Shimano Gearbox (I'm excited)

fatboyonabike

Captain oblivious
why are they not even entertaining the thought of Gates carbon drive style setup, surely the days of cleaning crud out of chain on a regular basis has to be numbered...
 

beeb

Dr. Beebenson, PhD HA, ST, Offset (hons)
Gates belts are really just a matter of mounting a different drive sprocket.

There is compromises with them though - they are less efficient than chain, and need a lot of belt tension (rear of bike needs to be quite stiff to prevent flex and potential tooth skip in SS or gearbox hardtail applications). In theory the belts shouldn't cooperate with the reverse bending round a tensioner, but bikes like @Zaf's Nicolai prove otherwise so that's something of a paradox. Also some users report poor cog life in gritty conditions.

If you're bothering to design an efficiency-focused gearbox like in Shimano's design, belt wouldn't really make sense IMO.

While I'm being negative - I really doubt Shimano would ever bring this design to market for "analogue" bikes. It looks like it's designed for (A) locking up the tech under a patent before anyone else gets a chance, and (B) adaptation to e-bike use to create an integrated motor/transmission unit. It would be equally marketable for urban and mountain biking in e-bike form (the bikes are generally hideous already), but I just dont see the benefits for a "analogue" bike.

If you're going to kill the cassette and derailluer, a casette in a box - and still having to ramp through gears - doesn't interest me. I'd rather loose a couple of percent pedalling efficiency and have instant shifting from true gears without having to have a direct driven (fixed hub) chain or only shifting while pedalling.

IMO, Pinion has made the best bike gearbox so far - but has a way to go yet. A Pinion style box with the ability to be integrated into the frame like the side-plate bolted to frame design used on Cavalerie/Effigear bikes to save weight, and replacing Pinion's low-engagment internal freehub with a sprag clutch or high-engagement ratchet would be two huge improvements to their current designs.

Truth be told though - I prefer the Effigear design overall for it's simplicity. Just a shame it's a little gear-range limited compared to the Pinion boxes. And after playing around with linkage designs the last few weeks - the Effigear offset output shaft is a real PITA in linkage packaging terms. If Effigear did a box with an additional 'speed' added and a concentric output shaft (a la Pinion) that'd be the duck's nuts IMO.
 
Last edited:

madstace

Likes Dirt
If you're going to kill the cassette and derailluer, a casette in a box - and still having to ramp through gears - doesn't interest me. I'd rather loose a couple of percent pedalling efficiency and have instant shifting from true gears without having to have a direct driven (fixed hub) chain or only shifting while pedalling.

IMO, Pinion has made the best bike gearbox so far - but has a way to go yet. A Pinion style box with the ability to be integrated into the frame like the side-plate bolted to frame design used on Cavalerie/Effigear bikes to save weight, and replacing Pinion's low-engagment internal freehub with a sprag clutch or high-engagement ratchet would be two huge improvements to their current designs.

Truth be told though - I prefer the Effigear design overall for it's simplicity. Just a shame it's a little gear-range limited compared to the Pinion boxes. And after playing around with linkage designs the last few weeks - the Effigear offset output shaft is a real PITA in linkage packaging terms. If Effigear did a box with an additional 'speed' added and a concentric output shaft (a la Pinion) that'd be the duck's nuts IMO.
Well put beeb, my thoughts almost exactly. I've put a fair amount of crap on Pinion and where I think they need to get to, but one thing they've definitely nailed is the packaging. The Shimano patent by comparison looks pretty bulky, doubt there'd be much love for an acoustic version. Having said that, with 2 cassettes in the mix I can't see where they'd stuff the zappy bits in for eMTBs either, but I'm no engineer.
 

Flow-Rider

Burner
. In theory the belts shouldn't cooperate with the reverse bending round a tensioner, but bikes like
You can run a tensioner pulley on the back of belts no worries, what you can't do is pinch the belt or use a small radius tensioner pulley, automotive applications mostly have tensioners on the back of the belt, it's nothing new it's been done for years.
 

RichJS

Likes Dirt
If the mass is centralized and not unsprung and rotating... I'm ok with it.
I know how to move 250+ grams off the cassette and towards the centre of the bike, whilst increasing the range of gearing from 400-500% to 600% or more. It's called triple chainrings and a front derailleur.

Would still love to buy a rohloff with STI-compatible electronic shifting. E14 looks cool but e-bikes suck.
 
Top