Retirement on an electric bike
07/10/2026The electric bike kit, here is the solution
07/10/2026
Nine Continent RH205 C type “s” and Rockrider 6.3 MTB
Alain already had a Rockrider 6.3 on which a Bafang 8FUN motor was fitted at the front.
For several reasons (precarious traction on gravel, nylon planetary gears etc…) Alain decided to evolve his bike with the objective of assembling a Nine Continent RH205 motor and Rockrider 6.3.
In the following lines you will find the chronicle of the fitting.
Order and delivery
Order placed on Monday, motor delivered three days later, with receipt of several emails + SMS from Power-e-bike to inform of the various statuses of the order. Nothing to add, except that for a price equivalent to what can be found in China, you are supplied by a French legal entity able to provide the warranty.
Unboxing
The box open, we remain a few seconds taking stock. A cardboard box (not visible in the photo) contains the controller, the half-throttle grip and the connectors.
The motor wheel is “splendid” as long as you appreciate this kind of beauty. The Nine Continent marking is present on the flange and a paper label indicates the winding.
The new version of the RH205C motor offers big 12G spokes (2mm instead of 13G or 1.8mm) visibly bigger than the previous ones, the “double-cross” lacing is classic, and the Anderson connectors for the motor phases can now be seen. Also note the new cable outlet located in the hub whereas previously the outlet was at the end of the motor axle, with a higher risk of tearing.
Taking the wheel out and turning it over, we can see that the DNP freewheel has been fitted (as an option). This part allows having the smallest sprocket in 11 teeth, which makes it possible to accompany the motor when riding at 40km/h. With a classic MTB freewheel of 14 teeth or more, you “pedal in the mush” at high speed, you ride too fast to accompany the motor.
Caution, to remove a freewheel from this motor, it is imperative to have the appropriate specific tool (the one sold by Decathlon is too narrow to let the motor axle pass. The motor supplier offers this tool.
In the box is also the controller Alain selected at his order:
As well as some connectors (and a shim whose usefulness we will see later) and a half-throttle grip:
 |  |
The wheel out of the box: double-wall rim, big spokes, DNP 11-tooth freewheel, connectors for Hall sensor and motor phases:
And here, the Rockrider 6.3 is positioned to welcome the motor wheel:
A very light pass of the file in the fork dropouts to remove the paint overcoat to position the motor axle easily:
We will unscrew a few screws to install the brake disc on the Nine Continent RH205C motor in 7*9 winding:
The disc is positioned, we start screwing:
Here we go, the disc is in place on the RH205C in 7*9 winding, as the label indicates:
A small detail of the double-wall rim and the start of the 2mm spokes:
Fitting the wheel, we notice that the disc touches a bit: the decision is made to machine a small tab (needlessly, as we will see later):
The tab is machined, it will shift the calipers by 1mm to face the disc:
We position the wheel on the bike:
The freewheel just passes, it is a matter of a millimetre, but it is good…
Fixing the wheel, unfortunately, the wheel no longer turns! It is nothing, just forgetting to position the small shim:
There it is in place, we can close:
But as a result, with the shim in place, the brake disc is offset: the small machined part is one too many, it was not necessary. We remove it and everything falls back into place as if the Nine Continent RH205 and Rockrider 6.3 pairing had been defined from the start!
Heading to the skate-park, we will take some photos in the grey autumn light with the wind sweeping the dead leaves.
The Nine Continent RH205 and Rockrider 6.3 marriage seems successful, the bike is really pleasant to ride:
- a basket on the handlebar allows going shopping or carrying supplies for the rides
- not visible in the photo, a watt-meter is positioned on the handlebar and allows continuous control of the essential battery parameters
- the controller is positioned on the frame, enclosed in an aluminium box for thermal exchange (the assembly does not heat up, the temperature was monitored over several hundred kilometres. What is notable is that the controller temperature rises when you stop riding, because the airflow no longer cools it) covered with a rain protection)
- a specific system allows on this full-suspension bike to carry the battery: the definitive battery is awaiting reception and will be positioned in the box closed by a padlock; for the moment the test was carried out with a big 48V / 20Ah Yuntong strapped on the bike
The impression compared to the version with the 8Fun motor at the front:
- the “Solex” effect (too much weight at the front because of the front wheel motor) has disappeared
- perfect traction on gravel – on the same course the front motor would skid
- throttle dosing is precise, the on / off effect has disappeared
- the motor noise is lower, the 8Fun tended to vibrate and resonate
- overall the bike is more supple, with more torque and easier to ride: in line with (and beyond) the expected results
- the bike has a rather nice look and the price / performance ratio is very favourable (let us not forget that a “legal” bike is limited to 250W and 25km/h!).
“Nine Continent RH205 and Rockrider 6.3”: an e-bike that does not disturb the skaters:
Caution: under the effect of the important weight, the spokes of the wheel may relax after a few kilometres: they will therefore need to be checked and if necessary re-tightened with a spoke key (a ¼ turn)
