Yamaha files patent for Enduro bike with CVT transmission
Yamaha recently filed a patent in the United States for an enduro motorcycle with a continuously variable transmission. The CVT, as it's better known, is one of the most efficient means of transferring power in an automobile application. Yamaha, as well as nearly every other manufacturer of modern scooters, already uses simple CVT transmissions in its line of small-bore scooters, but the gearless transmissions have yet to make an appearance for off-road applications. While the inherent efficiency of the design is one reason we are interested, we also imagine that the single cylinder engine design used by nearly every off-road motorcycle would be well suited to the CVT's strengths. New riders would likely appreciate the ease at which the machine would operate, as no gear lever or traditional handlebar-mounted clutch lever would be necessary to access the smooth and steady acceleration. While durability could be a potential concern, we're looking forward to seeing what the tuning fork company is able to work up.[Source: Gizmag]
Reader Comments (Page 1 of 1)
dragon sled 12:01AM (7/03/2008)
Now, I would like CVT in my V twin crusier, and sportbike, THankyou
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Paul Wujek 7:55AM (7/03/2008)
As well as scooters Yamaha also makes snowmobiles that use CVTs.
As someone who has on occasion traveled across a frozen lake at more than 160kmh (100mph) I can tell you that these transmissions can handle quite a lot of power and speed.
Nobody should have to worry about the strength and reliability of the transmissions.
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brn 10:01AM (7/03/2008)
"CVT, as it's better known, is one of the most efficient means of transferring power in an automobile application"
In theory maybe, but not in real world application (yet).
"the gearless transmissions have yet to make an appearance for off-road applications"
Unless you count my riding lawnmower.
Not sure what's "green" about this, but that doesn't seem to be a requirement for these blogs anymore.
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fadetoblack51 6:19PM (7/03/2008)
Are you sure your lawn mower has a cvt? a cvt wouldn't seem very logical since they aren't designed to lock down on a set speed. I think your mower probably has a hydrostatics drive, which were quite common on farm tractors.
BlackAdam 10:54AM (7/03/2008)
What, really on an enduro bike? It is a sport bike, shifting is part of the skill set needed to ride. I can see on a entry level bike but a true rider would pass on this, or at least should. On a 4 wheeler or snowmobile ok but seems very wierd no not want to shift on a dirtbike.
Polaris has auto trans on Quads for ever, are those CVT? I dont know.
CVT is ok on 4 wheelers (not really the sport ones though) but I just think shifting is so much of the fun while ridding on enduro bikes. Maybe I am in the minority.
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Seth 11:32AM (7/03/2008)
true, but as more and more motorcycle riders are not 'true riders' as you call them but just commuters looking to save on parking, gas, and traffic, a CVT is a welcome addition.
BlackAdam 12:19PM (7/03/2008)
Seth -
This is about a dirt bike not a commuter bike. Like I said a CVT is fine for a road bike or a trail quad or whatever but for a ENDURO BIKE - you know a dirt bike primarily used to RACE ENDURO or to run dirt trails off road. Most dirt bikes are not even legal to ride on roads, the few that are still are intended to run off road and only go on roads as a secondary feature. Why anyone would want to dirt bike as a commuter is beyond me. It like people who buy a Landrover defender and never take it off road. If you want an efficiant commuter bike they make those.
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Stip 7:22PM (7/04/2008)
Dual sport motorcycles like the Yamaha xt250 and the older xt225 make great commuter bikes. There are plenty of reasons people prefer them over road bikes. For example:
1. Most 250cc road bikes (other than the new Kawaski Ninja 250) have geriatric styling. I am thinking of the Honda Hawk, Honda Night Hawk etc.
2. Small dual sport motorcycles can get better gas mileage. I have a Yamaha TW200 and get around 80 mpg. Check out the Yamaha website or here:
http://tw200forum.com/forums/38867/ShowPost.aspx.
3. Many people can only afford one bike or don't have room for several motorcycles so why restrict yourself to one that can only travel on a highway? I use my TW200 to commute to work AND enjoy using it to ride off road with my friends. Why restrict yourself to a road bike with such a narrow focus?
diffrunt 2:53PM (7/03/2008)
In 1946 , my ServiCycle had CVT consisting of vbelts& floating
pulley. Worked good until crankshaft seals exuded 2 stroke mix excessively
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George Krpan 7:19PM (7/04/2008)
What's significant about this design is that, unlike scooters, the engine does not swing up and down with the swingarm.
I have owned a large displacement scooter, 460cc, and can tell you that the swinging engine ruins handling and ride comfort.
A couple of large displacement scooters are of the non-swinging design, Honda Silverwing and Suzuki Bergman.
Aprilia has just come out with a CVT equipped road motorcycle called the Mana. There is no clutch lever and the transmission can be operated in automatic or manual mode. It has an 850cc v-twin engine. Aprilia claims it is the fastest accelerating naked bike available.
I doubt if the Aprilia or this Yamaha employ the same kind of CVT that scooters use which is simply two pulleys joined by a belt.
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Navigator 9:17PM (7/10/2008)
Although this is about technology, it isn't new on a high performance motorcycle. Rokon built a terrific enduro bike in the 1970's that had a cvt transmission. They were quite good looking, but very expensive. I think they only build two wheel hunting haulers now, but they did build a nice bike then.
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