TruckRun RN04 Thru-Axle Hub Motor Conversion

[Stubbie Blue]

The TruckRun RN04 hub motor is fairly unique because it uses a 12x142mm thru-axle so it can be installed on many modern bikes.

Cost. I got it from Ali X seller PSR Ebike Store where it's listed for $368 but you can get up to 20% off coupons. It comes with an SW102 display and a torque sensing controller, but no wheel rim so you have to lace one up. I got a UnitPackPower 36V 10.5Ah bottle battery for $210.

Speed. It's only 250W so don't expect too much, but I can still get up to 28 mph on the highest level 5 assist (there is no throttle). On level 3 it can comfortably cruise at 22 mph with 160W of pedaling power. On level 1 and 2 it actually feels more draggy than without the motor.

Range. Did 45 mi at 21.5 mph on level 3 assist, increasing to level 4 towards the end as the voltage and motor got weaker. Did 35 mi at 24 mph on level 5 assist.

[stojos]

Nice conversion. I am looking into similar conversion for my road bike so that I can join my cycling friends when attacking big mountins.

Idea is to have a simple conversion that you can easily add or remove to road/race bike. Simple swap wheel, put bottle battery that inlcude controler into bottle holder and attach a single cable (only from battery to rear wheel).

The problem with your conversion is that it is not that cheap when you add battery to it, screen is wired that adds complexity and bottle battery does not look like a bottle (not as nice).

There are kits with rear wheel torque motor, bottle battery with controler and wireless screen like LVU's KF03S or Boosts in UK.

Rear wheel torgue motor with bottle battery with controler kit that still need wire for screen can be found maybe cheaper with yosepower.

[fenomeno]

Hi
Did you assemble the wheel?
How is the motor drag?
Thanks

[Stubbie Blue]

Hi
Did you assemble the wheel?
How is the motor drag?
Thanks

Yes I laced the wheel myself.
Unfortunately, there is a lot of drag when the motor is off or if you exceed the assist speed limit.

[Stubbie Blue]

I want to copy and paste a post I made in another thread comparing the TruckRun RN04 hub motor to a ToSeven DM02 mid-drive motor that I have on another bike:

TruckRun RN04 hub motor
Pros:
- Fits most thru-axle bikes.
- Can keep front derailleur and crankset, Q-factor.
- Torque sensor works okay. No 'ghost pedaling'. But I think the assist levels are based on speed limits where the motor cuts out, e.g. Lvl 1=25km/h, 2=30km/h, 3=35km/h, 4=40km/h, 5=45km/h, so they don't actually change the ratio of assist to your pedaling force.

Cons:
- Only 250W. Can only reach around 28 mph with a fair amount of pedaling power.
- A lot of drag without motor assist.
- I put on a 36V 10.5Ah battery so range is only 30-40 miles.
- You need to build the hub into a wheel rim.
- Has a Shimano HG 11/12 speed road freehub, so no SRAM XD/XDR or Micro Spline.

ToSeven DM02 500W mid-drive motor
Pros:
- Fairly powerful, and utilizes rear gearing. Can reach 28+ mph.
- I put on a 48V 20Ah battery so range is 70+ miles.
- The torque sensing works a bit better. You can change the ratio of assist.

Cons:
- Can only install on aluminum or steel bikes with a 'full tube' BSA bottom bracket shell and narrow chainstays for clearance from the motor gear.
- Q factor very wide at ~200mm plus I had to use a 16mm pedal extender on the left to even them out.
- Need to use special 1x chainrings made for the motor.

Overall I like the TruckRun RN04 better. You can put it on nicer bikes like a carbon road bike, and can keep your drivetrain and crankset with the same Q-factor. It also looks a bit more discrete than the ToSeven DM02 mid-drive. Actually I upgraded this bike with a carbon crankset and wheels to bring the weight down to 12.6 kg/27.8 lb with battery & motor.