New bottom bracket transmission?

kingfish254

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Wasn't there something like this call a Metro or Metropolis about 5 or 10 years ago? Seems like @gowjobs may have had one.
 
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Nov 24, 2009
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Wasn't there something like this call a Metro or Metropolis about 5 or 10 years ago? Seems like @gowjobs may have had one.
There are two or three different takes on the bb-integrated transmission. The one licensed by FSA for the Metropolis setup is a medium duty setup meant for comfort/commuter duty. This new-ish EFNEO, or whatever it's called is a heavy duty one really best used off road.
The New one also doesn't use a normal bottom bracket. It bolts into the frame in a cradle, and the bb is part of the unit, kind of like Bosch mid-drive electric setups.

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Apr 18, 2015
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There is also the Schlumpf two speed bottom bracket. Swiss made and priced to match:
 
Jun 13, 2015
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There's another company https://pinion.eu/en/gearboxes/ that makes some that work a lot like a manual transmission in a car (so it's got my approval), but with a rather clever cam-actuated pawl engagement for the gears. They come in different ranges for varying applications with the higher end line running an 18 speed with 636% gear range (!). The lower end line tops out at 12 speeds with 600% which is also really impressive. Requires a proprietary frame, though, and being German, requires "Pinion gearbox oil" which is probably some expensive, tough-to-source nonsense that voids the warranty if anything else is used. Other negative is the review I read criticized it for requiring the rider to stop pedaling to shift, which makes sense as the torque has to be taken off the pawls to disengage them, but would make this less optimal for racing or mountain biking (plus, the whole proprietary frame thing). Anyway, it's still cool tech I'd like to try out, even if I wouldn't buy it (and that's before seeing a price which I'm sure is crazy). They've got a blow up of the tech that gradually takes it apart as you scroll down. Worth checking out if you like mechanical stuff.
 
Jun 13, 2015
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No, the internal gear setup works similar to a constant mesh manual gearbox, but instead of synchros to apply power to the preferred ratio gear, it uses pawls set inside the second (idler) shaft actuated by a cam shaft that is rotated by the shifter instead of dogs or synchros. It would only need a clutch if the rider had to keep pedaling through the gear change, but that would have the same result as the rider just stopping pedaling, so there's no need for the extra complication and weight. Think of it like a manual on an electric motor—since an electric motor doesn't have to idle, the clutch is unnecessary to roll off from a stop (though, I wonder if a clutch should still be used between shifts as the drag of a still-engaged electric motor off power between shifts would cause a reverse torque on the gears . . . whatever). Anyway, I just deleted a whole explanation of how it works because the scrolling animation they have does a lot better a job at explaining it than I can.
 
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Sep 26, 2012
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gears = more things to break
Good point.
For that matter the fame, fork, wheels, and bars might break too. Get rid of them.

Come to think of it, I've definitely had chain and tires break on me. They're gone. Not sure I trust the cranks or pedals now either. Out.

You know once I had a seat that just wouldn't tighten up. Better chuck it to be on the safe side. And those seat posts can bend too if you're not careful. You know where it's going.

Thanks for the advice KCI!
Now when I go for a bike ride I'll just run everwhere.

Hmm... my knees are feeling a little sore. They might break..

:grin:
 
Feb 9, 2019
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frame
fork
wheels
bars
chain
tires
cranks
pedals
seat posts
Quite the litany, all of which I have broken/destroyed and some of them several times. Some have asked why my bikes are clean all of the time and the short answer is "inspection".

Frames? I've lost count.
Forks? About a half-dozen, including a Marzocchi Z-150 that cracked on the wheel clamp mounts.
Wheels? None that I have built for myself, but a few factory wheels have surrendered under me.
Bars? Bent up a few, but always try to buy the best for my contact points.
Stems: You forgot stems. I've snapped a few and cracked a few more.
Chains? I've lost count, including disintegrating some of the rollers on a few.
Tires? I haven't broken any, but have torn apart several in the dirt.
Cranks? The people at Race Face know my name.
Pedals? Several with destroyed bearing races, demolished cages and even a few snapped chromoly spindles.
Seat Posts? Only broke one, then switched largely to Thomson.
Saddles: You neglected to mention saddles, bent up many with steel/chromo rails and have snapped three titanium rails.

Adding more parts (especially moving parts) is counter-intuitive to me and my wallet. I've seen many under-engineered and shoddily crafted moving gizmos come and go in the past 35 years or so.

Do I have bikes with gears? Yes. Do I ride them often? No

YMMV
 
Apr 20, 2009
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Requires a proprietary frame, though, and being German, requires "Pinion gearbox oil" which is probably some expensive, tough-to-source nonsense that voids the warranty if anything else is used.
Differential grade gear oil. Learned that from the users manual of an MZ 250 2 cycle bike I had decades ago.
 
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