To make assist power feel smoother on an e-MTB, adjust the display's PAS level count and PAS sensitivity rather than maximum power. Use 5 or more assist levels for finer steps, keep sensitivity mid-range so the motor reacts within a fraction of a crank turn, and verify voltage and wheel size first. Change one value at a time and test on the same climb.
How Pedal Assist Actually Works: From Pedal Input to Motor Output
Pedal assist is a short chain of parts: a sensor notices you pedaling, a controller decides how much current to send, and the motor turns that current into wheel torque. Good e-bike assist response tuning starts with knowing which link in that chain you can change and which one is fixed in hardware. Most of what you feel as "smooth" or "jerky" comes from the sensor type and the controller's rules.
Here is the chain, step by step:
- Pedal crank and sensor. You push the pedals. A sensor reports either how hard you push or only that the cranks are turning.
- Controller. This is the small electronics unit that acts as the bike's brain. It combines the sensor signal, the assist level you picked on the display and the current speed. It then decides how much battery current the motor may draw.
- Motor. The motor converts that current into rotational force. This is the motor output torque, measured in N·m. The K01 and K02 motors are rated at 80 N·m.
- Wheel and tire. Torque reaches the ground through the drivetrain or hub, and the tire turns it into traction on loose gravel, roots or snow.
PAS (pedal assist system) is the set of assist levels you cycle through on the display. Each level sets an assist ratio: how much motor help you get for a given amount of rider effort. The assist ratio is a controller rule, not a hardware property. That is why display settings can change how the bike feels without changing the motor.
How the controller turns signals into current
Think of the controller as doing a simple calculation many times per second. First it reads your effort from the sensor. Then it multiplies that by the factor attached to your chosen level: a low level uses a small factor, a high level a large one. The result is a requested motor current. Finally it checks that request against limits, such as the maximum current the system allows and a taper that fades assist out as you approach the speed limit.
Here is a qualitative example on a torque-sensor bike. You press moderately hard on a climb with a middle level selected. The controller scales your effort by that level's factor and asks for a matching current. If you are well below the speed limit, the full request passes through. If you were nearly at the limit, the taper would trim it. Press harder and the request rises. Drop to a lower level and the same push yields less current.
Current becomes torque because a motor's magnetic force is roughly proportional to the current flowing through its windings. More current means more torque, until the motor or battery reaches its limit. On a geared hub motor, the internal reduction then multiplies that torque at the wheel.
Torque sensing versus cadence sensing
A torque sensor measures how hard you press on the pedals, usually through tiny deformations in a strain gauge (a thin element whose electrical resistance changes when it flexes). A cadence sensor (also called a speed sensor in our spec sheets) only detects that the cranks are rotating. It cannot tell a gentle spin from a hard stomp.
On the K01 and K02, the torque sensor sits inside the bottom bracket, so assist rises and falls with your effort. The K03, M1 and K05 use cadence sensors. The K03's two hub motors give 85 N·m each, and the M1 and K05 are rated at 55 N·m and 60 N·m. A cadence sensor says "pedals are turning, deliver the level's power". Motor torque and sensor type are separate things: a strong motor does not make a sensor smarter.
A hub motor sits in the wheel itself. The K01 and K02 use a geared motor, which has an internal gear reduction: a set of small gears that trade motor speed for torque. Gearing is part of why a 500 W motor (peak 1000 W) can climb a steep pitch. Rated power is what the motor can sustain, and peak power is a short burst.
Which Settings Change Assist Response, and Which Don't
Four settings change how assist feels: the PAS level count, PAS sensitivity, the start mode and the maximum assist speed. Voltage and wheel size also sit in the same menu, but they only describe your hardware. These e-bike display settings are reached on generic displays by holding UP and DOWN together for a few seconds until P01 appears.
Feel settings
- P05, number of assist levels. Usually 3, 5 or 9 steps. More steps mean smaller jumps between levels.
- PAS sensitivity. This sets how quickly the controller reacts to crank movement. On many displays it is further along the menu than P09, so check your manual. Not every display exposes it.
- P09, start mode. Zero start means the throttle engages the motor immediately. Non-zero start means you must pedal first. For a loaded bike on a steep pitch, non-zero start avoids a surprise lurch.
- P08, speed limit. It caps assisted speed. Keep it within the rules where you ride.
Base parameters, not feel tweaks
- P03, system voltage. It must match the 48 V pack. A wrong value can distort the battery gauge or shut the system down.
- P06, wheel size. This feeds the speed calculation. It must match your tire: 27.5" on the K01, K02 and M1, or 26" on the K03 and K05.
- P07, speed sensor magnets. This also feeds the speed reading.
Menus vary by display. The K01 and K02 use a KT-style P-menu, and the K03 uses the KT-INS01 display. Some values may be hidden or locked on your model, and that is by design. If a code in a forum does not exist on your screen, do not hunt for workarounds.
Why "Jerky" Power Happens on Steep Climbs
Jerky power on a steep climb comes from two causes: coarse assist steps and over-eager sensitivity. Climbing makes both worse, because the motor is working near its limits and every small change in assist shows up as a lurch.
Take one steep gravel pitch with two setups. With only 3 levels, each step has to cover a wide span of power, so moving up one level can mean a large jump in requested current. On flat ground that jump is mild. On a steep pitch the bike slows and the motor already runs near its ceiling, so the extra help arrives as a sudden shove, and the wheel may break traction. Your speed surges, then you overshoot and back off, and your cadence swings. With 5 or 9 levels, you can pick a level a notch up, and the added help is small enough that speed and cadence stay steady. This is the single biggest step toward smoother e-MTB power delivery.
The second cause is PAS sensitivity on cadence-sensor bikes. If the controller reacts to a quarter-turn of the cranks, every small backpedal or crank jiggle on rough ground triggers a burst of power. It also cuts power the moment the cranks pause. On the same pitch you feel a rubber band: power on, power off, power on. Speed pulses up and down, and you find yourself pedaling in uneven bursts instead of a rhythm. A mid-range value lets the motor engage within a fraction of a crank turn without reacting to every twitch, so speed and cadence hold more evenly. Torque-sensor bikes like the K01 and K02 are less prone to this, since assist follows your actual pressure.
Throttle versus pedal assist
A throttle grip is fitted on the K01, K02 and K03. A throttle bypasses the sensor logic and sends power on demand, which is why it can feel abrupt on loose surfaces. On EU public roads, ride in pedal-assist mode, because the pedelec category is defined by motor help that comes only while you pedal. Keep the throttle for private land and off-road use.
Step-by-Step: Tuning PAS Levels and Sensitivity Safely
Tune in small, reversible steps, and always keep a record of the factory state. This checklist works on any display with a P-menu. The goal is a set of changes you can test and undo one at a time.
- Record the baseline. Enter the menu and photograph every screen from P01 to P09, or write the values down. This is your restore point.
- Verify the base parameters. Check that P03 matches the 48 V system and that P06 matches the tire size printed on the sidewall. Do not edit P03 unless you are certain it is wrong.
- Set the level count. Move P05 to 5 levels, or 9 if you like fine control. Test before touching anything else.
- Adjust sensitivity to mid-range. Menus usually offer a short scale, often a handful of notches from slowest to fastest response. Mid-range means the middle of that scale: the motor engages after a short part of a crank turn, not instantly and not after a long delay. Exact values vary by display, so check yours. Change one notch at a time and ride the same climb after each change. Higher settings make the motor respond sooner, and lower ones make it wait longer.
- Review start mode. If a standing start surges, set P09 to non-zero start so the motor waits for you to pedal.
- Check the speed limit. Leave P08 within local rules. Do not raise it for feel reasons.
- Save and exit. Power-cycle the display so the controller reloads the values before you test.
- Reset if needed. If the ride is worse, re-enter the baseline values from your photos. It takes seconds.
Change only one value per ride. If you change three things and the bike feels better, you will not know which one helped. If it feels worse, you will not know which one to undo.
What this does to range
Range follows how much current you draw over the ride. More levels let you stay at a modest level instead of jumping to a strong one, which tends to save energy. Higher sensitivity means the motor fires more often, including on small crank movements, so it tends to use more battery. Lower sensitivity does the opposite. I cannot give a fixed percentage, since it depends on rider, load and terrain. Instead, repeat one familiar route after each change and compare battery drop.
Common Misconceptions About Assist Tuning
Most mistakes come from treating numbers on the spec sheet as dials that you can turn for free. Four beliefs cause the most trouble.
"Higher assist always means more climbing power"
A higher level raises the assist ratio, but the motor's rated and peak output stay the same, and so does its torque. On a long climb, a high level mainly drains the battery faster. Smoother delivery often gets you up the same pitch with less wheelspin. For more on how motor torque numbers compare, see our piece on why raw torque figures mislead and our e-MTB motor guide.
"Maximum sensitivity gives the fastest response"
Maximum sensitivity makes the controller react to the smallest crank motion. On rocky or rooty ground that means the motor pulses with every bump that moves the pedals. A mid-range value feels slower on paper but is more predictable, and predictable power keeps the rear wheel hooked up.
"Changing settings is harmless"
Most feel settings are safe to undo, but base parameters are not. A wrong voltage or wheel size gives false readings or a system shutdown. A raised speed limit can also put you outside the rules for your road category. The e-bike classes exist for a reason.
"A strong motor needs no tuning"
Motor torque and sensor type are different things. The K03's two 85 N·m motors have plenty of force, but its cadence sensor still needs sensible level and sensitivity settings to deliver that force gently. The same goes for the M1 and K05.
Sensor Types Compared: What Changes in Feel
The table below puts the two sensor types next to each other, using our own range as examples.
| Dimension | Torque sensor (K01, K02) | Cadence sensor (K03, M1, K05) |
|---|---|---|
| What it measures | How hard you push on the pedals | Only that the cranks are turning |
| Ride feel | Assist rises and falls with effort, like an extra leg | Assist arrives at the level's set power once pedals move |
| Steep climbs | Easy to modulate: push gently, get gentle help | Depends on level count and sensitivity to avoid surges |
| Where it lives | Inside the bottom bracket | A small sensor near the crank |
| Maintenance | Serviced with a splined bottom bracket tool | Fewer precision parts to service |
| Tuning importance | Lower: sensitivity matters less | Higher: P05 and sensitivity do much of the work |
| Best for | Technical climbing and low-traction surfaces | Heavy loads, snow and simple, robust riding |
If your bike has a torque sensor, you will gain less from tuning and more from learning to modulate your pedal pressure. If it has a cadence sensor, tuning is where most of the smoothness comes from.
How to Check the Result on the Trail
Judge a change by riding the same short climb before and after, and compare how power engages. Use a steep gravel pitch you can repeat, and pick the same gear and assist level each time.
- Standstill start. Stop on the slope and pull away. Does the power build smoothly, or does it lurch?
- Mid-climb stability. Ride over a rough patch. Does the motor pulse with every bump?
- Level steps. Move up one level. Is the added help gentle enough to keep your cadence steady?
- Display check. Watch the battery bars or power readout. Higher sensitivity and levels draw more current, so range will drop. Our 960 Wh pack gives a fixed energy budget, and every gain in punch is paid for in distance.
- Flat section. Ride a level stretch. A change that helps on the climb should not make the bike twitchy on easy ground.
When to stop and see a dealer
Settings cannot fix hardware faults. See a dealer if you notice unexplained cut-outs, error codes on the display, or assist that disappears under load. On the K01 and K02, a torque sensor fault produces erratic or missing assist regardless of settings, and the replacement torque sensor needs the right bottom bracket tool. If the P-menu changes did not help and baseline values restore the same symptom, the cause is not your settings.
Before any off-road trip, also check your tire pressure and charge the battery between 0 °C and 40 °C. Lower pressure within the tire's range gives more grip, and that helps smooth power delivery more than any menu setting.
Frequently Asked Questions
How do I make my e-MTB's pedal assist feel less jerky?
Increase the number of PAS levels to 5 or 9 so each step is smaller, and set PAS sensitivity to a mid-range value so the motor doesn't react to every small crank movement. Change one setting at a time and retest on the same climb.
Where are the PAS settings on a Kimdyma display?
Press and hold the UP and DOWN buttons together for 2–5 seconds until P01 appears, then use the mode button to step through P01–P09. Photograph the factory values first so you can restore them if needed.
Will changing assist response reduce my battery range?
Usually yes if you raise assist level or sensitivity, because the motor draws more current. Smoother settings can help efficiency by avoiding sudden surges, but total range always depends on terrain, rider weight and assist level.
Should I change voltage or wheel size settings to improve assist?
No. Voltage (P03) and wheel size (P06) are base parameters that must match your hardware. Incorrect values cause inaccurate speed readings or system faults, so verify them rather than tuning them for feel.