How To Ride a Mid Drive Ebike Without Breaking It

If you can ride a bicycle you already know how to ride a hub drive ebike. Not so a mid drive. Particularly a powerful one that can tear your chain apart. Fear not. The rules are simple.

“Mid Drives For Dummies”

This article is based on a portion of this post where I discuss the strength and weaknesses of different types of ebike motors. I link that article many times in help discussions, but usually only for the part about how to ride a mid drive without excess drivetrain wear, mechanical failures etc… so I am creating this standalone post on the subject… and stealing liberally from the original.

This post now has a companion: How to Build A Mid Drive Ebike That Doesn’t Break.

Mid drive motors on ebikes are very common in the production-line, name-brand-manufacturer ebike world. Its safe to say they dominate the industry for eMTBs. Why is this?

Hub motors power the bike … from the hub, so they are single-speed: their motive power has nothing to do with the chain, chainrings or cogs. Try taking off your chain and then go pedal the bike around. Pedal assist will work just fine. The chain and chainrings are only there for you to slug it out with; the motor couldn’t care less.

Since hub motors are single-speed, that means they are not happy climbing hills… for the same reason your life sucks trying to do the same thing with no gears. The only fix for this is to run thousands of watts thru the hub (we are talking 3-6kw or more, which is approaching e-motorcycle territory).

Unlike hub motors, mid-drives power the bike thru the drivetrain. They use the chain and the gears just like you do. This is a good thing for the same reasons its good for you.

Only a fanatic or a penitent rides hills on a single speed bike. So how is it ideal to do that with an electric motor? Spoiler Alert: it’s not. A single speed hub motor is often strong enough to help get you up that hill. But its not happy doing it, and its not good for the motor or (if it has them) the gears inside of it.

If you have only had a hub drive ebike you won’t realize just HOW unhappy, until you take your first proper ride up a steep hill on a mid drive ebike. Get it in the right gear from the start and the bike simply doesn’t care that its going up a hill. It scoots right up without breaking a sweat (it does go slower, since you are gearing down just like you would on a normal bike).

The benefit is multiplied when you look at a mid drive’s motor specs. Usually they are more powerful than a hub drive by a wide margin. A typical hub puts out 40-60 Nm of torque, with a very few going up to 80 Nm. Production mid drives usually start there as the bottom end. Aftermarket motors commonly put out 120-250 Nm.

The Cyc X1 powering my Guerrilla Gravity Smash delivers 180Nm of torque to the drivetrain. Couple that to the small front chainring and huge steel gear cluster in back: you can climb a tree no problem.

So What?

Well, if you aren’t familiar with what it means to have X Newton Meters of torque going thru your drivetrain, lets use the more common (but functionally useless) measure of watts:

  • That 180Nm motor pictured above has a peak output of 3000 watts.
  • A BBSHD or a Bafang Ultra peaks at 1750 watts (peak power on the BBSHD can also be maintained continuously so its REALLY a beast).
  • A 48v BBS02 is about a thousand watts.
  • your typical street-legal pissant EU motor is rated for 250 watts (pssst… the manufacturers are all cheating and delivering much more power than this. Don’t tell anybody).
  • A normal cyclist on an analog bike is capable of putting out roughly 300 watts over the span of a few minutes.
  • A professional sprinter/mutant can hold almost 1000 watts, but only for a minute or two (thats not enough to make a slice of toast).


Yeah ‘oh’ is right. Your mid drive is pumping a metric shipload of power thru your drivetrain. That power is likely more than standard bicycle parts were meant to handle. So how do you have a motor this powerful (its not as much of a boost as the math makes it sound like) and not bend, break or snap stuff?

The BBSHD powering ‘2fat’ – my 2wd titanum-framed awd fattie – runs off of a 52v battery that, combined with its 30a output, delivers sustained output of about 1500w if I choose to peg the throttle and drain the battery as quickly as possible (hint: I don’t do this).

It Ain’t Hard To Do Right…

…but you gotta do it. Here then are the rules of the game when riding a powerful mid drive motor. The goal is not to just avoid breaking things, but to also not wear them out unusually fast.

The Short Version: Keep the motor spinning.

Now the Long Version:

Keep The Motor Spinning

Here’s a basic tenet, true of all electric motors: Electrical power goes towards turning the motor over, which in turn is used to produce forward momentum. If there is resistance – which keeps the motor from freely spinning – then instead of motor rotation, the electrical energy is converted to heat. Mid drives have so much power they get really hot, really quick if not allowed to spin up.

But they are so powerful, they might not just stop at generating heat.

My 52v-powered BBSHD’d Big Fat Dummy has changed a bit since this pic was taken. It now has a 36T front chainring on dedicated to overland and forest riding. Slower but more torque-y for when the trail gets rough or goes away entirely.

Lug a powerful mid drive and the torque that is pouring out of it could tear your chain apart – if it can’t rotate it thanks to resistance. Or, you might discover what it means to ‘taco’ your front chainring or a rear cog. If your sins are not quite that egregious – and you just lug it gently enough to not tear something apart – then within the span of a single ride you can ‘peanut butter’ the nylon gears inside your motor. If that gear shreds its gone-soft teeth your bike becomes a pushcart until you open the motor up and replace some parts. 

Thats very, very bad. So don’t let it happen. Here’s how we do that:

When Coming To A Stoplight, Downshift!

Always. Either that or always stay in a lower gear in the middle of your cluster, so when you start up again the motor does not lug itself. Doing one of these two things, you spin up quickly and without any brutality being visited on the drivetrain.

From a standing start, a mid drive will slowly tear into the cassette body, or damage the pawls inside. this will eventually tear the freehub apart and kill the hub. Which means you get to build a new wheel.

On the left: 1000 miles of use… and I was nice to it! But this freehub body was still torn into a bit. What does yours look like?

If you downshift, that damage will not become severe for a long, long time (it happens with normal bikes, too). So remember: downshift before you come to a stop.

This is a gear cluster. Each wheel is a ‘cog’. Smaller cogs are higher gears (you go faster). Bigger cogs are lower gears (slower, distributes torque, gentler on the chain). This cluster is a SunRace CSMX8 11-46T: The smallest cog has 11 teeth and the largest has 46.

When You Want to Go Faster, Upshift

When working a mid drive, just like driving a classic sports car, you ‘row’ through the gears both slowing down and speeding up. Wait until your motor is maxed out before you kick it up a gear (up = a smaller cog in the back). Chances are good its going to be smarter to stay one gear down from what you would have used without a motor (down = a bigger cog in the back).

Why is that? Your bike will spin up to the same top speed on its next-highest gear (the next-bigger cog in back) as it will the highest one: But it will get there faster if you let it use the bigger/lower cog next to it. Mid drives are like that, especially when going fast on the street. Here again we are going back to not lugging the motor, and letting the mid drive spin the drivetrain faster than you would if you didn’t have a motor.

I am not talking about nailing the throttle and going along for the ride. You can certainly do that, but this spinning-faster bit is more about using the motor for an assist to allow higher cadence than you ordinarily could attain under a similar load, unpowered.

Again thinking of your mid drive ebike as if its an exotic sports car with a manual transmission: In between each gear you need to let off the power (stop pedaling or thumb off the throttle), shift and hit the accelerator (the throttle, or start rotating the crankarms/pedals). If you have a gear sensor you will not have to worry (officially) about the ‘let off the power’ part as that will be safely done for you.

If you want to pedal the bike and not use throttle at all, thats great. Use the lowest comfortable boost setting, and keep your legs spinning fast via smart gear choices – just like on a regular bicycle. Never lug the bike with slow pedaling up a steep hill. Be a spinner, not a masher.

If you are pedaling slow on flat ground, or downhill, you are not providing resistance to the motor or added pressure on the chain. There is a lot less to worry about insofar as cadence or lugging the motor is concerned. You do however need to ALWAYS do the following no matter the terrain:

Never Shift Under Power

Even if you have a gear sensor. Thats right I said it. Don’t trust the gear sensor unless you are forced to. Pause your input for a split second and do your shift.

More Specifics on Mid Drive Shifting here:
“Do I Want A Gear Sensor?”

Shifting while pouring huge watts into your chain is an ugly thing.  You will recognize your mistake the instant the result hits your ears.  It probably won’t kill the chain outright, but as you hear that chain smash from one cog to another you will know your bike hates you very, very much.

If you treat the gear sensor as a fail-safe rather than taking it for granted, you will be much more likely to avoid disaster. As you become familiar with riding your mid drive and how it behaves, you will naturally figure out how to push its limits and minimize that pause/blip when you shift. You likely will get smart enough to shift under power and let the gear sensor save your bacon. But for your first few weeks of riding this thing… treat the gear sensor as a backup, not the default.

Here’s a technique you want to learn as part of your education on operating a mid drive: Using your brake lever motor cutoffs as a clutch: Just slightly actuate the levers so the cutoff kicks in, but the pads don’t engage. Lift when the shift is finished. You can stay on the throttle or keep pedaling while doing this so the process is near-seamless.

Many ebike levers have this ability built into them. Magura MT5e levers have a mid-lever hinge that lets you touch the brakes and engage the cutoff without any pressure making it to the caliper.

Check out the little pin in the middle of this ebike brake lever. That is a hinge to give the lever a *touch* of give so you can cut the motor off without engaging the brakes.

Keep Chain Alignment As Straight As You Can

Mid drive motors tend to work in a lot wider range than humans do.  So you can leave the motor in a gear that would be too low for your cadence and let it spin away like crazy… it likes it that way.  So, this piece of advice is partly about how you ride the bike (i.e. what gears you let it sit in) but also about how you build it if its a DIY effort. 

You really only need three or four gears in the middle of your cluster on a mid-drive-powered ebike.  You want them to be the ones that let the motor spin fast.  You also want the cogs the bike is happiest in rpm-wise to not be cockeyed, front to back (i.e. bad chain alignment). So regardless of whether you built this bike or you just bought it, when hammering on the torque through the drivetrain do not do it when the chain is yawed wide to one side or the other.

On an analog bike you can get away with a lot, since you are only feeding back lets say 150 watts to it.  Feed it 1500 and that sideways-skewed chain will become a saw and chew right through your front chainring and rear cog teeth.  Be smart when you shift your gears (and when you build the bike in the first place).

The Stormtrooper is a simple BBSHD fattie – at its core a resurrected Motobecane Lurch frame, stripped, de-rustified and powder-coated – that once again uses a steel cluster and halfway intelligent riding to avoid any semblance of extra wear and tear in a VERY hilly neighborhood.

If this is a DIY build, learn in your first outing or two whether there are any problem gears you should stay away from.  There are all sorts of offset chainrings (plus 1mm and 2mm shims) available on the market. They cost money, but spending that money now means not spending it later after you have walked home.

Just Say No To Your Smallest Cog

Standard advice in DIY build circles is to Stay The Hell Away from your 11T small cog. If you don’t, you will wear it out very quickly – as in only a very few hundred miles. Or you will simply break it. Even if you are smart and pick a steel cassette cluster, the two smallest cogs in that cluster will typically be alloy. And as we all know… steel bends but alloy breaks. Those little cogs are just as likely to crack as they are to wear out superfast.

There’s a second reason to stay off the little cog. If you build your bike right, the best, straightest chain alignment is somewhere in the middle of the cassette. You want that to keep your chain from becoming a chain saw to your front chainring and your rear cogs. Since your teeny little cog is all the way outboard, that is worst case for chain alignment. On some bikes you’ll even start skipping your chain on that little cog, thanks to a skewed chain and high torque. Under serious power that is a recipe for cracking the cog… or maybe even breaking the chain.

And here’s a third reason: When you start riding your new wonderful bike build, you will likely find there is a point of diminishing returns that your littlest cog is well outside of. You can shift into a higher and higher gear but at a certain point… all those cheeseburgers you have eaten over your lifetime impose an upper speed limit. Shift to a higher gear and the motor just bogs down. If it can’t generate motion, it generates heat instead. And thats bad.

Testing my Stormtrooper’s 30a BBSHD running a 52v battery, I found the following: I built the bike with a cluster whose smallest cog was 12T, knowing the problems with 11T already. I found (with stock programming, before I revised it) I had a 33 mph upper speed limit on that 12T cog. But it took a city block to get up there. If I shifted to my second, 14T cog, my top speed was about 31 mph and I got there within maybe a hundred yards. On my 3rd cog in, top speed was about 28 and I zipped right up to it.

So… no real incentive to use the two smallest cogs.

Build Smart

If you bought your bike manufactured with a mid drive installed from the factory, this part has already been taken care of. If you are building an aftermarket conversion, you will have to buy components that are strong enough to handle the punishment your 1500w+ motor will mete out. Almost 100% of internet whining about mid drive reliability is from builders who fail at this stage.

While a lot of this article is repetition as I stated at the beginning, this is one place where I will just refer you to what I have already written elsewhere. Its only applicable to DIY builders so if thats you, go to this link and scroll down to the Mid Drive Motors section.

Or just go here as, since I wrote this post originally, I did a whole article focusing exclusively on avoiding mid drive build mistakes.

Quit Whining… Its Not Really This Bad

I am making this sound like a lot of work. Upshift this and Downshift that. Here’s the reality of it: You’ll figure out a happy medium real fast. You won’t need to do much shifting at all. I certainly don’t. Mid Drives live in a much wider gearing range than humans like to, so you will naturally need to shift less. You’ll figure this out soon after you begin riding.

As a builder the first thing I do is pick a chainring size thats suited to my terrain. Big ones for flat land. Littler ones for steep city streets. Tiny ones for the Sierras. Thats part of the magic as well. Most of the rest is you just picking a cog a couple-three steps up from the bottom of the cluster and staying there. Live with a little less top end speed, or say to hell with it and hammer it if you must. Let the motor spin you up so you can whizz past the small children playing ahead of you.

My Envoy cargo bike lives on the California coast, where nothing is flat. But I hardly ever have to shift. The egg sandwich, however, is no longer with us.

Wrapping it up

If you build with appropriate components, and ride it smart, even a high powered mid drive will essentially last forever.  Yeah sure you will wear out the chain and rear cluster in say three thousand miles, the smallest cog in half that, and the chainrings in 10.  But thats peanuts considering how many miles you put on the bike.

And you will have an absolute blast doing it!

The Pacific Fleet

or… I Have Too Many Damn Ebikes

Since I got back into bikes (thanks to ebikes being a viable platform to let this cardiac-issues ex-cyclist start riding again), I have gotten right back into building bikes up, oftentimes from scratch. At this point I really have to stop simply because I have no more room to park the things.

Up to this point I have only written about my Mongoose Envoy, a very recent arrival, and have just begun getting into my Surly Big Fat Dummy, which is more recent still.

What else is in the stable? I’ll do some very quick mentions here and then over time branch out and describe each more fully in separate posts.

The Other Bullitt

I usually try and come up with some kind of catchy name for a bike, but so far a worthwhile moniker has escaped me.

I needed another Bullitt, put simply enough, for my home on the California Central Coast. The benefits of a frontloader are so great over and above my longtail and midtail bikes, I found I was putting off rides until I left town and was able to use my Lizzard King to run the errands.

Since this was Bullitt 2.0 for me, I spent a lot of time improving on what I did with the Lizzard King. This time, we did 2wd again, but used a bigger battery. The battery box is completely hidden behind the frame rails. No ground clearance was lost and there’s no sign to anyone looking where the battery is. The now-two-chamber box holds the front motor controller and a plug-in, onboard battery charger. I lost a few kilos by using light weight aftermarket parts for the floor and steering tube.

Unlike the Lizzard King, which is all about flat-land cruising, this one is geared so it can climb walls, since if you want to get around in the Monterey Bay Area, you are going to have to deal with steep hills (especially since I live near the top of one).

And as part of that task, I ended up putting a couple more puzzle pieces together when it comes to BBSHD settings.

The Apostate

I needed a quick runabout bike I could toss into my car and then pull out and ride off with. I’ve been using The Smash for this, but it being a 29er on a Size L frame that also needs a big backpack to carry the battery… convenience is marginal. I want to be able to take my car into the shop for service, pull a bike out of the back without any fuss and ride home with it. Or load the car up and have room left over to stuff a bike in too so I can ride around at the camp site.

The Apostate is a medium-sized (18.5″ seat tube effective height) 1999 Intense Tracer frame with 26″ wheels. the frame borders on unique in that it has a frame that can directly accommodate and shield a mounted battery. So it does the job I need nicely. Fork is a 2000 Marzocchi X-Fly Z1. Rear shock is a new Fox as the original Fox Float RC was dead. It is the subject build for the How To Build An Ebike From Scratch series, so its components and construction story are told in excruciating detail.

The Lizzard King

So named because thats the name Larry vs. Harry gave this green color of their Bullitt cargo ebike. I bought a frame kit from Splendid Cycles up in Oregon in January of 2021, and did an all-out AWD build on this bike which I completed in March of the same year. That included putting in a basement that holds a secured (big) battery. This will be a bike that gets fairly extensively written up. For now I’ll just drop this note that the bike exists, I’m riding it, and here’s a couple of pictures.

The Great Pumpkin

So named because of its very nice bright candy orange color (done at a local powder coat shop for next to nothing) you can call this one my third generation of 2wd bikes. Twin 35a controllers. A single custom-built 30ah 52v (14S9P) battery with a BMS able to handle 90a continuous current. Twin 750w-rated geared hub motors that commonly peak (each) at over 1700w. This bike accelerates like a bullet if I let it do so. But to keep the frame in one piece and me from being launched into traffic I have toned down both motors. Now I am merely the first vehicle to the other side of the intersection after a stoplight turns green.

It has synchronized dual pedal assist as well as brake cutoffs that individually shut off both motors on application. It has thousands of miles on it; all street commuting. Gearing is set up for 34 mph at about 70 rpm cadence. That is just a bit faster than the motors can power the bike, so if I want to cruise down the street at 30+ mph I have to work at it a bit more than you would think for a fairly high powered ebike. I get a strong workout due to this gearing.

The frame is a chromoly Chumba Ursa Major, with a Surly Ice Cream Truck front fork where the brake adapter on that fork was specially modified to get around the ICT’s rear-wheel brake spacing.

For a closer look at this bike and its AWD system follow the link and lookit here.


While the build of this bike pre-dates The Great Pumpkin, it was actually designed as a next-gen design to follow another 2wd bike (see the Purple Thing below) that pre-dated both bikes. So if the Pumpkin is 2wd 3.0, this one is 2wd 2.0. This one does not have the single unified battery, and its handlebar config is not as well done (two clocked-position throttles are on the left grip instead of one on each thumb… I hadn’t discovered shifters that would allow me to do the latter yet). However, it also sports a 30a, 1750w mid drive powering the back, and has the same fat hub motor as the Pumpkin powering the front. It too has dual pedal assist, but done in a completely different way given the dissimilar motors and controllers. 2Fat was created because of the learned weaknesses of even a powerful dual geared hub design in hill country. 2Fat was designed to climb walls effortlessly, and it will, without issues of overheating or strain.

100mm custom wheels with a DT 350 Big Ride ratchet rear hub and steel cassette body, Lynskey titanium frame is a prototype made along the lines of Chumba’s Ursa Major ti version of that frame. Possibly it was made as part of a pitch by Lynskey to make the frames for Chumba. Its hard to say for sure so essentially, the frame is unique, or close to it. I do know it is visually almost identical to the Chumba production models except the dimensions do not match any of their production frames.

For a closer look at this bike and its AWD system follow the link and lookit here.

The Smash

A big departure from my usual bikes. The Smash is a 29er … and a bike with no job. With a 3kw Cyc X1 Pro motor, a 50a ASI BAC800 controller and a 20ah 52v backpack battery, this bike is strictly a hot rod. And no, despite those big power numbers its not as powerful as you might think. Certainly it doesn’t tear up trails. This is one of the last alloy frames Guerrilla Gravity made before switching to carbon fiber later in the same month I placed my order. The MRP Ribbon fork on the front is a jewel. Also has a RockShox coil spring, a complete SRAM EX drivetrain and my usual Magura MT5e brakeset.

I’m glad I took these pics right after the build was completed because it will never be this clean again. Ever. Also the pump location and top tube bags only lasted as long as this photoshoot as they violated my ‘festooning’ rule.

The Stormtrooper

So named because of its black/white color scheme. The Stormtrooper is just a really nice, simple fat tired ebike – with deep dish 90mm carbon fiber rims. Noteworthy on this bike is that it has plenty of motor and battery cabling running all over the place, but I sheathed the wires (even the brake and shifter lines) in white heat shrink. The matching color effectively hides all the wiring in plain sight for a very clean look. the bike is light and fun, with good range from its mid-sized 12ah potted ‘indestructo’ battery.

This frame was a rescued Motobecane Lurch that was stripped, sand blasted and powder coated.

The Mongoose

One of the few bikes I have written up here, The Mongoose Envoy has its own extensive writeup already. The Pacific Fleet’s first aircraft carrier thanks to the 44″ skateboard deck.

The Big Fat Dummy

One of the more recent addition to the Pacific Fleet, The Surly Big Fat Dummy is its second aircraft carrier, with a 40″ skateboard deck (and below-deck hangar) putting the length of this behemoth at just over 8 feet. This bike has a complete and detailed writeup here.


In no particular order, the ships that are no longer in the fleet

The Fixed

An even bigger departure is my Luna Fixed, which despite having custom DT wheels, is largely a factory bike and was bought primarily as a test platform. I fell in love with the design concept (stealth ebike), but it also had an internally geared hub, a Gates belt drive and torque sensing. These were three technologies I had yet to experience and I decided this bike was going to be how I learned about all three on one bike.

Its the only ebike I have ever ridden that feels like a road bike from the 1970’s. I re-did the handlebars to a more urban narrow config, added bar ends, changed the stem, saddle and pedals… not a lot else. Its for sale It was sold on eBay as I’m largely done with it, its still effectively new and I never ride the thing. I’ve always been a commuter and a utility rider and this bike is purely a leisure exercise, or for someone who needs to make a quick store trip and doesn’t already have a stable of bike better suited to the job.

I will miss one big thing when it sells: Its the only bike I can just toss into the back of my SUV and not make a major production out of loading onto a super heavy duty bike rack. Like recreational riding, I don’t do that either but someday I bet I wish I still could.


Now in the hands of a friend who needed a ride. Frankenbike was cobbled together from leftover parts from an upgraded electric bike, plus other goodies. It was my first 2-rack cargo-oriented bike. I painted the frame myself using Main Force Pursuit (MFP) Yellow. Google that if you don’t get it. The frame is identical to the Purple Thing, below.

The Stump

Murdered by a careless auto driver who t-boned it and me while I was thoughtlessly riding slow in the bike lane with headlights and after making eye contact. The Stump was a little hotrod that never made it past the initial shakedown cruises before its demise. Paid for by the other driver’s insurance company but left in my possession, I donated the damaged but still fully functional motor to another cyclist who could make good use of it

The Purple … Thing

Essentially this was 2wd 1.5. I transferred my parts from the 2wd 1.0 bike when I cracked the frame, and made a few improvements. Since it was an emergency build to get my daily commuter back on the road, I didn’t do a lot of measuring and took what I could get framewise. It didn’t quite fit me and a year later one of these motors and some of these parts moved to The Great Pumpkin. The frame is still sitting dust-covered in a corner of my garage.

The Colonel

The bike that got me started back on two wheels again and changed my life for the better. A Sondors Original fat ebike whose cost was so low at around $700, I was willing to toss the money out the window and take a chance this whole ebike thing was going to allow me to get back onto a bicycle. By the time my first year was up I had put more than 4000 miles on it. I had also changed out almost every component but the frame, and converted it to all-wheel-drive.

The Colonel died with his boots on. After almost 6000 miles on the road, supporting a whole lot more power and speed than it was ever designed to bear by its original Chinese overlords, the rear seatstay cracked at the lower rack boss. My philosophy on frame cracks is not to repair them as where there’s one crack there will likely be more showing up soon. Components were transferred to The Purple Thing along with several upgrades.

I Hate Ebike Torque-Sensing (maybe you should too)

Well, I don’t actually hate it, but it is a technology rooted in cycling’s past, whose existence was created to market a product to legacy riders.

As far as I’m concerned, torque-sensing’s existence is primarily owed not to the fact that it is a better system, but instead is a tool to help persuade an existing customer base (recreational, leg-powered cyclists) not to hate the product (ebikes) quite as much as they already do (either that or to sell ebikes while not cannibalizing sales of analog bicycle brethren).

Say what?

What is Torque-Sensing Pedal Assist?

On an ebike, when a torque sensor is used, it applies a strain gauge to the drivetrain (located either inside the bottom bracket, or in the back of the bike near the gear cluster).  This measures the amount of force you apply to your pedaling stroke.  If you pedal (work) harder, the assist you receive is dialed up.  If you pedal more softly – regardless of cadence – the assist level is reduced… or eliminated.

I have heard it said that torque-sensing “rewards pedal effort” and this statement is both correct and indicative of the root problem with its advocacy.  Old school cyclists hate the fact ebikes allow someone to make forward progress, without using their muscles in the first place.  By restricting/keying the assist to physical exertion levels, the fact that a motor exists at all is less difficult to accept – and more easily sold to the existing cyclist population.

It also allows an ebike to be sold without denigrating the old-school unassisted version.  Zillions of which are still manufactured for sale worldwide.  If torque sensing just makes it seem “more like a regular bicycle” then that helps preserve the perception that a normal bicycle is still every bit the desirable, viable product that manufacturers still need to sell millions of.

It is unfair to say torque-sensing is ONLY about these things.  Its not.  You will also hear people say torque-sensing results in the most ‘natural’ bicycle riding experience for them, since you still have to work hard on the pedals.  And the assist increases in proportion to your effort, just like a real bicycle.  An ebike goes faster of course, but a physical work ethic is still demanded.  So to be fair, torque-sensing does indeed give cyclists who want this a familiar and desirable experience.  There is nothing wrong with that.

What is Cadence-Based Pedal Assist?

In its simplest form, its nothing more than this:  Your assist level goes up or down based on how fast the crankarms are turning.  The amount of effort you expend could even be irrelevant if your gearing is low enough.  The only thing that matters is the rotational speed of the pedals/crankarms (strictly speaking it is the spindle’s rotational speed that is measured, but thinking ‘pedal rotation’ is easier to visualize).

So if you want more assist, you just turn your legs faster – not harder.  Again in simple circumstances this means you can get into a low gear and easily ‘ghost pedal’ your ebike, without expending any effort.  So you are breezing right along right up to either the speed limit of the ebike or the road/path you are riding on (please note I am not saying this always happens… only that it is possible with this type of system). 

Such a thing is utterly anathema; deeply, personally hated in the cycling community.  There, your progress and ability is hard earned through what can only be described as prolonged, personal, stoic suffering whose level outsiders neither understand nor hope to match.  Despite the spandex, funny hats and silly shoes, cyclists know they are endurance badasses (they really are).

Except, fate has dictated these solitary warriors suddenly have to share the road with the Griswolds, blowing past them in their two-wheel Trucksters.  Ebikes democratize cycling so that now… anyone can do it?  WTF!?!

… not a shock the response of cyclists to ebikes has been negative.

Far From Perfect

Finally, lets make the very important point that criticism of cadence-based systems is often entirely justified. Especially on low cost direct-to-consumer ebikes. Unfortunately, rather a lot of these systems have cadence-based pedal assist that is merely an on/off switch. It pays no attention to how fast the crankarms are turning, or how fast the bike is going. It justfires up and produces one of maybe five different power output levels, steady and regular.

Faced with that kind of behavior, its no wonder so many people think torque-sensing is the only way to go.

Its not so simple

I said above the description of cadence-based pedal assist was in “its simplest form”.  There are some big exceptions to this that most ridersare unaware of. Criticism of cadence-based assist systems can be entirely justified… but it should be recognized that the concept of cadence-based assist is not the problem, but rather to crappy, cheap-ass implementations of it.

There are some cadence-sensing ebike motors that have settings both complex and rather profound in how they impact the riding experience.  Notice I did not say ‘cycling experience’ because a central tenet of my rejection of torque-sensing is that ebikes are bicycle-shaped-objects, but not bicycles.  It is a mistake to treat them as if they should behave the same (unless that is something you expressly want).

The Cadence-Sensing Mid-Drive

If there is such a thing as a ubiquitous aftermarket mid drive on the market, its the Bafang BBS02 and its heavy-duty big brother, the BBSHD. There are zillions of them out in the world. If you want to find yourself a drive that has plentiful aftermarket support, countless users in discussion groups with experience to share, and myriad how-to’s out there on Youtube and the internet in general… well the go-to for those things are these DIY kit Bafang mid drives.

From the factory, quite frankly the performance settings on these drives is awful, and this is well-known. Pedal assist is overpowering and easily lets the bike run away from you. That powerful pedal assist also saps the range of the bike. But the bad news gets worse when you factor in the clunky, laggy motor engagement that bashes on the gears, and generally does its best to wear the bike’s drivetrain down sooner, not later.

Fortunately this is all very well known, and there is a rich settings interface hiding under the hood for these drives, with readily-available free software that will let you dig into the motors and completely change (i.e. tame) their character. With that in mind, here are some screen shots showing those settings.

Some cadence assist options are on the left side above. This isn’t even the Pedal Assist screen for this particular motor. These settings determine assist strength and when, based on both speed and motor rpms, the assist gets cut back.

Here you can determine how much the cut-back is when pedal assist is reduced, and more.  The graph explains how the various settings on this screen affect output.

This is not at all the simple on/off concept most people think of when they complain about what they think of as cadence-based pedal assist

Since this article was written in 2019, I have documented a cycling-oriented approach to this motor in BBSHD Programming for the Pedaling Cyclist.

The KT Controller And A Hub Motor

What everyone commonly calls the “KT” controller is in fact a product of the Suzhou Kunteng Electronics Co., Ltd. KT controllers can be found as original equipment inside of manufactured ebikes, and sold individually as aftermarket upgrades and components for builders who are building their own ebike. This is a company that has its products inside of many ebikes, but unless the owner reads the label on the controller, they would have no idea whether its a product made by this company.

I bring them up because KT controllers are very popular in the DIY ebike building community. They provide a quality product that offers features not readily available with other products in their class.

KT controllers use cadence-based sensing, but apply a proprietary algorithm that someone nerd in the basement was allowed to label as ‘imitation torque control‘. I don’t know where that comes from, but as their (poorly translated) web site says,

“Use imitate torque control mode to help achieve a smooth start-up of the vehicle, the power-assist drive will be smooth and natural. Electric power assist is with fast response and always consistent with the rider’s pedal action to achieve the effect of the torque boost.”

Thats fairly typical Chinglish marketingspeak, but they really are onto something.

  • When you start off from a stop, power ramps on via a recognizable curve. It doesn’t just flick from ‘off’ to ‘full blast’
  • The startup curve can be adjusted in three separate steps so if that on-curve is too strong, you can set one of three increasing levels of slow-start to give a more shallow slope to that startup curve.
  • When starting off and crankarm rotation and speed are both slow, power applied is high. This corresponds to what you need when starting from a stop.
  • As speed increases from ‘stopped’, power is smoothly dialed back, so the bike doesn’t run away from you. When cruising at high cadence, very little power is output.
  • If during that cruising speed you start going up a hill, the controller senses the combination of reduced speed and cadence and dials in more power to help you get up the hill.

The result is of course not ideal, but it is smooth and easy to adapt to, especially coupled to the other settings options that are available.

So What?

Once again, we see that we are not dealing with a clunky kind of on/off switch that cadence-assist detractors point to. There’s grey area to be had here when it comes to performance.

Torque-Sensing Can Be A Disaster

If you have a physical limitation, torque-sensing doesn’t help you get past it.  It does help you go faster while working hard.  Studies have shown ebikers in fact can work nearly as hard as, or even harder than bicycle riders… they just don’t realize it.  Possibly this is due in part to the exhilaration of being able to go faster, and stay in the saddle for longer periods.

Myself, I am a lifelong cyclist.  Or rather, I was.  I commuted daily for decades.  For many years I eschewed the use of an auto.  I commuted and even shopped for groceries by bike (being poor and single had nothing to do with this).  But after a couple of heart attacks, my cycling life was over.  To stay alive, I gave up the intensely personal activity I most valued.  Bummer.

A few years ago, I discovered ebikes, and the one I bought had cadence-based assist.  I had no idea there was any other way to do it at the time.  I did something many do not:  I treated the ebike – which looks like a bicycle but is not one –  as a new animal.  I threw out much of the knowledge on cycling I had acquired, and started fresh on riding technique.

At the start, pedal effort very quickly led to chest pain and an immediate need to stop doing that.  But I could go on if I incremented up the assist and incrementally lowered – but did not erase – pedal effort.  This allowed me to keep going (maintain forward progress).

I learned to treat the ebike like an exercise machine.  One that went places and was practical transportation.  Instead of directly coordinating effort with forward motion, I separated the two.  Effort was always maintained, and so was clicking off the needed mileage to my destination.  But the two no longer had a 1:1 relationship.  This decoupling of effort and speed while maintaining cadence solved everything.  The procedure in a nutshell is as follows:

  1. Set a preferred cadence
  2. As heart pain occurs (heart pain is not the same thing as getting tired) click up the assist level so effort is reduced – and keep moving. This relieves the heart pain gradually
  3. On recovery – I’m good after maybe a half block – reduce the assist level back down a click at a time and start working harder again
  4. All the while maintain the same cadence
  5. Rinse and repeat as the miles click off to destination arrival.

You are never just sitting in the saddle doing nothing but exercising your thumb on the throttle, unless you’ve really overdone it and have to enforce a complete break. But that should be very rare and only happen in the earliest stages of getting back on the bike and working out as a daily routine.

Again, to belabor the point:  I’m using the bike for utility and transportation.  My bike has somewhere to go, so the point of cycling is to reach a destination.  If I was a recreational cyclist then maybe its fine to slow to a crawl, or stop and sit on a bench for awhile.  But a bike as transportation is a different. The point of riding is to get somewhere .  So I must maintain forward progress, while managing a constant – but changing – exertion level.

Only cadence sensing is going to let you do that (and I know this from experience.  See Afterword below).  Its a different riding experience described most simply as a moving exercise machine.  Again… not a bicycle.

Different But Still Good For You

Over time and thru repetition, I scaled back the point where pain occurs to where I was able to manage it with gear changes (upshifts) and not changes to the assist level.  Now I’m running at top assist speed while maintaining pedal pressure and exertion at all times during the ride.  On my Class 3 daily driver I cruise right at 28-30 mph (legal in my jurisdiction) and I get to those higher speeds above the assist limit by myself.  All along doing so by maintaining a set, preferred cadence.

And if I overdo it, since I am now running at full power, I can just downshift (maintaining cadence on the easier gear) to take a break. I’ll go a little slower and dip down to the level where the bike starts providing assist again once its speed gets down into Class 3 territory. This is a different way to use cadence-assist.  I am not dialing back power: I’m always running at full blast and I’m working to get the bike up to where I am going fast enough so the motor pulls power back on its own due to its going over the Class 3 limit, or adds some in thanks to a downshift and reduced speed.

Note from The Future:
The above describes my experience using an awd geared hub bike with twin KT controllers and a big battery. This one in particular. That was quite some time ago, and its a platform I moved on from long ago. The kind of variations possible in a geared hub system are different than what they would be if I was, say, doing the same thing with a mid-drive-motor solution like a BBSHD. So, two entirely different cadence-based systems, and two different ways to achieve a good ride… but you have to go into it without thinking you know the answers already..

Broadening The Use-Case

Cadence sensing isn’t just for recovering invalids.  For the healthy rider, successful use of cadence-based assist as a hard-exercise tool is easily possible, and rooted in that rider not coming into the experience with pre-conceived ideas.  Don’t treat it like a bicycle (yes I am repeating this over and over on purpose).

Using the ebike as an exercise machine as you roll down the road, you’ll be getting fit during time otherwise spent sitting in your car and exercising nothing.  A torque-sensing ebike can do this too… but if the ebike is meant to also be practical transportation, your physical condition of the moment will have a direct impact on whether you make it to your destination.  Not so with cadence assist.

The Future

It took 34 years for the Tour de France to allow bicycles with derailleurs — because not grinding up a slope in the Alps on a single-speed was cheating.

… Isn’t it better to triumph by the strength of your muscles than by the artifice of a derailleur? We are getting soft.

-Henri DesGrange, world-renowned cyclist and original TDF organizer

If someone tried to make that same case today, their opinion would be regarded as fringe idiocy.

So lets take that same interval: 34 years from now, when ebikes have long-since become the accepted norm (just look at the sales figures) as derailleurs did a century ago… will we be espousing technology or methods rooted to the norms of the past?  Will a couple of generations of riders who have known nothing else continue to think of torque-sensing assist as giving a bike a ‘normal’ feel?

My money is on ‘no’.  Or more accurately… sorta-kinda-no.  I think for higher end bikes a dual system could become commonplace, letting riders choose one or the other as they see fit in the moment.  One mode for recreation.  One for transportation.

If it has to be a this-or-that binary choice, I think torque-sensing won’t survive the test of time.  Why?  Sheer weight of numbers, and the growth of the automobile replacement market.  Look at global ebike sales.  Only a small fraction of ebikes are sold in the European and North American markets, where recreational cycling is a thing.  Look at the Far East, where bicycles are simply utilitarian transportation and there is no stigma attached to effortless travel.  Whats the norm there?

Cadence-based assist.

UPDATE (February 2021):
Its already happening through a vector I hadn’t considered.  Recreational ebike riders are starting to upgrade from their cadence-based budget bikes to what the industry tells them was the ideal product: a better bike with higher end components and… torque sensing.  I’m seeing reviews from riders not inculcated in traditional cycling ethos, saying the bikes are no longer fun.  They can’t just get on a bike and zip around and enjoy the outdoors for as long as the battery holds out… now their bike is making them work at it.  What was once an unconsciously-achieved benefit (exercise) is now an enforced requirement.  Riders like this, new to the fold, don’t always appreciate the new rules.  With the pandemic rushing literally tens of millions of new riders into the fold, the spread of this effect could manifest itself far more quickly than the slow evolution I originally anticipated.


Lest I give the wrong impression… I have an ebike that uses torque sensing, and frankly I love it.  But its a recreational bike, not suited for a bike that has a job.  Going for a fun ride, where I don’t have a problem stopping and sitting down on a bench or a rock for awhile and enjoying my surroundings… Its almost perfect for that.  I wish I had time to ride it more.

But by its nature it can’t be a serious transportation tool.