Hey Guys i have recently got my rear sprocket changed from the service center and what i notice after that is my top speed has gone for a toss....i could do a 130 with ease even with a pillion but not even on a single seat i hardly touch the 125 mark....my bike is P220 FI 2 yrs old now and i use the same engine oil castrol active which the service center guys add....could somebody shed some light as might this be a possible different sprocket put on to my bike instead of the one which should have been...

i have pulsar ug2 with 6 fitment hole but i want to fit old pulsar 220 sprocket set 14/37 for top speed ,but it came with 4 fitment hole what mods should be done

@ yash3: No, it won't. The Chain Pitch in P220 is bigger (.520) compared to Unicorn (.428). You can choose the new P220's rear sprocket (36T) for slight overgearing.

Like I said before, there are not much direct fit & overgearing options for P220.

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.



A Sample photo of the front sprocket of my bike (Pulsar 180 UG3) is given below:



Sprocketing 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.

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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.

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Tyres: 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.

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Direct Sprocket Fits:

Apache RTR 160: Stock Setup: 13/44 teeth.

To overgear RTR 160, use the 14 teeth front sprocket from Yamaha YZF R15/ Fiero F2. (Thanks Aparajith)

Pulsar 220 DTS Fi (Old model): Stock setup: 14/37

To undergear it, use:
P200's rear sprocket, 38 teeth,
Karizma's rear sprocket, 40 teeth, (Thanks Prafultripathy)

Pulsar 180 and 150 UG3: Stock Setup: (15/43 and 15/44)

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 kit of Pulsar 180 UG4, which is 14/39. It might make your bike heavier, but you can remove the chain guard safely, as its maintenance free chain. Remove 2 chain links from the chain, to fit it.

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).

Yamaha YZF R15: Stock Setup: 14/42

To overgear it, use rear sprocket, 40 teeth from Yamaha FZ 16. (Thanks anirudh_fz1)

Yamaha FZ16: Stock Setup: 14/40

To overgear it, use front sprocket, 15 teeth from Honda Unicorn. (Thanks iamvik)
To undergear it, use rear sprocket, 42 teeth from Yamaha YZF R15. (Thanks anirudh_fz1)

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. (Bike India)

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)
Front 14T from Hero Honda Ambition/CBZ/Xtreme
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

To undergear, 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)

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)


More material would be added on later. Please suggest improvements to the topic by sending me PM's. --Samarth

I've an RTR180 with 14/46 sprockets. I'm "joelling" it, which will result in more power. Later this year, I'm going on a long long ride across India to conquer the himalayas (please note I'm from the southern end of the country). As this ride (yes I'm riding all the way) will involve lots of highway riding, I'm looking to overgear my bike by means of sprocketing for increased top end.

Are there any 15T gear sprockets or 44T rear sprocket (or both) that I can use on my RTR180? The RTR180 service manual says the rear 44T sprocket from the RTR160 is not interchangeable with the RTR180.

Another query - is is possible to swap out the entire chain and sprocket set with that of the R15s 14/42 setup?

Awaiting the experts reply....
Thanks,
Lijo

But since we're talking Joelled bike, you can go ahead with this.

Guys, I just googled my article and found it here, without credits:

• - Gearing, and re-gearing your bike. • NSIT Car Fanatics Forum •

Thanks bro. Yes, I'll get the stock one now. But when I hit the highway, I think I wont mind the lag to reach there given I can do a better top speed....

All these 17 PS bikes reaching higher speeds than 124 (like RTR180, Karizma, R15, etc.) have longer 5th/ 6th gears.
With acceptable weight & city based gearing, a 17 PS bike should do some 117 kmph or so real.
So, its never advisable to over-gear these 3 bikes. Nothing much will come out.

But since we're talking Joelled bike, you can go ahead with this.

@ nkz: Yes, 6% is about it for stock bike.

@ FlyingJian: Thanks. I have added that info in first post for all to see. And a Joelled bike performs good with overgearing too.

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Guys, I just googled my article and found it here, without credits:

• - Gearing, and re-gearing your bike. • NSIT Car Fanatics Forum •

Hi friends,

I am Maneesh Joshi from Pune.

I have a 10 year old Pulsar 150 - the very first model, wire wheels, round headlight, analog instruments. The front spkt is 14 teeth, 2 holes and rear is 42 teeth, 2 holes. Chain is 114 links, pitch of .428

I am a tourer and need low revs on the highway. Last Sunday, I did a Nasik and back trip to check out my bike for the forthcoming trip to Leh in July. She was doing exactly 60 kph at 4K rpm and 70 kph at 5K rpm with a total load of about 120 kgs.

Any suggestions for overgearing only the front sprocket by about 2 teeth? Let me explain. In mountains, I would prefer the low gearing of the stock setup to enable comfortable climbing while in the plains, the high gearing would ease cruising. Also, it is much easier to change the front than the rear, as all of us on this thread know.