top speed.
Taller gearing acquires higher top speed.
2. Shorter gearing increases mechanical torque allowing quicker acceleration.
Taller gearing decreases mechanical torque and decreases acceleration.
3. Shorter gearing shortens the usable speed range of any given gear.
Taller gearing increases the usable speed range of any given gear.
4. Shorter gearing can increase the bikes natural anti squat ability.
Taller gearing may decrease the bikes natural anti squat ability.
Each of these changes are important, however a decision on gearing must be made using more than just the listed pro's and cons from above. You must consider the current needs of you and the bike, factoring your current gearing and tire size.
To factor secondary drive ratio on a motorcycle simply divide the number of teeth on the rear sprocket by the number of teeth on the front sprocket. So if the gearing is 16 front and 45 rear the gear ration is 2.81:1, because 45/16 = 2.81. The higher the ratio the shorter the gearing will be. What that ratio means is number of turns the front sprocket will make to every 1 turn of the rear sprocket. A tall ratio would be 2.5:1 and a shorter ratio would be 3.5:1 in relation to each other. This ratio only determines the secondary drive ratio, not the final drive ratio which takes into account the primary drive ratio. However since the primary drive ratio will always stay the same, we consider the secondary ratio to figure out what differences we can make.
So now we know what chain pitch is, what gearing ratio is and how to change gearing ratio to alter the gearing of the machine. But what are the effects of changing drive ratio? Also what is the limit or range in which we can change it.
Some basics first. If we run shorter drive ratios we will increase acceleration, but reduce top speed. Running shorter drive ratios will also reduce fuel mileage due to the engine being spun up more all the time. Remember that the shorter drive ratio has the engine rpm's higher at any given speed than a taller geared machine. Now a taller geared drive ratio will decrease acceleration, but increase top speed. A taller ratio will also increase fuel mileage due to lower average engine rpm. We must also consider shift points and how it is effected by drive ratio.
Shift points will change with drive ratio. A bike with shorter ratios will shift more often and will have less speed range between each gear. A taller gear ratio will require less shifting and speed range will be greater in each gear. This is an important factor to gearing a motorcycle. It is no fun to be mid turn and have to shift up because you run out of gear. In contrast it is also no good to be in the middle of a turn with the bike running a very low rpm because the next lowest gear is too short. Changing the drive ratio can help eliminate those issues for best compromise on both the track and the street
Tire size is another factor to consider. Those running a stock tire size for the given machine may still want to pay attention. Tire sizes from different manufacturers will, as one may guess, have different overall circumferences even for a tire of the same denomination. The overall circumference is important because it also effects gearing. A smaller tire will have shorter gearing, with a larger tire having taller gearing. Changing the bike tire size from stock, to one of larger, or smaller overall circumference can have a vast impact on the drive and gearing of the machine and for performance reasons should be factored into the equation.
I noted earlier about " ANTI SQUAT
" properties. This is a minimal effect to consider unless your gearing change is aggressive. An aggressive gearing change would be a 600cc machine geared for stunting, where the rear sprocket exceeds 52 teeth. If you gear the bike using both front and rear sprockets to acquire your desired ratio, anti squat properties can be negated. If you gear taller however the change to anti squat can be more drastic. Taller gearing usually reduces anti squat and can effect bike handling on corner exits. This is usually not an issue however since most users don't typically gear taller than the bikes stock gearing. Most all riders will gear shorter. It should be noted however that aggressive gearing does have an effect that may or may not effect the bikes handling performance for better or for worse.
Now how to gear the machine, now that we know the effects. The best rule of thumb for a performance aspect is simple. Gear the bike to get to nearly redline in the highest gear on the longest straight. This has exceptions though. It is not always practical to gear a bike to use all 6 speeds when the bike barley uses 6th at all. What I mean by that is that many tracks may not have a long enough straight to get through 6th. So it may be best to gear to use more of 5th gear instead. This may mean gearing taller from where you are currently at. Also shift points may come into consideration if you are stuck shifting mid turn. So you may have to alter gearing to find the best compromise. In essence you want to be geared so that you are at nearly redline, in the highest gear practical on the longest straight, or fastest part of the track that still achieves usable gearing for the rest of the track.
For the street, gearing is not as important and the effects will be based more on rider opinion than hard fact. The most common gearing change heard is the -1 +2, 520 conversion. What this means is simple. The conversion part means the chain pitch and nothing else. The conversion has nothing to do with gearing other than chain and sprocket pitch. The size of the sprockets is in relation to the stock gearing of said bike. So a -1 +2 would reference the front and rear sprockets respectively to the compared stock sprockets. In this case The front sprocket would be 1 tooth smaller than the reference and the rear sprocket would be 2 teeth larger than the referenced rear sprocket. This change will increase acceleration and reduce fuel mileage. It will have the bike at a higher average rpm at any given time while traveling at any speed.
For the street rider, one should not ask if they will like the effects of changing the gearing. They should only know that there is a change and that the change can be calculated. The opinion of the change is just that; an opinion of that rider and his assessment. If you are looking for more acceleration you will have to gear shorter and accept the cons of that change. If you are not interested in the cons of gearing shorter, using stock gearing may be a better choice. In all cases going from the stock 525, or 530 pitch chain to a 520 pitch is a superior option and the stock gearing ratio can still be maintained. Remember that chain and sprocket pitch have nothing to do with gearing drive ratio.
How about chains again? Some important notes about chains and the master link type. Chains come with either a riveted master link or a clip type master link. The clip type is the easiest and should be considered the weakest link in the chain. A riveted master link is as good as any other link in the chain and is superior to a clip style link. Many people have good luck with the clip style. I however only trust a riveted master link. I feel that the troubles of installation far outweigh the advantages of a clip style link. A clip style link should never be considered for a bike above 600cc's of displacement. Basically the $80.00 dollar chain tool set, to me is worth the piece of mind over using a clip style master link.
Chains also come with several style of what is referred to as rings. You will here O-ring, X-ring and W-ring used to describe a chain. What they are talking about is the rubber ring that goes between the plates of the chain. The O, X, or W refers to the shape that the rubber ring has.
An O ring chain has a simple O ring and looks like this:
An X-ring has a different profile as can be seen in this pic:
And a W-ring has a very unique profile like this:
The different profiles do a couple things. First and foremost is keeps dirt and debris from getting in, and it keeps the chain roller lubricants from getting out. The O-ring chain has the lowest level of protection and usually has the lowest life expectancy. The O-ring chain is also usually the cheapest option. The X-ring chain is next in line and is pretty much as good as it gets. It has a longer life expectancy over O-rings and provides great performance. The best chain will have W-rings, however the amount of added performance over X-ring is debatable. The W-ring is the most expensive chain type and should provide the longest chain life. The X-ring chain is the most common replacement though and is perfectly fine in almost all applications. I always recommend replacing your stock chain with an X-ring or better. The X-rings are modestly priced, easy to find and provide a very long service life, even without meticulous maintenance.
If you were paying attention, you will remember I mentioned that you can calculate the effects of gearing. I wasn't kidding either. I have linked below a website that I feel is the best there is for finding out what gearing changes will do to your machine. It will even calculate the changes with different tire sizes. It can even show graphical data for those who like pictures instead of words, or letters. This site will calculate the potential outcomes factoring every possible change that can be made on a machine and is the best I have found.
Now a note about brands. I will not do links or list different brands because i am certain that you are able to shop on your own. The general consensus is that any major brand is good. If it is an ebay special from some shop in China that doesn't have a product website, it may be questionable. If the brand is cheap and the price is too good to be true; it probably is......
So what have we learned. Lets do a quick cap.
1. Chain size refers to pitch, which is the distance between chain rollers and sprocket teeth.
2. The chain & sprocket make up the secondary drive system of the machine.
3. Drive ratio is calculated by dividing the rear sprockets # of teeth by the front sprockets # of teeth.
4. Tire size does effect gearing.
5. You should gear for best overall performance not just theoretical or opinionated results.
6. You can use the Gearing Commander link above to calculate gearing changes.
7. The difference between short and tall gearing and their effects on bike performance.
8. That although minimal, anti squat can be affected if gearing changes are drastic.
9. That any major chain & sprocket brand will provide quality parts for your use. Avoid cheap unknown " ebay special " brands.
10. The different master link and chain ring types and their effect on chain life and dependability.
I hope this clears the air about chain & sprocket questions. It is as simple as it looks. It is a chain & sprockets. With a little bit of research you will find the answers you want much quicker than posting irrelevant questions as to what brand, or ratio to go with. Make your own educated decision using the info listed in this thread. I hope you all find this useful and self empowering. Thanks for reading and have fun.