Bafang m620 gear sensor extension cable

[tomjasz]

Or for those with motors that have overrun (such as the M620, the subject of this thread)....

BS a gimmick

 

[tomjasz]

Oh I wasn't taking offense ! I just figured why not , doesn't hurt having it ya know !

Hurts nothing but the pocket book. Its like pissing up wind. Fruitless.

 

[Jon A]

BS a gimmick

When is the last time you climbed a 30% grade in max power mode with the M620?

 

[Jon A]

Clearly you don't. I can explain it to you if you like. If you were riding mythosaurs in 2014 I'd give you props, but I'd still point out that experience may not be relevant to this very specific application.

 

[AHicks]

Invented for those with poor shifting skills. IMNSHO

Tom, with the built in delays and crap set up in the controller, that are there to help smooth this thing out. Without the sensor the motor may not stop immediately when you stop/unload while pedaling (it probably won't). That means the drivetrain may still have a load on it, even though you've done the normal pause as you shift - resulting in an unwanted crunch as you shift. The shift sensor is your assurance the motor WILL stop (right now) for your shifts. I don't even notice it 99% of the time, but it is something that may cause you to adjust your shift timing just a bit if you're brand new to it to get those sought after butter smooth shifts. ....

Point being, it may be less about poor shifting skills than what it might seem at first....

 

[Foxhound68]

Who knew shift sensors where such a touchy subject , my thought process is what's it hurt , it definitely cuts the motor when I shift so it's doing its job and what if I want to ride the bike more classically like a normal bike and shift more normally (not that I do on a ebike) why's a safety piece of tech ever a bad thing , it's not like I'm sacrificing something by having it on the bike !

 

[Gionnirocket]

Who knew shift sensors where such a touchy subject , my thought process is what's it hurt , it definitely cuts the motor when I shift so it's doing its job and what if I want to ride the bike more classically like a normal bike and shift more normally (not that I do on a ebike) why's a safety piece of tech ever a bad thing , it's not like I'm sacrificing something by having it on the bike !

I wouldn't sweat it... It's mostly personal preference and then add specific to the bike setup and motor with a dash of rider ability. If you find it a plus, by all means.
For me shifting isn't an issue so I eliminate one point of failure and clutter.
I hear they can be problematic if not kept clean.

 

[AHicks]

I wouldn't sweat it... It's mostly personal preference and then add specific to the bike setup and motor with a dash of rider ability. If you find it a plus, by all means.
For me shifting isn't an issue so I eliminate one point of failure and clutter.
I hear they can be problematic if not kept clean.

Mine came pretty safely located with all of the electric connections and cables under the cover on the side of the motor. That's not a totally sealed up area, but I'm not expecting a lot of trouble with it.

 

[tomjasz]

Point being, it may be less about poor shifting skills than what it might seem at first....

As a beta tester in 2014, support for a distributor, reseller, and rider I've had a GS on every bike. Just not my cuppa. Added complexity. I had to hunt for a 2021 BBS02B without the damn plug-in. The only time I recommended them was for kit builders using marginal IGH hubs. I do see they've gotten to be essential for some. I guess 8 years of shifting sans GS just makes me very comfortable to be without.

BTW, If folks are adding a GS I highly recommend the original version over the Chinese stolen design clone.

 

[tomjasz]

Clearly you don't. I can explain it to you if you like. If you were riding mythosaurs in 2014 I'd give you props, but I'd still point out that experience may not be relevant to this very specific application.

My apologies. You're a better judge of the use of the M620.

 

[AHicks]

As a beta tester in 2014, support for a distributor, reseller, and rider I've had a GS on every bike. Just not my cuppa. Added complexity. I had to hunt for a 2021 BBS02B without the damn plug-in. The only time I recommended them was for kit builders using marginal IGH hubs. I do see they've gotten to be essential for some. I guess 8 years of shifting sans GS just makes me very comfortable to be without.

BTW, If folks are adding a GS I highly recommend the original version over the Chinese stolen design clone.

No intent to start a pissing match, but I've ridden derailleur type systems since I was in my teens. It's not something I even have to think about. I just go. For you to talk down about people riding with them as though they were some kind of crutch makes absolutely no sense here. And to spend the time to track down a motor that doesn't have a gear sensor jack? What's that about? With the switch unplugged from the motor with a jack, what would be the difference in the motors with and without a jack?

And from a set up standpoint, you just run the shift cable through it and plug it in. There is no further setup involved....

I get how some, adding early versions just because they wanted the latest and greatest of a crappy design to help them learn how to shift might not have worked out so well, especially if these folks expected that switch to give them the equivalent of years of riding experience. I think we all know how that's going to turn out....

 

[Jon A]

Without the sensor the motor may not stop immediately when you stop/unload while pedaling (it probably won't). That means the drivetrain may still have a load on it, even though you've done the normal pause as you shift - resulting in an unwanted crunch as you shift. The shift sensor is your assurance the motor WILL stop (right now) for your shifts.

Exactly. All the technique in the world is completely meaningless if the motor is still pulling on the chain like a runaway freight train for a noticeable period of time after pressure on the pedals is eased or even stopped completely.
With tuning, I've been able to greatly reduce the overrun on the M620, but not eliminate it completely. In normal use on flat-ish ground, it feels like it's completely eliminated. But when climbing really steep hills in the highest power modes (exactly the situation where one is at greatest risk of breaking something) there's still way too much of it to expect the motor to obey my pedals' commands quickly enough.

The sensor allows the use of "proper technique" when shifting, ensuring that your "technique" is the only thing in play during a shift and the motor won't interfere, regardless of tune.

 

[tomjasz]

No intent to start a pissing match,

But you took the piss anyway.

nd to spend the time to track down a motor that doesn't have a gear sensor jack?

The plug is off the controller and about an 8" wire. Like the useless, to me, BBSxx lighting wires they're just unneeded wires coming out of my controller. KISS. Just something else I need to sort and protect.

My apologies. You're a better judge of the use of the M620.

I guess your need to confront missed the apology.

 

[tomjasz]

Exactly. All the technique in the world is completely meaningless if the motor is still pulling on the chain like a runaway freight train for a noticeable period of time after pressure on the pedals is eased or even stopped completely.
With tuning, I've been able to greatly reduce the overrun on the M620, but not eliminate it completely. In normal use on flat-ish ground, it feels like it's completely eliminated. But when climbing really steep hills in the highest power modes (exactly the situation where one is at greatest risk of breaking something) there's still way too much of it to expect the motor to obey my pedals' commands quickly enough.

The sensor allows the use of "proper technique" when shifting, ensuring that your "technique" is the only thing in play during a shift and the motor won't interfere, regardless of tune.

So the GS in place of programming? Does it read like the GS solves a motor problem?

 

[PedalUma]

Addressing OP. This is just three wires and it works like a brake lever cutout. Get a section of Cat 5 and some heat shrink tube to splice in your extension. Sometimes you can just cut the brake cable housing where you want to place it. That is easiest. I personally don't use them. They are for people who want to down shift under throttle up a hill and even then the drivetrain will crunch. I just ride like I ride a regular bike by easing off on pedal pressure when shifting. Same with a car with a clutch, you don't throttle and shift at the same time. You let off the gas for a second. My drop bar bike does not have any indicator displaying the gear be cause you can feel what gear you are in and can always look down at the cassette if you had to.

 

[Jon A]

I guess your need to confront missed the apology.

If it was intended to confront, it would have addressed you. The subject comes up a lot from lots of different people (PedalUma's post case in point) so I figured further explanation would be of benefit to everybody.

So the GS in place of programming?

As explained above, I was unable to eliminate it to my satisfaction (without causing other side effects) through programming (if somebody has an Ultra tune they think does it in conditions described above, please post it up as I'd love to give it a whirl). So in my experience, it does something that cannot be accomplished via programming. Most people buying a new Ultra bike these days can't program their motors at all either. The GS takes the motor out of the equation universally.

Does it read like the GS solves a motor problem?

"Problem" in the eye of the beholder, I guess. Many high end E-MTB companies brag about overrun as a "feature" that helps riders get over technical terrain where pedal strikes are an issue (on bikes that have no throttle obviously). I much prefer using the throttle in such situations.

If all I did was ride on the road in the mid to lower power modes, I wouldn't feel the need for a GS. But for me using the bike offroad, being able to shift it just like I do my manual bikes without the motor screwing things up is desired.

For those to whom drag racing their buddies is of the utmost importance, they certainly don't want a GS and keeping full power even if they briefly can't maintain full pressure on the pedals might be a "feature"....

 

[Jon A]

I just ride like I ride a regular bike by easing off on pedal pressure when shifting. Same with a car with a clutch, you don't throttle and shift at the same time. You let off the gas for a second.

Of all the bazillion builds you've posted, I haven't seen any with the Ultra. Please read explanation above.

 

[PedalUma]

Of all the bazillion builds you've posted, I haven't seen any with the Ultra. Please read explanation above.

These first two have the gear sensor burried in the bottom of a pit under the battery. I upgraded their cassettes, derailleurs and shifters. Those gear sensors were a pain. I do Bafang builds sometimes. They just are not very interesting to me. Over run is to make for a smoother ride. I find it imprecise. I like real time action and control. That is me in the fourth photo. The last two are a BBS02 that is cleaner than most. No cutouts & no gear sensor. I love the basket on the Rockstar! Oh, check out the phone apps photo.

 

[AHicks]

So the GS in place of programming? Does it read like the GS solves a motor problem?

From the sounds of it, you're going to need a ride on an Ultra with the Smooth tune and gear sensor installed. It's likely the only way you're going to see that they compliment each other wonderfully. There is never, not in any situation I've been in anyway, a point where that switch will piss you off....

 

[PedalUma]

From the sounds of it, you're going to need a ride on an Ultra with the Smooth tune and gear sensor installed. It's likely the only way you're going to see that they compliment each other wonderfully. There is never, not in any situation I've been in anyway, a point where that switch will piss you off....

It would be nice if you could enter a rider's gear sensor dwell-time preference among five choices into the display. The biggest lag would be for climbers with large cassettes. I would still personally rather use my foot to apply lag. If you power shift most IGHs you will kill them.