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#1
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Bodge for di2 to get lower gear?
A friend coaches a quadreplegic handcyclist, who has trouble with
shifting. we're thinking a bite valve might be rigged to make di2 work. But the 50-34 by 27 max cog is too high. I've heard the front and rear shifting is linked, but can anyone sugest a way to run di2 with two smaller chainrings? Right now she uses 28 (triple) by 28 lowest cog. Other suggestions, such as cable shifting options welcome too. |
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#2
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Bodge for di2 to get lower gear?
mtb Dad wrote:
A friend coaches a quadreplegic handcyclist, Now that would be a Zen coaching job. Don't you mean paraplegic? Chalo |
#3
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Bodge for di2 to get lower gear?
On Jan 25, 2:56*pm, mtb Dad wrote:
A friend coaches a quadreplegic handcyclist, who has trouble with shifting. *we're thinking a bite valve might be rigged to make di2 work. *But the 50-34 by 27 max cog is too high. *I've heard the front and rear shifting is linked, but can anyone sugest a way to run di2 with two smaller chainrings? *Right now she uses 28 (triple) by 28 lowest cog. Other suggestions, such as cable shifting options welcome too. If the build is custom, there's always using a second "bottom bracket" with a couple rings to step down the gearing, but that's not terribly elegant. What's wrong with using conventional mtb hand controls other than fugly lengths of jiggly housing? |
#4
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Bodge for di2 to get lower gear?
On Jan 25, 9:15*pm, Chalo wrote:
mtb Dad wrote: A friend coaches a quadreplegic handcyclist, Now that would be a Zen coaching job. Don't you mean paraplegic? Chalo No, arms are affected. I don't know the extent, but her hands and shoulders are good enough to operate the pedals, but not so good for shifting mechanisms. "quadriplegia, is paralysis caused by illness or injury to a human that results in the partial or total loss of use of all their limbs and torso; Paraplegia is similar but does not affect the arms." (wikipedia) |
#5
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Bodge for di2 to get lower gear?
On Jan 25, 9:32*pm, landotter wrote:
On Jan 25, 2:56*pm, mtb Dad wrote: A friend coaches a quadreplegic handcyclist, who has trouble with shifting. *we're thinking a bite valve might be rigged to make di2 work. *But the 50-34 by 27 max cog is too high. *I've heard the front and rear shifting is linked, but can anyone sugest a way to run di2 with two smaller chainrings? *Right now she uses 28 (triple) by 28 lowest cog. Other suggestions, such as cable shifting options welcome too. If the build is custom, there's always using a second "bottom bracket" with a couple rings to step down the gearing, but that's not terribly elegant. What's wrong with using conventional mtb hand controls other than fugly lengths of jiggly housing? Thanks. I will pass that along. I think it's the manipulation of smaller levers that's the problem. And, IIRC, she has her hands strapped to, or inserted in the pedals somehow, so moving them to shift is slow. From watching her, I'd say regular grip shifts are out too. Maybe a larger paddle-style handgrip/pedal, that she twists, like a grip shift but with more leverage? But then her wrist would be cocked in some gears, unless it was ratcheted. |
#6
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Bodge for di2 to get lower gear?
Why not go with a triple, with regular mechanical shifting, coupled
with a di2 electronic rear? Mount 27/38/48 rings on the triple with some form of cable shift - but that will not be used very often. Use the 12/27 cassette and she'll have the same low gear as she has now, and quick/easy electronic shifts. Even the able bodied rarely shift at the front, it's 99% rear. |
#7
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Bodge for di2 to get lower gear?
On Jan 25, 4:04*pm, mtb Dad wrote:
On Jan 25, 9:32*pm, landotter wrote: On Jan 25, 2:56*pm, mtb Dad wrote: A friend coaches a quadreplegic handcyclist, who has trouble with shifting. *we're thinking a bite valve might be rigged to make di2 work. *But the 50-34 by 27 max cog is too high. *I've heard the front and rear shifting is linked, but can anyone sugest a way to run di2 with two smaller chainrings? *Right now she uses 28 (triple) by 28 lowest cog. Other suggestions, such as cable shifting options welcome too. If the build is custom, there's always using a second "bottom bracket" with a couple rings to step down the gearing, but that's not terribly elegant. What's wrong with using conventional mtb hand controls other than fugly lengths of jiggly housing? Thanks. *I will pass that along. *I think it's the manipulation of smaller levers that's the problem. *And, IIRC, she has her hands strapped to, or inserted in the pedals somehow, so moving them to shift is slow. From watching her, I'd say regular grip shifts are out too. Maybe a larger paddle-style handgrip/pedal, that she twists, like a grip shift but with more leverage? But then her wrist would be cocked in some gears, unless it was ratcheted. Cancel that. Can't see how you'd do a rachet shift mechanism on a pedal. Maybe an elbow device on each side? One tap for up, two for down? Hey, that sounds familiar.... |
#8
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Bodge for di2 to get lower gear?
On Jan 25, 6:04*pm, mtb Dad wrote:
On Jan 25, 9:32*pm, landotter wrote: On Jan 25, 2:56*pm, mtb Dad wrote: A friend coaches a quadreplegic handcyclist, who has trouble with shifting. *we're thinking a bite valve might be rigged to make di2 work. *But the 50-34 by 27 max cog is too high. *I've heard the front and rear shifting is linked, but can anyone sugest a way to run di2 with two smaller chainrings? *Right now she uses 28 (triple) by 28 lowest cog. Other suggestions, such as cable shifting options welcome too. If the build is custom, there's always using a second "bottom bracket" with a couple rings to step down the gearing, but that's not terribly elegant. What's wrong with using conventional mtb hand controls other than fugly lengths of jiggly housing? Thanks. *I will pass that along. *I think it's the manipulation of smaller levers that's the problem. *And, IIRC, she has her hands strapped to, or inserted in the pedals somehow, so moving them to shift is slow. From watching her, I'd say regular grip shifts are out too. Maybe a larger paddle-style handgrip/pedal, that she twists, like a grip shift but with more leverage? But then her wrist would be cocked in some gears, unless it was ratcheted. How limited is her hand dexterity? That would be of huge interest to us in the peanut gallery. |
#9
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Bodge for di2 to get lower gear?
On Jan 25, 7:26*pm, landotter wrote:
On Jan 25, 6:04*pm, mtb Dad wrote: On Jan 25, 9:32*pm, landotter wrote: On Jan 25, 2:56*pm, mtb Dad wrote: A friend coaches a quadreplegic handcyclist, who has trouble with shifting. *we're thinking a bite valve might be rigged to make di2 work. *But the 50-34 by 27 max cog is too high. *I've heard the front and rear shifting is linked, but can anyone sugest a way to run di2 with two smaller chainrings? *Right now she uses 28 (triple) by 28 lowest cog. Other suggestions, such as cable shifting options welcome too. If the build is custom, there's always using a second "bottom bracket" with a couple rings to step down the gearing, but that's not terribly elegant. What's wrong with using conventional mtb hand controls other than fugly lengths of jiggly housing? Thanks. *I will pass that along. *I think it's the manipulation of smaller levers that's the problem. *And, IIRC, she has her hands strapped to, or inserted in the pedals somehow, so moving them to shift is slow. From watching her, I'd say regular grip shifts are out too. Maybe a larger paddle-style handgrip/pedal, that she twists, like a grip shift but with more leverage? But then her wrist would be cocked in some gears, unless it was ratcheted. How limited is her hand dexterity? That would be of huge interest to us in the peanut gallery. Ah, caught that other post. Limited would be the word. If she's able to operate a brake lever, though--I'm gonna make the assumption that a shifter shouldn't be too difficult--as the pressure involved is often less? Or is it the complexity of moving a hand from a brake, to a shifting position? The more details, the better. :-) |
#10
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Bodge for di2 to get lower gear?
"mtb Dad" wrote in message
... A friend coaches a quadreplegic handcyclist, who has trouble with shifting. we're thinking a bite valve might be rigged to make di2 work. But the 50-34 by 27 max cog is too high. I've heard the front and rear shifting is linked, but can anyone sugest a way to run di2 with two smaller chainrings? Right now she uses 28 (triple) by 28 lowest cog. Other suggestions, such as cable shifting options welcome too. Di2 ain't going to do the job on its own. I was trying to figure out if you could switch the cage on the rear derailleur, but probably not a good idea to mess with it. And the front... forget it. The reason it works at all (and works so well) is that you've got known quantities for it to deal with, and an outrageously-stiff chainring set. But maybe there's a simpler, more obvious solution. What if you matched up Di2 to an internally-geared hub? I'm trying to figure out why that wouldn't work. Obviously you'd still have to work the (manual) controls for the hub, but you might not have to do it too often. --Mike Jacoubowsky Chain Reaction Bicycles www.ChainReaction.com Redwood City & Los Altos, CA USA |
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