Changed my mind about my Gear Shift Sensor today - Disconnected it.

Tom@WashDC

Well-Known Member
Region
USA
City
Loudoun County, VA.
So back in Jan 21' I installed a Bafang BBSHD on a Fat Bike (below left). The install included a Gear Shift Sensor to montarily cut off the power during gear shifting. I was new to e-biking and figured that it would be necessary. I found the operation of the shift sensor to be smooth, and noticeable. Worked like a charm.
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In June 22 I took delivery of a Luna Z1 Ultra Mag (above right). I was surprised to find that it did not come with a shift sensor, and figured I would need to install one asap. Well, I didn't, and I've ridden the Z1 about 15 miles most every day since then, without a shift sensor. Yesterday, while climbing a very steep a hill under full power with the Z1, I stripped the 3 pawls on the rear hub (replacement pawls coming tomorrow). This morning I dusted off my trusty Fat Bike with the shift sensor and rode about 30 miles through the woods, trails, and over hill and dale. I found the shift sensor extremely irritating and superfluous. I disconnected it half way through my ride and I would never use a shift sensor again. Granted my riding skills and and shifting technique have gotten better since Jan 21'.

If you are new to mid drive ebike riding, or you are letting friends ride your bike occasionally I would recommend a shift sensor.
If you know how and when to shift, well, it's probably unnecessary.

* Full disclosure.
I just ordered a full suspension Frey Savannah Ultra Mag Step-Thru (below) for my wife. I'm upgrading her from her rear hub drive Aventon Level hardtail. I told her it's because she deserves rear suspension. She doesn't know I'm doing it because I want a better side piece for when my Luna Z1 is down for repairs! I ordered it with the Gear Shift Sensor so she doesn't F&@K it up!

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I distributed the beta versions in 2014. Documented in endless_sphere. I have a half dozen from the Walgreens release and as many for resent releases. All in my seldom used tool and parts box. IMO where they belong. Unused gathering dust.

That said, to readers, the device has its fans. Use what works best for you. There’s no right of wrong.
 
it seems like one those things that easily becomes second nature - let off the pedals just a smidge before you shift. are there bikes whose cadence/torque sensors aren’t sensitive enough to translate that into a reduction of motor output?
 
I personally have never thought I needed a shifter delay on my ebikes. Easing off on the power when shifting is something I do automatically.
On the other hand, many of the seniors I ride with should never ride an ebike without one. While on a group ride, when we come up to a hill, many of them will power up the hill, then, when they realize they need a lower gear they'll shift down while under power.
Lots of loud 'CLUNKS' from their drive trains. Seems gearing down before the hill is beyond their scope of comprehension.
 
Guys, know that not all e-bike motors (and the relevant controller programming) are the same. Some, including the Bafang mid drives (again, depending on controller programming) continue to run for a second (+/-) after the crank stops turning. This in the name of some pretty civilized controller programming. The shift sensor is there with this "after run" in mind, shutting power to the motor off as soon as a shift is detected. The effectiveness of this switch it totally dependent on the controller programming....

Point being, all may not be immediately obvious when it somes to this switch. Know what you're talking about before totally condemning the plan.....
 
Guys, know that not all e-bike motors (and the relevant controller programming) are the same. Some, including the Bafang mid drives (again, depending on controller programming) continue to run for a second (+/-) after the crank stops turning. This in the name of some pretty civilized controller programming. The shift sensor is there with this "after run" in mind, shutting power to the motor off as soon as a shift is detected. The effectiveness of this switch it totally dependent on the controller programming....

Point being, all may not be immediately obvious when it somes to this switch. Know what you're talking about before totally condemning the plan.....
Good point Al. I did drop my delay stop or decay whichever it was, down to zero on the BBSHD Fat Bike so the power would shut off as soon as I stopped pedaling. UART protocol on both controllers.
 
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...Seems gearing down before the hill is beyond their scope of comprehension.

i spent about a month admonishing my (then) 10 year old about this, every ride, the bottom of every hill. "are you getting ready to go uphill? downshift!"

still, at least 5 times she'd jump off the hill partway up because she had failed to shift and was afraid of shifting under full load on a steep hill because that sound is so bad. "my bike is breaking!"
 
I've never needed or found a use for the shift sensor and the BBS02B has a known bug that doesn't allow for the Stop Delay to be set below 20 or 200ms.
Being smarter than a derailleur is all it takes. 🙃

@Tom@WashDC
Frey looks nice... How much was it and do you know the weight? CANBUS or UART?
It is $4580 shipped. 70lbs, I believe it is UART but not sure. I will know in a few days.
 
It is $4580 shipped. 70lbs, I believe it is UART but not sure. I will know in a few days.
Wow... Price on that puppy has gone up.
I had looked into it mid 2021 and it was $3450 then. It was about the same time CANBUS was rolling out and I couldn't get a straight answer from them on which it would be. CANBUS is a deal breaker for me.
It was also about the same time I figured out a new programming strategy on the BBS02B so I hit the pause button. Still pretty happy with the BBS and the current build is about 53lbs.
But I am getting the spring time itch again and besides the weight it does check most of the boxes. Pretty slick for a FS quasi step thru 👍
 
Wow... Price on that puppy has gone up.
I had looked into it mid 2021 and it was $3450 then. It was about the same time CANBUS was rolling out and I couldn't get a straight answer from them on which it would be. CANBUS is a deal breaker for me.
It was also about the same time I figured out a new programming strategy on the BBS02B so I hit the pause button. Still pretty happy with the BBS and the current build is about 53lbs.
But I am getting the spring time itch again and besides the weight it does check most of the boxes. Pretty slick for a FS quasi step thru 👍
Yeah i saw those prices back then, they have shot up. Back then they were shipping straight from China I believe. Now they have a U.S. warehouse with some inventory, no doubt their costs have escalated a bit. I didn't ask about the CANBUS/UART protocol. FS quasi step-thru is the primary consideration for my wife. If it's CANBUS, It won't bother me too much if I can't modify the settings like the UART. I won't be riding it to much. If it does bother me, I can always install a UART controller and display for about $300. I'll let you know what it is when it arrives.
 
Yeah i saw those prices back then, they have shot up. Back then they were shipping straight from China I believe. Now they have a U.S. warehouse with some inventory, no doubt their costs have escalated a bit. I didn't ask about the CANBUS/UART protocol. FS quasi step-thru is the primary consideration for my wife. If it's CANBUS, It won't bother me too much if I can't modify the settings like the UART. I won't be riding it to much. If it does bother me, I can always install a UART controller and display for about $300. I'll let you know what it is when it arrives.
That's cool... and I have the same considerations as I age 🤣
fyi... You can't just plop a UART controller and display on a CANBUS setup. Mounting holes as well as cabling and internal sensors are all different from what I understand.
I've heard that the CANBUS setup is aggressive and power is sloppy.... If you do get a CANBUS, I hope things have refined over the months.
What was your order wait time? Typical from China had been 3 months.
 
Good point Al. I did drop my delay stop or decay whichever it was, down to zero on both bikes so the power would shut off as soon as I stopped pedaling. UART protocol on both controllers.
I figured you'd know what I was talking about. I was addressing those not so familiar with the Bafang mid drive motors.... -Al
 
That's cool... and I have the same considerations as I age 🤣
fyi... You can't just plop a UART controller and display on a CANBUS setup. Mounting holes as well as cabling and internal sensors are all different from what I understand.
I've heard that the CANBUS setup is aggressive and power is sloppy.... If you do get a CANBUS, I hope things have refined over the months.
What was your order wait time? Typical from China had been 3 months.
Speaking to "Kathy" at Frey Bike, she said 3 days to ship from CA warehouse. I ordered it on Friday. Should be here by next week. Yes, I have a friend that has a CANBUS Sondors Rockstar. He installed a UART controller and display. The controller assembly came pre-installed as one piece mounted with the side motor casing. He did need a new wiring harness and display.
 
The gear shift sensor throttle cut on my BBS02 is too short. I now engage slightly my front brake to cut the motor until the gear change is finished. Work very well for me.
There's many a trick that can be done with the bafangs... and I have/do use yours occasionally. You can adjust your breaks so that a slight pull on the handle has no breaking.
Another is set the Start degree to 5 or above. Then with a slight pause in pedaling the motor won't start again until you do at least a quarter crank and that's more than enough chain movement to shift.
I incorporate the above with an elevated Stop Decay, above 100 (1000ms) and with the briefest of pedal pause the motor re-engagement ramp up is much smoother.
 
Touching the front brake while shifting is quite natural for anybody who had a motorcycle.
Makes sense. Never thought of it like that!

The shift senser on my bike is barely noticeable. Have never paid much attention to it. The ONLY time I know it's going to kick my butt is when trying to downshift too late, at too low a cadence, then it's going to do it's best to stall the bike with the delay at the worst possible moment. Have learned not to even try the downshift. Just dial up the PAS level a notch or 2 and use some of that torque it has on tap for just this kind of thing.... -Al
 
Speaking to "Kathy" at Frey Bike, she said 3 days to ship from CA warehouse. I ordered it on Friday. Should be here by next week. Yes, I have a friend that has a CANBUS Sondors Rockstar. He installed a UART controller and display. The controller assembly came pre-installed as one piece mounted with the side motor casing. He did need a new wiring harness and display.
Let us/me know your source for the UART parts.
 
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