BBSHD with no SPEED sensor?

[onemorebicycle]

I went and splurged on a Bafang BBSHD with a DPC-18 display for my cargo bike. The install went okay, up until I realized I needed an extension cable for the speed sensor, due to the extra long wheelbase - makes sense, I just wish I had realized this before I ordered the kit from Bafang Direct, as I would have had them include the extra cable in the order.

So I'm currently awaiting the arrival of the necessary speed sensor extension cable. In the meantime, I'm really wanting to ride my new e-bike. But this also got me thinking, what happens if the cable fails out in the field? This certainly sounds like an Achilles' heel that needs an override option.

There is an article on the BBS02, link below, where the possibility of operating with a broken or missing speed sensor while in "non-PAS mode" is mentioned. I'm not able to find any mention of this for the BBSHD, nor can I see that option on the DPC-18 menus.
https://electricbike-blog.com/bbs02-installation/

What do you do if the speed sensor fails or the cable breaks? Is there a workaround to get back home until the sensor can be repaired? I will say the unit works for about a minute without the speed sensor getting a signal, but then error 21 pops up and the motor is no longer responsive to PAS or throttle.

 

[amberwolf]

Are you asking about bypassing the gear sensor (your title), or the speed sensor (your post)?

They're two different things, with different purposes. I don't think the gear sensor is necessary, though without the speed sensor the system times out.

Later firmware doesn't appear to allow disabling the speed sensor (it may have the setting but it doesn't obey it), so the only option I know of would be to create an overriding signal. this post
https://endless-sphere.com/forums/viewtopic.php?f=28&t=93575&p=1428810&hilit=bbshd+speed+sensor+error#p1428744
gives one way of doing that, if you don't mind building a little electronic module to connect in place of the sensor.

Alternately you could carry a spare cable and speed sensor, in case the existing ones fail.

Or wire a separate one to the other wheel, and a switch so you can simply switch over in the event of a failure.

 

[onemorebicycle]

Whoops, it should be speed sensor, I'll correct the typo in the title.

It doesn't sound like there is an easy way to run the BBSHD with no speed sensor, which is a significant con when overlooking this system.

Thanks for the reply.

 

[TommyCat]

Try setting the display's "Auto Off" setting to off... I think you will still have motor operation, but the display information is blocked.

 

[onemorebicycle]

Disabling the auto off setting doesn't seem to keep the motor running, for me at least.

I got the speed sensor extension and holy cow, I love this ride!

Now to clean up the wires...

 

[kcuf]

commercial cargo bikes

running around nyc

bbshd

haul large battery too

excellent combination