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Rohloff makes the case for Cyber Nexus
Not that I'm more familiar with the Rohloff 500/14 hub gearbox and
settling in to a pattern of using it, in thing stands out: for efficiency, you have to work it. I tend to avoid the geers 7 and below, because they make a depressing sighing sound. But even in the higher gears, I tend to stay in gear and mash my way up the incline rather than bother with the stiff gearchange. That is not the most efficient way to ride. It might make me fitter faster, but what we're discussing here is the bike's mechanical efficiency, not my respiration rate. Shimano's Cyber Nexus full-automatic hub gears on the other hand changes gears smoothly to permit the cyclist the maximum speed his pre- selected exertion level can provide. The rider exerts the same energy, regardless of the road. In my case this level was set with a minimum of experimentation and fuss at 80% of my maximum heart rate. No human can change gears as efficiently as Shimano's Cyber Nexus. I also have on another bike a manual version of the Nexus Premium/ Alfine gearbox the Cyber Nexus is built on, though I don't want to pretend I changed gears on that much smoother box (than the Rohloff) for maximum efficiency all the time. But a large proportion of the time I did use it well. The Rohloff with its even gearing steps but with its stiff change thus makes a convincing case -- for an automatic gearbox! I don't think it would be difficult to make an automatik Rohloff, and there could be a small market for it. Shimano's full-auto hub and derailleur gearboxes are still going but the prognosis is not good because Shimano has a long history of ruthlessly killing products which reach only niche markets. I fear that the Cyber Nexus will become merely a footnote to the electronically assisted (not automatic) Dura-Ace shifter derived from it. (The Dura-Ace shifter is a joke, a sop to the macho attitudes of the roadies, nothing to do with extracting the maximum efficiency from gears and cyclist.) However, Rohloff can work within much smaller, specialist markets. I for one would happily pay two or three hundred Euro for a kit to add electronic shifting (powered by the hub dynamo already on my bikes) to the Rohloff box. Andre Jute Visit Jute on Bicycles at http://www.audio-talk.co.uk/fiultra/...20CYCLING.html |
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Rohloff makes the case for Cyber Nexus
Per Andre Jute:
No human can change gears as efficiently as Shimano's Cyber Nexus. It might be a personality thing. I tried somebody's automatic-shifting bike once and it drove me nuts. OTOH, the guy whose bike it was loved it. Sometimes I want high RPMs, other times I want low RPMS (as in giving my butt a break going up hill)... regardless of ground speed. -- PeteCresswell |
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Rohloff makes the case for Cyber Nexus
On Apr 28, 12:37*am, "(PeteCresswell)" wrote:
Per Andre Jute: No human can change gears as efficiently as Shimano's Cyber Nexus. It might be a personality thing. * Well, no, it's a pretty obvious conclusion. The human will always be seconds slower on each gearchange than electronics can be. I tried somebody's automatic-shifting bike once and it drove me nuts. * OTOH, the guy whose bike it was loved it. Now that's a personality thing. He should have lent it to you for a week so you could get used to it. Sometimes I want high RPMs, other times I want low RPMS (as in giving my butt a break going up hill)... regardless of ground speed. That's just what you're used to on derailleur bikes. You need more than a short ride to get used to the auto box -- certainly I did, even coming to it from the same type of Shimano box, only manual. But, perhaps surprisingly after disagreeing with each of your subsidiary points, I agree with your overall point. Shimano set up the Cyber Nexus controls so that the "effort level control" is under the bottom tube, facing down to the road, way out of reach. They want you to set it once and forget it. So, if you can't get used to a steady cadence with the gearbox adapting, the Shimano implementation of full auto, as in the Cyber Nexus, is not for you. I also corresponded with a guy who had the derailleur type Shimano full auto on a Koga-Miyata, and he thought the effort control should be under his thumb. (Too complicated for most riders, I thought at the time, agreeing with Shimano.) An alternative is CVT which, with your cadence, puts effort control right under your thumb, as in the Fallbrook NuVinci CVT. Chalo several times mentioned the high weight of the NuVinci hub but I don't see the problem; it is clearly a commuter/daytourer's hub, so the weight doesn't matter all that much. Can't imagine racers of any kind looking at the hefty NuVinci though. Andre Jute You can ride only one bike at a time |
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Rohloff makes the case for Cyber Nexus
(PeteCresswell) wrote:
I tried somebody's automatic-shifting bike once and it drove me nuts. OTOH, the guy whose bike it was loved it. I have a bike which came with a Shimano automatic hub (4-speed). I persevered with it for a few months, and hated it - not the lack of gears, but the infuriating changing when I didn't want it to. A bit like automatic cars really. I've driven one at least weekly for many years, and still dislike that intensely. So I bought a SRAM Spectro S7 for the bike and fitted it instead. It's now 30,000 happy kilometres later. John |
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Rohloff makes the case for Cyber Nexus
On Apr 27, 5:11*pm, Andre Jute wrote:
No human can change gears as efficiently as Shimano's Cyber Nexus. It might be a personality thing. * Well, no, it's a pretty obvious conclusion. The human will always be seconds slower on each gearchange than electronics can be. Oh great. In addition to weight weenies, we can have seconds weenies. An alternative is CVT which, with your cadence, puts effort control right under your thumb, as in the Fallbrook NuVinci CVT. Chalo several times mentioned the high weight of the NuVinci hub but I don't see the problem; it is clearly a commuter/daytourer's hub, so the weight doesn't matter all that much. It's not just the weight, it's the efficiency of the NuVinci too. In any case, I'm with Pete Cresswell. I'd much rather choose when to shift. Does the CyberNexus know to shift at the dead points of the pedaling cycle (cranks near vertical) ? Shifting the Rohloff reminds me of releasing a camera shutter (rangefinder, not SLR) -- not in terms of the effort required, but in the sound and in how quickly it happens. (Full disclosu I made my own Rohloff shifter, but I'd have the same comments if I were using the stock control.) Tom Ace |
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Rohloff makes the case for Cyber Nexus
On Apr 28, 1:36*am, Tom Ace wrote:
On Apr 27, 5:11*pm, Andre Jute wrote: No human can change gears as efficiently as Shimano's Cyber Nexus. It might be a personality thing. * Well, no, it's a pretty obvious conclusion. The human will always be seconds slower on each gearchange than electronics can be. Oh great. *In addition to weight weenies, we can have seconds weenies. I used to have a fancy Ciclosport HAC4 (it broke a week or so after it ran out of warranty and I decided not to replace it because it just wasn't worth the EUR300 it cost back then). Among its facilities was a comparative laptimer, and you could download data to the computer to draw fancy graphs. I discovered that when I switched from Shimano Nexus 8 speed to the Cyber Nexus, same but auto, I cut about ten per cent off the shortest ride I did, even after I adjusted the overall effort control precisely to give me the same respiration rate at various points along a ride I took four or five days a week. There's nothing to account for it except that the gears are automatic and worked better than my (admittedly slack) gearchanging on the directly comparable bike except for manual gears that went before. An alternative is CVT which, with your cadence, puts effort control right under your thumb, as in the Fallbrook NuVinci CVT. Chalo several times mentioned the high weight of the NuVinci hub but I don't see the problem; it is clearly a commuter/daytourer's hub, so the weight doesn't matter all that much. It's not just the weight, it's the efficiency of the NuVinci too. In any case, I'm with Pete Cresswell. *I'd much rather choose when to shift. Does the CyberNexus know to shift at the dead points of the pedaling cycle (cranks near vertical) ? No. It's a very simple system really, which is possibly what makes it work so well. I measures speed and inclination and takes in the constant of the effort level the cyclist has chosen. Its adjustment method is to change earlier or later to maintain that effort level. Its genesis is clearly in racing cadence control. It is almost as if Shimano knew that one day they would put a cut down version in a premium Dura-Ace group. Shifting the Rohloff reminds me of releasing a camera shutter (rangefinder, not SLR) -- not in terms of the effort required, but in the sound and in how quickly it happens. (Full disclosu *I made my own Rohloff shifter, but I'd have the same comments if I were using the stock control.) This is interesting; the control is my least favourite part of the Rohloff (next to the kinesthetic "feature" of the agricultural way it works). Why did you make your own control? Does it have any advantage for other bicyclists? Andre Jute http://www.audio-talk.co.uk/fiultra/Andre%20Jute's%20Utopia%20Kranich.pdf |
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Rohloff makes the case for Cyber Nexus
On Mon, 27 Apr 2009 17:36:33 -0700 (PDT), Tom Ace wrote:
On Apr 27, 5:11*pm, Andre Jute wrote: No human can change gears as efficiently as Shimano's Cyber Nexus. It might be a personality thing. * Well, no, it's a pretty obvious conclusion. The human will always be seconds slower on each gearchange than electronics can be. Oh great. In addition to weight weenies, we can have seconds weenies. Humans can anticipate the need to shift so there's no need to count seconds. |
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Rohloff makes the case for Cyber Nexus
Ignore this part of the exchange, Tom:
(Full disclosu I made my own Rohloff shifter, but I'd have the same comments if I were using the stock control.) This is interesting; the control is my least favourite part of the Rohloff (next to the kinesthetic "feature" of the agricultural way it works). Why did you make your own control? Does it have any advantage for other bicyclists? I found your site and saw your DIY Rohloff shifter grip; answers my questions. -- AJ On Apr 28, 2:02*am, Andre Jute wrote: On Apr 28, 1:36*am, Tom Ace wrote: On Apr 27, 5:11*pm, Andre Jute wrote: No human can change gears as efficiently as Shimano's Cyber Nexus. It might be a personality thing. * Well, no, it's a pretty obvious conclusion. The human will always be seconds slower on each gearchange than electronics can be. Oh great. *In addition to weight weenies, we can have seconds weenies.. I used to have a fancy Ciclosport HAC4 (it broke a week or so after it ran out of warranty and I decided not to replace it because it just wasn't worth the EUR300 it cost back then). Among its facilities was a comparative laptimer, and you could download data to the computer to draw fancy graphs. I discovered that when I switched from Shimano Nexus 8 speed to the Cyber Nexus, same but auto, I cut about ten per cent off the shortest ride I did, even after I adjusted the overall effort control precisely to give me the same respiration rate at various points along a ride I took four or five days a week. There's nothing to account for it except that the gears are automatic and worked better than my (admittedly slack) gearchanging on the directly comparable bike except for manual gears that went before. An alternative is CVT which, with your cadence, puts effort control right under your thumb, as in the Fallbrook NuVinci CVT. Chalo several times mentioned the high weight of the NuVinci hub but I don't see the problem; it is clearly a commuter/daytourer's hub, so the weight doesn't matter all that much. It's not just the weight, it's the efficiency of the NuVinci too. In any case, I'm with Pete Cresswell. *I'd much rather choose when to shift. Does the CyberNexus know to shift at the dead points of the pedaling cycle (cranks near vertical) ? No. It's a very simple system really, which is possibly what makes it work so well. I measures speed and inclination and takes in the constant of the effort level the cyclist has chosen. Its adjustment method is to change earlier or later to maintain that effort level. Its genesis is clearly in racing cadence control. It is almost as if Shimano knew that one day they would put a cut down version in a premium Dura-Ace group. Shifting the Rohloff reminds me of releasing a camera shutter (rangefinder, not SLR) -- not in terms of the effort required, but in the sound and in how quickly it happens. (Full disclosu *I made my own Rohloff shifter, but I'd have the same comments if I were using the stock control.) This is interesting; the control is my least favourite part of the Rohloff (next to the kinesthetic "feature" of the agricultural way it works). Why did you make your own control? Does it have any advantage for other bicyclists? Andre Jute *http://www.audio-talk.co.uk/fiultra/Andre%20Jute's%20Utopia%20Kranich.... |
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Rohloff makes the case for Cyber Nexus
On Apr 27, 6:02*pm, Andre Jute wrote:
No. It's a very simple system really, which is possibly what makes it work so well. I measures speed and inclination and takes in the constant of the effort level the cyclist has chosen. If it truly measures inclination rather than effort, I'm even less interested in it. I mean, are you saying headwind or tailwind has no effect on what gear it selects? (Full disclosu *I made my own Rohloff shifter, but I'd have the same comments if I were using the stock control.) This is interesting; the control is my least favourite part of the Rohloff (next to the kinesthetic "feature" of the agricultural way it works). Why did you make your own control? Does it have any advantage for other bicyclists? I made my own control to use on drop bars; the third-party http://www.mittelmeyer.de/html/rennlenker.htm shifter wasn't available yet. Mine differs from the Rohloff shifter in having a cylindrical rather than rounded-triangular grip. To reduce shifting effort, I made the sections where the cables wrap smaller in diameter than in the stock unit (I couldn't change that by much though, I had to keep total rotation under 360 degrees). Tom Ace |
#10
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Rohloff makes the case for Cyber Nexus
On Apr 28, 4:09*am, Tom Ace wrote:
On Apr 27, 6:02*pm, Andre Jute wrote: No. It's a very simple system really, which is possibly what makes it work so well. I measures speed and inclination and takes in the constant of the effort level the cyclist has chosen. If it truly measures inclination It measures inclination for sure. Part of the Cyber Nexus Groupset is a a suspended fork (the best fork I've ever had or ridden even without the electronics) which locks up on hills and also when you're just starting off from standstill, but goes softer when moving smoothly on the level or downhill. rather than effort, Of course it calculates effort, to compare it to the effort level chosen as a target, but it measures effort indirectly. I'm even less interested in it. * I mean, are you saying headwind or tailwind has no effect on what gear it selects? A headwind and a tailwind affects the rider, and whatever affects the rider causes the gearbox to react. In a tailwind he pedals slower. The gearbox changes down so he can pedal faster and expend the effort level he selected to be the overall control. With a tailwind he pedals faster and the gearbox changes up. HTH. Andre Jute "The brain of an engineer is a delicate instrument instrument which must be protected against the unevenness of the ground." -- Wifredo- Pelayo Ricart Medina (Full disclosu *I made my own Rohloff shifter, but I'd have the same comments if I were using the stock control.) This is interesting; the control is my least favourite part of the Rohloff (next to the kinesthetic "feature" of the agricultural way it works). Why did you make your own control? Does it have any advantage for other bicyclists? I made my own control to use on drop bars; the third-partyhttp://www.mittelmeyer.de/html/rennlenker.htm shifter wasn't available yet. Mine differs from the Rohloff shifter in having a cylindrical rather than rounded-triangular grip. *To reduce shifting effort, I made the sections where the cables wrap smaller in diameter than in the stock unit (I couldn't change that by much though, I had to keep total rotation under 360 degrees). Tom Ace |
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