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World of Sprockets!
Gearing is a measure of all the components that determine the rate at which an engine's crankshaft's revolutions are transmitted, into the vehicle's speed. It comes from the word "gears" which are rotating cogs, which decide what speed the machine picks up, at a particular rpm.
Secondary gearing is related to front and rear sprockets of a motorcycle. Primary gearing is related to the internal gears, related to the gearbox.
A Sample photo of the rear & front sprockets, of 2 different Pulsars (180 & 220), is given below:
So, you can see above how the engine carries the power to rear wheel, via both the sprockets and chain.
Rear sprocket is often visible to all, its the front sprocket that's often hidden, which we can see in the above image.
Sprocketing, in general sense, means changing the front & rear sprocket sizes to affect gearing. It's one of the simplest and easiest mods. The basic info says that:-->
1. Bigger rear sprocket or smaller front sprocket, results in gearing biased towards acceleration, with some lag in top speed.
2. Smaller rear sprocket or bigger front sprocket, results in gearing biased towards top speed, with some lag in acceleration.
Gearing does NOT result in more or less power. It only affects how the power is laid, by changing the balance between top speed and acceleration. So, if one wants more top speed, and is prepared to lose acceleration a bit, or vice versa, then sprocketing is advisable.
Taller gearing results in better highway mileage, and short gearing results in less highway mileage. This is due to the fact, that in longer gearing, the machine travels longer distance for a particular engine speed (rpm), and vice versa.
Gearing maybe affected by: Sprockets' size change, rear tyre's size change, gearbox modification, clutch drag, etc.
Gearing is NOT affected by: Weight/ load change (pillion, etc.), front tyre change, free flow air filters/ power mods, etc.
-----------
Change Measurement: Final Gearing Value: The sizes of front and rear sprocket (measured in "no. of teeth" the sprockets have) determines the final gearing.
It is calculated by Rear Sprocket Teeth divided by Front sprocket Teeth. Like Pulsar 180 UG4 has a 14 front and 39 rear setup. So, its stock final gearing is 39/14 which is equal to 2.786.
Final gearing is for comparison between different sprocket combinations, this way:
45/15= 3.000 (Let's call this "Setup X")
44/14= 3.143 (Under gearing, compared to "Setup X", means more acceleration)
39/14= 2.786 (Over gearing, compared to "Setup X", means more top speed)
Higher Final Gearing value signifies moving gearing towards acceleration (short gearing), and vice versa. So, when changing both sprockets from stock, the new gearing value should be calculated to determine which way you're going with gearing.
But if you overgear too much, you might need a very long stretch to achieve a good top speed, or you might not achieve it at all. So, for a stock bike, a gearing change should be within 10% at maximum, that's it!
--
Rear Tyres size change affect Gearing: Rear Tyre change (size) may affect overall gearing, if the profile (height) is affected due to this change. A higher profile increases gearing, while a lower profile decreases it.
A tyre with size 120/70 has a normal height of (120mm x 70%) which is 84mm. But, the broadness of the tyre rim can change the "final height".
A broader rim gives less tyre height, as tyre is rubber, and it expands over the broader rim, causing lesser ride height & lower gearing. And of course, vice versa too. For example, if you fit the R15 rear tyre on your Pulsars, you might not change gearing at all, because although the R15 tyre is of lower height, but the Pulsar rim is narrower than R15's, and a narrow rim raises the ride height.
Front tyre size change doesn't affect gearing, although it may contribute to a different ride height, weight and different speeds on the speedometer.
============
Direct Sprocket Fits:
Remember that your stock chain can be successfully adjusted for upto 2-3 teeth changes in sprockets. Beyond that, you may or may not require a new chain OR you may be required to remove some links from the chain. For the sake of pillion travel, the chain play should be adequate. After re-installing the chain, move the bottom portion of chain upwards, it should go upto 10-15mm only, not more or less than this.
Remember that you might need to purchase the whole kit instead of just the sprocket depending on where you purchase it from. These sprocket combinations are direct fits to the mentioned bikes:
Apache RTR 160/ 160 Fi: Stock Setup: 13/44 teeth.
To overgear RTR 160, use the 14 teeth front sprocket from Yamaha YZF R15/ Fiero F2. (Thanks Aparajith)
To overgear RTR 160, use the 14 teeth front sprocket from Apache RTR 180. (Thanks Khanz)
Apache RTR 180: Stock Setup: 14/46 teeth.
To overgear RTR 180, use the 15 teeth front sprocket from Bajaj Pulsar 150/ 180 UG3 only! But, buy a sprocket holder ring and the nuts to suit, as the RTR ones do not match the Pulsars' sprocket. (Thanks FlyingJian & lijok)
To undergear RTR 180, use the 13 teeth front sprocket from RTR 160, its a direct fit. (Thanks Utkarsh Stunty Sharma)
Pulsar 220 DTS Fi (Old model): Stock setup: 14/37 on .520 pitch.
To undergear it, use:
P200's rear sprocket, 38 teeth,
Karizma's rear sprocket, 40 teeth, (Thanks Praful) HOWEVER NOTE THAT, its not advisable to use Karizma sprocket, because its a very tight fit and the smaller sprocket holes, the threads on the studs get compromised, so you might have to use a new studs set (12x4) everytime you upgrade your sprocket.. plus wear and tear while riding. (Thanks ashwinprakas)
Another choice is to use P180 UG4's rear sprocket (39 teeth). (not confirmed yet, but it should fit I believe)
KTM Duke 200's rear sprocket, the one with 4 fitment holes and 43 teeth (not 6 holes), (Thanks joelkraju)
Pulsar 200 DTSi: Stock setup: 14/38 on .520 pitch.
To overgear it, use P220's rear sprocket, 36-37 teeth,
To undergear it, use Karizma's rear sprocket, 40 teeth, (Thanks Praful)
Pulsar 180 UG4: Stock Setup (14/ 39 on the .520 chain pitch setup. 104 links.)
To undergear it well, use a 43 teeth sprocket from a Duke 200.
The entire Duke 200 chain kit will fit, but the Duke's chain is too long, and you might need to use Pulsar 180 UG4's original chain or cut 6 links of Duke's chain. Cutting Duke 200's (or any other O-Ring) chain's links is not recommended. (Thanks chinmay_7d)
To overgear it, use P220's rear sprocket, 36-37 teeth,
To undergear it, use Karizma's rear sprocket, 40 teeth, (Thanks Praful)
Pulsar 180 and 150 UG3: Stock Setup: (15/43 and 15/44 on .428 chain pitch. 124 chain links.)
To undergear it, use Discover 135 Sports' Front Sprocket, 14 teeth. But you will need Discover's lock plate and nuts. (Thanks Prabhakar 150)
To overgear it, use the complete chain-sprocket kit of Pulsar 180 UG4 or Pulsar 200 (first ver.), which is 14/39 and 14/38 respectively.
You can remove the metal chain guard and instead, use plastic chain guard from Discover 135 Sports (Rs. 74) after drilling a hole in it, as its maintenance free O Ring chain. Don't put oil, just put chain spray on it. Remove 2 chain links from the chain, if you can. Otherwise, it will require link cutting later on as the chain wears out. (tried by Samarth 619 on P180 UG3)
For ONLY slight gearing change, you can use P150 UG3's kit in P180 UG3 (for undergearing) and P180 UG3's kit in P150 UG3 (for overgearing).
Pulsar 150 UG2 (Analog Meter): Stock setup: ~/44
To overgear, use a 40 teeth rear sprocket (with 6 fitment holes) from LML Freedom. It requires cutting 2 links from the chain. (thanks hotshot.vipin)
(The rear sprockets of FZ, R15, Pulsar UG2 and earlier, LML Freedom, have 6 fitment holes. Others mostly have 4.)
Bajaj V15: Stock Setup: 14/42
For overgearing, You can fit Pulsar 220's chain and sprocket kit. Although, since the front sprocket's lock is not available separately, you'll have to use ring lock. (Thanks @AvmPro )
Yamaha SZ-R: Stock Setup: 14/42
To overgear it, use rear sprocket, 41 teeth from Yamaha FZ v 2.0 OR 40 teeth from Yamaha FZ16 i.e. version 1. (Thanks auggyds)
Yamaha YZF R15 Version 1.0: Stock Setup: 14/42
To overgear it, use rear sprocket, 40 teeth from Yamaha FZ 16. (Thanks anirudh_fz1)
Daytona Kits for R15 (may be expensive):
To undergear it, get the Daytona Kit's 13 teeth front,
To undergear it, get the Daytona Kit's 44 teeth rear,
To overgear it, get the Daytona Kit's 40 teeth rear.
To undergear it, use the 13 teeth front sprocket from Apache RTR 160 (get it with locking ring and those 2 bolts) costs around 70 for sprocket and 12 for ring.
To overgear it, use the 15 teeth front one from R15 v2. But beware, you need to loosen the chain to accommodate this one, if yours is dialled at first setting then chances are this one isn't for you. costs about 120 for ring and sprocket.(Thanks to Tanmay26)
Yamaha FZ16: Stock Setup: 14/40
To overgear it, use front sprocket, 15 teeth from Honda Unicorn or Bajaj Pulsar 150/180 UG3. (Thanks iamvik and)
To undergear it, use rear sprocket, 42 teeth from Yamaha YZF R15. (Thanks anirudh_fz1)
Daytona Kits for FZ16 (may be expensive):
To undergear it, get the Daytona Kit's 13 teeth front or 42 or 44 teeth rear.
(For both R15 version 1.0 and FZ16, Daytona kits provide a choice of 40/42/44 teeth sprockets for rear, 13 teeth for front, and either a 122 or a 130 link chain, so you can choose your new gearing accordingly)
Honda Shine 125: Stock Setup: 14/~
To overgear it, use front sprocket, 15 teeth from Honda Unicorn. But, you'll have to shave off the sides of the sprocket so it matches the chain pitch. (Bike India)
Honda Stunner 125 Carb: Stock Setup: 14/~
To overgear it, use front sprocket, 15 teeth from Honda Unicorn. (Thanks cmahajan)
Honda Unicorn 1st and 2nd Gen: Stock Setup: 15/42
Honda Unicorn 3rd/4th onwards: Stock Setup: 15/43
Direct Fits - With Chain pitch .428 (Unicorn Chain)
with Rear 38T (Ambition)
with Rear 46T (CBZ Classic)
With Chain Pitch .520 (Karizma chain):
13T/40T of Karizma
13T(ZMA)/38T(P200)
Hero Honda Karizma: Stock Setup: 13/40 on .520 Pitch.
To overgear, use a 38 teeth Rear Sprocket from P200, but P200 chain length is not sufficient. Adjust your Karizma Chain after installing. (Thanks Shreeni for above info)
KTM Duke 200: Stock setup: 14/43 on a .520 chain pitch. 110 chain links.
To overgear your Duke 200,
1. use a 36 teeth sprocket from P220 DTSi. (confirmed, thanks joelkraju)
2. use a 37, 38, 39, 40 teeth sprocket from P220 DTS Fi, P200 older, P180 UG4 or Karizma. (not confirmed, but these sprockets should definitely fit I think.)
CT100B: (Stock 14/42, .428 pitch)
Since the CT100B's front spocket has a 17/14/4 spec (compared to 20/16/4 for majority of sprockets), overgearing it by front sprocket becomes a challenge.
But, Gen1 Platina 125's 15 teeth front sprocket is a direct fit for overgearing. Thanks to [MENTION=37035]ashwinprakas[/MENTION] for the info.
============
Gearing Commander Website: Guys, we can find final ratio by using any combo of sprockets by using (Rear no. of teeth/Front no. of teeth) formula.
But what if we change a lot of things like, both sprockets, rear tyres, Primary Ratio, rear rim, etc.?
Fear not, there is a solution. You can find out all about the gearing even before trying it out. Plus it has stock info on gearing of many bikes. You can use the below website for calculating gearing by entering everything that affects gearing:->
Gearing Commander: Motorcycle Speed, RPM, Chain & Sprockets Calculator (Credits: Sir Old Fox)
============
I'll be adding more info. Please suggest improvements to this topic by sending me PM's/ posting here. --Samarth
Secondary gearing is related to front and rear sprockets of a motorcycle. Primary gearing is related to the internal gears, related to the gearbox.
A Sample photo of the rear & front sprockets, of 2 different Pulsars (180 & 220), is given below:
So, you can see above how the engine carries the power to rear wheel, via both the sprockets and chain.
Rear sprocket is often visible to all, its the front sprocket that's often hidden, which we can see in the above image.
Sprocketing, in general sense, means changing the front & rear sprocket sizes to affect gearing. It's one of the simplest and easiest mods. The basic info says that:-->
1. Bigger rear sprocket or smaller front sprocket, results in gearing biased towards acceleration, with some lag in top speed.
2. Smaller rear sprocket or bigger front sprocket, results in gearing biased towards top speed, with some lag in acceleration.
Gearing does NOT result in more or less power. It only affects how the power is laid, by changing the balance between top speed and acceleration. So, if one wants more top speed, and is prepared to lose acceleration a bit, or vice versa, then sprocketing is advisable.
Taller gearing results in better highway mileage, and short gearing results in less highway mileage. This is due to the fact, that in longer gearing, the machine travels longer distance for a particular engine speed (rpm), and vice versa.
Gearing maybe affected by: Sprockets' size change, rear tyre's size change, gearbox modification, clutch drag, etc.
Gearing is NOT affected by: Weight/ load change (pillion, etc.), front tyre change, free flow air filters/ power mods, etc.
-----------
Change Measurement: Final Gearing Value: The sizes of front and rear sprocket (measured in "no. of teeth" the sprockets have) determines the final gearing.
It is calculated by Rear Sprocket Teeth divided by Front sprocket Teeth. Like Pulsar 180 UG4 has a 14 front and 39 rear setup. So, its stock final gearing is 39/14 which is equal to 2.786.
Final gearing is for comparison between different sprocket combinations, this way:
45/15= 3.000 (Let's call this "Setup X")
44/14= 3.143 (Under gearing, compared to "Setup X", means more acceleration)
39/14= 2.786 (Over gearing, compared to "Setup X", means more top speed)
Higher Final Gearing value signifies moving gearing towards acceleration (short gearing), and vice versa. So, when changing both sprockets from stock, the new gearing value should be calculated to determine which way you're going with gearing.
But if you overgear too much, you might need a very long stretch to achieve a good top speed, or you might not achieve it at all. So, for a stock bike, a gearing change should be within 10% at maximum, that's it!
--
Rear Tyres size change affect Gearing: Rear Tyre change (size) may affect overall gearing, if the profile (height) is affected due to this change. A higher profile increases gearing, while a lower profile decreases it.
A tyre with size 120/70 has a normal height of (120mm x 70%) which is 84mm. But, the broadness of the tyre rim can change the "final height".
A broader rim gives less tyre height, as tyre is rubber, and it expands over the broader rim, causing lesser ride height & lower gearing. And of course, vice versa too. For example, if you fit the R15 rear tyre on your Pulsars, you might not change gearing at all, because although the R15 tyre is of lower height, but the Pulsar rim is narrower than R15's, and a narrow rim raises the ride height.
Front tyre size change doesn't affect gearing, although it may contribute to a different ride height, weight and different speeds on the speedometer.
============
Direct Sprocket Fits:
Remember that your stock chain can be successfully adjusted for upto 2-3 teeth changes in sprockets. Beyond that, you may or may not require a new chain OR you may be required to remove some links from the chain. For the sake of pillion travel, the chain play should be adequate. After re-installing the chain, move the bottom portion of chain upwards, it should go upto 10-15mm only, not more or less than this.
Remember that you might need to purchase the whole kit instead of just the sprocket depending on where you purchase it from. These sprocket combinations are direct fits to the mentioned bikes:
Apache RTR 160/ 160 Fi: Stock Setup: 13/44 teeth.
To overgear RTR 160, use the 14 teeth front sprocket from Yamaha YZF R15/ Fiero F2. (Thanks Aparajith)
To overgear RTR 160, use the 14 teeth front sprocket from Apache RTR 180. (Thanks Khanz)
Apache RTR 180: Stock Setup: 14/46 teeth.
To overgear RTR 180, use the 15 teeth front sprocket from Bajaj Pulsar 150/ 180 UG3 only! But, buy a sprocket holder ring and the nuts to suit, as the RTR ones do not match the Pulsars' sprocket. (Thanks FlyingJian & lijok)
To undergear RTR 180, use the 13 teeth front sprocket from RTR 160, its a direct fit. (Thanks Utkarsh Stunty Sharma)
Pulsar 220 DTS Fi (Old model): Stock setup: 14/37 on .520 pitch.
To undergear it, use:
P200's rear sprocket, 38 teeth,
Karizma's rear sprocket, 40 teeth, (Thanks Praful) HOWEVER NOTE THAT, its not advisable to use Karizma sprocket, because its a very tight fit and the smaller sprocket holes, the threads on the studs get compromised, so you might have to use a new studs set (12x4) everytime you upgrade your sprocket.. plus wear and tear while riding. (Thanks ashwinprakas)
Another choice is to use P180 UG4's rear sprocket (39 teeth). (not confirmed yet, but it should fit I believe)
KTM Duke 200's rear sprocket, the one with 4 fitment holes and 43 teeth (not 6 holes), (Thanks joelkraju)
Pulsar 200 DTSi: Stock setup: 14/38 on .520 pitch.
To overgear it, use P220's rear sprocket, 36-37 teeth,
To undergear it, use Karizma's rear sprocket, 40 teeth, (Thanks Praful)
Pulsar 180 UG4: Stock Setup (14/ 39 on the .520 chain pitch setup. 104 links.)
To undergear it well, use a 43 teeth sprocket from a Duke 200.
The entire Duke 200 chain kit will fit, but the Duke's chain is too long, and you might need to use Pulsar 180 UG4's original chain or cut 6 links of Duke's chain. Cutting Duke 200's (or any other O-Ring) chain's links is not recommended. (Thanks chinmay_7d)
To overgear it, use P220's rear sprocket, 36-37 teeth,
To undergear it, use Karizma's rear sprocket, 40 teeth, (Thanks Praful)
Pulsar 180 and 150 UG3: Stock Setup: (15/43 and 15/44 on .428 chain pitch. 124 chain links.)
To undergear it, use Discover 135 Sports' Front Sprocket, 14 teeth. But you will need Discover's lock plate and nuts. (Thanks Prabhakar 150)
To overgear it, use the complete chain-sprocket kit of Pulsar 180 UG4 or Pulsar 200 (first ver.), which is 14/39 and 14/38 respectively.
You can remove the metal chain guard and instead, use plastic chain guard from Discover 135 Sports (Rs. 74) after drilling a hole in it, as its maintenance free O Ring chain. Don't put oil, just put chain spray on it. Remove 2 chain links from the chain, if you can. Otherwise, it will require link cutting later on as the chain wears out. (tried by Samarth 619 on P180 UG3)
For ONLY slight gearing change, you can use P150 UG3's kit in P180 UG3 (for undergearing) and P180 UG3's kit in P150 UG3 (for overgearing).
Pulsar 150 UG2 (Analog Meter): Stock setup: ~/44
To overgear, use a 40 teeth rear sprocket (with 6 fitment holes) from LML Freedom. It requires cutting 2 links from the chain. (thanks hotshot.vipin)
(The rear sprockets of FZ, R15, Pulsar UG2 and earlier, LML Freedom, have 6 fitment holes. Others mostly have 4.)
Bajaj V15: Stock Setup: 14/42
For overgearing, You can fit Pulsar 220's chain and sprocket kit. Although, since the front sprocket's lock is not available separately, you'll have to use ring lock. (Thanks @AvmPro )
Yamaha SZ-R: Stock Setup: 14/42
To overgear it, use rear sprocket, 41 teeth from Yamaha FZ v 2.0 OR 40 teeth from Yamaha FZ16 i.e. version 1. (Thanks auggyds)
Yamaha YZF R15 Version 1.0: Stock Setup: 14/42
To overgear it, use rear sprocket, 40 teeth from Yamaha FZ 16. (Thanks anirudh_fz1)
Daytona Kits for R15 (may be expensive):
To undergear it, get the Daytona Kit's 13 teeth front,
To undergear it, get the Daytona Kit's 44 teeth rear,
To overgear it, get the Daytona Kit's 40 teeth rear.
To undergear it, use the 13 teeth front sprocket from Apache RTR 160 (get it with locking ring and those 2 bolts) costs around 70 for sprocket and 12 for ring.
To overgear it, use the 15 teeth front one from R15 v2. But beware, you need to loosen the chain to accommodate this one, if yours is dialled at first setting then chances are this one isn't for you. costs about 120 for ring and sprocket.(Thanks to Tanmay26)
Yamaha FZ16: Stock Setup: 14/40
To overgear it, use front sprocket, 15 teeth from Honda Unicorn or Bajaj Pulsar 150/180 UG3. (Thanks iamvik and)
To undergear it, use rear sprocket, 42 teeth from Yamaha YZF R15. (Thanks anirudh_fz1)
Daytona Kits for FZ16 (may be expensive):
To undergear it, get the Daytona Kit's 13 teeth front or 42 or 44 teeth rear.
(For both R15 version 1.0 and FZ16, Daytona kits provide a choice of 40/42/44 teeth sprockets for rear, 13 teeth for front, and either a 122 or a 130 link chain, so you can choose your new gearing accordingly)
Honda Shine 125: Stock Setup: 14/~
To overgear it, use front sprocket, 15 teeth from Honda Unicorn. But, you'll have to shave off the sides of the sprocket so it matches the chain pitch. (Bike India)
Honda Stunner 125 Carb: Stock Setup: 14/~
To overgear it, use front sprocket, 15 teeth from Honda Unicorn. (Thanks cmahajan)
Honda Unicorn 1st and 2nd Gen: Stock Setup: 15/42
Honda Unicorn 3rd/4th onwards: Stock Setup: 15/43
Direct Fits - With Chain pitch .428 (Unicorn Chain)
with Rear 38T (Ambition)
with Rear 46T (CBZ Classic)
With Chain Pitch .520 (Karizma chain):
13T/40T of Karizma
13T(ZMA)/38T(P200)
Hero Honda Karizma: Stock Setup: 13/40 on .520 Pitch.
To overgear, use a 38 teeth Rear Sprocket from P200, but P200 chain length is not sufficient. Adjust your Karizma Chain after installing. (Thanks Shreeni for above info)
KTM Duke 200: Stock setup: 14/43 on a .520 chain pitch. 110 chain links.
To overgear your Duke 200,
1. use a 36 teeth sprocket from P220 DTSi. (confirmed, thanks joelkraju)
2. use a 37, 38, 39, 40 teeth sprocket from P220 DTS Fi, P200 older, P180 UG4 or Karizma. (not confirmed, but these sprockets should definitely fit I think.)
CT100B: (Stock 14/42, .428 pitch)
Since the CT100B's front spocket has a 17/14/4 spec (compared to 20/16/4 for majority of sprockets), overgearing it by front sprocket becomes a challenge.
But, Gen1 Platina 125's 15 teeth front sprocket is a direct fit for overgearing. Thanks to [MENTION=37035]ashwinprakas[/MENTION] for the info.
============
Gearing Commander Website: Guys, we can find final ratio by using any combo of sprockets by using (Rear no. of teeth/Front no. of teeth) formula.
But what if we change a lot of things like, both sprockets, rear tyres, Primary Ratio, rear rim, etc.?
Fear not, there is a solution. You can find out all about the gearing even before trying it out. Plus it has stock info on gearing of many bikes. You can use the below website for calculating gearing by entering everything that affects gearing:->
Gearing Commander: Motorcycle Speed, RPM, Chain & Sprockets Calculator (Credits: Sir Old Fox)
============
I'll be adding more info. Please suggest improvements to this topic by sending me PM's/ posting here. --Samarth
Why can't he respond to me??
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