Our rating system
Our ratings are only worth something if they can be checked. That's why they rest on five published criteria, applied identically to the three motors in the catalog, and on an overall rating that is nothing more than their average. No hidden coefficient, no flattering rounding, and no score that comes from anywhere but the grid below.
The five criteria
Torque and pull
What the motor can actually move, and how quickly it responds. This criterion combines the claimed maximum torque and the controller's maximum current — two inseparable values: 160 Nm behind a throttled controller doesn't behave like 160 Nm behind 30 A. It rewards capacity on climbs and under load, and penalises a reserve too thin for the intended use.
Mechanical fit
The ease and reliability of the install. This criterion measures the width of the bottom bracket range covered, the bulk of the housing, and tolerance for tight frames. A motor that claims a wide range but whose bulky housing blocks the fit on many frames gains nothing here: it's real feasibility that counts, not the line on the spec sheet.
Pedaling feel
How the assistance arrives. A sensor that scales the help to the force applied structurally scores better than a cadence sensor, which works in steps and delivers the same effort whether you press hard or not.
A direct consequence for this catalog: all three BBS kits run on cadence, so none can stand out on this criterion. That's a range-wide limitation, and we would rather have it show up in the rating than remove the criterion to flatter all three models. What a torque sensor would bring is explained in cadence sensor or torque sensor.
Ecosystem and parts
The availability of spare parts, displays and documentation, and the ability to work on it yourself. The BBS series is well served here by a very wide ecosystem: a display can be swapped, a controller reprogrammed, and installation tutorials are plentiful. A motor whose parts come through a single channel only would lose points here.
Value for money
What the motor offers relative to its reference price. This criterion doesn't reward the cheapest motor, but the one whose performance best justifies the sum asked. It accounts for what the model demands from the rest of the bike: a kit that requires a reinforced drivetrain costs more than its price tag suggests.
How the overall rating is calculated
The overall rating is the arithmetic mean of the five criteria, rounded to one decimal. It is therefore fully recalculable from the five bars shown on every product review.
Redo the calculation with your own criteria
If the parts ecosystem doesn't matter to you because you're leaving the install to a shop, drop that line and redo the average over four criteria. The ranking changes, and that's normal: our rating is a starting point, not a verdict.
The scale used
| Score | Reading |
|---|---|
| 9.0 to 10 | Excellent on this criterion, a reference in the range |
| 8.0 to 8.9 | Very good, with no significant caveat |
| 7.0 to 7.9 | Solid, with a limitation identified and accepted |
| 6.0 to 6.9 | Passable, best reserved for a specific use |
| Below 6.0 | Insufficient for the use the model claims |
These scores aren't comparable with those of another site: they only measure the motors in this catalog, against each other, with this grid. A 9 here says nothing about a 9 elsewhere, and a two-tenths gap between two models shouldn't decide a purchase on its own.
What the rating doesn't tell you
An overall rating replaces neither the measurement of your bottom bracket, nor the question of the bike's legal status, nor your total budget. The comparison of the Bafang range and which Bafang motor to choose for your use cover these three points, which outrank any rating.
Finally, these ratings rest on manufacturer data rather than on road tests: we have not assembled any of these motors, and our method page explains exactly what that implies — including the limits it places on the words we choose.
FAQ
Why a simple average rather than a weighted one?
Because a weighting is a hidden judgment. With a simple average, anyone can recalculate the overall rating from the five bars published on each review, and above all redo their own calculation keeping only the criteria that matter to them.
Does a rating of 9 out of 10 mean the motor will suit me?
No. The rating measures the motor’s qualities, not how well it fits your bike. An excellent motor that doesn’t clear your bottom bracket remains unusable, and no rating fixes that.
Do the ratings account for price?
One criterion out of five is dedicated to it, weighing the performance against the model’s reference price. The other four describe the motor independently of what it costs.
