REVIEW: QR-E 250W ELECTRIC BOOSTER BICYCLE MOTOR AND B60i AND B70 BATTERY

[ybao]

As someone who loves e-bikes, I truly enjoy admiring these models.
The Qiroll e-bike attracts me with its delicate design and light, elegant character, and it would be even more appealing with the addition of a pedal-assist (PAS) cadence-sensing system.
I also came across the GBoost e-bike, which stands out for its strong climbing capability, giving it a confident and capable presence.

GOOST ebike

 

[3dxl]

My Qiroll Pro still powering good on my bike in 2026 during daily commute. No problem. Battery still runs well since my first post. Anyone still rocking Qiroll?

Video:

 

[3dxl]

Another bike with Qiroll Pro (latest version) still alive after daily abuse on all weather. However it started to sound like turbine jet like the first one if i keep boosting/throttle up. I suspect the inner clutch was loose or grinding along.

 

[BluePixel]

View attachment 208574
Another bike with Qiroll Pro (latest version) still alive after daily abuse on all weather. However it started to sound like turbine jet like the first one if i keep boosting/throttle up. I suspect the inner clutch was loose or grinding along.

I had the same problem. Today I decided to teardown the motor as deep I could without destroying it... And I have good news. Behind the Metal Discs on the side of arm (on Mute Pro: plastic design parts) there are the screws which fixate the motor. I took the screws out and pried the black plastic sides on the motor off. I didn't got deeper than this but I cleaned everything and put some oil on the barrings ( I don't know if it was a good idea) and screwed everything back in place. And now it is silent again . I don't know if it was the oil or the cleaning or both feel free to test...

I think there are no gears or clutch inside because of the very clear magnet fixation you can feel while turning it slowly with your hand. That's definitely a good thing for robustness.

 

[3dxl]

I had the same problem. Today I decided to teardown the motor as deep I could without destroying it... And I have good news. Behind the Metal Discs on the side of arm (on Mute Pro: plastic design parts) there are the screws which fixate the motor. I took the screws out and pried the black plastic sides on the motor off. I didn't got deeper than this but I cleaned everything and put some oil on the barrings ( I don't know if it was a good idea) and screwed everything back in place. And now it is silent again . I don't know if it was the oil or the cleaning or both feel free to test...

I think there are no gears or clutch inside because of the very clear magnet fixation you can feel while turning it slowly with your hand. That's definitely a good thing for robustness.

I did manage to remove three screws but all i got was a an enclosed metal cylinder and 3x wires connected. I still dumb founded on how to open the cylinder motor as i don't see any screw enclose it. This is on PRO model. I knew the motor inside is still spinning when i stop the bike/ brake abruptly to a halt (stop) but the motor can be heard spinning and i felt the internal clutch is not engaging it fully while the outer roller not moving at all. I have to unplug the battery to turn it off. ** Qiroll engineer support please take note of that.

 

[glerner]

Maybe interesting for some people , I am not using my to much and I don t want the battery to die so I make a small box with an usb port so Incan charge mobil or other device when I go camping

 

[shinhao]

Hi everyone! I'm running a Qiroll motor on my Strida LT. Specifically, I'm using the QR-E PRO-MAX model.

The stock setup uses a fixed screw to set the gap, but as my friction tape wears down and my tire pressure drops slightly, a gap starts to form. This leads to slipping and power loss.

Since I'm on a Strida with standard tires (I can't pump them up as high as road tires), this happens more often than I'd like. I'm tired of manually adjusting that screw every few rides. Does anyone have a better way to keep the motor tight against the tire automatically? Thanks for any advice!

 

[RunForTheHills]

I didn't know they still made friction drive motors. Isn't it tensioned by a spring? I would recommend going to a mid-drive or hub drive motor kit instead.

 

[EMGX]

I used a spring loaded door hinge, the kind that you can adjust tension. The ones with a strong spring worked best but there can be fitment issues due to the length of the hinge so it depends on the mounting location and clearances for your specific bike.

 

[shinhao]

I didn't know they still made friction drive motors. Isn't it tensioned by a spring? I would recommend going to a mid-drive or hub drive motor kit instead.

I didn't know they still made friction drive motors. Isn't it tensioned by a spring? I would recommend going to a mid-drive or hub drive motor kit instead.

Thanks for the suggestion! I actually considered buying a new e-bike, but I really wanted to try modding this classic Strida LT first. I only need a little boost for starting from a stop, hitting hills, or fighting headwinds in the city. It’s more about giving an old bike a second life than having a high-power machine!"

 

[shinhao]

I used a spring loaded door hinge, the kind that you can adjust tension. The ones with a strong spring worked best but there can be fitment issues due to the length of the hinge so it depends on the mounting location and clearances for your specific bike.

"I've actually seen your thread and the photos you shared! It’s a genius way to maintain constant downforce. I’m definitely going to give the spring-loaded door hinge a try. Thanks for sharing such a clever solution!"

 

[EMGX]

Post up pictures when you get around to it. This thread has a lot of potentially helpful information on a number of aspects for Qiroll users.
I've used a few different types of spring door hinges, they all worked for my applications. They tended to be made of stainless steel which can be a challenge to drill mounting holes. I found carbide bits and oil helped (along with patience).