A look at the different types of motorcycle transmissions.. and also would the proposed "automatic" motorcycle from TVS Motor cut ice..??
A couple of days back major Indian national publications/automobile blogs/sites broke out the Official news from TVS Motor that they are ready to launch a slew of new 2 wheelers (by 2013) with an a newly developed automatic transmission technology. TVS has also officially stated that they are eyeing to put this new technology across scooters, step thru mopeds (for markets like Indonesia) and also on motorcycles..!!
Bajaj had put a 3 speed automatic transmission on its Saffire scooter in 1999
Honda VFR1200F features a sophisticated automatic transmission..
As my blog covers specifically motorcycle related stuff, what would this proposed "automatic motorcycle" from TVS would be like?
Q1.Doesn’t TVS already make the "clutchless" Jive model?
Q2.Does it mean that the new motorcycle would feature a “clutchless+gearless” mechanism from its scooters like the Wego?
Since all the sites have more or less "copy + pasted" the official word from TVS, the complete details is actually not clear for a layman.
Official Photo: New engine platform from TVS Motor with the new Automatic Transmission Technology
Basic understanding of the "types of transmissions" usually found on two wheelers
1. With Manual Gears with a Manual Clutch:
This type of transmission is currently found nearly across all motorcycles sold in India.
Best possible fuel efficiency : The wastage of precious fuel is minimum when the gears are selected judiciously
Rider control: Such a transmission lets the rider remain in control of the bike according to his wish.
Tiresome to ride in traffic: The clutch has to be depressed a lot while riding in traffic giving the left hand a good workout
2. Manual Gears with an "Automatic" Centrifugal Clutch:
This mechanism has been adopted on the TVS Jive motorcycle. In this case there are gears which need to be changed manually (by the left foot) but there is no manual clutch that needs to be engaged with the left hand. While changing gears all that the rider has to do is to let go of the accelerator which brings the "centrifugal clutch" into play, this allows the rider to change gears without the need for a manual clutch.
This mechanism is quite popular among step thru models sold in the South-East Asian countries like Indonesia, Thailand etc. Since TVS produces step thru models with such mechanism in Indonesia, plonking one on a motorcycle (Jive) platform wasn’t too difficult for them.
Decent fuel efficiency- Since the selection of gears is done manually the fuel efficiency remains good
Not sporty - Even South East Asian riders find this clutchless mechanism not sporty to ride. And yeah pulling wheelies, stoppies, burnout’s or even sliding around without a clutch would be very difficult.
Riding without a clutch is unnatural for Indians: It is something that Indians are not used to. During my test ride of the Jive, it was awkward for me to adjust to riding without a clutch lever. No wonder the Jive has not found too many takers in India so far.
3. CVT (Continuously Variable Transmission) with No Gears – No Clutch..!!:
This type of transmission of currently found across all automatic scooters sold in India. This transmission does not have a clutch or gears. The 2 wheeler moves ahead just with the twist of the accelerator.
The transmission mechanism consists of a belt which moves over two conically shaped pulleys.
Image courtesy: howstuffworks.comAdvantages :
Seamless drive - Since there is no clutch to engage or gears to operate riding a vehicle with such a transmission is virtually child’s play.
Also the power delivery is smooth/without any jerks
Low Fuel Efficiency - Since the drive belt moves over two conical pulleys, there is slippage of the belt over the pulleys while transferring the power, leading to loss of power which results in comparatively lower fuel efficiency.
The above actually answers the question why a 110 cc Activa scooter with CVT mechanism returns around 40 kmpl whereas a 110 cc Twister motorcycle with manual gears returns around 70 kmpl..!!
4. Automatic Transmission (with no manual clutch or manual gears):
This type of mechanism is similar to riding vehicles with CVT mechanism. i.e one doesn't have to bother with either a clutch or gears. But unlike a CVT mechanism they actually have gears and clutch, just that the gears and clutch are inside the engine which are automatically operated mechanically and (in case of advanced systems) electronically by the engine depending on the speed / load on the vehicle. The Honda VFR1200F is a model which features an automatic transmission system.
Better fuel efficiency than CVT mechanisms - Since there are gears ideally there should not be loss of energy/power like on a CVT mechanism
The automatic mechanism is complicated- Unlike a CVT mechanism which is quite simple in operation, an automatic transmission has to be accurate in changing the gears according to the ride conditions. If the automatic shifts aren’t accurate then the vehicle would feel like it’s “hunting for the right gear” to move forward.
Also the shift mechanism has to be fast and smooth to provide a seamless / jerk free ride experience.
The TVS Automatic Mechanism:
From the news reports I understand that TVS seems to be developing the 4’th type of transmission mentioned above. It plans to install this mechanism first on its scooters (staring from 2013) and then have plans for motorcycles too. Currently they seem to be ready with an engine platform of 110 cc and have stated that they can be scaled upward to 250 cc. One news report does state that a motorcycle fitted with this mechanism would have the option to change gears at the touch of a button.
New transmission promising on a scooter...
The main benefit of this new transmission is the “promise” of better mileage/fuel efficiency. TVS in its official release have quoted a figure of 20% better fuel efficiency than a normal “CVT” scooter. That should roughly mean an increment of 8 kmpl over a normal 110 cc “CVT” scooter with 40 kmpl fuel efficiency. So a 110 cc scooter which will return 48-50 kmpl..?? Not bad I’ll say, after all in India who doesn’t like more mileage..?? This could really work in favor of TVS.
But then the new transmission system has to be really robust, accurate and reliable to work flawlessly, else it will be irritating to ride. In fact TVS is not the first in India to try such a transmission system. Bajaj tried a 3 speed automatic system on its “Saffire” scooter in 1999 before reverting back to the conventional and simple in operation CVT system for the next upgrade which was the “Wave” scooter.
Same “automatic transmission” on a motorcycle? Not very sure..
- A 100 cc Twister with manual gear control returns around 65-70 kmpl and this new motorcycle with automatic gear control would return 48-50 kmpl..??
- Agreed riding this type of automatic motorcycle would be stress free in traffic and definitely not awkward like the Jive, but then why not opt for the automatic scooter in its place?
- One does not get the extra storage space on a motorcycle which is present on a scooter
Also let’s not forget the loss of control over the gears and the “less sporty” feel of riding an automatic somehow make this proposed new transmission on a motorcycle very “un-motorcycle like” to me. But as one news report does state that a motorcycle fitted with this mechanism “gears can be changed with the touch of a button”, I’ll have to say that I have to ride one to believe.
Internationally Honda VFR1200F is a model which has a sophisticated automatic transmission with auto mode and also button type electronic gear change. But then the VFR1200F hasn’t really set the sales charts on fire.
Seriously TVS, why not try to build more sporty and potent “desi” bikes than try to crack a comfortable commuter code..?? But nevertheless respect from my side for trying out new and innovative technologies in India.
News source: Hindu, India Today
- Ride Review: TVS Jive [May 2010]
- TVS introduces ABS on it's Apache RTR 180 model [Mar 2011]
- "ABS good for the race track": Says TVS [Jun 2011]
This is to remind that the Views or Opinions in the blog are entirely mine unless explicitly stated. The Views and Opinions published in this blog should in no way be related to any other person or organization associated -- directly or indirectly -- with me.