Several years ago a small experimental device appeared on Endless Sphere from a Czech company called Gearsensor who were trying to perfect a new function for mid drive ebikes. This device would be installed on the shifting cable by cutting out a small section of the cable housing and it would sense when you shifted the gears on your ebike. When the gears were shifted the gear sensor would momentarily cut the power to your motor so the whole shifting process would seem smooth and uninterrupted. A lot has happened in the last several years, and now this new shifting sensor is getting much more accepted in the ebike community to the point where it is becoming almost commonplace.
There are so many opinions out there about this Gear Sensor. Is it a must have? Will it integrate seamlessly with my BBSHD\BBS02? Where should I buy it? I’ll attempt to answer most of these questions in this article.
My first exposure to the Gear Sensor was while testing the E-Rad branded BBS02 drive system last year in this article. My feelings about the gear sensor have not really changed from that article, I still think that it should be bundled with the BBS02 from the get-go. There is a lot of reasons this hasn’t happened, but those are kind of boring are outside the scope of this article. What has happened is that Bafang has finally woken up and smelled the coffee and is not including a dedicated gear sensor plug on the BBSHD controllers when drive units are ordered with that plug installed. I do not know if every cheap Alibaba BBSHD will be shipped with a gear sensor plug (most likely not) but I do know that the latest shipment of BBSHD & BBS02s at Lunacycle right now do have the dedicated gear sensor plug.
Do I need a gear sensor at all?
When it comes to shifting under load and understanding the problems it creates with the drive system you have to think about where all the tension is on your drive system. Almost all the tension is on the top of the chain. This is why when you have a front derailleur and you shift under load on the front ring that is when the links in the chain will generally break apart. With a rear derailleur, you can shift under load and it doesn’t make much difference since the bottom chain line is not under tension. Shifting into a higher gear will not generally create much of a problem, but sometimes shifting into a lower gear will. The gear sensor senses when you are shifting and what direction you are shifting in and it cuts the power for an appropriate period of time for the shift to complete.
Almost all shifting problems I’ve ever had with the BBSxx have come from bent derailleur hangers or misaligned derailleurs. In my experience, a properly tuned and straight derailleur should not break chains even when shifting under load. Many people who use the BBSxx just tap their ebrakes when shifting under PAS which essentially does the exact same thing as the gearsensor.
What about with my fancy expensive IGH?
For an IGH it’s a totally different story. Many 3 speed IGHs like the Nexus 3 and the Sturmey Archer 3 speed hub seem to not complain too much when shifted under load. I have beaten the crap out of my 3 speed IGH’s and shifted them constantly under load without any issues. Other IGH like many more delicate 7 or 8 speed IGHs will absolutely self-destruct if they are shifted under the full 1500W load of a BBSHD, so a gear sensor would be absolutely mandatory in that instance.
Must I have the dedicated Higo controller plug to use a gear sensor?
This is one area where people seem to get really confused. You can hook up a gear sensor to either ebrake cable hookup on the BBS02 or BBSHD and it will work just fine. The delay is a little longer, but most people will probably not even really notice the difference. Any gear sensor bought with a Higo style plug will work with ANY BBS02 or BBSHD on the market.
Are there different gear sensors for IGH and Derailers?
Yes, figure out what setup you’re using and get the right gear sensor for your setup. If you are using a CVT like a Nuvinci N330, N360, N380 or N171 or if you are using a Roloff IGH then you will want the gear sensor for standard derailleurs (not the IGH gear sensor). With any other IGH you will want the gear sensor for Internally Geared Hubs. I know, it’s really confusing, blame someone else, I just work here.
Where do I buy a gear sensor?
Until very recently the only place stateside you could buy a gear sensor stateside was from Lectric Cycles for $75 + $15 shipping here. Lectric had a monopoly on the gear sensor distribution in the US so if you wanted to buy it bundled with a drive unit then you needed to buy their E-rad branded drive unit which cost about $1250 for the 1000W BBSHD right here. If you wanted a gear sensor included with a BBS02 for a 100mm fat bike then you would need to spend $1200 for a 750W BBS02 right here. Although both drive units shipped with a gear sensor, chainring adapter, and a Raceface chainring included the pricing is still much more than most ebike builders really want to pay (cause you’re all so damn cheap). As of about a month ago you could order a gear sensor from Paul at em3ev in China as a $50 add-on to a BBSHD, but I can’t find a listing for the individual gear sensor anywhere on his website.
As of right now Luna Cycles has gear sensors in stock which they are selling here for $50 +$5 for shipping. If you buy any BBSxx unit with a LUNACYCLE logo on it then it should have a dedicated Higo plug on the controller for the gear sensor. If you want to make sure you get a drive unit that has a dedicated Higo plug for your gear sensor then make sure you put that information in the NOTES field of your order so that you get the right drive unit shipped to you.
Are all gear sensors the same?
This gear sensor you buy from Lunacycles, Lectric and Paul are all exactly the same product. There are no differences between them. While there are differences between the IGH and the derailleur versions of gear sensor, between different vendors they are exactly the same product. For info on gear sensor dealers in your country, click here.
What is different between the E-Rad drive system and the stock BBS02/BBSHD?
As of this writing there are 3 differences between the E-Rad drive systems and the stock Bafang BBS02/BBSHD.
- The logo on the side of the drive unit says E-Rad and not Bafang or something else (If you order a thousand of them they’ll print whatever you want on the side, I’m ordering ones that say “FUCK YOU BIKE THIEF” on them as soon as I raise $500,000 on Kickstarter to place an order with Bafang.)
- As of about a month ago, all BBSxx drive units produced by Bafang are going to ship with the extra gear sensor Higo plug exactly identical to what Lectric is selling. Many of the drives that are currently for sale on Alibaba or ebay will not have it. When it doubt ask your vendor before you buy. If they don’t know what you’re talking about then just buy from someone else who knows what the hell they are selling.
- The programming on the E-rad is slightly different from the stock Bafang programming. I would not say the programming is that much better, just different. Instructions on programming your BBSxx unit as well as Lectric’s firmware settings click here. For programming that doesn’t suck just use ‘Karl’s Special Sauce’. It will void your warranty, but it’s well worth it.
That’s really it, there are no other differences between the E-rad drive system and any other BBSxx drive unit you buy anywhere else. That means you can get a BBSHD from Lunacycles for $699 here and add a gear sensor for $49 and a Luna Eclipse 42T chainring for $99 and you’re still $400 ahead of the E-rad one and the only difference is the controller programming and the logo. Take that $400 you save and buy a 52v shark pack for $435 here and you’re ready to roll. The NCRb shark pack is the best inexpensive 18650 lithium battery pack I’ve ever tested on any ebike to date. If you’re using a BBS02 then get the NCRb cells and if you’re kicking it with the BBSHD then I strongly suggest the PF cells. 52v batteries are the only way to fly on the BBSxx units, and Lectric will not warranty any of their drive units that are used with a 52v battery. Luckily, Lunacycle will.
In the end, the choice is yours of whether to go with the gear sensor. In all honestly, I could take it or leave it, $55 buys a lot of
drugs beans and rice. My two E-Rad branded BBS02 drive units are my least used ebikes in my garage, and I seem to get by just fine without a gear sensor on my other 10 ebikes. If you’re an ebike fanatic and you don’t mind springing for the extra $50 it might be worthwhile for you. I’ve just gotten in the habit of not pedaling for two seconds when I want to shift, then shifting and then starting to pedal again. As the power slowly ramps back up your shift will be silky smooth and chain-crunching free.
It’s not that hard to do. You’ll be $55 richer for it, but hey it’s only money right?