# Transmissions



## Sparticus (Dec 28, 1999)

Ever since mentioning it within a thread in another forum, I've been thinking about the differences in riders' shifting & gearing needs between traditional human-powered bikes and ebikes. I think we'll see major changes here. Soon.

I'll explain.

I don't currently own an ebike but one day last summer a buddy let me borrow his. We were building a 24' footbridge over a creek and the ebikes present, one of which was his, proved invaluable when it came to hauling heavy materials for the bridge uphill from the locked gate (aka our vehicles & supplies) into the job site on singletrack.

Anyway it didn't take long for me to realize that I didn't have to shift much. The bike's power assured this. Nor did I need the 12 gears his bike had. Half that many would have been plenty. Again, because power. I enjoyed the range, just didn't need all the in-between gears.

This led me to wonder why ebikes have derailleurs like traditional human powered bikes. How about a Pinion-esque (gearbox) ebike? This thought led me to the next question: Do we suppose Pinion is working on an ebike of their own? Of course -- they must. Specialized is not the only company to embrace the "innovate or die" credo.

Which led me to the next logical question: Do we suppose that Shimano, Brose, Bosch, etc. are working on new ebike motors that include built-in transmissions? NOT derailleurs?

Yes, we do.
=sParty


----------



## NS-NV (Aug 15, 2006)

I think it is a backwards step for emtb‘s to use the ancient tech derailleur.


----------



## Bigwheel (Jan 12, 2004)

Already here for a few years: Continental Bicycle Systems - Drive Units Another one popped up a bit ago that uses the Enviolo system that looks similar.

At this point, heavy, complex and unproven. However as time goes on there is certainly an effort to make it happen. Personally I don't have any issues with a conventional derailleur system as I can work on it if something goes wrong and know enough to keep it in the appropriate gear at the appropriate time.


----------



## miamia (Sep 6, 2014)

Here is one: Revonte - Revonte


----------



## RickBullottaPA (Mar 4, 2015)

I shift often on my eMTB. I like control over my cadence and pedaling effort. Also, most eMTBs use a combination of a torque sensor, speed sensor, and cadence to control the boost, so just staying in a tall gear isn't ideal.

I would consider an alternative to a derailleur if it was light enough.


----------



## DtEW (Jun 14, 2004)

Sparticus said:


> I don't currently own an ebike but one day last summer a buddy let me borrow his. We were building a 24' footbridge over a creek and the ebikes present, one of which was his, proved invaluable when it came to hauling heavy materials for the bridge uphill from the locked gate (aka our vehicles & supplies) into the job site on singletrack.
> 
> Anyway it didn't take long for me to realize that I didn't have to shift much. The bike's power assured this. Nor did I need the 12 gears his bike had. Half that many would have been plenty. Again, because power. I enjoyed the range, just didn't need all the in-between gears.


I think this is all an artifact of not owning an e-bike, and using a borrowed one.

Because if you own one, you will most likely tune the output (beyond mere on-the-fly mode selection) to levels that 1) approximate a manual bike while compensating for the increased mass; 2) a reasonable e-assisted mode for when you need to hurry-it-up-a-bit past the boring sections; and 3) an all-out mode to bail you out of trouble.

Your buddy probably has his loaned bike tuned to what he feels are approximations of those for him, and uses the modes appropriately, which can mean anything from actually getting a workout (instead of a joyride), maximizing range for an epic that will require the full charge, or just keeping from deeply-cycling the battery in order to prolong its life. Some people even turn off assist altogether when possible.

It is likely none of this was what you were doing, as your first ride was probably part test-drive and part joyride. It certainly was that when my significant other was demo-ing e-bikes. My admonition to her on the trail (watching her ride) was to use her gears. Her feedback after the demos were, "is there a way to turn the assist further down?"

You were probably over-assisted, which is why the low-energy-loss, chain-and-derailleur gearing that is there for getting the most out of the bike... seemed superfluous. It won't be when you start using it as your own, and move beyond the first-ride idea that this is a different thing from your actual (manual) bikes, and therefore you will use it in a way accentuate the differences. Because when you start using it normally, its usage will likely be only a variation on that of your manual bikes. Because ultimately, the constraints between a manual bike and an e-bike are the same (i.e. over-exuberance vs. efficiency per distance) ... just at different points.

***

This is not to say that there isn't a place for internal transmission e-bikes, as others who have responded have indicated. It's just that the priorities for those are not the same as that of typical enthusiast MTB/road usage, whether that be bulletproof reliability (eg. rentals) or keeping chain marks from your pants (eg. commuting). There's a reason why not even DH MTBs have gone internal transmission.


----------



## Gutch (Dec 17, 2010)

I also shift all the time rather that switching power modes. It would be cleaner set up though, however the weight deal could be more than a derailuer, like others have pointed out. Sram use to have the 8spd Ebike cog (which they may still have that i put on my 2016 levo, now its 12spd!


----------



## highroad 2 (Jan 24, 2017)

Gutch said:


> I also shift all the time rather that switching power modes. It would be cleaner set up though, however the weight deal could be more than a derailuer, like others have pointed out. Sram use to have the 8spd Ebike cog (which they may still have that i put on my 2016 levo, now


I tried the Sram 1x8 but did not care for the wide gear spacing for my style of riding.
After 4 years and several thousand miles of single track on 3 different assisted bikes, I have found that chain stretch and free hub failures have been an issue for the steep terrain I ride.

It is asking a lot of a transmission to have close gear spacing, wide range, e-bike durability and reasonable cost and weight.
You would still have a chain that stretch's unless cog belts are up to the task.

If this transmission exists I want one.

I just ordered an Onyx rear hub for $650 not including spokes and labor to re build a fat tire wheel


----------



## Wheelspeed (Jan 12, 2006)

Seems reasonable except that, if I was buying, I would go for the smallest battery to be lightest weight, and maybe that battery wouldn't have the torque to power through limited gears.

That is, I would want the most "bike-like" bike. Not saying the bike you described couldn't succeed, but personally, I'd choose a mfr offering a lightweight mtb with a little boost assist (assuming a 10, 11, or 12 spd cassette is useful for that style bike).


----------



## Sparticus (Dec 28, 1999)

Sounds like a gearbox ebike may be forthcoming from Yeti...








Multi-Body Vehicle Suspension Linkage by Yeti: Part 4


Yeti’s new E-bike patent.




wheelbased.com





Quote from the linked article:
*Brief Summary (tl;dr)*
_
Yeti are introducing an E-bike with a gearbox. As with every other bike, the motor and gearbox are located at the bottom of the downtube. This system is a 6-bar system that uses the Watts 4-bar system from the first article. One pivot of the 4-bar system is attached to the front triangle and the other pivot is attached to the gearbox housing. Yeti say this is a novel design that provides numerous advantages such as weight and manufacturability. Additionally, linkages can be placed more freely, allowing designers to fine tune more easily._

=sParty


----------



## RBoardman (Dec 27, 2014)

I've wanted a gearbox ebike for at least three years now. Ever since I rode a Zerode with pinion gearbox, I thought having the power of an ebike would take away all the disadvantages of a gearbox on a normal bike. Now we just need someone to make one that is cleanly integrated without a huge weight penalty. If you add a battery and motor to this bike I would buy it in a heartbeat, love the high pivot idler + gearbox.


----------



## Sparticus (Dec 28, 1999)

RBoardman said:


> I've wanted a gearbox ebike for at least three years now. Ever since I rode a Zerode with pinion gearbox, I thought having the power of an ebike would take away all the disadvantages of a gearbox on a normal bike. Now we just need someone to make one that is cleanly integrated without a huge weight penalty. If you add a battery and motor to this bike I would buy it in a heartbeat, love the high pivot idler + gearbox.
> View attachment 1917561


A riding buddy just ordered one; I believe it's in stock. He already has a custom Pinion-equipped Co-Motion hardtail. I'm eager to get a glimpse of the Zerode when it arrives.
=sParty


----------



## RBoardman (Dec 27, 2014)

Sparticus said:


> A riding buddy just ordered one; I believe it's in stock. He already has a custom Pinion-equipped Co-Motion hardtail. I'm eager to get a glimpse of the Zerode when it arrives.
> =sParty


The problem with current Zerode is they are still extra drag from the gearbox and they have grip shifts that do not shift under power. Other than that, the bikes feel so good going down hill with all the weight off the rear end and I'm sure maintenance is far less.


----------



## Ogre (Feb 17, 2005)

Just shave all that stuff off and make them single-speeds. Electric motors are good at torque. Electric cars don't have transmissions, why should e-bikes? Use the weight savings to add a bigger battery.


----------

