BBSHD torque sensor upgrade

[Sakkie]

Does anyone know if something like this is doable? The torque sensor sucks on the BBSHD. I took a ride on my wife's store bought BH bike and it was a completely different (better) experience.
I enjoy the power and DIY experience with the BBSHD, but would like to improve it if possible.

[Louis]

The only improvements are going to be in the programing of the controller. But there is no torque sensing available. A majority of eBikes do NOT rather opt for PAS.
One of the best explanations come from another source. Google around for BBS02 or BBSHD and PAS

"The PAS system on the BBS range of motors, works like a switch. It does not increase assistance as you pedal faster, it simply makes the motor turn at a programmed rpm (percentage of the full speed actually) and current/power level (again, percentage of the max current setting), when it has detected that the pedals are turning (this can be confirmed by pedalling very slowly, as when you do this, the motor will drive at the same higher speed, ragrdless). The speed and max power provided for each PAS setting are programmed into the controller and cannot be changed by the end user (can be adjusted with and the appropriate USB cable and software). The power provided by the motor when used in PAS mode will increase, if it detects the load has increased (such as changing to a higher gear or approaching a hill), then reduce again as the load goes back to a constant level (this is a programmable parameter, knows as keep current). As previously stated, the motor speed does not significantly increase or decrease if you pedal faster or slower, and that is why we suggest the PAS level is used to control the pedalling cadence (motor speed) so that it matches your comfortable pedalling cadence. When using on steep inclines, it should be ensured that the motor is spinning as fast as possible. DO NOT USE A LOW PAS LEVEL AND PEDAL UP STEEP INCLINES USING PEDAL ASSIST, as this is a great way to kill the motor and controller. It is much better to use as low a gear as possible, and a high PAS level (or use the throttle to increase the motor rpm). Motors like to spin fast, when they are working hard!"

​The last line is really important on the BBS01 and BBS02. But I use the same suggestion my HD's.

[jc2eb]

haha, how can something that doesn't exist suck? :)

The retail bikes with Bosch drives and torque sensors are amazing like Haibikes, etc. Amazing riding experience. Bafang feels like a kludge in comparison. Hopefully one day it will be supported. I would have to imagine someone is working on it.

[skymon]

Well, havent ridden one but Bafang does make a mid drive with torque sensor. Just not that much torque to sense from what I can gather.

[Sakkie]

Yes, it would be cool if they can come up with one that sucks less.

[spinningmagnets]

The "turn key" BH ebike you bought your wife has a much better "torque sensing" PAS, instead of the more affordable "speed sensing" PAS found on the BBSHD. However, it is...(how shall I put this delicately?)...more expensive.

ebikes.ca has a "torque-sensing" BB crankset you can buy, but...it is ...."more expensive"

You have the option of buying the controller programming cable and using your computer to play with the settings, in the hopes of "fine tuning" it (I'm told the power-delay is a safety feature that can be eliminated, but...I don't know). Best of luck http://lunacycle.com/parts/bafang-pa...ramming-cable/

[TonyO]

Beam TS has a torque sensor, but after more enquiries I realized that because it is tied into the chain it would only work with a hub motor. I think the only type of torque sensor that would work as a retrofit would be one that measures the torque through the crank arm and have a wireless connection to the controller, it would only require the unit to be fitted to one crankarm, but it would be rather expensive.

[squirrelpie0]

For those of you wondering about the Bafang Max Comfis mid mount system with a torque sensor. Here are a few details. The system does exist and you can order it apparently directly from China. It has been shipping to OEM for a year or so, and though pop ups on my computer are frequent promoting it, details are sketchy and response from inquiries to Bafang unanswered.

The unit has a special mount similar/the same as used by Bosch and Yamaha. This mount is listed as an 'Accessory' which you would have to weld into a bike frame. Pretty involved in a DF but should be fairly simple on a TT Rover which has a 2" square tube front boom. The details on MOFSETS, parts and controls are non existent, but probably industry standards or what Bafang has been using in their BBxx units.

Servicing/diassembly of the Max Comfis looks a simpler more modular design. Don't know how this compares to Bosch/yamaha and have not been able to find parts breakdowns for those either, but expect they will become available as more units hit the market and DIYers get into it.

Anyhow here is the link I found that does show a breakdown/ assembly even if short on details. Looks like the mid/plastic gear is larger? Anyone find better info?

https://www.youtube.com/watch?v=Of3UsjiBvtU

[calfee20]

I watched the next video which was a road test of that new Bafang unit. Well it sounds awful. I am so glad my BBSHD is nearly silent. http://www.youtube.com/watch?v=BHb5L6Cz9FU

[squirrelpie0]

Think the noise level you hear on this video is result of microphone placement sensitivity rather than a noisy unit. Note the road gravel noise, shifter/derailleur noise, and the freewheel ratchet noise. Don't think from the repurts I seen the motor is as noisy or any noisier than the BBXX units

[calfee20]

There is a lot of other noise but compare when he is pedaling and when he is not and the gear/motor noise jumps out at you.