Sprockets 101: Torque or Top End Speed

We get a lot of questions over here at Common Motor about Sprockets, so many in fact we thought it was time to go in depth on teeth counts, gear ratios and everything sprockets. In this video we dive into the depths of how to know what sprocket setup is best for your bike; what a gear ratio is and how to find it; top end speed versus torque; how do I know what drive chain length I need after changing sprocket size; and the list goes on. Don't stumble about in the dark looking for spacely sprockets or caswell cogs, by the end of the video Brenden will give you all of the information you need.
Parts You May Need:
Front Chain Sprocket | Honda CB350 / CB360 / CB450 and Sprocket Retaining Plate: www.common-mot...
Front Chain Sprocket | Honda CB500K / CB550 / CB750: www.common-mot...
Rear Chain Sprocket | Honda CB350 / CB360: www.common-mot...
Rear Chain Sprocket | Honda CB450 / CL450 / CB500T: www.common-mot...
CB550 37 Tooth Rear Sprocket: www.common-mot...
Drive Chain (530 Pitch): www.common-mot...
Motorcycle Chain Breaker / Chain Press Tool Kit:
www.common-mot...
Honda Chain Lube: www.common-mot...
www.common-motor.com

[@wanderingtrd9382]

Not often you get a company like this who cares enough to teach people how to do it all in depth and talk with its customers. Videos have gotten really good from the first ones and liking the new music! Thank you common motor for all the dedication! (Thats Common-Motor on the Internets)

[@xxDOTH3DEWxx]

Big fact

[@Common-motor]

Our company is only as big as our community! Keeping wrenches in hands and bikes on the road is kinda our whole bag.

[@SeakalalaMojapelo-yg8jm]

Thank you, that deserves to be 101, life changing details.

[@IceBergAbe]

Regarding the picture at 9:01, if you increase tooth count on the drive sprocket, I’m pretty sure you’d Lower your RPM(-500) at a set cruising speed, not raise them(+500). It could also be said that you’d increase your cruising speed at a set RPM

[@prototype9904]

I noticed that to haha

[@jemand-6594]

Why has this no views ? Such a good video! 🤙🏻

[@Common-motor]

I'm glad you're digging it!

[@killer4981]

Because the audio

[@chachasheeda1931]

Exactly!

[@mark.e.p]

This is really informative. I find even with a 5 speed gearbox on the 450 with standard gearing l'm searching for another gear so l've gone up one tooth on the front and it's perfect. Great stuff guys!

[@Stylelss]

One of the best videos I’ve seen for this topic

[@saadathasif5775]

From a large sprocket The torque is reduced but the mileage is increased and the resistance against the frontal wind is increased and in addition it uses more power when going uphill.

[@NA-oq4ty]

Large front sprocket or large rear sprocket

[@saadathasif5775]

@@NA-oq4ty Front Sprocket with 16 Teeth

[@seatime674]

On my newer KLR 650 I went up 1 tooth in the front and dropped 4 in the back and lowered Rpms 950, I created another freeway gear😊

[@douglascary9280]

I've been wondering about the sprocket set up. THANKS!!!

[@michaellawrence5492]

Torque gained from off the line to a possible higher top end gain on a level I would say is stated more or less. Not mentioned though is the real useful effect occurring upon "each gear" from first to top gear in regards of the change in mph range gained or lost of each that will be effected. What the factory suggests is an all round market guess. I do not sport bikes anymore I simply just cruise ride thus go for taller gears for reasons of mpg and lower notes from the exhaust, however first one must learn where the average rpm is upon their use and move it up or down in rpm to mph ridden most of the time.

[@lancegordon2363]

Thanks this was exactly what I was needing to find out and you explained it very well

[@abdulazizalhamar_]

Woow!! This video is so informative and everything is clear, i loved it.👌🏻❤️

[@harrisashraff]

Really a good educational and informative video. This video deserves more views.

[@stevieneilson2451]

Best vid I have watched regarding this subject. 👍🏻👏

[@whatacrazyride1658]

I stumbled on this and that bike looks just like my first bike....Honda 360T. I haven't seen one in years. Nice

[@1989Rangerxlt]

Great video I would like to know what would be a good cruising sprocket change for a 125cc xpro Cafe style bike?

[@mebeasensei]

If you want more torque, which patten is better for chain life if the ratio is about the same? A longer chain or a shorter one?

[@joachimvonborstel1258]

Wow.. change that tire while at it.. :) Love the work you guys do!

[@Common-motor]

Thanks for your support!

[@creed426]

Thank you for your video, I have a question: what does it mean 15 /48 on sprockets, I would like to know which is the best sprockets to have on a Suzuki GSXR 1100 stock motor after adding Mikuni RS Series Carburetor (RS36-D3 K) - 36mm. For fast response. Thank you again.

[@brokemangarage729]

Great information video. Been holding back on buying sprockets.

[@nickjames205]

One product I would love to see you guys make would be a clutch push rod seal retainer. Something that would hold the pushrod seal in place and address the problem that the 350s seem to have. That is when the seal pops out and pukes oil all over the road.

[@terencemeehan8237]

And the rear tire. It happens on the CB450 also.

[@SSCartelMuscle]

What's the best sprocket sizes for top speed on Kawasaki H2 so I could go 248 mph

[@tammyforbes2101]

I had a new but old 74 CB550 In that exact orange paint job, he is setting in doesn’t of but that’s a 360 I think! Couldn’t see it to good! Hell of a bike I put 75k miles on it and at times used it like a dirt bike to even mudded it some time 😂! Thing had a big ol crash bar in it so you could just lay it right over no problem wouldn’t mess a thing up! I should have never sold it, my dad had the 750fourk to in brown! Ugly color but nice bike thing would fly for it’s time! It took a fast car to get around you and other bikes didn’t have a chance especially the harleys we would just ride away from them easy!

[@TheMrFelin]

Does this mean that if you put bigger front sprocket or lower back sprocket that will will get better gass mileage? That way you won't need to rev the bike as much to get to the wanted speed?

[@Common-motor]

Exactly! If you are getting the two sprockets closer together size wise you are increasing top speed which would give you a bit better fuel economy. You will be going faster while the engine is working the same as it used to at a slower speed. It's probably now going to be you much but that's the idea.

[@steep_vi77ain89]

Excellent video, I find it a bit annoying that 1st gear on my bike doesn't really get through a turn at an intersection. So my 2 choices are either rev out first and complete my turn or grab for second halfway through the turn. Will changing my rear sprocket size from 41 to 38 help get me a few extra mph in 1st? Or do I have that backwards

[@Common-motor]

Forgive me! I had a huge lapse and I had it backward. Going down in size will give you a bit extra in first. I was completely wrong the other day!

[@thegrimreaper6926]

It helps increase your speed but lessens your torque.

[@bonsatago9220]

Which is better for better mileage in cruising speed?

[@bruceschmitz1984]

I have a Coleman BT200x I put a 10 tooth on front and 60 on the rear tire 6-1ratio which Wii give me lots of torque correct it’s with a torque converter 30 series

[@malikjoseph8171]

I got a question from 2.125 (16-34) to 2.0 (17-34) does it makes a difference in top speed?

[@robertkavanagh774]

I have a question for you, I know zero about sprockets and chains. I have a 2009 klx250s don't know what type of chain and sprocket I need. It's still on my bike. How can I get the number of teeth while still on my bike.

[@ramcharger9146]

Really wish you could get Best of both worlds with the torque on takeoff and the top speed

[@DeMoNiC36]

Thanks for the information 👍👍👏👏

[@mrt271984]

08 kawasaki eliminator bn125a want to gear down what would be the best setup for that. quicker off the line speed.

[@jayshaw63]

I'm in the process of changing my wheel bearings. When reinstalling the four stud bolts into the hub, should the studs be greased? There was light surface rust on the studs and inside the sockets when I pulled them out.

[@Common-motor]

Greasing helps keep them from sticking when trying to remove them in the future.

[@Oldvelocette]

Great video thanks for posting 👍🏻👍🏻

[@Common-motor]

Thanks for watching!

[@jimcox6661]

I have a Honda rebel 250 , I'd like more top end for highway ?

[@jolianelian9064]

I have 2017 crf250r stock sprockets 13t-49t i think to replace it with 14t-48t i want to get more top speed and still get power in the wheelies

[@emoservedwithfries]

I have math clarifications for you: In your example of 2.125 and 2.117. If your jumping from a lets say... 2.53... (I don't know if that ratio actually exists) does the sprocket weights matter? I figure in my scenario the 2.117 is better because more weight is pushed to the center of the bike.

[@ragemadd6340]

This is helpful, thanks 👍🙏

[@AceTim1080]

I don't quite understand the text at 9:02. If a smaller front sprocket gives more torque, but less top speed, wouldn't it require a higher RPM to reach the same cruising speed as a larger front sprocket, not less?

[@mark.e.p]

I've gone up from a 15 to 16 front sprocket and it drops the revs by about 500 rpm than previously as I felt I was needing another gear.

[@garyhannan4682]

Those were my thoughts too

[@YellowCab76]

Do the sprockets have to be changed in pairs when looking for a higher top speed or would changing one of the two be ok?

[@lauriskojro2399]

Only change one for example by one tooth at front and you will see a noticeable feeling.

[@DheszAcosta]

What's the best combination for z200 motorstar.. Thank you

[@devendraharrichand6902]

What's the best sprocket combination for both speed and power

[@malikjoseph8171]

Thank you, i've learned alot😊

[@Foxlone]

Thank you very much!

[@charlesbarnett2724]

Very helpful. Thank you

[@Rocke03]

Does all rear sprokets need the cush? Or bushings

[@jayheyliger2736]

What size sprocket should i b running on a 420 chain 10 tooth in the front 38 in the back currently?

[@M1IKIE]

So now I'm curious bc I want more torque so should I go smaller in front or bigger in back?? Which is better and why??

[@Common-motor]

both will do the same thing! changing the front is just cheaper and easier.

[@TheBobyoung10]

Any way to increase both top end speed and torque or keep the torque the same as stock id like to get the full 120 out of my speedometer but i also live in a hilly area

[@kieranbrodrick960]

I’ve got a Lexmoto Venom sk125 22 with a 15 tooth sprocket on the front and a 41 tooth sprocket on the rear, it currently tops out at about 60mph, i want a higher top speed of like 70 but want to have decent acceleration aswell, could y recommend me a sprocket size combination so achieve this. Good video aswell!

[@Common-motor]

Ahh, the ole' conundrum. You can't get both, you either get more top-end speed or more torque/acceleration.

[@Hsp44]

@@Common-motor does shorter gearing actually increase the torque or just make it come early??

[@thegrimreaper6926]

@@Hsp44 no it decreases. If you have less than that it will increase your speed but reduces your torque.

[@joshuasalisbury789]

So if I went up to a 15 front from 14 I’d get more top speed but my 125 struggles to rev to top of 5th (top gear) so would this be ok?

[@jimflammer9370]

Great video, thanks man.

[@samuelmontenegroserniotti7146]

Would you recomend to tune your sprockets so your cruising speed rpm matches your top torque foot-pounds rpm? For example lets say that my bike tops torque at 3000 rpm. Would it be ideal for me to tune my sprockets so at top gear and full throtle my bike remains at 3000 rpm? Or It would be preferable to aim for the top hp? Wouldnt it be too harsh for cruising? Would this make the engine work at its best or would we be forcing it to perform under more stress?

[@dougsz28]

I want to reduce engine RPM at 70mph from 5000 to 4000, what sprockets should I change and by how much?

[@caroltenge5147]

get a 17 tooth in front, and 38 in the rear.

[@charlezboboiboy6200]

I suggest u try to reduce the rear sprokets 2 tooth at the time till u get the result as u want but if added more tooth u will get high torque n low high end speed also increasing the rpm

[@jesusleonjimenez8393]

By any chance, you have some research papers that relate the role of torque and speed with the size of the sprockets? I am an engineering student and that will be helpful, thanks.

[@AJ-nf6gf]

Just check the ratio difference, it will give you torque reduction/increase

[@MrReniks]

whats the difference between a rubber dampened front sprocket and a steel one?

[@maddmavic]

So I went one up on the back a while ago and didn’t care for it but is that the same as doing one tooth in front or is there more effect with back then front or opposite ?

[@Common-motor]

The front will make the change twice as effective whether its up or down. We recommend changing two teeth at a time when changing the rear to have a noticeable difference. Front sprockets are also cheaper and easier to replace.

[@maddmavic]

@@Common-motor I tried one back a while ago and it was a Moto now change but it wasn’t the feel I liked my quad has such a low first gear I barley use it with factory. So I am going to try a ore tooth in front now n see what happens

[@Rohitnarayankar27]

I have a yezdi roadster with stock 13 in front and 45 in rear ( i might have wrong info) want to change it to 12 front and 48 or 52 rear will it increase my mileage as well as will have taller gear soo I have to shift less in trafic and better at highway cruising and will it be better for ladhak ride or Nepal ride.

[@NA-oq4ty]

Not an expert so this is my two cents. No it won't increase your mpg. I don't know the bikes but you are increasing applied rpm which uses more gas at speed. Your change out looks like it would be good for occasional off roading.

[@toofastnobrakes]

Would one tooth up in the front be enough to help lower highway rpm?

[@Common-motor]

You should be able to lower RPM by about 500 in most cases.

[@bruceschmitz1984]

I have a mini bike with cat 30 series 10 tooth front and a 60 in back should be better torque

[@olafsolafs9950]

Soo if i put on small one in front and back small one in back on eletric atv what it will do?

[@Common-motor]

It depends where you are starting! The closer in size front and back is, the more top end speed. The further apart, the more torque.

[@bylifeorbydeath]

What was the torque spec?

[@dfox3076]

ive gotta say tho i mainly wear out back sprockets so i have no idea what this guys on about #yeah im pretty rough rider but do main Tane the the main but

[@Common-motor]

Are you maybe keeping your chain too tight?

[@dfox3076]

Na i don't reacon matey not the way I ride im better off with a tight chain about 1inch up an down with the swag taken up not too sure i know if its loose just fucks me gear but not sure about the front sprocket cause I don't seem too wear them out

[@xatzimimikos]

Is that possible to be done in a k 1200 s?

[@marcofelipelopes3081]

i got a question, how can i calculate the aproximate diference in speed for each gear? in %. i want to change the sprokets on a cub i have, orginally is 50cc but now it has a 70cc engine. and i want to compensate with the sprokets. the option is going from the stock 48/13 to either 48/14 or 45/14, so stock is 3.69 ratio, then 3.42 then 3.21 respectively .. i dont want too much difference, just maybe a increase in top speed from 50kph to 60kph

[@Common-motor]

Hey Marco, Im sure there is an equation for it but I don't know of one myself currently. Sprocket ratio is primarily what's used in the industry but if you come across an equation I would love to know it

[@Cuzwoo]

hey all. Please help. I've got a 125 cruiser and my front spocket is a 14T front and rear is 41T. Im thinking of changing both of them too a 16T front and 48T rear. I've found out the diffrent ratio's and its going from 2.93 to 3.00. If I was to change the sprockets over would that put stress on my engine or would it be fine? And is having a higher number on the ratio better or not? Thanks

[@faisalaryan2101]

Honda cg 125 top is good speed plz help sparkat no Original sparkat 15 ..38 but no good speed plz help sir top speed

[@ColHeat]

Anyone know why rear sprockets are not reversible?

[@davesearches4950]

Not that there's anything wrong with changing the stock gearing, but as Jay Leno often says, "The guys who designed it went to college, they know what they're doing". I tend to agree with that sentiment.

[@MrFurley69]

And they also set bikes up to meet emmision requirements, and best fuel consumption. So yes, you can change the sprockets and get better performance

[@d-nice2866]

14t 36t is it possible to get more speed and a lil torque changing sprockets?

[@Common-motor]

Nope! One or the other. They are opposing forces in the game of changing the sprockets.

[@astaroth282]

What bike do you have?

[@richardconnor1789]

If I go one down on the front and two up on the back is my speed faster or slower Than wats displayed on the speed odometer??

[@missfixitCanada]

Don’t count me on it but I believe that the sprockets wouldn’t change the speedometer since the speedometer reads off the revolutions on the front wheel, so I don’t think it would make any difference

[@danimoro100]

Well explained 👍

[@Common-motor]

Glad it was helpful!

[@MrRixxxYT]

If my bike does 15kmph smoothly on 1st gear and i want to increase it to 20-25kmph smoothly on first gear what should i need to increase or dcrease the rear sprocket teeths ?

[@daddyhobo2]

increase tooth count in front sprocket and decrease tooth count in rear sprocket. boh options will give you a higher speed in each gear. i suggest going up 1 tooth count on your front sprocket

[@MrRixxxYT]

@@daddyhobo2 thank you brother 🙏

[@rapturev1457]

thanks!

[@shanedubray1388]

So if we do the 17 front and a 34 back, the speed will increase?

[@KevinMartenUglin]

1t on front sprocket equals -3t on back sprocket so if you change lets say 40t rear sprocket to 34 it changes speed a little bit and if you switch out a 14t front sprocket for 17t it increases the speed

[@tyee4u]

your graphic at 9:01 contradicts everything you say previous.

[@mightymighty3236]

Tell me.if i go down one tooth on the front how much mph do i lose on top speed

[@Common-motor]

It depends on the motorcycle! You will usually have a 500 rpm gain going at the same speed though

[@jayshaw63]

My CB360T has a chain guard riveted to the sprocket. Not needed?

[@Common-motor]

I'd leave it if you have it and its in good shape! Not necessary safety wise is a good idea.

[@manuramesh1]

what if front 15 to 14 and rear 47 to 49, no need to change the chain link?

[@Common-motor]

You should be okay! If you are already at an extreme of your chain adjuster maybe not but otherwise you might be fine

[@kuttalu]

your stock setup is 15/47, which means your drive ratio is - 3.13. you're changing it to 14/49 wich result in a final drive of 3.5. oh boy, you're gonna loose a hell lot of top end and gain wheely popping acceleration. with this set up, you're gonna hate your bike on highways.

[@stevenstee5066]

Need the tank present un your left side😜

[@jonathanbarela8269]

Hey just a question. On the chart in the video at exactly 9:00 minutes is. When you put +500 rpm does that mean your bike cruises at 500 reps less or 500 reps more. Im trying to get top end speed, so i need to add in the front and reduce in the back. But does that mean my bike will run 1000 rpm higher or lower?

[@Common-motor]

Hey Jonathan, you have it backwards! The +500rpms means if you make that change(in this case +1 tooth on the front sprocket) you will need to be going 500rpms faster to maintain the same speed. this would decrease your top speed but increase the torque. If you are wanting increased top end speed you want to either DECREASE the FRONT sprocket size or INCREASE the REAR sprocket. Easiest and cheapest way to increase speed slightly it to go down 1 tooth in the front.

[@musabzain2168]

@@Common-motor I think u got it wrong there. Think again

[@Common-motor]

@@musabzain2168 We totally got it wrong the day I left this comment! It's exactly the opposite of what I said. I've explained it too many times and now I'm mixing things up haha. Bringing the sprockets closer together in size=more top end speed, pushing them further apart=more torque. Thanks for catching that Musab.

[@williamhaines856]

great

[@gloriouschannel3683]

guys help me out. i have a yamaha yzf r125. with a custom 183cc cilinder malossi kit with powercommander. my mc does 125km/u. stock it normally does 130km/u. and right know my mc is max at 10k rpm. i struggle to stay on the highway. what do i do to get more top speed easy. right know it does 100km/u easy then struggles at 110km/u to 125km/u.

[@Common-motor]

I sounds like you're giving it everything its got! Even getting on the highway with a sub 200cc motorcycle is good.

[@gloriouschannel3683]

@@Common-motor so i can't do anything to make it faster? Without breaking the bank

[@Common-motor]

Thats what I'd imagine. Not familiar with that specific bike but you aren't going to gain significant enough speed to warrant the price.

[@gloriouschannel3683]

@@Common-motor the weird thing is with the original 125cc yamaha engine people buy a ecu and it goes 150km/u. Thats the weird thing

[@kuttalu]

@@gloriouschannel3683 1- change full system exhaust. 2-drop rear sprock tooth by 2 or 3, 3-remap the ecu to perfomance mode.

[@entertainmentwithsocialedu4473]

Sir, I want to make my Gixxer Suzuki 150cc on good speed , how can I do it and by changing sprockets . Plz Say me about this.. what I have to do for my bike to make good speed , I don't have any idea Sir , so plz plz help me out .

[@entertainmentwithsocialedu4473]

Sir, I have Suzuki Gixxer 150cc Bike , I really want my Bike on little bit more speed , what I have to do ?

[@Common-motor]

easiest way is to go with a slightly bigger front sprocket

[@noahway13]

If you are used to riding pedal bikes, it is the same effect.

[@adrianaosuna9426]

Harly

[@67maxfield]

How tf do I get first gear to go faster!!!

[@xCLUNKx]

You don't, 1st is to get you moving, sounds like you want to kill your engine in 1st!

[@67maxfield]

@@xCLUNKx lol ive come to learn this. I thought there was somethin wrong w my bike. The gears are a tad short for my liking but its mostly cuz i suck and dont wanna consistently switch cause theres so many fucking stops around town lol. But im gettin used to it

[@AlmightyThor82]

You need a tire dude!

[@sanesaint8725]

And I think you don't answer anyone's questions why even put up a video

[@foonigan3571]

comment 100 :D

[@arronjohnston742]

good video, could of been better simply by leaving the music out of it.......... so annoying when trying to listen 😠😡

[@248714]

Awesome vid. Very Helpful