Fit check. Install. Ride.
One clear path from “Will it fit my bike?” to a safe first ride. Pick your situation below and get only the guidance you need.
- Fit check
- 60sec
- Typical setup
- 5–10min
- Mounting
- 2screws
What are you here to do?
Choose the route that matches your stage instead of reading the whole guide.
I’m checking whether QIROLL fits my bike.
Confirm frame space, tire surface and moving-part clearance. For an unusual frame, send a photo before ordering.
Start compatibility checkI already have a kit and want to install it.
Go straight to mounting, cable routing, low-speed testing, video tutorials and the current QR-E manual.
Start installationFour checks. One confident fit.
If all four are clear, most standard road, city and folding-bike installations are straightforward.
6 × 4cm clear space
Find a flat mounting area close enough for the roller to reach the tire.
Continuous center tread
A smooth or lightly grooved center tread gives quieter, more stable contact.
Moving-part clearance
Keep the motor and cable clear of brakes, chain, fender and folding joints.
Correct roller angle
The roller should meet the center tread squarely, without sidewall contact.
Ask for a fit reviewFind your mounting path.
Start with the closest frame type, then continue to the installation sequence.
Before you pick a mounting spot.
Steel, aluminium and carbon frames
All three take the QR-E, and there are several mounting positions to choose from.
Reverse mounting
On many road frames the motor can also be mounted reversed — worth trying when the standard position is tight.
Riding fast most days? Choose QR-E PRO
If you regularly ride near or above where MUTE assistance tapers off, the QR-E PRO is the better match.
Brompton with fenders
Some fender versions need the fender removed. Folding is unaffected after installation.
Three stages to first ride.
Mount, connect and test in that order. Stop if the roller slips, touches the sidewall or changes position under load.
Position and align.
Choose a clean frame area, tighten both M5 screws evenly and center the roller on the tire tread.
Safety note
Never let the roller contact the tire sidewall.
Route and secure.
Connect keyed plugs without force. Leave steering or folding slack and secure cable away from moving parts.
Lift, test, recheck.
Test the driven wheel at low speed, then verify tracking, screw tension, braking and steering before riding.
Care note
Do not use WD-40 or another solvent-based cleaner on rubber sealing or friction surfaces.
Guided installation
Use the videos for sequence and the current manual for model-specific checks.
The roller slips or assist feels weak under power.
Work through these in order: rear tire pressure may be low, which cuts contact force; the roller may not be pressed in the full 1.5-2 mm; the tread may be knobby, deeply grooved or have grit embedded in it; or the friction layer may be worn, wet or glazed. Confirm the roller is centered on a continuous tread, square to the tire and that both screws are evenly tightened, then dry any moisture before testing again.
How hard should the motor press against the tire?
Hold the motor against the rear tire, then tighten the bolt in small steps until the roller presses in about 1.5-2 mm. Turn the wheel by hand to confirm firm, non-slipping contact. Too little pressure slips; too much adds friction-layer and tire wear, so adjust gradually as the manual describes.
Can the roller touch the tire sidewall?
No. Reposition the motor so the roller runs on the center tread. Sidewall contact can reduce stability and damage the tire.
The lights do not come on, or the motor only flashes green, after connecting.
First check that the power lead and plug are fully seated and correctly oriented. A motor left idle often enters sleep, and a green flash is usually sleep rather than a fault, so hold the square button for about 3 seconds to wake it. A battery left in storage can enter protection mode, so charge it once and retest. If there is still no light, stop re-plugging or opening the unit and contact support.
On the test stand the motor keeps spinning for a while.
That is normal. With the rear wheel off the ground there is almost no resistance, so it takes longer to stop. After releasing the assist button, use the bike's own brakes to stop the wheel, and keep hands, clothing and tools clear of moving parts. Never stop the roller or wheel by hand.
With the wheel lifted I cannot feel any difference between ECO and Sports mode.
That is expected. With no road load, the motor reaches high speed quickly even in ECO, so the modes feel similar. After your bench checks, compare the modes at low speed in a safe, open area on the ground.
Can I clean the motor with WD-40?
No. Solvent-based cleaners can damage rubber sealing and friction surfaces. Wipe the motor dry with a clean towel.
Need a specialist’s eye?
Send a clear side photo after installation so support can confirm frame clearance, roller angle and cable routing.
Manual & support
Keep the current manual with the video sequence for model-specific checks.
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