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An all-automatic CVT based bicycle?
Hi all!
Question : Is it possible to remove handlebar shifting and make an automatic shifting bicycle with a Nuvinci hub? How is it possible? I tried to juggle with this a bit here : http://cozybeehive.blogspot.com/2008...d-bicycle.html I like the Nuvinci hub design. Its unique but I obviously never had one myself to try out. What are your thoughts when comparing this to previous CVT transmissions? Did anyone use it and have any problems in high torque, low speed situations? Thanks! |
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#2
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An all-automatic CVT based bicycle?
On Jun 4, 3:01*am, bicycle_disciple wrote:
Hi all! Question : Is it possible to remove handlebar shifting and make an automatic shifting bicycle with a Nuvinci hub? How is it possible? I tried to juggle with this a bit here :http://cozybeehive.blogspot.com/2008...vt-based-bicyc... I like the Nuvinci hub design. Its unique but I obviously never had one myself to try out. What are your thoughts when comparing this to previous CVT transmissions? Did anyone use it and have any problems in high torque, low speed situations? Thanks! Ellsworh already make one, "The Ride". I've not ridden one and so I've no idea how it rides regarding high torque and low speed situations. It might be the $3999 price tag that's putting me off buying one. |
#3
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An all-automatic CVT based bicycle?
On Jun 4, 10:27 am, Marz wrote:
On Jun 4, 3:01 am, bicycle_disciple wrote: Hi all! Question : Is it possible to remove handlebar shifting and make an automatic shifting bicycle with a Nuvinci hub? How is it possible? I tried to juggle with this a bit here :http://cozybeehive.blogspot.com/2008...vt-based-bicyc... I like the Nuvinci hub design. Its unique but I obviously never had one myself to try out. What are your thoughts when comparing this to previous CVT transmissions? Did anyone use it and have any problems in high torque, low speed situations? Thanks! Ellsworh already make one, "The Ride". I've not ridden one and so I've no idea how it rides regarding high torque and low speed situations. It might be the $3999 price tag that's putting me off buying one. Marz, I know and few reviews I saw were positive ones. But the bike features handlebar twist type shifting. The challenge is make an automatic bicycle that "thinks" on its own Thats a tougher task. |
#4
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An all-automatic CVT based bicycle?
On Jun 4, 7:02*pm, bicycle_disciple wrote:
On Jun 4, 10:27 am, Marz wrote: On Jun 4, 3:01 am, bicycle_disciple wrote: Hi all! Question : Is it possible to remove handlebar shifting and make an automatic shifting bicycle with a Nuvinci hub? How is it possible? I tried to juggle with this a bit here :http://cozybeehive.blogspot.com/2008...vt-based-bicyc... I like the Nuvinci hub design. Its unique but I obviously never had one myself to try out. What are your thoughts when comparing this to previous CVT transmissions? Did anyone use it and have any problems in high torque, low speed situations? Thanks! Ellsworh already make one, "The Ride". I've not ridden one and so I've no idea how it rides regarding high torque and low speed situations. It might be the $3999 price tag that's putting me off buying one. Marz, I know and few reviews I saw were positive ones. But the bike features handlebar twist type shifting. The challenge is make an automatic bicycle that "thinks" on its own Thats a tougher task. Get one of these to measure power (and let you know what it is in a readable format): http://www.quarq.us/Spiders/CinQo.html Then hack together a program on one of these: http://www.gumstix.com/waysmalls.html And use some servo controller to operate the shift: http://www.phidgetsusa.com/servo_controllers.asp If you really wanted to get crazy, you would progrma different "maps" and be able to switch amongst them with voice control. Joseph |
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An all-automatic CVT based bicycle?
"bicycle_disciple" wrote in message
... Question : Is it possible to remove handlebar shifting and make an automatic shifting bicycle with a Nuvinci hub? How is it possible? I tried to juggle with this a bit here : http://cozybeehive.blogspot.com/2008...d-bicycle.html Do you suppose you gain anything by having an automatic transmission on a device that can usually be powered through a single gear? |
#6
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An all-automatic CVT based bicycle?
bicycle_disciple wrote: Hi all! Question : Is it possible to remove handlebar shifting and make an automatic shifting bicycle with a Nuvinci hub? How is it possible? I tried to juggle with this a bit here : http://cozybeehive.blogspot.com/2008...d-bicycle.html I like the Nuvinci hub design. Its unique but I obviously never had one myself to try out. What are your thoughts when comparing this to previous CVT transmissions? Did anyone use it and have any problems in high torque, low speed situations? Thanks! Shimano already turned their Nexus hub gears into an automatic gearbox for bicycles. In the top model, called Cyber Nexus or Di2, the system consists of the following: -- Di2 8 speed gearbox, essentially same as Nexus 8sp Premium (redline) and Alfine box -- Stepper motor attached to box to perform actual gear changes -- Computer unit to instruct stepper motor when to change -- Special version of Flight Deck to act as control/infomation centre -- A switch to select among several gearchange modes if desired -- Hub dynamo to provide power for all units (the only battery in the entire system is a is a small flat CR2032 hearing aid battery to keep the presets alive in the Flight Deck) In addition, Shimano's Di2 Groupset also includes -- active front and rear suspension, under the control of the computers and switches described above An alternative version of the same system works with derailleur equipped bikes with, IIRC, 27 speeds; it switches the derailleurs rather than a hub gearbox but otherwise works much the same. Shimano's Cyber Nexus/Di2/Smover system (Shimano uses all these names, and a few others for the same components...) works very much in the way that Joseph suggests you should turn your adaptation of the NuVinci into an automatic gearbox. First the rider chooses a level of exertion on a dial with 8 stops on the CPU box; this is like, on a lesser bike, choosing a pedalling cadence and specifying your crankwheels and cluster of sprockets accordingly. Now the rider just gets on and pedals. Gears are changed up for him when he speeds up, and down when he slows down. He can additionally choose among four programmes (by switch, not by voice command as Joseph wants -- it's bad enough talking to your computer in private, but talking to your bike on the street is really weird!) which are manual, Ds, D, and L. Manual is obvious: the gears switch up and down as you instruct and the box stays in the gear you select. D is the standard drive mode, fully automatic. Ds locks out the lowest gear and changes up more quickly than D; it is the sporting mode of the autobox. L is the leisure mode, and changes into an easy-pedalling gear as sooner than D, and hangs on to easy pedaling gears as long as it can. In all manual modes when you stop the computer changes the box down to the lowest gear permitted in that mode, 1st for D and L, 2nd for Ds. In other words, it is a fully automatic box, set and forget if you want to, with additional very pleasing facilities if you want to use them. In addition the active suspension works the opposite way to that of a car: when you're going slowly it is set to hard to save all your power for acceleration, ditto for going up hills; on the downhill or going fast on the level the computer sets the suspension soft for comfort. I might point out that this entire Shimano Cyber Nexus system probably weighs less than NuVinci hub. Thus, when you have added CPU and control elements, plus dynohub to provide power, to the NuVinci, it will weigh much more than the Shimano Cyber Nexus system, which shifts imperceptibly and whose distinct intervals are around 14 per cent of its range. CVT by itself is not enough to overcome all those advantages that Shimano already has, including crucially the fact that the Nexus 8 speed box is proven beyond any doubt, and the not forgetting the monstrous benefit of Shimano's history of making fabulous parts cheaply. Furthermore, Shimano has their target market right in the crosshairs: their Cyber Nexus system takes clean, fully enclosed, roller brakes, entirely suited to sort of monied rider who doesn't llike getting his hands, or his clothes, oily. By contrast the NuVinci designers are under some kind of a misapprehension that sporting riders will buy a CVT gearbox, otherwise why did they make the thing take a disc brake? Personally, I think that the NuVinci will be gone in a couple of years; its first makers have already failed and sold out. Shimano, selling a lighter system built on the solid foundation of proven, even loved, components, and at a very keen price, couldn't create a mass market, or even a large niche market for an automatic bike in the obvious place, at the top of the market for city and credit card touring bikes; the evidence for this is that there are now very few of the Cyber Nexus bikes listed out of even the few that were made, and Shimano is trying again at the very bottom of the pile with, for instance, the Trek Lime. If Shimano, who have a lot of marketing nous and clout, couldn't do it, Johnny-come=latelies with only a single mousetrap to their name, and a poor grasp of the motives of users of mousetraps (as I have already proved), are most unlikely to last the course. However. If you are really so much in love with CVT that you want to spend your time and pocket-money trying to make the NuVinci automatic, you could start with the pretty inexpensive (for what they are) Shimano Cyber Nexus parts already well designed to to the job. You would need the CPU, the control switch, the Flight Deck, some cables, and a source of power which had better be the Cyber Nexus specific dynohub which already has a speed sensor built in which responds to the CPU, and the stepper unit. The immediate job will be adapt the stepper unit to switching the NuVinci box; if that fails, get a linear or rotary stepper unit and attach it to the cable itself and try to make the Shimano CPU control it. Once you can make the stepper unit move the CVT box in seven discrete steps (for eight speeds as in the Nexus 8, because that's what the hardware you're adapting is set up for), then it will be time to spend some time learning programming so as to work with the flash ROM inside the CPU to see if you can programme a continuously variable response to torque input. HTH. You can see my own Cyber Nexus automatic bike at http://members.lycos.co.uk/fiultra/B...%20Smover.html and about halfway down the page is a clear photo of all the elements required to make an automatic gearbox work on a bicycle. Andre Jute http://members.lycos.co.uk/fiultra/B...20CYCLING.html |
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An all-automatic CVT based bicycle?
On Jun 4, 6:13*pm, "
wrote: On Jun 4, 7:02*pm, bicycle_disciple wrote: On Jun 4, 10:27 am, Marz wrote: On Jun 4, 3:01 am, bicycle_disciple wrote: Hi all! Question : Is it possible to remove handlebar shifting and make an automatic shifting bicycle with a Nuvinci hub? How is it possible? I tried to juggle with this a bit here :http://cozybeehive.blogspot.com/2008...vt-based-bicyc... I like the Nuvinci hub design. Its unique but I obviously never had one myself to try out. What are your thoughts when comparing this to previous CVT transmissions? Did anyone use it and have any problems in high torque, low speed situations? Thanks! Ellsworh already make one, "The Ride". I've not ridden one and so I've no idea how it rides regarding high torque and low speed situations. It might be the $3999 price tag that's putting me off buying one. Marz, I know and few reviews I saw were positive ones. But the bike features handlebar twist type shifting. The challenge is make an automatic bicycle that "thinks" on its own Thats a tougher task. Get one of these to measure power (and let you know what it is in a readable format): http://www.quarq.us/Spiders/CinQo.html Then hack together a program on one of these: http://www.gumstix.com/waysmalls.html And use some servo controller to operate the shift: http://www.phidgetsusa.com/servo_controllers.asp If you really wanted to get crazy, you would progrma different "maps" and be able to switch amongst them with voice control. Jesus, Joseph -- and Mary, too, not to mention begorrah, sodom and gemorra. Talking to your computer in your study is bad enough, but talking to your bike in public is really weird! But this isn't a new idea, as Shimano's Cyber Nexus already has different application maps, called D, Ds and L, which regulate how quickly the gearbox changes up, and in the case of Ds for a sportier ride locks out first gear. Shimano, thankfully, put those on a thumbswitch rather than by voice command. The application maps apply a power curve which has eight steps set on a rotary switch directly on the CPU, which you might consider in the same way as switching camshaft profiles in an internal combustion engine. Fuller description at http://members.lycos.co.uk/fiultra/B...%20Smover.html An analogy with a racing/road bike might be a cyclist and his trainer deciding on a cadence for the cyclist (Cyber Nexus 8 step desired power output dial or profile of camshaft chosen for auto engine) and then choosing the crankset and sprocket cluster to match the road (Cyber Nexus three drive modes or electronic map on auto engine). Andre Jute http://members.lycos.co.uk/fiultra/B...20CYCLING.html |
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An all-automatic CVT based bicycle?
On Jun 4, 9:32 pm, "Tom Kunich" cyclintom@yahoo. com wrote:
"bicycle_disciple" wrote in message ... Question : Is it possible to remove handlebar shifting and make an automatic shifting bicycle with a Nuvinci hub? How is it possible? I tried to juggle with this a bit here : http://cozybeehive.blogspot.com/2008...vt-based-bicyc... Do you suppose you gain anything by having an automatic transmission on a device that can usually be powered through a single gear? What a curmudgeonly old luddite you are, Tom. Let the young man have his dreams of making something, or making something better, or even reinventing the wheel. Who knows, if we encourage him he might invent something to make even you seem, by magic, as fast on your bike as a young man. Andre Jute http://members.lycos.co.uk/fiultra/B...%20HUMOUR.html |
#9
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An all-automatic CVT based bicycle?
"Andre Jute" wrote in message
... On Jun 4, 9:32 pm, "Tom Kunich" cyclintom@yahoo. com wrote: Do you suppose you gain anything by having an automatic transmission on a device that can usually be powered through a single gear? What a curmudgeonly old luddite you are, Tom. Let the young man have his dreams of making something, or making something better, or even reinventing the wheel. Who knows, if we encourage him he might invent something to make even you seem, by magic, as fast on your bike as a young man. Andre, one of the problems is that too many people think "improvement" is "speed". I don't want to discourage someone from inventing anything they want. But can't a good bicycle remain a good bicycle? Look KG241 Time VX Elite Colnago C40 Eddy Merckx EX Pro Basso Loto Raleigh CX Atala CX converted to a touring bike. |
#10
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An all-automatic CVT based bicycle?
On Jun 4, 1:13 pm, "
wrote: On Jun 4, 7:02 pm, bicycle_disciple wrote: On Jun 4, 10:27 am, Marz wrote: On Jun 4, 3:01 am, bicycle_disciple wrote: Hi all! Question : Is it possible to remove handlebar shifting and make an automatic shifting bicycle with a Nuvinci hub? How is it possible? I tried to juggle with this a bit here :http://cozybeehive.blogspot.com/2008...vt-based-bicyc... I like the Nuvinci hub design. Its unique but I obviously never had one myself to try out. What are your thoughts when comparing this to previous CVT transmissions? Did anyone use it and have any problems in high torque, low speed situations? Thanks! Ellsworh already make one, "The Ride". I've not ridden one and so I've no idea how it rides regarding high torque and low speed situations. It might be the $3999 price tag that's putting me off buying one. Marz, I know and few reviews I saw were positive ones. But the bike features handlebar twist type shifting. The challenge is make an automatic bicycle that "thinks" on its own Thats a tougher task. Get one of these to measure power (and let you know what it is in a readable format): http://www.quarq.us/Spiders/CinQo.html Then hack together a program on one of these: http://www.gumstix.com/waysmalls.html And use some servo controller to operate the shift: http://www.phidgetsusa.com/servo_controllers.asp If you really wanted to get crazy, you would progrma different "maps" and be able to switch amongst them with voice control. Joseph Thanks. Good information so far. I already figured that one of the biggest challenges will be on programming. Other than PIC microcontrollers, could a PLC be used or is that overkill? I still do not understand if there's a difference between the two...I know PLC's can be programmed with special software, I have a little experience with those. Joseph : Even I dreamt of voice operation. It would be really ridiculous going "computer ! shift, downshift, shift, downshift..." on a climb or a city sidepath. BD http://cozybeehive.blogspot.com |
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