Have you ever thought you don't get much out of that big bulky display that came with your BBSHD or BBS02 Bafang mid-drive motor?
Maybe you wish you could get rid of your display entirely because either you want to be super stealthy or you have a speedometer/computer you prefer and you find the display redundant. Maybe your wireless computer stopped working when you plugged in your Bafang display and you want it back. Maybe you want a real volt/amp/watt meter like the Batt Man and don't want yet another display on your bars. Maybe you just want your bars to be as clean as a regular bike. Maybe you thought that with a Bafang BBSHD or a BBS02 you were just stuck with it. How else can you turn your motor on and off? If any of these maybe’s ring any bells or match any of your thinking then read on.
You will be glad to know you can dump your display, turn your motor on and off, keep your throttle and still retain your favorite PAS setting. You can even get rid of the Bafang speedometer sensor and speedometer cable and just use the one on your computer or use the Batt Man watt meter from Luna which is a more useful display. This makes your throttle the sole e-bike addition to your bars. Here's how you can do it:
To turn on the motor without the display you just need to short the red and brown wires that are in the display cable together. Here is an image of the BBSxx display cable connector on the controller side:
The orange wire is PL and the brown wire is P+. Cutting into your cables to tie these wires together can be risky. The easiest and safest way to jumper them together is to just plug in the bafang programming cable and you are set. The brown and orange wires are tied together inside the programming cable. If you take this simple approach you can just buy a programming cable and plug it in but you will need to find a place to tuck the cable and usb/ttl/uart adapter part on your bike - but it is small. You will want a programming cable anyway so you can set up your controller to default to your favorite PAS level and set up other parameters for best throttle control. (More on configuration programming in a moment.)
Alternately, You can just buy a programming cable or one of these and cut the connector off. Just solder the orange and brown wires together, plug it in and you have display eliminating jumper.
If you don’t have an extra display connector and don’t want to wait to buy one you can pick up a jumper at your local hobby or electronics store and do this:
Just be careful to get the jumper on the right pins of the display connector on your controller cable and don’t accidentally bend them. The pins are very thin.
You can also put an on/off switch on the brown and orange wires if you don't want to plug/unplug your battery each time. So the whole project is that simple - program the controller and when you are done leave the programming cable or connector/jumper plugged into the BBSHD or BBS02 controller instead of the display and go for a displayless ride.
To turn the motor completely off you need to unplug the jumper/programming cable. If you are worried about potential battery drain (there is very little without the display) by leaving it on and don't want to plug/unplug it each time you can wire it to a simple 2 pole switch.
When you unplug your display and jumper the orange and brown wires using one of the three ways described above try just going for a ride. It might be just the way you like it. To configure the controller for optimal use without a display you will want to go to Penoff's Hobby Page and download the configuration software and read the help file that explains how it works. A list of programming resources can be found here.
If any of your controller settings are set to 'by displays command' you may want to change it because you DON'T HAVE A DISPLAY! They will however default to what your display was last set at. (If you disconnect your battery after rides that may not be true. I haven’t tested that). Start with a good set of program settings found in a file with the extension .el. Use the one that came pre-programmed into your BBSHD or use another one from someone you trust. A list of these and other great configuration insights can be found here.
Here are a few parameters you can play around with. On the Pedal assist tab- set designated assist to whatever PAS level you like best. For me that is 2 or 3. Set Speed Limited to 40Kmh, Time of Stop to 5 or a little higher if you like slow cadences, set Current decay to 6, Stop Decay to 0. I like Keep Current at 60 to ease off the motor when you come up to speed pedalling but others like it at 100 to keep the throttle on full no matter how fast you are pedalling. Lots of other tweaks you can make that apply to bikes with and without displays.
If you like to use a computer on your rides you may be in for an added bonus. Many wireless computers stop working when the Bafang display is plugged in. This is also true of many other ebike kit displays as well. So once you get rid of your display an added benefit is you get back accurate speed, distance, elevation, slope and more with your own computer.
So that's one way to clean off your bars. There are however many other compromises we are forced into with an e-bike conversion that make for less than satisfactory handlebars. I have struggled with messy bars on many bikes moving shifters, brakes, control switches and throttles all over the place with many less than ideal compromises before coming to what for me is the perfect solution. I finally got my bars exactly how I want them. Read about it here.
Oh, and one more thing. If you really like setting PAS levels on the fly while riding then you are like me and you are stuck with using a display. Thankfully we now have the DPC-14 which to me is the first display I don't absolutely resent giving handlebar real estate to. The above instructions are best for throttle junkies and those that find they use one PAS setting all the time.
What do you think about going displayless?
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.
If you like these ergonomic clamp on grips (I do), they are the Ergon GP1 single twist grip. The left grip is normal sized while the right one is shorter to match with the half twist throttle. If you get the Nexus/Rohloff version of the same grip it is an even better fit because the right grip is another 10mm shorter.
So that is how I got my bars exactly how I wanted them. Some of you may want to go a step further and get rid of your display entirely because either you want to be super stealthy or you have a speedometer/computer you prefer and find the display redundant. Maybe you just don't like a big bulky display and want your bars to be as clean as a regular bike. Maybe you thought that with a Bafang BBSHD or a BBS02 you were just stuck with it. How else would you turn your motor on and off? If that sounds like something you might be interested in click here.
Have you dealt with handlebar clutter on an e-bike?
Anything you have tried to make it work or simplify it?
Mid-drive motors like the popular Bafang BBSHD and BBS02 have many advantages over hub motors including: 1. Low and middle center of gravity for better balance. 2. Use of the drive train by the motor. On a hub drive the motor only has a single gear while a mid-drive motor alomg with the cyclist gets to use all of the gears so the the motor's RPMs stay up in it’s most efficient range where power is maximized and battery use is more efficient. This allows the bike under motor power to 3. Go fast and climb steep hills much better. 4. Retain the quick release hubs on both wheels to make fixing a flat easy or removing the wheels quick - the way we like it. I remember adding a 19mm wrench to my seat bag toolkit so i could change a flat on the road with a rear hub motor - not ideal.
However despite these great benefits most mid-drive motors require a huge sacrifice over hub motors. These motors have a single gear up front requiring us to sacrifice our front derailleur and 2 or 3 chainrings to a single chainring. This means your 27 speed is now a 9 speed. If you want to go fast with a comfortable cadence you get a large chainring. If you want to climb hills you get a small one. Unfortunately, you can't have both. People with steep hills to climb are putting small chainrings on their BBSHD. Because of the architecture of the BBSHD chainrings smaller than 42 teeth tend to mess up their chain line. It also sacrifices their top speed. If you stay with the 46 tooth chainring that comes on the BBSHD or put an even bigger one on it you can bog the motor down on steep hills even in the lowest gear. Hence, we see the single track and San Francisco crowds putting on 42 tooth and smaller chainrings like the Luna Eclipse or Lekkie all the way down to the 30 tooth Luna Mighty Mini. These are great for climbing but at the expense of speed and chain line below 42t.
The 10 or 11 tooth high gear you have on your cassette is as high as it goes so if you want speed and a higher gear the only lever you have to play with is the front chainring. This you do at the expense of your low gears for climbing. But I did say you could have it all in the title above didn't I? Indeed you can if you upgrade to a wide range cassette. If you have an 11-32t or 11-34t like mine you are in for a hill climbing eye-opener when you move up to an 11-42T wide range cassette. You still have your top speed 11 tooth high gear but now you have a 42 tooth low gear in the rear to grind up the hills with. As for the front chainring no need to go below 42T for the steepest hills so you can keep your chain line intact. In fact I had a hard time finding hills the stock 46T couldn't handle. You will still want to upgrade it just on principle though (and to save weight) as it is a plain, heavy piece of stamped steel, whereas the new chainring upgrades from Luna and Lekkie are a lightweight and attractive upgrade.
So what is entailed in the upgrade? It depends on what you are starting with. If you have a 10 speed cassette already you are in luck. Most wide range cassettes are made for 10 or 11 speeds and you can just add a wide range cassette. Sunrace makes a good one that is 11-42T with 10 or 11 cogs. You may need to make some changes to your derailleur like a Wolf Tooth Components Goatlink or a longer B-screw to enable it clear the 42 tooth cog.
If however, you are like me and have an 8 or 9 speed cassette you will need to upgrade to a 10 speed as that is where the new wide range cassettes start. (Edit: the previous sentence is no longer true as Sunrace now makes wide range cassettes 11-40/11-42 for 8-speed and 9-speed drive trains. Available here.) Fortunately, Shimano and SRAM 8 and 9 speeds have the same cassette body type as the 10 speed so without needing to get a new hub and wheel you can upgrade the cassette. In addition to a new cassette you will also need a new shifter and derailleur. This can all be had for less than you might think. I will give a list of the components I used later. This is also an excuse and an opportunity to get some good performance components in your drive train. While I was at it in addition to a nice drive train upgrade, I took the opportunity to fix up my handlebars using Shimano I-Spec B components. Handlebars can get pretty crowded and awkward for DIY e-bikers. More about that upgrade here.
The bike I started with was a Cannondale Lefty with a 9 speed cassette. After doing a BBSHD conversion on it I loved everything about it except for the unfortunate tradeoff between speed and climbing ability the loss of 2 of my chainrings forced on me. It was while researching my options that I discovered that this limitation could be overcome with a wide range cassette but I would need to upgrade my drive train to a 10 speed. The best 11-42t 10 speed cassette at the best price I could find was made by Sunrace. I got the Sunrace CSMS3 steel cassette.
I recommend the Sunrace CSMS3 rather than the lighter and more expensive CSMX3 aluminum cassette. It is cheaper and made of steel but with the high torque of the BBSHD bearing down on it, it will hold together better. Karl Gesslein found out the hard way that the MX3 aluminum version will not hold together under BBSHD loads and he wrote about it here. In an update to the article and a picture of a trashed MX3 he says, "Forget about the aluminum version of this cassette, only buy the steel version CS-MS3 do NOT buy the CSMX3 which will catastrophically fail under any real power. You have been warned."
After researching more into drive train components I went with the Shimano XT M786 Shadow+ 10 Speed Rear Derailleur with a medium cage. The medium cage coupled with a Goatlink allows this mass produced (read that less expensive) high-end derailleur to clear the massive 42T cog on the Sunrace CSMS3 cassette. Here it is installed on the Lefty with the Wolftooth Goatlink and working flawlessly right out of the box.
I chose an I-Spec B compatible shifter so I could get my handlebars the way I wanted them. The shifter is a Shimano XT M780 10 Speed Trigger Shifter. More on getting the handlebars right here.
This upgrade turned a great mid-drive conversion into what for me is the ultimate e-bike. I love it and if you have struggled with the speed vs climbing power mid-drive motor issue, you will too.
What do you think about mid-drive gear ratios on your e-bike?