Practical limit for number of rear cogs in the future?
#76
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Just to be argumentative, but in the future you wont need gears, we will all be riding electric bikes. Actually, I agree with Andy K's discussion of the physical limits, no matter what marketing wants. In fact, I can see a day where marketing starts pushing fewer gears as better to sell bikes to people that already have them.
#77
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I went through all the post to make sure I did not miss it somehow and realized no one mentioned it.
Yep, 636% range (more than my Rohloff), rated for 60 000 kms.
Only downside for me personally - no easy retrofit to non-Pinion specific frames and so no easy way to transfer between bikes (right now it takes me about 2 hrs to relace rohloff to different rim and put it on another bike, I switch once or twice a year between cross frame and 29+ frame)
Yep, 636% range (more than my Rohloff), rated for 60 000 kms.
Only downside for me personally - no easy retrofit to non-Pinion specific frames and so no easy way to transfer between bikes (right now it takes me about 2 hrs to relace rohloff to different rim and put it on another bike, I switch once or twice a year between cross frame and 29+ frame)
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IMO anything over 9 speeds is just plain over kill. With a triple in front that makes 27 gears. Why in the world could you want or need more.
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Bicycle gear ratios - speeds, gear inches
#80
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It is too bad the 10mm pitch drivetrain didn't catch on, but on the other hand, it makes sense, because it changes everything.
Weight matters to some and not to others, but given two bikes that are functionally identical and at the same price, the one that is three pounds heavier is a lot less desirable, even to non-aficionados. Weight matters to everyone, to some degree.
Weight matters to some and not to others, but given two bikes that are functionally identical and at the same price, the one that is three pounds heavier is a lot less desirable, even to non-aficionados. Weight matters to everyone, to some degree.
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Compacts match the range of a triple with a little less complexity and weight. Unfortunately, the middle range is handled rather poorly by compacts. A 38-42 ring is far superior to a 34 for flats.
I ride on flat and rolling terrain and it's very inconvenient shifting from 34 to 50 as you increase speed from the high teens to low twenties. Not only do you shift rings but you upshift 3 gears in back; not fun when you don't have multi shift. And then back again as your speed slows. It's frustrating and I don't know why more riders don't complain about it.
So, you have to settle either for: riding a bit slower and/or at higher cadence in the small or dealing with a lot of noise and lower efficiency drivetrain if you stay in the big. These problems don't exist with a 38 to 42 ring.
I think even a 36 would be an improvement; perhaps I can swap rings for a 50/36 setup?
I ride on flat and rolling terrain and it's very inconvenient shifting from 34 to 50 as you increase speed from the high teens to low twenties. Not only do you shift rings but you upshift 3 gears in back; not fun when you don't have multi shift. And then back again as your speed slows. It's frustrating and I don't know why more riders don't complain about it.
So, you have to settle either for: riding a bit slower and/or at higher cadence in the small or dealing with a lot of noise and lower efficiency drivetrain if you stay in the big. These problems don't exist with a 38 to 42 ring.
I think even a 36 would be an improvement; perhaps I can swap rings for a 50/36 setup?
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IMO people also tend to over think gearing. Both my bent and trike have triples in front. My simple method of shift is--------------shifting across the rear with each of the sprockets in front. Granny for going up steep hills and sometimes into the wind. Center ring used most of the time on the flats or easy hill. Large chain ring for down hill and with the wind. Pick the chain ring in front according to the terrain, and shift across the rear according to feel.
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In terms of actual numbers I have no idea. But consider this. Your innermost cog has to be somewhere to the right of the centerline of the hub or the wheel will collapse. The centerline through the single chain ring, or the bisection of the distance between double rings, or the center ring of a triple, has to bisect the cassette. So increasing the width of the axle to maintain the integrity of the rear wheel constrains the reduction of Q-factor. Also, in extreme cases, the width of the rear tire also plays into this. The innermost chain line has to clear the rear tire.
Then there's the chain angle that stresses the chain, enhances friction, and can cause the chain to rub against the next larger cog. Chain angle increases as chain stay length decreases.
Then there's the chain angle that stresses the chain, enhances friction, and can cause the chain to rub against the next larger cog. Chain angle increases as chain stay length decreases.
#84
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IMO people also tend to over think gearing. Both my bent and trike have triples in front. My simple method of shift is--------------shifting across the rear with each of the sprockets in front. Granny for going up steep hills and sometimes into the wind. Center ring used most of the time on the flats or easy hill. Large chain ring for down hill and with the wind. Pick the chain ring in front according to the terrain, and shift across the rear according to feel.
A 1x is comparatively much simpler (coming from somebody who doesn't like 1x setups for most people). Shifting goes as follows. "If it's too hard, hit this lever, if it's too easy, hit this lever."
#85
Non omnino gravis
I made a gradual shift to 1X, going from 50/34 to 48/34 to 46/34 and then finally a single 42T in the front. I don't miss that front derailleur at all. Plenty of range, and I'm apparently still young enough to survive with "big" steps between the gears.
#87
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The thing about road 1x is that it's impractical to start with 2T jumps if you want tight spacing, and if you start with 1T jumps, it's impossible to avoid annoying ratio jump discontinuities even if you are totally non-limited by cog count.
You could solve the problem by doubling the sizes of all the sprockets, but that's impractical with a half-inch-pitch chain. You could switch to itsy-bitsy chain pitch, but then the costs would shoot way up and sprocket life would be reduced.
With the capabilities of modern derailleurs, the flexibility of modern chains, and with e-shifting and synchro-shift becoming a thing, personally I'd like to see a modern take on half-step.
50-46
11-13-15-18-21-25-29-34-40-46-54
But, some people might still say that you lose the smooth shift pattern at the outer edges if you want to avoid cross-chaining.
SO.
Wild solution: Switch the chainrings around. Put the big ring on the inside and the little ring on the outside!
46-50
11-13-15-18-21-25-29-34-40-46-54
Even, reasonable-chainline shifting all the way from 46-11 (~110GI) to 50-54 (~24GI). 20 gears with step sizes of around 8%.
You could solve the problem by doubling the sizes of all the sprockets, but that's impractical with a half-inch-pitch chain. You could switch to itsy-bitsy chain pitch, but then the costs would shoot way up and sprocket life would be reduced.
With the capabilities of modern derailleurs, the flexibility of modern chains, and with e-shifting and synchro-shift becoming a thing, personally I'd like to see a modern take on half-step.
50-46
11-13-15-18-21-25-29-34-40-46-54
But, some people might still say that you lose the smooth shift pattern at the outer edges if you want to avoid cross-chaining.
SO.
Wild solution: Switch the chainrings around. Put the big ring on the inside and the little ring on the outside!
46-50
11-13-15-18-21-25-29-34-40-46-54
Even, reasonable-chainline shifting all the way from 46-11 (~110GI) to 50-54 (~24GI). 20 gears with step sizes of around 8%.
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I suppose there might be one or two newbies here that might have needed to have that pointed out, but I would have just let them wonder about it.
#89
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A modest proposal:
Make 1/2 inch pitch chain obsolete.
The 12.7mm -- 1/2 inch pitch chain is way too big. It's heavy and limits the cog choices.
It's time to bring back the Shimano "10 pitch", 10mm chain. Or even smaller.
Make the chain narrower, too. Now you can fit 15 cogs.
In 1/2 inch equivalents, 11 12 13 14 15 16 17 18 19 20 22 25 28 32 36. Lots of close shifts and gears for steep hills.
Since we are redesigning everything, allow for more variation in the chainring sizes. Not fitting smaller than 34 chainrings was short sighted.
12.7mm vs 10 mm equivalent ratios (rounded to the nearest whole tooth):
10 tooth cog is the same as a 13 cog in 10mm.
20 tooth to 25
30 tooth to 38
34 chainring to 43.
50 chainring to 64
There's a limit to the diameter of the smallest cog that still fits on the cassette body. So the whole assembly can't just shrink down to 80% of the current sizes. Or can it?
Make 1/2 inch pitch chain obsolete.
The 12.7mm -- 1/2 inch pitch chain is way too big. It's heavy and limits the cog choices.
It's time to bring back the Shimano "10 pitch", 10mm chain. Or even smaller.
Make the chain narrower, too. Now you can fit 15 cogs.
In 1/2 inch equivalents, 11 12 13 14 15 16 17 18 19 20 22 25 28 32 36. Lots of close shifts and gears for steep hills.
Since we are redesigning everything, allow for more variation in the chainring sizes. Not fitting smaller than 34 chainrings was short sighted.
12.7mm vs 10 mm equivalent ratios (rounded to the nearest whole tooth):
10 tooth cog is the same as a 13 cog in 10mm.
20 tooth to 25
30 tooth to 38
34 chainring to 43.
50 chainring to 64
There's a limit to the diameter of the smallest cog that still fits on the cassette body. So the whole assembly can't just shrink down to 80% of the current sizes. Or can it?
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I might be possible to eliminate cross chaining with a high cog cassette 1x by electrically moving the chainring laterally inboard or outboard to optimize chainline depending on what cog is selected. I could imagine the chainring could be attached to a splined carrier on the crank.
John
John
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OK, all I want for now is 2X12 or 2X13 wireless eshifting with up to 6 cog multi shift in both directions. And maybe double the battery life of current Di2.
But y'all are playing 4D chess. Some of you should be engineers for Shimano SRAM and campy instead of posting here with these skillz.
But y'all are playing 4D chess. Some of you should be engineers for Shimano SRAM and campy instead of posting here with these skillz.
#92
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I might be possible to eliminate cross chaining with a high cog cassette 1x by electrically moving the chainring laterally inboard or outboard to optimize chainline depending on what cog is selected. I could imagine the chainring could be attached to a splined carrier on the crank.
John
John
#93
Non omnino gravis
Not to mention unnecessary-- my chainline is perfectly straight when on the 6th cog, so there are 5 above and 5 below. It's only 35mm total between the center of the 1st and 11th cogs, so the chain is never deflecting more than 17.5mm, roughly 3/4". Unless carefully shifted, I imagine a triple would have greater amounts of possible deflection. Which is why I don't favor a triple-- above and beyond the duplicate ratios, there are gear combos you simply can't/shouldn't use.
#94
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The thing about road 1x is that it's impractical to start with 2T jumps if you want tight spacing, and if you start with 1T jumps, it's impossible to avoid annoying ratio jump discontinuities even if you are totally non-limited by cog count.
You could solve the problem by doubling the sizes of all the sprockets, but that's impractical with a half-inch-pitch chain. You could switch to itsy-bitsy chain pitch, but then the costs would shoot way up and sprocket life would be reduced.
With the capabilities of modern derailleurs, the flexibility of modern chains, and with e-shifting and synchro-shift becoming a thing, personally I'd like to see a modern take on half-step.
50-46
11-13-15-18-21-25-29-34-40-46-54
But, some people might still say that you lose the smooth shift pattern at the outer edges if you want to avoid cross-chaining.
SO.
Wild solution: Switch the chainrings around. Put the big ring on the inside and the little ring on the outside!
46-50
11-13-15-18-21-25-29-34-40-46-54
Even, reasonable-chainline shifting all the way from 46-11 (~110GI) to 50-54 (~24GI). 20 gears with step sizes of around 8%.
You could solve the problem by doubling the sizes of all the sprockets, but that's impractical with a half-inch-pitch chain. You could switch to itsy-bitsy chain pitch, but then the costs would shoot way up and sprocket life would be reduced.
With the capabilities of modern derailleurs, the flexibility of modern chains, and with e-shifting and synchro-shift becoming a thing, personally I'd like to see a modern take on half-step.
50-46
11-13-15-18-21-25-29-34-40-46-54
But, some people might still say that you lose the smooth shift pattern at the outer edges if you want to avoid cross-chaining.
SO.
Wild solution: Switch the chainrings around. Put the big ring on the inside and the little ring on the outside!
46-50
11-13-15-18-21-25-29-34-40-46-54
Even, reasonable-chainline shifting all the way from 46-11 (~110GI) to 50-54 (~24GI). 20 gears with step sizes of around 8%.
On the other hand, it requires two shifts to get the single-step gear change that keeps you from getting dropped, and when going hard front derailleurs balked at dropping the chain to a ring that was only three or four teeth smaller.
#95
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Not to mention unnecessary-- my chainline is perfectly straight when on the 6th cog, so there are 5 above and 5 below. It's only 35mm total between the center of the 1st and 11th cogs, so the chain is never deflecting more than 17.5mm, roughly 3/4". Unless carefully shifted, I imagine a triple would have greater amounts of possible deflection. Which is why I don't favor a triple-- above and beyond the duplicate ratios, there are gear combos you simply can't/shouldn't use.
#96
Senior Member
and when going hard front derailleurs balked at dropping the chain to a ring that was only three or four teeth smaller.
I haven't personally used a half-step system, but my general experience is that small gaps make for good shifting. When going up, the chain has less ramping to do, quicker to catch the teeth and get fully in the new ratio.
I haven't really thought about the big->small jump, as coercing the chain to drop down isn't generally very problematic. If anything, I'd think a small leap would help the chain get reliably caught, less likely to drop off the inside.
#97
Senior Member
Compacts match the range of a triple with a little less complexity and weight. Unfortunately, the middle range is handled rather poorly by compacts. A 38-42 ring is far superior to a 34 for flats.
I ride on flat and rolling terrain and it's very inconvenient shifting from 34 to 50 as you increase speed from the high teens to low twenties. Not only do you shift rings but you upshift 3 gears in back; not fun when you don't have multi shift. And then back again as your speed slows. It's frustrating and I don't know why more riders don't complain about it.
So, you have to settle either for: riding a bit slower and/or at higher cadence in the small or dealing with a lot of noise and lower efficiency drivetrain if you stay in the big. These problems don't exist with a 38 to 42 ring.
I think even a 36 would be an improvement; perhaps I can swap rings for a 50/36 setup?
I ride on flat and rolling terrain and it's very inconvenient shifting from 34 to 50 as you increase speed from the high teens to low twenties. Not only do you shift rings but you upshift 3 gears in back; not fun when you don't have multi shift. And then back again as your speed slows. It's frustrating and I don't know why more riders don't complain about it.
So, you have to settle either for: riding a bit slower and/or at higher cadence in the small or dealing with a lot of noise and lower efficiency drivetrain if you stay in the big. These problems don't exist with a 38 to 42 ring.
I think even a 36 would be an improvement; perhaps I can swap rings for a 50/36 setup?
I notice that a lot of riders just cross chain from the big ring to the bigger cogs on the cassette. Not sure they even notice or care. From a gearing perspective a triple is hard to beat, but it has fallen out of fashion long ago. Decent stock bikes with triples are few and far between.
#98
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I think Porsche has a GPS-enable transmission algorithm that "looks ahead" and anticipates what gear will be needed "next". Combine that with some sort of heart-rate or glucose-level monitoring technology and you could have a bicycle transmission that would figure out what gear is "optimum".
But riding until you're stupid is half the fun, ain't it?
But riding until you're stupid is half the fun, ain't it?
Thus, one doesn't even have to think about pedalling or resting. The bike will do that for you too No slacking
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Didnt like my 50/34 + 11-32 either. Not enough low gears from the big ring and not enough high gears from the small ring. > constantly shifting up and down on the rings (+ cassette) to get a half way decent chain line.
I notice that a lot of riders just cross chain from the big ring to the bigger cogs on the cassette. Not sure they even notice or care. From a gearing perspective a triple is hard to beat, but it has fallen out of fashion long ago. Decent stock bikes with triples are few and far between.
I notice that a lot of riders just cross chain from the big ring to the bigger cogs on the cassette. Not sure they even notice or care. From a gearing perspective a triple is hard to beat, but it has fallen out of fashion long ago. Decent stock bikes with triples are few and far between.
However, such cassettes are a lot less widely available in shops and usually cost about double the price of "ordinary" (11, or 12 T starting ones).
#100
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The problem with a question like this is that it's asking to predict the future.
We can reason based upon our experience with the components that are available today but new ideas are coming up all the time. Who knows where that's going to go. My prediction is that the bike of the future will have one front and one rear sprocket and a belt drive. How it provides for different gear ratios I have no idea.
Yeah and this is coming from a retro grouch. The techno wienies are probably thinking computer chips.
We can reason based upon our experience with the components that are available today but new ideas are coming up all the time. Who knows where that's going to go. My prediction is that the bike of the future will have one front and one rear sprocket and a belt drive. How it provides for different gear ratios I have no idea.
Yeah and this is coming from a retro grouch. The techno wienies are probably thinking computer chips.
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