Torque sensing bottom bracket for Efneo planetary

[offGridDownUnder]

I have an Efneo 3 speed planetary crankset. They are not responding to emails.

Does anyone know if there is a torque sensing bottom bracket that works with the Efneo? The left crank and the right gearset/crank are square taper.

Thanks.

 

[lnanek]

Last time I emailed with them, they said they are out of business. So that might be why the lack of response. The official docs say you can only use the bottom bracket they provide. So not wanting to take legal responsibility for any old bottom bracket standing up to the stress the gearbox puts on them might be another.

That said, if you search, there's a write up of someone who combined the bottom bracket torque sensor of a Rad ebike with the Efneo bottom bracket. They did have to hire a machine shop, though.

There are other ways to measure torque too, though. Like Grin has a hub with it built in, nowadays, I think. Bionx definitely had a hub with it built in. Other systems sense torque with a plate at the rear drop outs.

 

[amberwolf]

If the Efneo mounts just like any other JIS ST crankset, then you can use it on any JIS ST BB, whether it is also a TS or not. If it has restrictions on what BB's it will mount to, then you have to use those restrictions to narrow down which BBs it would work with (TS or not).

You can buy non-BB torque sensors. As noted above, Grin sells their All-axle motor with one built in, but that sensor and others like it are available as parts. There are also other hubmotors with integrated sensors, some of them the same ones as Grin.

For the separate sensors you could still build them into a regular rear wheel if your motor is not in the rear wheel hub.

I haven't checked to see where they're sold yet, but a few of the available types are discussed here:

Rear all axle v3 with torque sensor

https://ebikes.ca/product-info/grin-products/all-axle-hub-motor.html Came out in the Christmas newsletter. Super stoked to see the torque sending quality

endless-sphere.com

 

[E-HP]

The manual states: "on the right side the BB cup has a specified diameter of 46 millimetres and we need precisely 30,5mm of axle standing out". What they mean by standing out isn't clear. I assume the 46mm is the OD of the stationary cup. In any case, it may be possible to mate it with a normal square taper BB if you can match the dimensions, but that doesn't work for most torque sensing BBs. A lot mate up to their own spider for mounting the chain rings.

 

[amberwolf]

I'd venture that "standing out" means laterally clear of the entire BB, lockring, etc.

i.e., 30.5mm of BB spindle sticking out past the lockring/etc, so the Efneo can fully be tightned down and secured to the spindle.

 

[lnanek]

Efneo did push the chain line out pretty far on my bike I installed it on. Had to flip the cupped sprocket on my Nexus hub to get the rear poking out similarly and avoid chain drops.