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At How Many Cogs Does the Madness End?

  • At 12-spd road/13-spd gravel (what it is now).

  • At 13-speed everything.

  • 14-speed

  • 15-speed

  • 16-speed

  • 18-speed

  • 20-speed

  • More than 20 (!!)

  • “Something something CVT” (even though that doesn’t answer the Q, and CVT is heavy).

  • I’m terrified to even guess.

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Banned Sock Puppet
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Might be a fair concern. Current 12-speed chains are already barely wider than 3/16”.

As we keep narrowing the chain, where’s the breaking point? Both figuratively and literally. 💥

Or short of that, when do we get to a ridiculously short lifespan/replacement cycle.
But parts wearing out faster is good for the economy, right? The only other option is for wider hubs which of course causes issues with chain line in extreme gears.
 

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Discussion Starter · #43 · (Edited)
But parts wearing out faster is good for the economy, right? The only other option is for wider hubs which of course causes issues with chain line in extreme gears.
Yup. And wider hubs also obviously mean wider chainstays, so your heels and/or cranks can hit them, unless they spec a wider crank (high Q-factor) along with it.

Which many ppl don’t want, as it impacts pedaling efficiency and aerodynamics to be in a more splayed-out position like that. 😕

So, it kinda mostly falls to narrower cog spacing to shoehorn more gears in there.

Though rim-brake road could go to 135mm frame spacing w/out the poop hitting the fan.
 

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Yup. And wider hubs also obviously mean wider chainstays, so your heels and/or cranks can hit them, unless they spec a wider crank (high Q-factor) along with it.

Which many ppl don’t want, as it impacts pedaling efficiency and aerodynamics to be in a more splayed-out position like that. 😕

So, it kinda mostly falls to narrower cog spacing to shoehorn more gears in there.

Though rim-brake road could go to 135mm frame spacing w/out the poop hitting the fan.
So no 148mm Boost spacing for road bikes?
 

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Discussion Starter · #46 · (Edited)
So no 148mm Boost spacing for road bikes?
Road bikes usually have short chainstays, which make very wide hubs difficult to accommodate without causing the problems discussed earlier.


Edit- for anyone still unclear on why that is, note how your chainstays flare outwards and get farther apart along their length.
 

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Road bikes usually have short chainstays, which make very wide hubs difficult to accommodate without causing the problems discussed earlier.
True. So if we want more gears, we need to have paper thin chains and gears or bring back the quad rings.
 
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How about an eight speed internally geared hub with a cassette and thirteen more gears? That's 104 gears with one chain ring, 208 with two and 312 with a triple.

There'd probably be some duplicate gears in there, but I'm not gonna try and sort that out.
 

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Discussion Starter · #49 · (Edited)
How about an eight speed internally-geared hub with a cassette and thirteen more gears? That's 104 gears with one chain ring, 208 with two and 312 with a triple.
The slam on IGHs are that they’re simply not quite as efficient as chain drives, aka they lose watts— though a high-quality IGH such as Rohloff can narrow the gap a good deal (for a price/$$$).

Interestingly, looking it up… CVTs are even less efficient than IGHs. 🤔

This kinda leads me to think that the ‘Day of the CVT’ for bikes (at least non-electric ones) is very far off, if ever. The added weight was already a turnoff.
 

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Discussion Starter · #50 ·
Interesting test/comparo on the efficiency of various IGHs, CVT, and single-speed chain drive:


And also one on 1x chain-drive efficiency vs 2x:

 

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Interesting test/comparo on the efficiency of various IGHs, CVT, and single-speed chain drive:


And also one on 1x chain-drive efficiency vs 2x:

Great articles!


Sent from my iPad using Tapatalk
 
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Discussion Starter · #53 · (Edited)
That’s really interesting… a hybrid IGH-chain drive approach.

With the main goal to be a 1x drivetrain with 2x gearing ratios, courtesy a 2-speed hub that provides a ‘virtual small chainring’ in one speed, and ‘locks up and gets out of the way’ for the other speed (‘virtual big chainring’).

IOW, they’re using a 2-speed hub to get rid of the front derailleur and second chainring.

Pretty neat, and probably more efficient than any pure IGH drive, even Rohloff.

But, the cost is a bit of a shocker (2400 GBP, which is about $3400 USD) for everything you need, including their rim (why are you required to use theirs only?).

Plus, no matter how much they insist otherwise, it’s likely not as efficient as a chain-drive, as it has both chain-drive and IGH frictional losses to contend with (just less of each).

It’s cool, but the price alone likely ensures it’ll remain niche.

Honestly, it’s really hard to beat good old-fashioned chain drive (aka, The Champ going on 136 years now)… it’s simple, robust, cheap, and highly-efficient.

All that, unless you fark up and design it not to be. 😕
 

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Discussion Starter · #54 ·
This thread…

3000+ views
13 votes in the poll

Sigh. 😕
 

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This thread…

3000+ views
13 votes in the poll

Sigh. 😕
Lurkers will lurk. I wonder if it keeps track of lurkers who don't have accounts.
 

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That’s really interesting… a hybrid IGH-chain drive approach.

With the main goal to be a 1x drivetrain with 2x gearing ratios, courtesy a 2-speed hub that provides a ‘virtual small chainring’ in one speed, and ‘locks up and gets out of the way’ for the other speed (‘virtual big chainring’).

IOW, they’re using a 2-speed hub to get rid of the front derailleur and second chainring.

Pretty neat, and probably more efficient than any pure IGH drive, even Rohloff.

But, the cost is a bit of a shocker (2400 GBP, which is about $3400 USD) for everything you need, including their rim (why are you required to use theirs only?).
This is a pretty cool concept. I'm sure the cost will come down over time. But being proprietary... I don't see it going anywhere.
Ridley bikes is supplying bikes with them though.


Plus, no matter how much they insist otherwise, it’s likely not as efficient as a chain-drive, as it has both chain-drive and IGH frictional losses to contend with (just less of each).
It definitely can be more efficient.
In the 1:1 ratio, the hub is locked. So there's no loss in efficiency. But you have a straighter chainline from the 1x, so it would definitely be more efficient than a 2x setup.
When the hub is unlocked in the 0.7 ratio, you'll lose a bit from the internal gears. But you still have the benefit of a straighter chainline. And you also have a larger front ring, which is more efficient than a small ring on a traditional setup. So it could be a wash.

While a few gear ratios in the unlocked mode may be less efficient, the overall average efficiency is most likely equal or higher.
 
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