Scooter CVT transmission explained 

I am 35 .. I am driving scooters all my life, address ,gillera ,vespa,beverly , liberty... First time in my life i learnt how scooter transmission work ! Thanks bro .

damn, son, there are some smart ppl who can invent this kind of stuff. Engineering is incredible!

i learn much more from you than a 8 hour pay per class,Thank you.

everything is so clear when you get a real demonstration! I had looked at pictures and text explanations for a while but coudn't really imagine how it really worked... Now I understand why they say a CVT has essentially "infinite gears". Thanks!

Very well explained! Even the smallest things in transmission can make a difference in performance. I've bought my second scooter - 2013 Aprilia SR50R (carb ) and I''m rebuilding it to 70cc ,i did rebuild my 1st scooter Yamaha Aerox to 70cc too ,but only changed the pipe, cylinder kit and air filter. It ran good for the small amount of tuning i did. But the SR50R i'm tuning a lot more -sport transmission ,Yasuni pipe , streetrace 70cc ,bigger carb ,intake etc. ,thanks to this video I learned a bit more about transmission tuning. I'm surprised that in USA the scooter tuning is also popular. I'm from Europe (eastern europe - Latvia) and here it's a very popular thing amongst teenagers and even adults. You can pass the moped exam if you're 14. ( I'm 16 btw.) We even have a scooter forum ,official scooter meetings twice a year (10 or 11 years since the 1st one) with cast-iron and aluminium class drag races , and a lot of scooter riders upgrade their rides a lot to win those drags..even porting cylinders and engine blocks. In the past I thought that in USA people only put 150cc big bore kits on their 4 stroke chinese scooters and that's all with tuning :D but I'm surprised that there are 2 stroke powerful builds with all the known brands - Malossi ,Polini , Stage 6 etc. A subscribe and like from me.

This was far easier to understand than those fancy 3d animations thanks man . Lv from india

great explanation.. your voice needs be louder from beginning though...

Great vid, I'm fixing my friend moped and found the clutch variator destroyed, thanks

He made this vid to flex off the burnt titanium drive face 🤣🤣. I’m joking but nice vid I’m gonna start working on mopeds my self starting with my Aerox

I like CVTs in scooters, ATVs and snowmobiles but in cars I hate them. Mine blew out right after ended warranty what bullshit. Not cheap and easy but the opposite.

Finally, someone who can fully explain the functions of a CVT! I have a V-Moto Milan II 50cc and from the sounds of this video, installing all those components is possible, am I right? I'm in Australia and I've hardly seen any modified scooters in Adelaide...

Wow thats nice man actually i understand everything the way you explained and i also assembled those scooters in the philippines like honda dio mostly two stroke that was way back before and have a knowledge in putting those things for racing but financial is a big concern on our side that time so....but hope someday....hehehe thanks guys

I think you could've done that whole video with the camera in the tripod.

very good explanatory video And with very good image and sound quality It is a mobile phone or a camera thanks

You are OUTSTANDING at explaining things!!! Thumbs up! Those Polini engines kick ass!

Super cool video, I didn't know I could run it with the transmission cover off , I have a stock Wolf 50cc scooter very low miles and it started making a squeak noise during initial throttle, it sounds like my belt is slipping a little bit until I get going , after watching this video I'm confident I can fix it . thanks

Great video explaining the variator and clutch. Super helpful to see it in action too. Thanks, really informative.

a really great practical explaination on scooter transmission, great job!

What an incredible and interesting explanation of how the CVT works.

i just clicked the dislike button because no one else did. hahaha sorry, great video, i have been trying to understand this for ages. i changed my belt and am getting issues after a few days. need to open it up again and check cooling system i think and possibly the shims. thanks for doin this video.

Thank you for this video! I've learned a lot and I'll be applying it to my XMAX 300 when 12,000 miles come!

See also snowmobile , Honda CVT , ALL THE SAME principle.

Wish I could buy this cvt kit for my 2017 honda forza 125 cc

Dude great job on the explanation confidence level went up after watching your video Thanks

Can you tell the most common reason(s) why belts wear out (way) too soon?

What scooter is that?

may i ask how are the rules for you in the u.s. because i love to work on my scooter its fun and "relaxing some times" but if my scooter makes it to 80 kmh/ 50 mph they will take away my license and if you really unlucky the also conficated your scooter here in the netherlands. and what i always show the cops is he orignal manual from my piaggio typhoon. it says at 50mph atleast keep about 10m/33ft from the car in front of you. and they just say that its not true.

Use a freakink’ tripod ... it is very annoying to see you struggle to manage the components and video at the same time .... treat your viewers with some respect 😡😡😡

this is the point i know you know its a nice feeling plus the sound of the engine is also to my heart

I love this channel. So much learning and fun!!! I have a 2008 Zuma 50 2T I been overhauling with yalls videos. Thank you

Thorough explanation. Appreciate it!!!!

Recently bought a scooter and been searching for this video for some time. Good job explained all ive been wondering about. Keep up the good work. 👍

So x 1000 = this guy!

Excellent video. Can you explain the pros and cons of rollers versus sliders? Thank you.

I wish you had worked on my bike , ,maybe know I would be able to say I have one , instead of scraps

Can you please tell me exactly what scooter that is or where to get all the stuff for that CVT? I have several project ideas that a CVT would be perfect for. They’re small engine projects and this looks tough enough and simple enough that I can make it work.

That is so damn cool!

A very good video.. i am searching for scooter engine working video , i got this in 2 to 3 days after it......good explanation..

How many RPM do you have on your clutch spring and center spring?

Great video..changed output shaft and seal on malaguti f15 rr 69cc. Used to do 50mph. Changed belt and rollers at same time. Now moped only goes to 30 but nice and 20 up a hill. Any ideas? Old flat rollers were 4.8g. tried 6g, 4.7g and now 4g.

Now i know how my scoot works 😁

What is the perfect weight for rollers to get max speed? I already changed my cluthch springs to race springs.

Gotta love the sound of a well-tuned bike. 2T😍

Does shimming the variator a little like .5-1mm shim affect top speed?

Excellent presentation and content ! LIKED/SUBSCRIBED !

Hello!! Very great video.. Very clear explanation. Anyway just want to know why do you use Polini? Im still looking which one to get. Polini or Malossi? Any tips? Im riding Yamaha Aerox 155cc

How about a bbk install video? Let's see how easy it is.

Great video! How do I make sure that I have the proper weight sliders vs the proper clutch tension springs ?

Just disassemble the cvt and you will know how it works believe me that's what i do :D

I need some help with buying the right clutch assembly. I have an 80cc bbk , 139qmb engine

Really good visual explanation :)

I have a question, my cvt belt was worn out from 17,5mm to 16mm. but I ordered and installed 18,5 a thicker belt, I added some shimings in variator so the belt would stay as low as possible and it was as high as high in the rare (clutch plates). but it's still the same belt doesn't go all the way up on the variator, I squeezed the belt in the clutch as much as I could And I THINK THAT MY CLUTCH DOESN'T LET THE BELT GO ALL THE WAY UP 😫😫

iam a heavy dude 135-140 kilo and i got a stock 50 cc scooter whit me on it its slow starting up but ok in top speed, how or what do i chance to make it faster in the start up ???

please, someone, let me know how you adjust for hills and heavy loads and stuff. say you want to rid up a hill and pull a heavy trailer, how does this system account for that? surely the gearing ratio should be adjustable according to how much torque you want and not just set for general riding on flat terrain? how could one account for this if this system does not? some way to interfere with the centrifugal adjusters or something?

On earth we call that torque drive

Hello from Romania . Quick question : i have a 2023 Vespa GTS 300 HPE Super Sport with 4000 km , and i recently upgraded it with a Polini Speed Bell Evolution , Polini Black Rollers 13 grams , but also changed the belt with a Piaggio original belt and also a new original Piaggio V-Belt Pulley . The clutch remained the original one , but at some low speed acceleration and then braking , or when i release the throttle at low speeds , i can hear a metallic rattling sound coming from the transmission , It sounds like some keys are dangling in your pocket over some coins , something like that , for a short period of time , maybe 1 second . Have you experienced this sound after changing things at transmission ? Many thanks

Just subscribed! Awesome video bro!

the belt does not go all the way to the outer diameter of the variator. your missing out on top speed. sorry to bust your bubble, but it needs more work. maybe a smaller belt.

I'm looking at a Tao Tao 50 pony (I know... but it's what I can afford) Want to do some mods ie BBC and exhast. Also If I install 5.5 gram roller weights or 7 gram sliders in the CVT What color/size "clutch springs" and "contra spring" should I try first? Thanks in advance to anyone who responds

Hi man what do you call that adapter on the rear shock nut that you can use to raise the scooter with a paddock stand?thanks

So if my bike is only hitting about 8400 rpm’s and holding when I pin the throttle, what can I do to make it hit a higher rpm and have more speed? I have 1500 rpm springs, and I’m running 5.5 gram rollers or 5 gram one of the two, the bike is a 139qmb with a 50mm bbk on it , just a free barn find I built to wheelie but it’s really got me into scooters and I really wanna understand how to easily tune; bike will only do 41 mph @ 8400 rpms

Hi brother, i am from India. I have a question ❓ I own TVS Ntorq 125cc scooter and willing to upgrade the performance can you suggest something good for my scooter as in India we don't have performance part available. Regards Anthony

Does a stock Yamaha zuma muffler flow pretty good ? The reason I ask is I like the sound of the Zuma's stock muffler. I was thinking of installing a zuma muffler onto my Wolf booter

I've got 6.5 and 8.5 gram rollers in my 50 cc zummer gy6 taotao now it's going 45mph on straight but sometimes it bogs down why,?? And I have ten gram rollers coming Monday so I was gonna take the 6.5 gram rollers out and put the ten gram rollers in should I or no

This video is verry informative and it seems ro be hard finding that on youtube for scooters i have Peugeot speedfight 2 100cc but im lost knowing what parts to get for tge transmission 😂

Hello dude..Pretty nice vid. What do you think is the problem if the belt start to raise in front before the cluth is engage to rotate the wheel (cvt aftermarket)?

Super video! Great explanation of CVT! # question. Is there a CVT cover with a kickstart Leaver that is available for my 2018 125cc Zuma.

Damn good explanation, no doubt, with great visuals to boot. However, you left off at a crucial point of understanding, the rear pulley... PLEASE make a rear pulley video as good as this one! No point in purchasing what I don't understand, yet.

I have a 2003 yamaha bws, did a brake stand and it started to wheel hop. I developed a vibration and eventually lost drive. IS it usually a belt that snaps or the cvt went to shit. I still have to take it apart to have a look.

Appreciate your time spend learning the dynamics of it and enlightening us❤

nice video.. have also got 4 scooters right now and also share some works related to them.. lets share our experiences so that more people can benefits from it. TQ

Beautifully explained! Oh i did love that.. oh it stinks.. smells good! :)

Was that originally a stock horizontal minerelli engine? I have a Yamaha BWs cw that I want to put a horizontal minerelli l/c engine into with all high performance internals & don’t know weather to just buy rc one 70 cases instead??

Amazing video, full of info that a normal person can understand!

I always wonder what exactly happen inside of my Honda Vario's CVT, now I know

I have a big boar kit for it to turn it to 80cc but I kinda don't wanna put it in because it goes 45 now but it's just not enough power up hill still only about 20-25 mph please guide me help thanks

Hi, im from philippines, just wanna ask, i have honda beat FI scooter, its 110cc, how can i make my scooter faster a little without modifying the block and head, i change my pipe from stock to exo r6, silent type, stock rollers are 15g, 800rpm clutch spring and center spring, how much weight of rollers should i put and how much rpm for clutch spring and center spring if i want more acceleration and speed? Thanks a lot and ride safe,

Thanks for this. Do you have any idea, why is it that: on my scooter when i start mmoving with the bike at the beginning its shaking the whole bike for a few seconds and then its smooth again at a higher speed. So its shaking at the beginning of the speed up process, is the clutch spring not ok, or the whole clutch worn and not cathing the clutch house properly? Do i need to replace all parts or just spring or other parts?

No constant oiling needed as there are no chains. has simple parts. unlike cvts in cars, cvts in motorcycles are super reliable as that rubber belt has way less power to manage than those poor metal belts in cars which have to transmit at least 100hp to a 1.5 ton car. has no problems with crossing waters as tranny has its own cover. cheap to own and cheap to maintain. easy to use and comfortable. scooters are awsome

The back pulley is called the torque driver

question: so if ur motor is slow acceleration and you reduced the weight of roller but then how do you deal with top speed loss??

Are CVTs on scooters reliable or do they break often compared to manual transmissions on motorcycles?

I was riding mine today when there was a horrible high pitch scraping sound and the engine immediately cut. I was riding in my yard so I just pushed it up to my house, but while doing so there was a scraping sound coming from the transmission. It was a crappy Dykon Fugati 50cc, is it possible it's just the belt? However, I tried to start it again and there were no signs of combustion, so I'm not sure if it's the engine. I'm mad because I just put the carburetor back on it today, now this. It has 1,123 kilometers, 698 miles.

some one told me if youre reversing while your engine is turned on it will cause damage or it will risk damaging the motorcycle? is it safe to reverse while its turned on or its better while its off?

hello guys i want some help about the springs the contra and the clutch springs i had the stock one and changed it for red one but it like snapped my belt and now i want to get other spring but im not sure what to get the red one was 2000rpm and it was the hardest its 80cc 4t scooter i want to make it to have nice start and final drive i was thinking getting yellow contra and white clutch springs but im not sure can it still snap my belt

hello guys i want some help about the springs the contra and the clutch springs i had the stock one and changed it for red one but it like snapped my belt and now i want to get other spring but im not sure what to get the red one was 2000rpm and it was the hardest its 80cc 4t scooter i want to make it to have nice start and final drive i was thinking getting yellow contra and white clutch springs but im not sure can it still snap my belt

does changing the drive face make much difference?? new to bike and tuning so sorry if this is a dumb question

If I were to do the "sharpie trick" and I get som sharpie marks left, do I need other weights? Other clutch springs? Harder or softer? Lighter or hevier weights?

the performance parts a joke what's the point of trying to squeeze power from a 8hp engine. Just get a bike with bigger engine. My bike has 20k miles on it with original clutch.

Hi Should the crankshaft lock? Their is some play moving it by hand or should it move freely? Just ordered new belt as old one was loose. Thanks Great Vid

My transmision its shift to soon its like when you give throtle its going like 2-3 sekonds good then its shift and its has low power whats to change ?

What are good cvt upgrades to run in a 139QMB? Like what’s a good clutch? Good variatior?

Where are you guy's located I just purchased a 2008 zuma 50cc always wanted one anyhow I want to do get it built to be a reliable daily. So my desired goal is to be able to reach at least 50mph and definitely want off the line torque for wheelies.

I have a 1985 Honda Elite 150 4 stroke, when I look in the carb and turn the throttle the vacuum piston in the carb does not lift up more than a cm, it runs okay but wont top out, I thought that the throttle cable was supposed to slide the vacuum piston up to let more air in, or is this incorrect? thank you

you are stunning. That was really amazing and I enjoyed every sec. May I know what's the weight of CVT mechanism? Nothing but CVT.

I own 2011 model CVT motorcycle. I thrown 50K kilometer on it. It runs as fine.

Hin guys, I'm in Australia, I own a 2015 Suzuki Burgman 200. I'm happy with the power, but would like to reduce engine RPM at freeway speeds... cruising at 65mph the tacho indicates over 7400 rpm, if I could drop that a little it would cruise more comfortably. Also, from take-off it revs to 4,500 or so before starting to move away from a standstill... Am I asking too much to get the clutch to kick-in a bit sooner? Do you ship to Australia? Cheers, Geoff, Perth, Australia.

Anyone can help me with a few questions about re gearing my gy6! What's the stock gears and all that!

Can you make a video, explaining in what order to tune your cvt? do i start with rollers and dial in my vario first or do i start with the clutch?

BRILLIANT mate thanks. Is it possible to increase speed just by fitting a wider BELT. Just 5/ 10k faster ?? I have 4 different scooters. HONDA 150 PCX. HONDA BEAT. HONDA SCOOPY.. SUZUKI NEX. . Probably the PCX. Would be nice. A little faster ??? What's your thoughts ? Thanks. Dave