Go faster by changing sprockets!

[@thehoneybadger8089]

Dividing the DRIVEN by the DRIVE will give the gear ratio, which, for most of us who are mechanically inclined, is more understandable. 45/15->3:1 and 42/14->3:1, 48/15->3.2:1, 42/15->2.8:1, 40/15->2.67:1, asf. The lower the ratio, the higher the speed, within the power limits of the engine, of course. Remember, it is normally easier to change the DRIVE sprocket and usually allows use of the same chain. However, going smaller causes a tighter turn which leads to more stress on the chain. Going bigger may cause clearance problems with the engine case, especially if the chain is allowed to become a little loose.

[@DNiits]

(2) So, by dividing 14 by 52 (14/52) you get 0.269 and by dividing 14 by 46 (14/46) you get 0.304. If you calculate the percentage difference between the two (0.304/0.269), you end up with a 13% difference. 13% of 150mph is 19.5mph (150*0.13=19.5). Your new top speed will now be 169.5mph with the new sprocket set up! (150+19.5=169.5) Hope that helps =) (see first part of this text below)

[@bryansmith943]

😅plp00lpp0ppplp0009o9o9o9op0lplk79p0plppllpll6ullp0llp7j7😢iul0lpllllllllllil😢ki😢kl8i8illplk😢llp0ll7ill😅p😅😮😮

[@Richard-yq2mm]

I tried this way back in 1976 on a new Kawasaki KZ900 LTD (I'M OLD AS DIRT). After the 500 mi. break in, installed all kinds of goodies. New seat, riser with pull back handlebars, a 16" hog tire & wheel and 4 into 2 drag pipes (took the baffles out) SWEET sound. Adjusted the carbs & adjusted needle valves (more fuel). Last thing I went up 2 teeth on the drive sprocket. To adjust for smaller diameter back tire and raise the top MPH. This grandfather of superbikes now did over 140+. Way back then that was quick, fast, loud and King of speed for a naturally aspirated bike. Then in 1981 I bought a 1976 sportster XLCH and had a machine shop make it about as fast as the Kawa. But that's another story. Thanks for reading my long winded comment.

[@jbroadbelt6]

I read this comment but it took me 3 years

[@awizardalso]

Years ago, I rode a 350CB Honda back and forth 40 miles from Millersburg to Canton, OH 4 or 5 times a week. I dropped the back sprocket from 36 to 30 teeth, since the bike wasn't made to cruise at 60mph. The only problem is that the bike was no longer suitable for 'city' riding. It was like starting out in 'second' gear. Increasing the rear wheel sprocket tooth number will increase acceleration but decrease maximum speed due to to engine RPM limits. Conversely, decreasing the rear wheel tooth number may increase cruising speed at a particular engine RPM, but it decreases acceleration and also decreases clutch life! Still, I appreciate your video.

[@Birdie_MH_]

20:05 The 17/42 gearing is actually a 21% gain from the original 15/45

[@markabrams7936]

For what cc would this be suitable for, really need to know. Plss!!!

[@Birdie_MH_]

Mark Abrams Any cc really, from a 100cc dirt bike to a 1300cc hayabusa. It just depends how you want the motor to perform, go bigger for more torque off the line or out of corners, go smaller for more top end and straight line speed

[@nyndmrts]

No need for rocket science, just ride a bicycle with gears and understand yourself, by witnessing how much effort you need in each gear. How easily you can accelerate with smaller front gears and how fast you can go, after it try shifting gears. Best to understand the logic...

[@aymanabantas2309]

is 17/36 good for a motorcycle 250cc?

[@nyndmrts]

@@aymanabantas2309 her motorun dislisi ayri be abi. 250 cc demekle olmaz.

[@kennybruno7584]

Loved the video! Great basic theory of how the different sprocket ratios work. The math at the end was off by 0.03 when he divided by 0.30. He should have divided by 0.33 using the same number as he used earlier. As a result it would have only increased 21% instead of 33%. I was scratching my head at the end with the math portion which is why I decided to clarify how he got to that conclusion for anyone else wondering the same thing. No biggie...he still made his point very clearly, thank you!

[@theoverengineer]

Kenny Bruno Good catch. The correct figures are inserted in speech bubbles, only showing when viewed from a desktop/laptop.

[@fitz235]

You're spending way too much time explaining very basic math, But thank you for taking your time to make this video. I appreciate anyone who shares knowledge.

[@MisterFuturtastic]

There are some people who are terrible at math like myself though who much appreciate the simplified version! :)

[@fitz235]

Sorry about my selfish comment :)MisterFuturtastic

[@theoverengineer]

***** Thanks for watching guys. Yes, in any case, I don`t want to insult anyone`s intelligence, I just make basic videos and I list all the steps for a task, so others can try new things and save or explore.

[@fitz235]

***** theoverengineer Yes, thanks Dylan and thank you OverEng. I'm sorry if I came off judgmental or critical. I really appreciate people like OverEng to educate others and Dylan for recognizing and speaking up for OverEng.

[@theoverengineer]

SaigonIntel Thanks for watching, no worries.

[@theoverengineer]

Perfect math. Can also (0.304/0.269) = 1.13, leave the answer on the calculator`s display, then x 150 = 169.51 That`s your calculated final theory top speed. Wind resistance over 120 mph will eat much of that increase away.

[@Tushad1985]

This is brilliant. Finally understood how this works! Thanks for taking the time.

[@motorizedbicyclenation53cu90]

Weird shit is I’ve had some set ups go faster with a bigger sprocket like a centrifugal clutch or engine that just needed a little more so it could hit its max rpm but hell it happens sometimes lol depends on ya set up usually smaller is faster but weaker and larger is more torque

[@shawngoldsberry747]

Hey you did an excellent job explaining this to people. It's amazing how many lightbulbs you turned on. On the other hand it's disgusting how education system didn't turn these light bulbs on.

[@04enduro]

why so many people still not understand and asking simple questions? READ THIS AND THINK ABOUT IT: - Bigger drive/engine sprocket = increase top speed. - Bigger driven/wheel sprocket = lower top speed. NOW THINK ABOUT THIS: - Whenever you increase speed you LOSE engine power and acceleration - Whenever you lower top speed you have MORE power and better acceleration. - If you want exact calculations on how you can increase top speed or power to your vehicle, you really have to watch the whole video and use the same formula he uses, if you don't understand, rewind the video and listen to him carefully. OK one more time: 14/50 is my standard. *Changing one sprocket at a time: 15/50 will be more top speed BUT less acceleration. (+1 to drive sprocket) 14/52 will be less top speed BUT better acceleration. (+2 to driven sprocket) *Changing both sprockets at the same time: 13/48 will BOTH lower top speed (-1 drive sprocket) BUT also increase top speed (-2 driven sprocket)...(from standard remember!). So that means changing both in the same way (less teeth OR more teeth for BOTH) can change the top speed and acceleration, it just depends how many teeth you change on each to how much change it makes. This means: when changing both at the same time; -1 drive/-1 driven is less of a change than -1 drive/+1 driven. +1/+1 is less of a change than +1/-1. Refer to the previous details to see which sprocket does what... -Technical info.: As the video shows, you cannot physically change your engine output Horsepower, it just effects how efficient the engine is at driving the wheel... more top speed = less engine efficiency, less top speed = better engine efficiency.

[@theoverengineer]

04enduro Well said, thanks!Here are some ideas why people ask simple looking questions: (there`s nothing wrong with anybody) - Showing once or watching once does not translate into mastery of anything or does not enable anybody to function at a self-sufficient level of a skill (any skill, eg hanging a door, loading a magazine, lube clutch cable) - Inverse proportions are not instinctive. Direct proportions are instinctive. (Bigger engine = more weight) In direct proportion the words indicating change (adjectives) are both the same, positive (bigger, more). Could be negative too, but both, again. (Smaller engine, lighter bike). Inverse proportions are tricky (bigger rear sprocket = less speed) because the adjectives are opposites. On top of this, we have a mix of direct and inverse relations in the same topic. In changing sprockets some relations are direct (bigger front = more speed), and some relations are inverse so patterns become hard to follow. - Most people don`t know how learn or to use a textbook: read/watch - start skill - read/watch on - continue with skill - read/watch more - continue with skill - finish, check back & repeat with another set of numbers - Learning takes time: people first observe bike performance fine detail, then think up some possible solutions, then search for answers, then make some sense of the answers/solutions found. Curiosity moves all this, it`s the best and biggest thing that has to happen for learning to take place. - The skill of comparing final drive combinations in percentages is not explained. Comparing drive ratios as decimals is one thing, math with % is another skill, building the 2 together is skipped over around 17:25 - 18:30 - The skill of calculating speed gains/losses in km/h or mph is not explained, just implied in 2 x 11 sec around 18:45 & 20:20 The short math is: say bike tops out at 160km/h, new final drive provides a 5.4% gain: new theory speed is 160 x 1.054 = 168.64km/h. If people make the effort of being curious, want to learn something and ask questions, I make the effort and answer them. Over and over. The same questions. I don`t mind. Learning basic new skills needs frequent checks anyhow, plus it`s new people every time. I also don`t mind viewers helping other viewers with offering re-phrased versions. For learning to happen, if a certain explanation is not fully meaningful, alternative or different explanations maywork out. Usually, a learner gets something new out of every different approach. With one single explanation it is never possible to capture complex things, plus there are different learning styles, too. Thanks for sharing your summary and watching!

[@04enduro]

theoverengineer You're a very humble and considerate person and made some good points in that reply that I agree with. It personally seemed, to me, as though some people never even pressed play on the video though, this is why I wanted to make a summary. I just want to state that my intention wasn't to be demeaning or mean to anyone, I just wanted to make a bold comment that is easy to read so hopefully it could answer some questions. Great video btw!

[@mohammadnisaar2179]

Hey 04enduro,theoverengineer. The statement of more top speed less efficiency is wrong,as you know bigger drive sprocket more speed at the same rpm compared to the small drive sprocket...at the same rpm more speed means more distance you are covering with same fuel consumption... More distance with same fuel consumption means more efficiency I assume you should have worked that much out for yourself funny enough and also upgrading bigger drive sprocket is not always the case because it is limited by the space provides by the manufacturer while you can relatively step down the driven sprocket for the same results...but top speed is not the only solution for higher efficiency we also need enough torque to maintain it that's what the aim of the manufacturer's is...to maintain good speed with adequate torque for best efficiency...We can always tweek and play with these as per our satisfaction but at the end of the day...sharing knowledge upgrades it...no hard feeling lads...I love and respect the way you question to know the things instead of just blindly believing it...do consider writing back...peace✌

[@waspbulgasari4498]

theoverengineer well said, you're too kind of a person! now you can be a teacher, jwk bur here I ask this, can you still do this video(again) with the engine dispacement coefficient on the calculations?

[@robertheinkel6225]

I put a one tooth larger front sprocket on my Honda 350, years ago. It lowered the RPMs at road speed, but was harder to launch off the line.

[@jordanhoyle577]

you did good because i now understand thanks

[@Joms7]

same here, thanks. from philippines.

[@ghara8567]

My man what about the RPMs you making the engine rev faster but in theory you're really not going faster that was the RPMs you were doing it's going to be revving at 6,000 RPMs I think you got a little bit mixed up there watch some other videos

[@jordanhoyle577]

@@ghara8567 who?

[@ghara8567]

More torque takes off faster less RPMs in the short end but you lose speed in the top end I think that's what you were trying to say

[@jordanhoyle577]

@@ghara8567 where did I say that? 🤔

[@froberts120046969]

I went up 1 tooth on front and 3 down on rear. My speed stayed relatively the same but i did notice a significant drop in top end RPM's

[@noblentnt4217]

How big of a drop in rpms? I have a 250 and I'm trying to make it not work as hard at highway speeds

[@TroyaE117]

Guys, be careful about altering final drive ratios. The manufacturer has put a lot of time in to selecting them. That does not make them all perfect, but they are likely to be a good compromise between torque at the back wheel and top speed. If you change the gearing you will trade torque for speed.

[@brufnus]

+TroyaE117 Indeed, but for certain uses it makes perfectly sense to do it. The factory compromise is largely to satisfy most drivers with an acceptable tradeoff between top speed and acceleration. Street racers will benefit from a higher ratio, whereas tourers might like to reduce the engine speed (which I've done myself on my GSX 1100 EF with 16/40 teeth instead of 15/42 standard. I love cruising like that, with only some 3.000 rpm at 90 km/h. :-D

[@thegatesofsleep]

TroyaE117 I agree with you Troya, however for riders like me it makes total sense. I'm thinking about putting a smaller rear sprocket on my ZX1000R because I'm a BRAND NEW rider and I 100% don't need all the acceleration/torque that the factory sprocket produces. When I'm a better rider I will put it back to stock, or even trade some top end for more torque.

[@brufnus]

It does come at a price though, if you increase the ratio later on. You'll have to rev the engine faster at any given speed (that's why I went the other way like you want to initially - I have plenty of torque despite of this, and I love cruising with less engine rpm at any given speed). c",) But then again - my GSX 1100 engine enjoys almost full torque (about 10.7 kgm) at less than 3.000 rpm.

[@babymetalfansmetalfans9615]

+brufnus great!!

[@fixitrippitreckit6963]

TroyaE117 yes finally someone who under stands

[@kraven4444]

19:48 You rounded the .33 to .3 and that makes a big diff. .4 / .3333 is 1.20 ( 20% increase ) and .4 / .3 is is 1.333 ( 33 % increase )... There's a big difference between 21 and 33.

[@lsatrelawny4761]

I spotted that as well. Gives 242, more realistic.

[@theoverengineer]

Exactly the effect. Gain top speed will always lose torque and acceleration. Good stuff.

[@chachasheeda1931]

What if we only change sprocket From 14 t front and 41 t back To 18 t front and 30/28 t back Why it slows down in 4th gear.. what is the solution to that . Imean without alteration..

[@Justfun-gg8xi]

@@chachasheeda1931 That 18t and 30t will give you a lot of Acceleration Loss. but still that Topspeed will be almost Same Or May decrease Greatly Due Road which Road type is . if that On Drag race that won't Give you change on winning and Also in track. I wouldn't recommend That kind of Gearing that make your motorcycle Downgrade For me. I would recommend Back to stock. But Let me know what is your purpose changing. If your planning Faster. Choose Fastest acceleration First It will big Help if Your Getting a Race and Next is Top speed. if you're Street Acceleration still practical due helping In Overtaking. Slow overtaking is Dangerous. Bonus:Believe in Jesus that He will paid Your Sins and He will raise you from the Dead. And the Father also raise him from the dead so will you be Save. Benifits of Eternal Life no End. If we are still alive You can Worship God You Get Guidance as long you listen. God will never for leave us Even we have Troubles he will help us

[@chachasheeda1931]

@@Justfun-gg8xi lots of love broo.❤️❤️❤️❤️❤️🥰🥰🥰🥰❣️❣️❣️😍😍😍😍😍😍😍😍 My main purpose is a challenge... Basically... But there is a difference that i want to race with alterationbike and win on genuine bike with sporket or minor alterations .. i mwan nothing with engine (pistion head cylinder etc) Whil the oppobike is alter... Has bigger piston head cylinder bore clutch box etc... Now i tell tou that genuine bike top speed is etc 90 95 while on somebokes of same company it is 110 115 ... While the opponent biike even after being alterd so deeply gives 110 115 120 max 125 ! And their alter bike engine life is approx three months... While genuine you have life in years.. I want them to show that company is not a fool.. while you can get more speed with such foolish engine modification... The moderately acceleration is acceptable but i want top speed. To be more.. as 130 With no engine modification .. onle intake fuel of high grade and sprocket i want to achieve that..

[@Justfun-gg8xi]

@@chachasheeda1931 if legal race purpose. You Should improve your Aerodynamics. Also Aerodynamics are huge impact. I would suggest stock Sprocket. Huge change on sprocket affect your rpm. Low gearing More rpm more acceleration and Reduce topspeed but fastest Topspeed reach which is more practical. Than Long gear which takes time to Reach Top speed. Also Weight Matters but don't Try Make your Wheels Thin If your Using at Street Is Dangerous only use in Drag legally but not also i track. Also Try to remove your ecu limit or Cdi Limit if you have ecu Let it tune and Dyno Tune If you have cdi let it Tune and dyno if possible for your Model and buy after Market so that i can be tune. If You planing also in streets Make use you have abs Brake for more safe Remember More power more responsible. Bonus: Believe in Jesus that He will paid Your Sins and He will raise you from the Dead. And the Father also raise him from the dead so will you be Save. Benifits of Eternal Life no End. If we are still alive You can Worship God You Get Guidance as long you listen. God will never for leave us Even we have Troubles he will help us after dead Reunited with God No pain You will share God wealth You will Rule with Him

[@chachasheeda1931]

@@Justfun-gg8xi what if i change the the size.. i mean increase it .. on same bike.. And use hioctane fuel.. and high tyre pressure.. ?? And how can i alter cdi ?? No alter is available right now in Market?

[@slicaltimistic1]

That was excellent configuration dude. Getting better understanding by getting more information. So spending more time explaining is well worth it. Keep up the good work.

[@footballkicker70]

Probably the most useful video I have ever watched. Really explained everything on my level. Well done.

[@theoverengineer]

Cheers!

[@theoverengineer]

Correct. Top speed will increase, getting there (acceleration) will take significantly longer. Will also need a longer chain.

[@maungsacca]

Maybe you should use the term "top speed" instead of faster. Faster implies acceleration which actually goes down if you increase top speed gearing. So which is faster a quicker acceleration or a higher theoretical top speed? For most motorcycles they are set up for a top speed. But most of the time you never use that. So to accelerate faster you reduce the front one tooth or up the rear 2 teeth. Each adjustment loses top end speed. eg. 1 tooth on the front of my cbr600rr changes top from 260 to 240 kmh. But how often do i drive 260?

[@brufnus]

I disagree. Going faster = moving at at higher speed, not implying anything about acceleration.

[@drgrunn174]

maungsacca it depends; if your bike is with bad ratio you will get on highway speed on 6k rpm ... by increasing the front gear (increasing the ratio) you may drive at the same speed with 5k rpm, which will give you better mpg (better fuel economy) ... it really depends where and how are you riding. In the city the opposite will be better, as when in stuck traffic the lowest possible speed is needed, and also I never shift on 6th ... so in city I may decrease the ratio and will start with lower speed -> 'clutch economy' and also can shift to higher gear and again fuel economy.

[@markcayton6712]

The terms "fast" and "quick" are two different things. FAST is regarding a steady speed. QUICK is regarding acceleration. Changing your gearing can make you faster but not as quick, or it can make you quicker but not as fast.

[@theoverengineer]

I also flipped the formula at min 18-19, but the results are the same. Textbook formula gives you the drive ratios of 2, representing original stock or "old", and 3 representing new amount. 3/2 or new/old then = 1.5 With my alternative approach the "old" drive ratio, representing stock is the denominator, divided by the new ratio; 0.5/0.33333 = old/new = 1.5 Same thing, new ratio is 50% faster.

[@theoverengineer]

Thanks for the feedback, I`m not on facebook. Fastest is: just post your questions here. I`m in-an-out-of classes, and busy, but can see and answer messages here fast.

[@danfuerthgillis4483]

A big tip is cross chain on purpose by setting up the front derailleur off set by adjusting the front derailleur mount twisting it to allow the 3rd ring up front ( 3 ring system) to work with the 24 or 32 tooth cogs on the back. This setup allow for proper cross chaining with zero issues.

[@ARBAAL1522]

I am wondering what Jack Norris , would do.?

[@daveybrunalli5207]

he would kick the teeth out of the sprocket's mouth

[@rodrigoruffa7460]

He would ask his brother Chuck what to do, for sure...

[@tonydelpilar]

Can you please explain how to figure out the new # of chain links needed after changing gearing ratio? I’m going from 16/45 to 15/48 on my 2001 GSXR-600. Wheelbase is 55.1 in. , stock # of chain links is 110 (525 pitch) , & chain slack should be from 0.8-1.2 inches. Thank you in advance!

[@joel9526]

I will make it simple for you. A bigger rear sprocket will get you off the line quicker. a smaller rear sprocket will get you off the line slower but will be quicker at top end.

[@mbasinfo2551]

+Sir. Sir Wrong, sorry guys - what sort of engineers do we have here?? Engine power does not change as a result of gear ratio alteration and it is that (engine kW vs all up weight AUW; kg) which determines acceleration rate, until near to top speed, where drag (e.g. air friction) becomes the limiting factor - ultimately absorbing all available kW thus acceleration reduces to zero. Top speed is (principally) determined by engine kW vs aerodynamic drag (i.e. frontal area x drag coefficient) and other friction al losses. AUW (kg) has virtually no influence, given sufficient roadway, time and absence of police radar etc, to finally reach top speed! Back to the point - any competent rider will simply change his (or her) gearshift points to compensate higher or lower final drive ratio. However, one thing that does alter when applying a higher final drive ratio is that (the typically 5 or 6) gearbox ratios become effectively spaced further apart. So, what was a snappy close ratio shift might start to feel more like an old 4 speed wide ratio clunker of British origin circa 1950's ;( Hope this helps - just pedal harder boys!! cheers // Steve (aero-engineer, ex-motoGP racer + decades off-road & enduro etc)

[@jacobramos5083]

nope, that's backwards lol

[@theoverengineer]

Sir. Sir is right, nothing`s backwards. May be the fractions, but they don`t come with vectors.

[@antorangejuiceclef8527]

MBAS Info dam !

[@theoverengineer]

Look at min 1-5. If I flipped the numerators and the denominators, the fractions would give you the results 8/4=2 and 12/4=3. Now 3 is more than 2, and it needs more explanation why drive ratio 3 spins the rear wheel slower than drive ratio 2. It is easier to see that 0.33 is less than 0.5, so more teeth on the wheel sprocket makes the bike slower. You are right, in textbooks the formula is given as driven/drive but I was going for a visual approach on what combination spins the wheel faster.

[@carlitosASJ]

thanks man ...i loved this...i was mostly confused with the acceleration of my bike and did all the math myself a few months back but was still a little confused but i came to the conclusion that...ppl that made these machines know what they are doing so forget my theory their is the best in both speed and acceleration so why change it

[@theoverengineer]

Yes it would and it will. That`s exacly the idea. Some limits apply though, because your engine is not getting actually more powerful. As you tweek every bit of mechanical advantage out of changing the sprockets, wind resistance devours most of the theoretical gains.

[@ViceVersaMusik1]

Awsomeness! ! ! Great video man, I was just lookin for a video on this subject dude.. Great Work Dude!!!

[@theoverengineer]

Good one. Exactly. Bigger drive sprocket or smaller driven sprocket or both, and a new chain that works with both new sprockets.

[@waheedaazize7911]

If only my all my math teacher were like you...math would have been my favorite subject

[@junaidkamal]

:D

[@aldrinabatayo4470]

These is a very good ratio and proportion calculations, but if we talk about speed you must also consider the torque it give by these variations of engine and rear sprockets.

[@777Guitarmaster]

One of the best explanation, I ' very ever seen.Thank you very much.! Great video!

[@SsaliGeoffrey-ct8bk]

You have taught me how to calculate I changed the sprocket the machine is faster.thank you.

[@albion2742]

It will not go faster if the rider cannot pedal a higher gear ratio, same as a m/cycle top speed will not increase if the engine does not have enough power to pull a high gear, my motor cycle is faster in 5th gear than in 6th gear as the 6 th is like an overdrive.

[@theoverengineer]

Will also not go faster under a fat guy, on a steep hill, on flat tires, if the haystack is too big (India, Africa, ...), on a muddy road after the monsoon, with a worn chain that skips the teeth ... the list can go on forever.

[@albion2742]

You still need the power to use a high gear.

[@theoverengineer]

Yup, nobody argues that. This video though isn`t about gearbox design, rpms or engines and top speed.It is solely about final drive and going faster.

[@albion2742]

I understand, some others always think that a high gear will make them go faster,I am sure you understand what I was trying to explain.

[@theoverengineer]

Yup, thank you for commenting. I thought about re-titleing or re-working the intro to make it clearer for everyone (it does come up periodiucally, especially Asian riders of 125-or-so-cc`s) but you can`t clip another file to it in youtube without changing its address. I`ll try to add slides.

[@ghostduster1]

Thank you for the thorough explanation. I couldn't make sense of the explanations I got on a few cycling websites.

[@SakibChoudhury]

17 / 42 setup and .40 / .33 equal 1.21 now subtract 1 so it is .21 multiply 100 you get 21% speed gain not 33 % ... but great video though

[@hamzasarfaraz9250]

Exactly

[@swarajsbangera]

thats because factory setting is 100% so add on the addition speed gain thats how math work bro

[@kristers9960]

so i have sprocket on my aprilia derbi senda sm with 60 teeth, should i change it to 58 to get my bike littlebit faster?

[@theoverengineer]

Don't know if you should, 58 will be faster if there is not much head wind.

[@bruddak1143]

4:58 LooL damn trucks. Nice video, thanks

[@louf7178]

Brudda K LOL...Jake Brake.

[@08halit]

when u use 2 teeth sprocket front and 12 rear the bike will have a stronger pull on lower gear ratio but slow speed and when having higher end gear ratio the bike will have higher top speed but it will have weaker pulling force.. there is more to this callculation like the size of the engine (hp - Nm ) that in a way gives you more to play with or less depending on what u own..like i have a 05 busa and when looking upp the specs it is to have 17 front and 40 rear it makes around 2,35.. this bike has around 160whp and about 100nm of torq.. if i choose 16 fr and 40 rear i get 2,5 end gear thats a bit faster and if i chose 18 front then i get 2,22 end gear,,it doesnt look much on paper but how much off a difference does it do,,that would be a fun test to do

[@theoverengineer]

Thanks, good on you, bro. Never stop being curious, forget deadbeat teachers.

[@DNiits]

(1) If you know the top speed of your bike, it isn't too hard to calculate. I have a 14/52 setup on my zx6r (original owner was a stunt rider) and i know that my bike tops at about 150 (or so) mph. I i wanted to calculate the top speed of a 14/46 setup (what i'm thinking about doing) all I need to do is find the percentage difference of the two (by following the steps in the video) and then adding that percentage to the original top speed of 150mph.

[@theoverengineer]

Simple logic failed physics class, due to being clueless about the meaning of work. More work is done when turning a bigger sprocket with more teeth then a smaller when the force (N, or kg-f, or lb-f) applied to the chain is unchanged. It does take less force to turn a bigger sprocket though when the work (Nm, lb-ft, or J) is kept constant, ie the engine is not gonna get any amount stronger. So by mounting bigger sprockets at the rear the bike's force can do more work, speed drops though.

[@chrisw5742]

I have a 26" bmx SE Racing Quadangle. I had to put larger sprockets on it both front and back. The other ones were cheap and one bent and it was really hard to peddle on dirt trails. . Now it rips up the track with the proper gear ratio.

[@theoverengineer]

Nice! If you have a video of it , post a link here.

[@chrisw5742]

@@theoverengineer I will make one :-)

[@chrisw5742]

The rear sprocket is smaller. I was wrong lol

[@theoverengineer]

It's ok. In your vid, might want to consider a "before-after" layout, comparing original gearing, speeds or time on a familiar course versus new gearing. Or whatever you come up with.

[@chrisw5742]

@@theoverengineer Gonna make the vid today...

[@WisdomInExperience]

Hey I think its the diameter of the sproket determines the drive ratio than the number of teeth ? Right

[@theoverengineer]

+Shriram Karpur The pitch diameter does, it results in pitch circumference, which is then divided by a whole number, the teeth. So we might just forget about (pi) and pitch radius and work with a straight whole number. Can`t do that with pulleys, sheaves and wheels.

[@E46TY]

Shivo hum teeth not diameter🤦🏽‍♂️

[@genosmith8852]

Both right you can have two 48 Tooth but one a #25 C/L and one #60 C/L both roller chain connecting links same ratios in relationship to chain size

[@abdulmuhaimin6451]

Try it to believe it. But as well it need also to mod a little bit on the bore/stroke as well as the carb/ gearbox.

[@larrymenezes3374]

Hi theoverengineer . I have a 200cc bike. The stock sprocket size is 14/39, I know that if I change to 14/45 I will have an increase in torque and acceleration but will reduce in top speed. Pls guide me what will happen If I change to 17/45? will I have an increase in torque or will I have an increase in top speed? or will I have an increase in both compared to my stock sprockets? According to you instructions... My stock 14/39 sprocket has a drive ratio of 0.35, If I change the driven sprocket to 14/45 it has a drive ratio of 0.31 which I guess means increase in torque but decrease in top speed, I f I change to 17/45 it has a drive ratio of 0.37. So does this mean that my torque and acceleration has decrease and top speed has increase compared to my Stock sprockets?

[@theoverengineer]

larry menezes Good thinking. The 0.37 means that, compared to the 0.35, torque and acceleration drop by 2% and top speed increases by that 2%. In case of the 0.31 compared to the 0.35, torque and acceleration increase by 4% and top speed drops by 4%.

[@abbywendt1988]

do the math he showed you EXACTLY how to figure it out..

[@yessure5291]

www.gearingcommander.com/ see here

[@HORNET6]

Larry Menezes you will just cancel out the decease of rear sprocket gearing.

[@yessure5291]

www.gearingcommander.com/ shows every combination possible.

[@johnkennethmanas1655]

Question: will any sprocket sizes as long at it have the same ratio, will have the same effect?

[@GnarledBat47]

Was just thinking that, probably

[@ilLUZiiVeGaming]

It really has nothing to do with the amount of teeth it more to do with the diameter of the sprockets.

[@theoverengineer]

Correct. It has to do with the pitch diameter of the sprocket, gear, sheave or pulley. Since the teeth are the same size on the bike`s sprockets to fit the 525 chain, math works with the number of teeth, no need for pi and exponents.

[@hiyadroogs]

I have a Enfield Bullet fitted with a 8.5 bhp diesel engine. Originally fitted with a 19T drive sprocket & 38T wheel sprocket, 2:1 ratio. The geared speed at 3600 rpm was 61.5 mph by gps, which it could only reach down hill. The gentle cruising speed in calm conditions was approx 40 mph (2340 rpm), & it would average circa 145 mpg at those speeds. The 350 petrol version on which it was based was fitted with a 16T drive sprocket, which gives 52 mph @ 3600, which the diesel can pull more comfortably on the level in calm conditions. But with the added bonus of my being able to turn the fuel screw in, so that at 40 mph, It now achieved 182 mpg. The 350 petrol engine develops a max 19 ft/lbs to the diesel's 16 ft/lbs, & reaches its torque peak later in the rpm range @ 3500, where the diesel torque peak of 16 ft/lbs at 2500 has dropped to 12.5 ft/lbs by 3600. So even the 16T is a little tall for the diesel at 50 mph plus. By dropping the drive sprocket down to a 15T, (2.53:1) which gives 48.6 mph @3600, I have increased the torque at the back wheel by 26.66% compared to the 19T, while simultaneously backing off the fuelling, which now gives 190 mpg @ 40 mph, (2963 rpm) (diesels don't of course require a stoichiometric air/fuel ratio. Don't try leaning off your petrol engine, or it will sieze!) & being able to cruise at full geared speed almost regardless of wind conditions. & my average speeds over distance have increased against the 19T sprocket, despite the loss of a potential 13 mph of top speed! An all round win!

[@theoverengineer]

Thanks for sharing, good stuff. Shoot and link a video about your bike projects.

[@haggeoromero]

very good job explaining this concept.

[@theoverengineer]

Thank you.

[@FabioPascuaThePilot]

That last division, you made an error not typing the 3 several times (just once), and the result is different, your bike will be 20% faster, not 33%. Other than that, very easy understanding explanation.

[@PaulodeMelo]

Can't stop picturing and laughing at your 2 teeth sprocket

[@masterzz57]

what about a 1 tooth sprocket

[@samthewizzy]

How about just a disk with sand paper for friction

[@Elgattou]

What about nothing.

[@chrisw5742]

I think those teeth need to be brushed.

[@arthurtaylor1053]

Ha,ha

[@slicaltimistic1]

Excellent Job doing these Calculation. That is exactly why I was doing these configuration. To get the speed that I wanted.

[@theoverengineer]

Thanks for watching.

[@RedpillPortugal]

Am I the only one thinking about the regular mountain bike sprocket example? Simple does it. The bigger the drive sprocket the slower you go, the smaller(less teeth) in the driven wheel gear the Faster you go

[@theoverengineer]

Actually, the bigger the drive the faster you go

[@damionloya4746]

Your wrong if you put 4 tooth sprocket with a 2 tooth sprocket on the back tire for one turn the tire will turn twice if you put a 22 tooth srocket with ten you will eccelerate faster to 20 miles an hour but you will only go twenty if you did for an for your bike will take off slow as shit but you will your top speed will increase buy how ever fast your crank will turn

[@theoverengineer]

Dune buggy project: If the engine is way undersized, (buggy too heavy) the inertia (juice to move mass) will choke and brake the engine`s loadbearing thinnest parts (not the valves). Usually, clutch springs will prove to be weak, friction plates slip and burn out, bolts holding at the crank journals rip out of the block, con rods bend, gear teeth grind off, axles with key ways twist and valve timing fails. That`s worst case scenarios. Everything needs to be the right size, not just the sprockets. The engine will last the longest if the drive sprocket is as small as possible to fit on and the driven sprocket as big as you can get. Buggies also have a lot of rolling resistance (sand) that keeps stressing the engine during operation, not just at start.

[@levietom4136]

if the durability and usage is match.the bike will last long,today manufacturer does not invent 100% long life bcoz comercialism prevail.designs made inventors more encouraging to alleviate its morale

[@bigbig6534]

14/32 can make more pickup or more top speed??..please

[@theoverengineer]

not enough data

[@huaweibest5647]

please... how about a biycle

[@theoverengineer]

Thanks for chipping in with a thourough comment. Much valued.

[@MistaReason1]

Tire size also makes a difference

[@theoverengineer]

+Mista Reason Sure does: kzbin.info/www/bejne/r3i1iZh9js6KorM

[@MistaReason1]

Thanks. I just switched my quad racer set up of 13t 36t to 13t 38t with 18 tires . Will going to 20 tires be or should I stay with 18. I'm not worried about top speed, I just want quick take off. I mostly ride trails & play on the drag strip.

[@theoverengineer]

+Mista Reason Bigger tires don`t help in your case. If anything, smaller tire circuference helps with slow speed control and explosive acceleration. Stay with the 18, anything smaller gets stuck easily in gnarly terrain.

[@nneilwwaters9990]

Great video, who would have thought primary school maths would have come in handy!

[@danieyzrstudio6420]

Small for great pickup. Big for great topspeed

[@sdqsdq6274]

lol

[@balentincamargo5248]

x ShaRkz. Thanks

[@myriad860]

why does this channel not have million of subs? great vid very educational thank you

[@theoverengineer]

Thanks for watching. Yeah, I don`t have the corporate backing, ... and no cute kittens on the channel.

[@Ihelpanytime]

7:37 "Speed tops" Bad english (Sorry for my LOL)

[@DJeimaXe]

If my front sprocket has 6 teeth; and that I want to install a 17 teeth around it; will it make my bike go faster? (Even though the rear sprocket will always be bigger than the front.) *This upgrade of the front sprocket will make the bike to loose a small speed performance for more acceleration, correct?

[@MrXsnuff]

accelaration > top speed all day

[@deletevil]

Agreed! But only till you start to miss the top end lol

[@E46TY]

Congrats you just went from 0-20 mph in 1 second and i went from 0-50 in 3👍🏼👍🏼👍🏼👍🏼

[@cooliodiablo6117]

Acceleration doesn’t mean shit though if your top speed is piddly. Yea you may be the first one out, but you’re also going to be first to be run over once the big dogs catch up.

[@theoverengineer]

I agree, there is no real need to modify. Options to modify (when changing chain) are given by sprocket manufacturers by plus or minus a few teeth than what a bike gets shipped with. These choices are within reasonable safe limits, that`s what their mechanical engineers are there for. See Sunstar`s site and graphs on torque vs power. Bike manufacturers don`t actually make any sprocket, tire, chain, electrical components, etc. They design (quite well), contract out, assemble.

[@magicalempire]

imagine 1 tooth then we need to go to the dentist...

[@theoverengineer]

Bigger sprocket on the rear will help. The rest are difficult to do, but this is what creates fast acceleration: faster revving engine, shorter stroke, more pistons, higher compression ratio, less mass on everything, less friction everywhere exc. rear tire, less or zero slip on rear tire, lower center of gravity, negative chain pull angle.

[@theoverengineer]

Exactly, or increase displacement. Along with it, increase air flow in, increase exhaust capacity, increase gas flow, re-program ECU, check valve timing, check spark strength to ignite increased amount of gas and air, beef-up piston, pin, bearings and crank to perform with the forces of increased compression. Long list, and that`s not the end of it. It works though.

[@kuhndj67]

Modern street bike 'speed' (top speed I'm assuming) is generally limited by power available and drag... gearing doesn't play much of a part (it can change the torque available at top speed by moving where in the engine torque curve the top speed is attained and thereby move the top speed by a bit). Dirt bikes and older street bikes (5 speeds) are more likely to be gear limited and in that case changing the final drive ratio will indeed change your top speed. Most folks these days who change their ratio are doing it to trade off acceleration vs. fuel economy. Manufacturers seem to often opt for economy and many riders add a couple teeth in the rear to improve acceleration (which will have a modest negative effect on economy).

[@theoverengineer]

Spot on, thanks for watching.

[@MANVIRSINGH1313]

helpful video......sir i am going to increase the teeths of smaller sprocket......increasing by 2 will be enough in order to get better milage??? or more to increase

[@leeneeslynys774]

Now i need to know how torque and speed changes depending on Tyre size

[@2LateIWon]

10:11 explain it this way you have to climb 10ft theres a 10ft stairway that has 8steps and a 10ft stairway with 16 steps. Which will be easier to climb? 16 because each step is smaller. Great Video

[@theoverengineer]

Exactly. Thanks for the idea!

[@norincobrocapri46]

eg. 2th fr v 4th rear, is usually expressed as a ratio of 2:1 ie 2.0, not 0.5.

[@pamelatragas7638]

norincobro capri I thought the same thing. This method seems a bit unconventional. Driven/drive is how I have always known it.

[@theoverengineer]

Pamela Tragas Good observation. In math, any ratios, including gear ratios can be flipped as they are independent amounts. Sine law: A/sinA = B/sinB can be flipped sinA/A = sinB/B. Try with A = 2, B = 4, angle A = 30 degrees, angle B = 90 degrees. It`s gonna be 2/0.5 = 4/1 which is the same as 0.5/2 = 1/4

[@lehsamkaramdin8969]

By changing sprockets you can't get any difference under 300cc m.cycles.(due to engine power and wind resistence) But one can increase his torque by changing sprockets under 300cc motorcycle(maybe for wheelies or offroading) Correct me if its not the case.

[@theoverengineer]

50 % correct, always possible to gear DOWN, used extensively on dirt / enduro bikes. To gear UP, results will be marginal under 300 cc, correct.

[@charlesbenoitthomad]

Doing a 1966 rock on. So far I'm at 13/13 sprocket ratio. But I'm mostly driving around in 4-5. If I what to go faster would a 13/11 ratio work beening that the rear sprocket is smaller.

[@theoverengineer]

That`s right, 13/11 will go faster

[@DJeimaXe]

OK, so the acceleration will take longer if it was a 17 teeth; the 6 teeth had actually felt like that it was taking longer to accelerate. I was trying to figure out on what creates a faster acceleration. (I REALLY THANK You for your reply!!)

[@homerelesperance2857]

Excellent explanatory video of understanding how drive sprocket and wheel sprocket (Driven Sprocket) correlates to speed, acceleration & torque! :)

[@theoverengineer]

Thank you for the feedback.

[@pangian97]

is that truth that if i change drive sprocker to smaller and bigger behind the bike while pop up wheelie easier?

[@theoverengineer]

that`s right, that`s why stunt bikes have like 60 teeth on the rear

[@xShin1000]

what if my drive gear is 15 then my driven sprocket is 32 what will happen?? is it my motorbikes make faster and also acceleration?? or it will make it slowly?.. i just wanna make it fastspped my motorcycle especially in a long distance rides.. please reply..

[@theoverengineer]

Harvey Tresplacios Need all 4 numbers

[@thehoneybadger8089]

"In one case, the wheel is going a turd as fast, but in the other it's going half-assed."😂🤣😂🤣😂🤣🙃🌵

[@tookymax]

I question if you will accelerate slower after changing the driven sprocket to less teeth. You would be shifting from 1st to 2nd to 3d at the same rpm's but that means at higher speeds as well. You would be using the lower gears a little longer to bring the rpm up but I doubt you would be any slower at acceleration. Any physicist out there?

[@TiberiusStorm]

20:15 If you use two threes the percentage changes. Here: 0.40 divided by 0.33 = 1.21 minus the 1 x 100 = 21% increase. However, 0.40 divided by 0.3 = 1.333 minus the 1 x 100 = 33%. So what is the right answer?!

[@theoverengineer]

Technically it is 17/42 divided by 1/3 = 1 and 3/14 = 21.42 .... % increase so 21% is close enough

[@TiberiusStorm]

theoverengineer Yes but in the video you said 33%. That was my point!

[@norincobro658]

Ratios are expressed as driven sprocket (rear) divided by the Drive sprocket (front). Your ratios are only correct when it applies to pushbikes, where the Drive sprocket is Bigger than the Driven sprocket. Pushbikes are Over-driven, (so how would YOU then express this?) On a motorcycle the Drive is Smaller than the Driven,. So then lets say the bikes have sprockets with 44 teeth and 15 teeth. The motorcycle ratio is 44/15 = 2.9333333 :1. The bike ratio is 15/44...........= 0.3409091 : 1 Can you now see why "your" way is incorrect and confusing. Otherwise it's a great vid. Thanks for your correspondence. Tony

[@norincobro658]

GAR A Cool. Now what are you going to do with all this new-found knowledge!

[@norincobro658]

GAR A Hope it all goes well. Let us know the results of your modifications.

[@lem6070]

+norincobro here's the rule that i know. when you calculate gear ratio driven gotta be divided by driver and you are right about your calculation. when you pedal about quarter of front sprocket, rear wheel can go 1 cycle. not like motorcycle front sprocket need to go almost three times to make rear wheel rotate 1 cycle.

[@joea1018]

Thank you so much. I have a heads-up job interview, and this is one of the questions. I'm going to tell them this example.

[@theoverengineer]

Glad it was helpful!

[@tryinggalet1975]

thanks for that wonderful video now it makes sense. i just want to know if the proper breakin of a motorcycle will affect the speed? for example i have a 150cc bike if i breakin it properly will i reach the top speed of 150kph with all stock including sprockets? and if i didnt breakin it properly will the bike become weaker? thank you

[@nutmegger1957]

Where ARE you, anyway? In the parking lot of a Truck Stop? (lol). Thanks for taking the time to explain this. Appreciate it.

[@knoobzman6952]

Wondering if this 300 will do the 266kph.. inhave it too but. Need to upgrade the ECU of course.but still impossible to reach the 266kph.. im happy for 155+kph of my ninja

[@LifesAdventures555]

Well done, especially for those with basic math skills to understand. As was said by another, it is not the number of teeth but the diameter which reflects the circumference which is really in action here. Then take into account the ratio of the driven sprocket to the diameter of the rear tire which determines the 'horizontal footprint' that is laid per unit time for a given power/RPM setting.

[@theoverengineer]

Correct. It is called "pitch circumference", - along which teeth, belts, chains mesh, (dismissing teeth overhang) it applies to gears, sprockets, pulleys, sheaves universally.

[@Prod.TeaStew]

I’m still having a hard time understanding wether to put a smaller drive sprocket on to get more acceleration or to put a bigger rear sprocket on the back to get more acceleration...

[@aimansyuhaida]

I would like to know how a 125cc motorcycle down the right sprocket to make changes to increase speed

[@SeventhMarch]

i have a 44T/16 cog set on my single speed bicycle, what do you suggest to improve speed?

[@theoverengineer]

44/15 will be faster if you can power it without dropping cadence. Might wabt to try this spreadsheet variant: kzbin.info/www/bejne/noLRiGRti9qUfdU

[@MohamedTarek-qm3vf]

Great explanation dear, I only have one thing that if I could understand I could finally give my brain a break. Why does torque increase when I switch to a bigger sprocket ? I definitely understand why the speed decreases, because of the number of teeth. But I still don’t get why torque increases!!!

[@theoverengineer]

Excellent question. In short: longer leverage. Check out a brilliant explanation here kzbin.info/www/bejne/gICvpYZqi7qWrLM

[@anas_moto]

The best ever video to explain sprocket ratios 👍

[@theoverengineer]

Glad you think so!

[@stefanielarsen1508]

hey, very clear instructions! Im building a small one person dune buggy and using a 600cc 4 cylinder race bike engine (1984 YAMAMA FJ600). Now, Im pretty sure i need to increase the teeth on the driven sprocket OR decrease the teeth on the drive sprocket, BUT, the dune buggy weighs quiet a bit more then the motorbike did.. How would i calculate the sprocket size knowing the engine needs to pull more weight? Thanks a lot

[@Nobitzu]

So I have a 150cc project bike, I have arrange 14T/42T for its stock combination which gives 127km/h then change it to 15T and14T/40T with 105km/h and then tried 15T/42T which gives out tops of 117km/h, I was trying to figure out which is the best sprocket arrangement before I get intouched with the engine

[@Playaa1Fly]

Hello, great video. I have an Aprilia rs 50 and my sprocket is currently 14t front and 53t back. I would like more acceleration without taking too much off the top end speed so what would you recommend? Thanks

[@theoverengineer]

jack crawford If you mount 54t rear, then acceleration is +1.8% but speed is -1.8%.If you mount 55t rear, accelerations is +3.7% but speed is -3.7% It you mount 56t rear, acceleration is + 5.6% but speed is -5.6% Try this last 56t rear, the 54t and 55t are not making a big enough difference, unless loosing 5.6% in speed is unacceptable.

[@CanadianCHICK27]

Ok lets say that on a 4 wheel drive machine that is shaft driven in the back with a sprocket on the right side shaft where the chain runs to the front of the machine witch has a sprocket to drive the front axle. this is whats tricky tires on the rear are a bigger overall diameter than the front tires how do you calculate for the front tires to spin at the same ratio as the rears

[@bernieolivera5632]

I like the way you broke down the numbers. To me it’s simple and makes sense. That just may be me, I like math. What happens if the sprocket size is reversed? If the old sprocket is 36 teeth and the new is 41. Using 15/36 and 15/41, is that almost 14% reduction of speed? I have a 9 tooth and 36 tooth sprockets. If I change from a 36 to a 41 tooth sprocket I also get almost a 14 % reduction. I guess my question is do I have more control with a 36 or 41 tooth sprocket? More torque verses top end speed. Thanks for the video.

[@theoverengineer]

Control at what speed? Riding trail slowly? Small front works. Accelerating out of a corner on track? Big front may work depending on corner speed. Control straight line? Control hill climb? Control is a different topic. Thanks for watching.

[@aabatery333]

so the higher # of teeth on the front sprocket and the lower # of teeth on the rear sprocket will increase speed but slow down acceleration and torque and its the complete opposite effect for a lower # of teeth on the front sprocket and a higher # of teeth on the rear sprocket than on on the stock sprockets that come on the bike

[@MRSBA7]

nice video, but, will a chain conversion kit, will increase torque But decrease top speed?.. who wants that.. it would overrev the bike? or it wont be affected?

[@Radeon_-so7fj]

A bmx bike has bigger drive then the driven sprocket is it still the same concept