Final Drive Gearing KTM Duke 390 125 200 250

How do you ride? Stunt, track, supermoto, street, adventure, commute? The list is endless but your bike only comes with one set of gearing. Does it work for you or could you customise it to suit you a little better. In this video we discuss what you can do to change your bike to suit you better.
If you have a 390 and ride long distances or fast I recommend changing to a 16 tooth front sprocket. If you do a lot of low technical riding say in heavy traffic then try a 14 tooth front sprocket. If you are riding a 125 then the engine has less torque so be careful about making the rear sprocket smaller than 45 and a 15 tooth front sprocket may cause you to lose acceleration and top speed.
Stock gearing on the gen 2 Duke:
390 15/45
125 14/45
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Rear Sprocket 50 Teeth: bit.ly/MotoMiri...
O-Ring Chain 520 SRO6 120 Links: bit.ly/MotoMiri...
Galfer Wave Front Disk DF940CW
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[@markhingst5368]

Well explained, another consideration not mentioned is that going more than one tooth down in the front usually adversely affects chain wear due to the chain being pulled in a tighter radius.

[@MotoMirius]

Yes indeed it can. But the small end of the small Dukes run a 14 on the front, so it's within what KTM are happy with.

[@markhingst5368]

@@MotoMirius ohh for sure, it's a small consideration, not likely to be noticeable on most machines just something to be aware of for anyone thinking of going -2 or more

[@MrBraamSmit]

Thanks for the video David! Good to see your videos again. I wondered how your acceleration had changed with your 50 tooth, this answers my question!

[@MotoMirius]

Thanks Braam. Videos are coming slowly at the moment but I have more planned. Skäl. David

[@gtshub3707]

I bought my first motorcycle (2021 duke 200) about two months ago and your channel has been a blessing! Thank you for the good information and taking your time to explain things thoroughly!

[@MotoMirius]

Glad to help and thanks!

[@pabloleon1241]

You always have a nice explanation on every subject. I bought a 46 tooth rear sprocket from KTM power Parts and keep the 15 tooth on the front. I found no diference on riding.

[@MotoMirius]

The differences are subtle, and one tooth on the back will make a very small change. Skäl David

[@bollockyknob6341]

Time you got a new mitt from Halfords Dave 🤔 seriously though, love your videos. I'd be lost finding my way around the 390 without your stuff! Please keep it up!

[@MotoMirius]

Ha! Lol, yes I do! Thanks. Much appreciated. Skäl. David

[@darrenhowes9336]

Awesome video as always. I'm learning alot

[@MotoMirius]

Glad to hear it and thanks!

[@MyAccountDuh]

Love the content you provide. I’m finding my 14’ 390 too jerky in slower traffic. Would you recommend the change to 16T as well or is that just for smoother gears on the top end.

[@MotoMirius]

I run a 16 because I have a 50 tooth rear sprocket. Some people say that a 16 on the front instead of the stock 15 makes it smoother in slower traffic. I find the main reason for the bike being jerky in slower traffic is because the revs are too low - it's really not designed or intended for that use. Here in the UK it's legal to lane split, so I'm rarely in slower traffic for long so it's less of an issue. First try keeping the revs up by dropping gears - don't lug the bike, if you find yourself in first for long periods slipping the clutch then try a 16 and see how that works for you. Skäl David

[@liambollman8925]

Hi David, love the video! I have got a KTM 125 Duke 2019 with stock gearing. I am thinking of getting a 15T front sprocket instead to lower the revs a bit at high speeds. Do you think that would work? Should not bring the acceleration down that much right? thinking of that you said that a front sprocket change on a 125 might worsen both acceleration and top speed.

[@MotoMirius]

Hi Liam and thanks. I've not tried it with a 125 but as with all 125s they have less torque which means they are more sensitive to gearing changes. Even with the 390 larger changes in this direction mean some people stop using sixth gear so I suspect you will find the same, and you will trade off loss of top speed or only being able to get into sixth on long straight roads with enough run up or downhill. But that may work for you and considering that the front sprocket is quite cheap, I suggest that you give it a go and see if you like it! Skäl David

[@ldbacer]

I'm thinking of a 16t and 45t for a duke 200cc. what do you think of this combination?

[@MotoMirius]

What are you looking to achieve with that combination?

[@ldbacer]

@@MotoMirius I want more power between 40 km/hr to 110 km/h More accelerate than final speed

[@MotoMirius]

200 is I think 14 stock, so this is going to reduce your acceleration and also probably reduce top speed but improve your fuel consumption on long journeys by dropping the revs. If you want more acceleration you need to add a bigger rear sprocket - since you can't really use a smaller front sprocket.@@ldbacer

[@JerryR390]

Again you are very correct, with my engine swap i had ran trough a large combination of sprokets when i was after top speed i ran 15 - 41, 15 - 42 but in city i could only use 1st, 2nd and 3rd gears. now i want more usability of the bike and im running 14 - 45 and to me is perfect.

[@MotoMirius]

Thanks for sharing. Yes, I currently have different wheels with associated sprockets and chains depending on what I'm using the bike for!

[@Paulie3051]

Question on this; I have a KTM 390 stock. I’m not a racer. I just like to go for long rides, what would be your best recommendation for front and rear sprocket? What would you recommend. I also don’t burn rubber every corner. I really like to take care of my bike.

[@MotoMirius]

Stock is pretty good. Currently I have a 42 on the rear - but only because I'm doing a lot of motorway riding and I want to bring the revs down below 7k for fuel economy while riding at the same speed as the rest of the traffic. I like the 48 on the back for faster riding on small roads where speed is much lower. So the answer is that it really depends on how you ride your bike - there is no single answer. Changing the front sprocket is a good way to see how it changes things without spending a lot of money on a new chain and rear sprocket - so long as you only use it for a short time it will not be damaged by a worn chain.

[@Raez_XL]

Very educational. Love watching your videos.

[@MotoMirius]

Thanks Raymond. Much appreciated. Skäl. David

[@yori8784]

I have a feeling that the duke 390 itself got loads of torque, so if I were to change to front and rear to 14/43, this will give me an increase in top speed but reduced in torque and acceleration am I right? The video was incredible by the way. Thanks for the information!

[@MotoMirius]

Stock 15 45 has a ratio of 0.33. 14 43 has a ratio of 0.33. So it will have no impact at all except perhaps in more wear on the chain slider and risk of then damage to the swinging arm. If you want more top speed then 15 43 or 15 42 depending on what you can find. But top speed even with the 390 is quite reliant on rider weight/ frontal shape since the wind pressure will eventually stop acceleration - it is still only a 390 not a litre bike.

[@yori8784]

@@MotoMirius I think you're right. Thanks for the information. The frontal shape really slows down my duke from my experience😂

[@martinpearce7420]

Hello thanks for all the information I’ve googled and eBayed for a 50 tooth could you recommend a make renthal don’t seemed do one and don’t want to buy monkey metal just a strong good sprocket thanks again for All your KTM 390 tutorials :)

[@MotoMirius]

Supersprox might do one. Bagoros Performance make a 48. Or you can use a 14 front with something a little smaller on the back like a 46

[@martinpearce7420]

Thanks mate:))

[@gringo19860]

Hi David, where did you get your 14T sprocket from? Hard to find here in NZ... Do you know if the Duke 125 one (which I think is 14T) fits?

[@MotoMirius]

They are hard to get at the moment Steve - COVID has caused real issues with supply. I waited a couple of months whilst my normal supplier had it on back order. Eventually I just trawled around websites until I find one that had it in stock - helps to vary your searches and I found it by searching the JTS part number. 125 doesn't fit as the inner transmission is a different size (wondered that too).

[@leonkennedy7757]

Great content, i have a question, what do you think about a 16-45 relation in a 2015 duke 390?

[@MotoMirius]

Thanks. As with all gearing, it depends on how and where you ride. It's a popular choice amongst those who like a more laid back riding style or who use the bike for every day riding and spend more time at higher speeds.

[@leonkennedy7757]

@@MotoMirius i would like to have the same power, the 44 hp that the 390 originally has but with a little bit more of top end and reach high speeds with lower rpm. I ride in Colombia because is my native country.

[@MotoMirius]

@@leonkennedy7757 Gearing doesn't change power but it does alter torque. If you ride somewhere hilly you might not like the change, if you live somewhere flat then you may get the change you desire. There are no simple answers to this question - it is not a formula despite what some websites would like you to believe. This is why I recommend trying for yourself.

[@chrisquaile7979]

Great video , I love my 200 2016 duke , short commute bit slow at higher revs on dual carriageway , which front sprocket + 1 or 2 teeth for slightly higher 60 - 70 running on lower revs , thanks

[@MotoMirius]

Thanks. You might find the latest Bagoros Performance video interesting - it suggests that the Dukes all share the 390 gearing which isn't ideal for the smaller Dukes and going the other way might give you better running on the dual carriageway. Skäl David

[@gringo19860]

Hi, thanks for this! Just to confirm, if I want to city commute more "smoother" (higher rpm = less jerky in slow traffic, so not having to slip clutch all the time) on my '19 Duke 390, without losing too much at top end, would you recommend just going to 47T on rear? KTM Powerparts just offer a 46, but that would be barely noticeable right? Thks

[@MotoMirius]

I would recommend going for a 14 on the front and see how you get on. The 47 on the back will need a new chain as well, possibly also a front depending on how many miles you have on it. Given the ratio is 3, a 14 will give you 48 on the back. Skäl David

[@nitinchopra8416]

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[@MotoMirius]

Thank you to India! Skäl. David

[@thornbergz2560]

Nice video! I’ve got two questions! First I’m going to change the gears ⚙️ both front and back I want to get a higher top speed any advice? The other question is that something broke on the block over the front gear! On my bike what could that be? It’s on the block

[@MotoMirius]

Depends which bike you have and the conditions you are riding in. Bear in mind that the gearing charts online are theoretical assuming unlimited torque. With smaller bikes like this, top speed is very dependant on things like rider weight and lying flat on the tank, which is why you will see higher top speeds being recorded in India. If you drop the ratio, in theory the bike will go faster but in practice the bike will reach a point where it is unable to accelerate any faster because it lacks torque. Bagoros Performance have a video where they achieve a higher top speed on the 125 by increasing the ratio - because it produces a better match to the torque curve. In practice the stock ratio on the 390 is already close to licence losing speeds in the UK, so it isn't something that I test often and I'm more interested in getting the ratio better for how I ride at legal speeds. Block over the front gear?

[@thornbergz2560]

@@MotoMirius its hard to explain a little better! Now we are at the front gear holding the chain, above there is something on the block if it’s a holder from the block to the power distribution or something else! It’s hard to explain but it broke when the chain broke and I want to know if it’s anything that is necessary!

[@MotoMirius]

@@thornbergz2560 Impossible to say from that description what it is. If it isn't leaking oil you are probably OK.

[@gammagonad1657]

I’m waiting to try a 16T sprocket, but I’m not sure what type and # of inner splines. Also the correct bolt hole pattern. I know it’s a 520 pitch, but there has to be more to it. Can you point me in the right direction for a 2022 Duke 390

[@MCLARZ]

@@gammagonad1657Hello sir, I’m from Philippines maybe you can give your observation about 16T in front sprocket? How about your rear sprocket how many teeth you are using? I have 16T for front sprocket and I have also 43T at rear sprocket and a 2018 powertronic, this thing are not yet install to my KTM Duke 390 2018 but hopefully if I will go vacation I can install all this and I will update about my top speed soon.

[@iridemanila]

Nice video it was very informative

[@MotoMirius]

Glad you think so!

[@meizee3662]

Hey sir . any thoughts on the 15 42t combination for a duke 390 bs3 ? im more on touring and country sides with a little twisties . hope you can help 🙏

[@MotoMirius]

Hi, I'm using that at the moment because I'm doing some motorway riding, should be fine for touring, twisties might be a little less exciting.

[@tonytrevino3204]

I ride my Duke around 65 to 75 mph for long distances, What gearing should I use so it wont the revving so high?

[@MotoMirius]

Try a 16 on the front.

[@tonytrevino3204]

@@MotoMirius Thanks I'm going to try that.

[@andrewbyrne425]

Would changing these affect you speedometer reading? If so, I’d love to see a video on it!

[@martinskamla6789]

Andrew Byrne no it won’t the speedometer is based on the front abs sensor so no worries

[@MotoMirius]

Indeed it doesn’t. Skäl. David

[@ianparker1456]

@@martinskamla6789 what if i change the front sproket

[@martinskamla6789]

Ian Parker it still won’t affect the speedometer the speedometer is based on the speed of rotation of the front wheel not the engine

[@tomwatson3522]

2019 duke, will 14-45 gearing be fine for stock pipe, highway east riding?

[@MotoMirius]

Reducing the front sprocket increases the gear ratio, slowing the bike down. Depends how fast you ride - if you stick to 50 mph, it would be OK, but not really an ideal choice in my opinion. Skäl David

[@MotoMirius]

👍

[@YoannBsk]

Hello, where do you buy the 16 tooth sprocket? I can not find it on internet in France... Thank you ✌️

[@MotoMirius]

Broaden your search to outside France. I imported from the US. Skäl David

[@YoannBsk]

@@MotoMirius can you give me a link or a website? I still cannot find it, and my local ktm seller says that he didn't know where it can be buy...

[@MCLARZ]

The same question where I can buy front sprocket 16T. I’m from Philippines and I’m here in Saudi Arabia. I already have a 43T and I’m searching where I can but 16T front sprocket for my Duke 390 V2.

[@user-kq5dw4ss2v]

Did you have to recalibrate the speedometer? if so how did you do it? (planning to do this with a duke 125, is it a different process?)

[@MotoMirius]

Speedo reads from the ABS sensors, so no this has no effect. Not sure what they used on the pre ABS models but it would still be the wheels I would think.

[@akshaycjois6676]

Hi David, I need a suggestion,I own Duke 250 I want to install 48 teeth instead of stock 46 teeth how many chain links I need as per my knowledge 114 links will work correct me if wrong

[@MotoMirius]

Hi, well I use a 116, not sure how you've calculated but you have to allow not only for the teeth but the extra height of the rear disk. You might be OK with 114 but typically you would buy something like a 120 and cut to length.

[@pangtundure]

Why not have like Mountain 🏔️ Bikes like 12 sprocket on the back 🔙?

[@MotoMirius]

Because a mountain bike chain has to be flexible to move sideways and that isn't strong enough for motorbike torque - which is why motorbikes have gearboxes instead.

[@mr.mystery-X]

hey. so i trust u. thats why i'm here. so what do u think what can i take for the tvs apache rtr 200. also for front and the behind side..

[@MotoMirius]

Well, I've never even seen one of those so I can't be too specific, but yes, this applies to all bikes. Unless you intend stunting with a small bike you shouldn't look to change the gearing too much so one tooth on the front will give you an idea. What you need to be careful of is the chain line - if you put smaller sprockets on it can rub on the front of the swinging arm (can cut through it), and too big can hit the chain guard - but normally easy to modify. Good luck! Skäl David

[@mr.mystery-X]

@@MotoMirius thank u david.. u r the führer and the verführer in the ktm modified area

[@tomwatson3522]

So, 2019 390 duke, what sprocket combo do you recomend for stock motor easy riding in the country side?

[@MotoMirius]

Well that really depends what your countryside looks like. Where I live stock is pretty good. If you live in wide open plains you might cruise a lot more and go for a smaller rear or bigger front. If you live in twisty mountains then maybe 48 rear etc. I would recommend riding and finding what’s limiting you. Different people will choose different setups for the same conditions. Skäl. David

[@mithunpendurkar7234]

I have 2017 Duke 250. I've recently changed the sprockets to 45 teeth rear and 15 teeth front. I don't get the top speed that used to get before the change. Should change again to the stock sprockets or should I just go for rear sprocket with 47 teeth? FYI - The stock gets the 14 teeth front and 46 teeth rear sprockets. Appreciate your reply. Thank you.

[@MotoMirius]

15 45 is the standard ratio for 390 but the 250 has less torque so it will struggle to get the same top speed even though people think it will make the bike faster. Try the 14 with the 45 and see if that helps. If not try the 47 and don't be afraid to try with the 14 as well.

[@mithunpendurkar7234]

Thanks for your reply. I'll switch the front sprocket to 14 teeth. Also do I have to increase the chain links if I switch to 47 teeth? The new chain with 112L is already installed a week ago.

[@MotoMirius]

@@mithunpendurkar7234 It depends how many links the new chain added, you are likely to need a new chain on 15-47 but you might be OK on 14-47 (but probably not - rear sprocket tends to require new chain)

[@mithunpendurkar7234]

@@MotoMirius Thanks a lot. Will definitely implement as you mentioned. Have a great week ahead.

[@mithunpendurkar7234]

Hi, I've changed the front sprocket to 14 teeth and kept the rear sprocket to 45 teeth. But I hear sounds like kit Kat kit Kat sound from the front sprocket. Is it from sprocket or from the engine?

[@tonytrevino3204]

I going to go with a 16-44 and see what bike rides like when I go on long road trips .

[@MotoMirius]

Not sure that 44 will make much difference - I suggest trying the 16 first and then tune from there - you might end up wanting a 43

[@tonytrevino3204]

I was thinking the same thing but was worried if my chain would be too long but if it looks like I can I'll order the 43 when it's time to get a new chain. You'r video opened my mind to a small problem I had when going on a long rides Thanks for doing it .

[@MotoMirius]

@@tonytrevino3204 The advantage of only changing the front is that you should have enough chain adjustment to run with the existing chain whilst getting a noticeable change in gearing.

[@tonytrevino3204]

@@MotoMiriusCan links be removed from a new chain?

[@tomwatson3522]

2019 390 duke, how come you change the rear sprocket, why not change the front sprocket to 14 tooth? Will smaller front sprocket cause chain to run more on the swingarm rubber??

[@tomwatson3522]

Does changing to 14 tooth cause chain to rub more on the rubber swingarm guide???

[@MotoMirius]

14 with a stock rear would increase wear on the swingarm rubber yes. I went with a larger rear because it's a more long term solution - changing the front is a good way to experiment with a different ratio. With the larger rear sprocket which is acceptable for everyday riding I can now easily drop to a 14 if I ever wanted to play with stunting and the larger rear would help keep the chain off the swinging arm. Skäl David

[@persasz]

Hi, when you will upload video how to easily removable db-killer akrapovic?

[@MotoMirius]

It’s on my list to do. It will be soon. Skäl. David

[@adamstyles823]

Would love to come on a ride when its finally finished. will be fun

[@MotoMirius]

Thanks. Is a bike ever finally finished? Skäl. David

[@oliverabbey4271]

what is the best modifications for the duke 390 to be able to reach or just bellow 200kmh?

[@MotoMirius]

One of the biggest modifications to make is to install a smaller and lighter rider - this is why all the videos showing the highest top speeds come from India. RC tends to be faster because the engine produces a little more power and the bodywork is more aerodynamic so these need to be addressed on the Duke as well.

[@xlrull]

my duke 250 i change front sprocket to 13T it increases my top speed to 90mph before stock setup only get 80mph on 14t ... weird right??

[@MotoMirius]

No, doesn't surprise me - it's why I tell people not to use sites like gearing commander with a small capacity bike - the issue with a small bike is that it has limited torque so what you are seeing is that you get a better torque curve to hit top speed with the changed gearing. You can see a similar result in this video from Bagoros Performance for the 125, while the 390 shows little change. kzbin.info/www/bejne/nKa7hamvmc11o8U

[@sadhasiva231]

Heloo bro I am from india 2018 model my duke 200 I want to install duke 390 chain sprocket I was good or bad

[@MotoMirius]

As far as I'm aware you already have a 390 sprocket.

[@CallsItLikeISeizeIts]

Are the 390 duke and 390 ADV rear sprocket,bolt patterns same if wanted to put 50T on 390 Adv?

[@MotoMirius]

As the ADV is a new bike you would need to ask someone who sells the sprockets this question. Skäl David

[@tinks43]

A darn sight easier than my old T140V 🙈 Great too see you mate 👍🏻

[@MotoMirius]

Thanks Dave. Running slow on the videos at the moment. Trying to work on the content a bit but need more talent 😅. Skäl. David

[@hannesdobbelaere]

is there a 16t front sprocket available somewhere, and would this even fit? the 390/401 engine?

[@MotoMirius]

I run a 16 as you can see in the picture and there are no fitment issues. Can't comment on the 401 as I don't have one but given its the same engine I can't see any issues. Almost certainly will need to order online as with most parts.

[@MagicGate_357]

There was no rattle with the stock sprocket, but when I change to this sprocket, there is rattle to the touch after installation. Does this apply to you?

[@MotoMirius]

It's normal for there to be some a small amount of free play in the sprocket - your old one might have had a little corrosion holding it in place.

[@MagicGate_357]

@@MotoMirius I see, it is normal to have play. Thanks for the reply.

[@MotoMirius]

Don't worry, we all think this when we first notice the free play! Just make sure the keeper plate is properly tightened.@@MagicGate_357

[@superbikesquadracer]

Love your content mate! My rc 390 adac cup, (road legal) super bike has a top speed of 190 km/h.

[@MotoMirius]

Thanks. Cup bikes are very nice. One day I must try an RC. Skäl. David

[@superbikesquadracer]

@@MotoMirius You defnetly need to! You will instantly feel the power diffrence! Specially with the full Akra racing exhuast and cup map

[@TheJWC56RSA]

Good practical info!! Thanks David!!

[@MotoMirius]

Thanks for that. Much appreciated. Skäl. David

[@pedroplatzerdamotta]

Hey! I really would like to see a POV video of this 15:50 gear ratio in 390. Showing its 0 - 60, maybe a top speed as well. Can you make this for us please?

[@MotoMirius]

I am currently saving up for a new camera I can use on the bike so that sort of video will become possible. As noted in my other reply 0-60 also requires good gear changes - if you've ever watched drag racing you will know that there are a lot of factors that influence how fast you can hit 60 even doing it again and again the same day with the same setup, so be very cautious what you see on videos! :) Skäl David

[@pedroplatzerdamotta]

@@MotoMirius I see. yeah there are a lot of factors for a good 0 - 60 for sure :) Personaly I like this idea of having to change gear more often. My objective is to turn duke in something more similar to a dirty bike/Supermoto. Thanks for the reply David, I hope you get a nice camera for your vids. Best regards!

[@MotoMirius]

@@pedroplatzerdamotta Thanks. Yes, my gearing and riding style are supermoto based. I'm not too interested in top speed on this bike.

[@pedroplatzerdamotta]

@@MotoMirius Nice! David, just one more question. Does It provide Power wheelies?

[@MotoMirius]

@@pedroplatzerdamotta The 390 will provide power wheelies off the line as stock. You won't get power wheelies out of a small four stroke engine at speed without a little assistance. I don't get them because I have a dirt bike riding style where I sit on the tank

[@motologist1917]

i installed 16T front nd 32T rear sprocket on duke 200 but after 3000kms my racer kit is so noisy , can u tell me the reason behind it

[@MotoMirius]

What is a racer kit? 16:32 doesn't sound like a suitable ratio for a 200 - it will put a strain on the transmission as the engine won't put out enough torque to run that ratio.

[@bruterohan.390]

Duke 390 front sprocket little side play is it normal or not?

[@MotoMirius]

Yes, this is normal

[@aaquifkhan9071]

Hey Man . I've brand new 2020 Ktm RC 390 .I wanna change Rear sprocket . With 56 t Rear or 13 front . For better acceleration . I don't want top end ?🙏🙏🙏. Can u suggest me better Acceleration Ratio. Sprocket 🙏

[@MotoMirius]

13 front (if you can find one) may give chain slap and wear against the swinging arm unless you also have a larger rear sprocket. 13-45 is about the same as 15-48. This gives better acceleration in each gear - but remember is means that each gear covers only a shorter speed range, so you will need to change gear more often to hit the same speed as the stock ratio. So if you want a faster 0-100kph time, a bigger sprocket on the back may be slower than the stock ratio. I recommend watching the Bagoros Performance video kzbin.info/www/bejne/nKa7hamvmc11o8U

[@aaquifkhan9071]

@@MotoMirius thanx a lot

[@se7enrider106]

Hello.. I have got a duke 250 which has sprocket size of 14/46.. I replaced it with the one that comes with the 390 which is a 15/45..i was wondering if this would affect my gearbox or engine in course of time..would this change hamper the engine in any way?

[@MotoMirius]

That surprises me as the 125 runs 14/45 so its odd for the larger engine to run a bigger ratio. It probably won't harm the engine - really that's mostly down to your riding style by either being in too low or too high revs. It's likely to make the bike more sluggish on acceleration and may drop the top speed, but it's not big change so it should be fine.

[@se7enrider106]

@@MotoMirius yes the acceleration has dropped a bit.. Not by a great margin though...i was told that this would affect my engine in the long run so i wanted to clear my doubts.. Thanks alot👍👍

[@MotoMirius]

Just keep the revs up. The thing that is most likely to damage engine and transmission is lugging the engine which is running it at low revs.

[@se7enrider106]

@@MotoMirius okay thanks Buddy👍👍

[@John-hi2yi]

Nice video love the intro

[@MotoMirius]

Thanks John. Much appreciated 👍. Skäl. David

[@fernandomendez2303]

Hey bro, can you help me? I need to buy the stock sprockets for Duke 200, i cant find It on my country, Do you know any store on eBay or amazon??

[@MotoMirius]

Stock sprockets come from a KTM dealer, I normally buy online, your KTM dealer can get them otherwise so they would not be able to service the bikes and they buy them from KTM - so always possible to buy. But they don't sell the 200 in the UK so for example if I buy a 390 sprocket online - www.fowlersparts.co.uk/parts/view/00050002059 Skäl David

[@dsj66u]

Hi mate I have a duke 125 2021 stock rear is 45 I want a lil more acceleration what size do you recommend thank you

[@MotoMirius]

Bagoros Performance recommend the 48 rear for improved acceleration and top speed for the 125 - which would be a 13 on the front - but I'm not sure a 13 gives enough clearance on the swinging arm.

[@dsj66u]

@@MotoMirius so keep the stock font to 15 and change the back to 48 of is is 13 front 48?

[@MotoMirius]

I believe that the 125 runs a 14 front as stock not a 15. Going down one tooth in the front is about the same as going up three teeth on the rear.

[@dsj66u]

@@MotoMirius gone for the 48 and a new chain and will the train guard fit on all will I have to lose it

[@MotoMirius]

@@dsj66u Chain guard will be just fine

[@uncopino]

i want more top speed on my 390 cause suffer from the engine reving too high at highway speeds. but i don't know how much i can gear up without making the bike uncomfortable in traffic. idk... the thing does start in 3rd gear so how bad can it get? i'd like to have my engine at 7000rpm when at 130kph instead of 8000rpm. is it too much of a change?

[@MotoMirius]

To be honest, this is not a bike designed for long distance, high speed highway use. It's a fast revving, sports bike engine. You can certainly make a change in the gearing and I suggest first trying a 16 tooth on the front. Too much of a change will place strain on the engine and transmission, so try a small change first and then see how that goes. If the 16 works but isn't enough impact, try a smaller sprocket on the back. Skäl David

[@uncopino]

@@MotoMirius sure i do mostly traffic and twisties and that's why i love the sh't out of the thing. but highway happens every once in a while

[@uncopino]

@@MotoMirius and i can tell you the little beast can handle some touring. i have side panniers and i took it for weekend trips like 300km away a few times and it was super fun as long as i could avoid the highway

[@MotoMirius]

@@uncopino Yes, I know it can tour - but as you say, not so much on the highway. It can do even that, but it's just not the best tool for the job.

[@shubhamdesai3023]

Hi moto mirius, i know I'm too late to comment on this video. I need your guidance on 16:42 sprocket ratio (Duke 390 2019) which is equivalent to 2.625 compared to 3 (15:45) stock gear ratio ⚙️. Is it safe to do this ? Also I noticed ktm official sells powerpart sprockets in available sizes as 42, 43, 44 for the D390. I understand that it would result in higher top speed but will it totally kill the initial stock torque that I used to get ? , and will i have to change gears too early in traffic 🚦 ? Also would the stock 112 chain links fit 16:42 sprockets or do I need a bigger chain ? ⛓️. Note that, I'm running a Powertronic + Quickshifter + BMC air filter + DNA air lid + decat free flow SC project exhaust. Need your assistance ✌️

[@MotoMirius]

Replied on Instagram - first reply seemed to disappear.

[@crossknight3030]

Can you give a tip about the baby duke 125cc? Thank you 😁

[@MotoMirius]

Going for a smaller ratio to improve top speed on a 125 may not work very well unless you have a long flat to build up speed, but may still be worth experimenting with the front sprocket. Skäl David

[@crossknight3030]

@@MotoMirius thank you

[@oblivion12575]

Would you please tell me about back seat cover of your bike?

[@MotoMirius]

You can see the video here Powerparts Seat Cover Install KTM 390 125 250 Duke kzbin.info/www/bejne/fKDGaJmkq6dqo8k. There is a playlist of all my 390 videos. Skäl. David

[@Gt7LapTimes]

125 duke i have 13-44 but the 14-44 is best?? With 13-44 run 120 top speed limiter,the 14-44 130 is posible?

[@MotoMirius]

There is no best - there is only the right gearing for what you want to do with the bike. The issue with the 125 is a lack of power - just changing the gearing will not change that - at top speed you are pushing a lot of wind resistance. Gearing change should allow you some increase in top speed if you have a long flat run up but dont be surprised it its actually slower. Skäl David

[@HUSKY7-1]

If it was all so easy changing it, why edit out the removal of the sprocket?

[@MotoMirius]

Because changing the sprocket wasn’t the purpose of the video. There is enough detail in the video for anyone to copy the process. If people want a video showing the full details then I will obtain a 14 tooth sprocket. Skäl. David

[@nilsjohananti2337]

I’ve got a 12-45 on my 125 and they use the same so you can get smaller

[@MotoMirius]

Good to know. I was sure I’d seen smaller. Skäl. David

[@danzilsmith8859]

How do you like that set up and what is your top speed

[@tomwatson3522]

So, 2019 duke 390 gearing? 15 front, 48 rear? ????

[@MotoMirius]

Stock is 15:45 on 2017 to 2019 as far as I’m aware. 2020 390’s might have changed.

[@LiteralAlDS]

great content!

[@MotoMirius]

Thank you! Skäl. Da

[@willyangabrigo1174]

If i change the rear to 48, do i nyd to change longer chain?

[@MotoMirius]

Yes. It's why it's cheaper and easier to change the front sprocket down one tooth to a 14 (assuming you have a 390), but may not be the look you want.

[@jessnegron8174]

Where you buy the sprocket 16t

[@MotoMirius]

These aren't easy to find online as not many people sell them. You will just have to hunt down someone who has them in stock.

[@reup4023]

Driven makes a 16T, if you’re in the U.S. they can be found easily. Across the pond, I don’t know.

[@karanbundhela3336]

ktms do restrict the top speed of all 200 250 390 i guess they have speed limiter beside rev limiter because here bajaj ns 200 has same engine but same engine does 150kmph whereas duke 200 does 135kmph and can lemme know piggyback ecu like powertronic works in close loop

[@MotoMirius]

Rev limiter restricts top speed. Baja probably has a different gearing. If you are concerned if a piggyback works or doesn’t in closed loop I suggest you choose a mapped unit instead.

[@karanbundhela3336]

@@MotoMirius i use powertronic it has ignition timing plus fuel map but im unsure how it works plus im planning fof ecu remap i hope it would be better option what you say on this ?

[@MotoMirius]

Have you watched this? kzbin.info/www/bejne/l6iXhp6BhLCcrNk First you need to understand exactly what it that you want to achieve. No one can advise you unless you first tell them what it is that you want.

[@cranky1812]

Bajaj ns200 doesn't do 150kmph, that's speedometer error. Bajaj motorcycles have around 10 to 12 kmph speedometer error. KTM has only 2 to 3 kmph speedometer error.

[@cranky1812]

@@karanbundhela3336 for closed loop first you need to install a wideband oxygen sensor with standalone ECU.

[@odinhbjelland]

Nice video

[@MotoMirius]

Thank you. Skäl. David

[@paulnodpod]

You can get a Ktm duke 125 front sprocket size 13 teeth on eBay

[@MotoMirius]

Yes they are available from a number of sources. I’m unsure if it brings the chain too close to the slider. I’m currently waiting for a 14 but the supplier is out of stock! Skäl. David

[@brayans634]

So 14.43 give you both top speed and acceleration?

[@MotoMirius]

Compared to stock you can either go for acceleration or more top speed. 14:43 gives you a ratio of 3.07 which is pretty close to stock. Skäl David

[@ayushmhetre1373]

What's you Duke 390 milage

[@MotoMirius]

It’s about 3,000 miles. Skäl. David

[@markcunninghamtube]

"You might wonder, why would anyone want to do that. And the answer is" - wheelies

[@MotoMirius]

Ha! Some also do it because they want to rev the engine less as they ride along at 3,000 revs. I don't really understand why someone would buy a Duke and then ride it like this when they could buy a Honda. But that is just my opinion!

[@markcunninghamtube]

@@MotoMirius Have you happened to try clutch up wheelies on the duke 390 before and after switching the sprocket out on different gears? Thinking about switching out my back sprocket. On first, easy enough however second and above is quite tough and not that much power. What results have you gotten with second and beyond with the alternative sprocket?

[@MotoMirius]

@@markcunninghamtube Stunt riders change the rear sprocket for a reason, so yes, it does make a difference. I would say second gear is always going to be harder on a small bike. It depends what you mean by clutching up - people on bigger bikes are 'clutching up' but really they are just relying on power to lift the front end and that is where you will struggle with a small bike - technique is everything.

[@rickmancr]

If KTM geared the bike correctly, it's unlikely that raising the gearing will make it faster. Conversely, if the gearing is too high to begin with (as with a CB450 I owned many years ago, that was faster in 4th than in top gear) the bike could be faster when you lower the gearing. It's never as simple as higher gearing = faster.

[@MotoMirius]

I agree in general with you but the fact is that enough people have played with the gearing on these bikes to have established the baseline facts. KTM and Honda have very different approaches to bikes. Skäl. David

[@JH09SUMIT]

KTM geared this bike very short in my opinion.

[@dheerajd.p5034]

New into💥💥

[@MotoMirius]

Thanks 🙏. Skäl. David

[@Firby1988]

My duke 125 is well into the 10’s of thousands of rpm doing 60 lol

[@MotoMirius]

I can imagine. Skäl. David

[@doodle0007]

what are you trying to say here?

[@MotoMirius]

What part is unclear? Skäl. David

[@jaimielibbi1]

What’s happened with the bobber type builds, dukes suck

[@MotoMirius]

Bobber builds are coming back soon. I have a big list of things I want to do including revisiting some things that I want to tweak. Skäl. David

[@mevinpaupamah4935]

Moto 150

[@jaimielibbi1]

get back to p

[@MotoMirius]

Who is p?