Topic Approved.

Each gearbox has its own merits and demerits and its not possible to choose the best of all worlds, for all situations. CVT doesn't generally excel in mileage, and in big engines this becomes a big problem.

But we do have one Automatic motorcycle, VFR 1200R and people largely are not too fond of it. Because the performance category loves to be in control.

I do wish that, I could ride a street bike with Honda's MotoGP kind of gearbox: which has no power loss while shifting gears. Rev up and just shift the gear while accelerating itself. But obviously Honda was not talking much about it anyways, don't know the latest report though.


OT Response: Apart from the engine's power and mileage, the other factors affecting the choice of an engine are compatibility with the frame, intellectual rights/ patents, public acceptance, risk under varied conditions, pollution norms, etc.

One reason is that the Wankel engine gets destroyed if there is no load at high rpm, like high revving in neutral. And we have no idea if it matches pollution norms with that quick 3 stroke (in a way) burning.

Mayank - Pls go through this review; you'll come to know some of the comments made about CVT - 2009 Aprilia Mana 850 Review - Motorcycle USA

And...hope you're aware about VFR

this one worth debating.. I feel this has more to do with perception than purpose. Cvt motorcycles probably represent commuterish feel rather than a cruiser or spotrs version.
There are high cc scoots in the market. It probably would not attract the 'biker'

the vfr1200 has a dual clutch transmission and not a cvt

but my question specifically was

CVT has become very popular in 4 wheelers then why not 2 wheelers

CVT has become a by default transmission type in most high end cars..

why not bikes?

yes i agree manual transmission gives u more control

but i happened to go through this article on how stuff works and in an animation it showed how CVT performs better than manual...
(i guess that was comparing regular driving)

but if CVT can be tuned to perform at the range of engine speed where maximum power is always given..isnt it better than the manual

i do prefer manual as well but it was just a thought in my head so asked

If you want CVT get a scooter.

Period.

^^^ Cost???
And takers for motorcycles. Serious riders find more fun with shifting gears, commuters worry about the cost.

Apart from the usual "clutch + gear" control.. one big factor which goes against CVT is LOW FUEL EFFICIENCY due to slippage of the belt over the pulleys.

The 110 cc Activa returns around 40 kmpl
The 110 cc Twister returns around 70 kmpl

Does anyone still wants CVT in his motorcycle?


Actually true.

actually that makes me wonder...why CVTs are advertised with better efficiency when in practical life u get better in the manual??


PS if activa has tyres the size of twister(diameter) i bet that 40 wud be 50+
but scooters are meant to have smaller tyres

smaller the tyres lesser the efficiency

correct me if i am wrong

"Better" in relation to other CVT scooters.

A CVT can't match the fuel efficiency of geared transmission


Larger wheels does not automatically mean better fuel efficiency.. had that been the case, all cars/auto rickshaws would have had huge tyres.

Also a geared scooter like the Honda Eterno returned great fuel efficiency (around 50-55 kmpl) despite having a 150 cc engine..!! But thing is people look for ease of riding (no gear, no clutch) in a scooter.. hence they are ready to sacrifice fuel efficiency. That's the reason who Eterno did not click.

A motorcycle with CVT..?? Hmmm let me see:

>> I don't get storage space like a scooter
>> My wife won't ride a motorcycle like she can a scooter
>> I don't get fuel efficiency of a similar capacity geared motorcycle


Why should i get a motorcycle with CVT..?? If I want a CVT i would rather go for a scooter.

CVT has not become the default in high end cars. DCT has.

CVT gives pathetic mileage. DCT doesnt.

In CVT there are no gears as such.
The engine continuously varies the gear ratios.
CVT = continuous variable transmission.
DCT = Dual Clutch Transmission

In theory, this is how DCT works.
there are 2 clutches.
One engages the current gear, and the other the next gear.
So that ensures lightning quick shifts, which sometimes even the human cant match.
Thereby ensuring its popularity.
And since it works on pre-defined gear ratios, it gives far better fuel efficiency than a CVT.
But DCT are big and heavy,(2 clutches) so they cant fit on a bike.

And as for the CVT,
CVT is slow.
Gives bad FE.
And it continuously varies the gear ratios.

i beg to differ hyperretard

cvt has a more liner power delivery and better fuel efficiency
but my query is though on paper its shown cvt has better FE but practically we dont see the same in motorcycles..like the example given
honda activa 110 40kmpl
hnda twister 110 70kmpl

why is that?
or is it the fault of the manufacturer?

HowStuffWorks "Cars with CVTs"

CVT - what the Continuously Variable Transmission is and how CVT works

i dont have evidence from big motorcycle companies but we have big car companies like merc,audi,etc which have incorporated cvt with a very large enginealmost double the size of normal cars and comparable mileage(i am not saying equal..i am saying comparable theres a difference)

i have a little idea about dct but havent read much into it...my topic was for cvt in bikes and not dct but we can change the topic to automatic transmission

the dct ensures lighting fast shifts agreed but they ALWAYS shift much quicker and humans CANT match it..

the auto transmission which changes gear for you has power losses not the other system with infinte gear ratios

cvt is more for city and commuter use(normal and luxury cars both included) the jap car makers mostly are going for cvt
dsg/dct is for performance cars, the european car are going for dct

so complete manual transmission is going to be history in a few years for cars atleast

so what is the future for motorcycles?


@payeng

i didnt understand your first statement

what do u mean by better in terms of other cvt scooters

my point was cvt is advertised having better FE than its manual counterpart

i am no supporter of cvt but i guess the major dissadvantage for cvt over manual is the user acceptance
one doesnt get the feel of being in control of the vehicle

True that ... I love shifting & its dynamic option which gives you chance to accelerate as per your convenient...

If you are in a rush or in aggressive mood take each cog to 7000-8000 rpm or else relax with 5k shifting

Aren't dual clutch gearboxes preferred over cvt for street and even for racing purpose? Better control over drivetrain is one of the advantages. eg There are times when you really want to hold on to a particular 'gear' which cant be done with a cvt.

FE- i might be wrong but i think the FE of dual clutch boxes should be comparable if not better than cvt. Short clutch engagement time and definite gear ratios are somethings that favour better efficiency. Also how efficient the the belt and pulley system compared to pulleys?

edit- also why o why would you want automatic transmission in a regular motorcycle? Gear shifting is one of the essence of biking. Most bikes have good enough torque spread so you dont keep on shifting. Auto are less efficient, costly and arguably less fun. Even a car enthusiast complains about the fact that manufacturers are going away from manual transmissions. Yes, car racing involves autos but for them winning is more important that joy of driving. Also motorcycle racing doesn't involve auto boxes, wonder why?