Then come the links to two must read articles on the nuances of BBSxx programming delivered from the hard hitting pen of  Karl Gesslein on his e-bike blog. Read Karl's words very carefully. There are some hidden nuggets in there like his warning about the "Time of Stop" parameter where he says, "I strongly recommend setting this to 5, especially if you want to use the PAS system without using e-brakes."  Setting this higher (which is typical) can unexpectedly hurl you into traffic or into a tree if you are in the backcountry.  I actually like to set this to 10 or 12 as I occasionally don’t down shift when I should and don’t want the motor to stop from timing out at slow cadences.  Note: Stefan Penov renamed this 'Stop Delay' which makes more sense.

I should also point out that when you download Stefan's version of the Bafang software you will get another not to be missed gem in a pdf help file he wrote. It can save countless hours scratching your head trying to figure out how the controller configuration tool works and what the parameters do. I included it on its own in the above links but it also comes in Stefan’s zip file.

So in a nutshell, to configure the controller in a BBSHD or BBS02 you should go to Penoff''s Hobby Page and download his upgraded Bafang Configuration Tool. With it will come his help file. READ IT! Get a Bafang Programming Cable and don't forget to read Karl's articles for important insight into what you are about to do.

Stefan Penov is an engineer living in Norway where he commutes by bicycle - now e-bike.  He posts occasionally on ES. On his hobby page in addition to rewriting the Bafang software he posted the blow by blow tale of his BBS02 conversion project in two parts and then concludes with this gem "Next post will follow after some time and it will be about the software used for tuning of Bafang’s controllers. I am currently rewriting it but it will take me some time. Why do I do that? Because I can." How cool is that? I think Stefan is describing a lot of folks in the DIY e-bike community that donate time to help newcomers and each other in all of the various e-bike forums. Why do we do it? Because we can. We also know the more we help others ride e-bikes the better the planet we live on will be for all of us.

Oh, and one more thing - a bit of a rant about the confusion surrounding configuration vs programming ... For some reason I think Bafang started the confusion by putting their configuration tool in a folder called 8funprogrammingsw. It is not really programming.  Stefan Penoff made programming changes to the configuration tool but he rightly called it a configuration tool and not a programming tool.  Stefan went into the source code and made changes to fix it and make it better, that is programming.  When we use the tool to change parameters in the controller, that is more appropriately called configuration.  

​Matt at Empowered Cycles has been working with Bafang for many years and he told me that because you are only tweaking parameters and making configuration changes to the controller, it does not void the warranty as some have said.  When you use this configuration tool you are not actually reprogramming your BBSxx controller.  If you were to modify the firmware in the controller then you would in fact be reprogramming which could void the warranty.  To my knowledge Bafang has not released the source code for the controller and no one is actually doing this.  

The configuration tool only changes parameters that tune the motor for a particular bike and/or rider.  Now that doesn’t mean you can’t make changes that are insane and even dangerous, it just means that with the configuration tool you have the freedom to make adjustments that fit your riding style and preferences and are free to explore the limits of what your bike and motor can do without voiding your warranty.  You can even use it to force limits on your motor to make it fit within the legal limits of wherever you live.
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With Bafang now shipping controllers with a built-in gear sensor cable and gear sensors now available from multiple U.S. resellers we now have a better option to consider to protect our drive train while shifting. 

If you use PAS and pride yourself in saving $50 by learning manual shift techniques like lightly squeezing the brake or back pedaling to cut the motor before shifting, you may not be a candidate for the new shift sensor. If you ever bought a car with a manual transmission for the pure joy of being in direct manual control, pressing in the clutch and moving the shift lever, you may also not be a candidate. However, you will not be doing something natural like pushing a clutch to shift, you will be unnaturally pulling the brake or back pedalling to shift which may not bring the same pure joy. 

However, if you use PAS and like me don't like to do something unnatural like squeeze the brake or backpedal to shift and despite your best attempts to master these techniques find you occasionally shift before the motor cuts out and you hear and feel a hard 750W+ clunk go through your drive train then you are definitely a candidate for the gear sensor. The ability to shift gears just like you always have without worrying about what the motor is doing with the PAS system or whether you can even let off the throttle (think gripping the bars on a hill riding single track) has got to be nice.

If you use PAS without a gear sensor there is an often glossed over controller programming parameter under "Pedal Assist" called "Time of stop" that can make a huge difference. The "Time of stop" value is multiplied by 10 to get the number of milliseconds after you stop pedaling until the motor stops. Most vendors selling Bafang mid-drives are setting this to a value of 25 which introduces a full quarter second delay (250ms) between the time you stop pedaling and when the motor actually quits. This is why people use brakes and back pedaling to ensure that power to the motor is cut before shifting. If you set it to 5 (don't set it any lower or PAS will stop working) then it only waits 1/20th of a second (50ms) before cutting the motor so you can just stop pedaling and then shift and the timing works out. Karl Gesslein, in his "Hackers Guide to Programming the BBS02 and BBSHD" makes the statement, "I strongly recommend setting this to 5, especially if you want to use the PAS system without using e-brakes."

Even if you get a gear sensor you will want to adjust this value down to between 5 and 12 so the motor stops more quickly after you stop pedalling under PAS.  Curiously, out of 5 vendors and experts with recommendations, all of them but Karl and now Luna recommend a value of 25. Trust me, changing this to 5 makes a HUGE difference. Unfortunately, a side effect of this setting is that at slow cadences the pulses from the PAS magnetic poles are coming slow enough that there is a greater than 50ms delay between pulses and the motor never engages. If this happens, you are probably in too high of a gear anyway.

The solution of course is to shift to a low enough gear that your cadence is high enough that it doesn't time out between PAS pulses or perhaps try a compromise value of 10 or 12. I set mine to 1o because I am sometimes lazy and don't always shift to a faster cadence. You can play with optimizing this for your own style by playing with numbers between 5 and 25 but it will be a compromise.

If you install a new gear sensor to cut the motor during shifting you will not need to worry about it. That's what I did and I really like the seamless shifting without thinking about it and potentially thrashing my drive train. You get smooth shifting without stopping pedaling or messing with the brakes to get the motor to stop. The motor cuts out as soon as I start to shift and comes back on right after shift completes. Timing is very smooth. Feels like a real pro set-up - sweet.
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Have you made a decision on a gear sensor?  Why or why not?
Gear sensor available here
Gear Sensor User Manual

Handlebars can get pretty cluttered on an e-bike and some combinations of controls on a DIY e-bike just don't work well can get downright crowded and awkward. We often have to make less than ideal compromises in locating our handlebar controls and equipment.  Here is a set of bars where the best compromise required the shifter to be placed so far from the grip that it is an awkward and sometimes dangerous maneuver to shift.

Now I happen to like half twist throttles and rapid fire shifters. Unfortunately, most rapid fire shifters do not clear the large bulge on the half twist throttle.  ​ After giving up trying to make the rear derailleur shifter work where it belongs on the right side, I ended up turning it upside down and moving it to the less cluttered left side - definitely not ideal.

 
Some DIYers just move the throttle over to the left and keep the shifters where they belong on the right but having spent years on motorcycles, I just couldn't get use to that.  So the shifter ended up being upside down and backwards. It worked but not what I wanted. I wanted to find a way for all of my new e-bike controls to fit with the regular bicycle controls exactly where they are supposed to be.  That is when I discovered Shimano I-Spec. brakes and shifters.  I-Spec is simply a design that allows the shifter to share the same clamp as the brakes if they are both I-Spec compatible.  It turns out SRAM was the first to do it and Shimano's answer was to come up with I-Spec.  In improving it Shimano has released several versions, I-Spec A, B and II.  I am not going to go over the differences here as there is a good article covering that here.  While I was upgrading my drive train to a wide-range 1x10 cassette to give the best possible range of gears for a BBSHD, I took the opportunity to clean up my handlebars using Shimano I-Spec B components. ​  I upgraded my Avid BB7's to Shimano Deore M615 Hydraulic Brakes which are I-Spec B compatible.  I replaced my 9 speed Deore derailleur and shifters with Shimano XT 10 speed components.  More about the unbelievably superb (for BBSHD conversions) wide range cassette and drive drain upgrade here. The shifter is an I-Spec B Shimano XT M780 10 Speed Trigger Shifter. 

Not only does the I-Spec B shifter clear up space on your bars by sharing a clamp with the brake lever but the shifter levers are raised higher off the bars such that they clear the bulge in the e-bike twist throttle and are in the perfect location,  Sweet.  Additionally, the left side allows the Bafang Power/PAS control switch to be located in a better position right next to the grip.