Cytronex · Front hub · United Kingdom
Cytronex
Maker list
Battery in the offer. Charger included. 25 km/h.
British front-hub system. The motor is built into a wheel for the bike you already own. 250 W, about 198 Wh.
- Continuous
- 250 W
- Class
- 25 km/h
- Energy
- 198 Wh
- Axle
- 100 mm quick release

Part by part
Every piece. Tap one.
01
Front wheel
Motor in the fork
- Continuous
- 250 W
- Peak
- Set with the build
- Mass
- On the sheet
- Sizes
- 700c, 26, 27.5
Cytronex is a front motor wheel for 700c and 26 and 27.5. Continuous rated power is 250 W. Claimed peak is Set with the build. The wheel mass is on the fitment sheet.
Read the build notes
Steering takes the extra mass. The fork, the axle and the brake mount are the fit, not the rear dropout. British front-hub system. The motor is built into a wheel for the bike you already own. 250 W, about 198 Wh.
02
Fork and axle
100 mm quick release
- Axle
- 100 mm QR
- Load
- Fork and crown
- Brakes
- Disc
- Formats
- road, hybrid
Axle is 100 mm quick release. The fork has to be a fork the manufacturer allows a hub motor to live in. Carbon forks without that written allowance stop the fit.
Read the build notes
Quick-release nuts are not the torque strategy. The axle seats fully, the washers are the ones in the kit, and the skewer closes on the arm as well as the dropout.
03
Torque arm
Reaction into the fork
- Required
- Yes
- Clears
- Caliper and blade
- Axle
- 100 mm QR
- Brand
- Cytronex
The torque arm is required on Cytronex and it is not always in the motor-only price. Where the required list names it, it is bought with the wheel, not after the first ride.
Read the build notes
The arm clears the disc caliper and the fork blade. It is a Cytronex part for this axle, not a rear-hub arm turned around.
04
Controller
Included controller
- Model
- Included controller
- Voltage
- 36 V
- Cut-off
- 15.5 mph
- Throttle
- Not fitted
Included controller is the brain of Cytronex. It is named because a generic box with the same voltage is not this system.
Read the build notes
Cut-off is 15.5 mph. No throttle is fitted on this configuration. Pedals stay.
05
Battery
Not in the motor offer
- In the offer
- No
- Allowance
- Maker list
- Voltage
- 36 V
- Controller
- Included controller
Cytronex is a wheel and a controller. The battery is a separate purchase. The cost band holds Maker list so a complete bike can be priced without pretending a pack was included.
Read the build notes
The pack has to be one Cytronex names for Included controller. A 36 V pack that happens to plug in is not that pack.
06
Charger
Follows the pack
- Included
- No
- Allowance
- Maker list
- Pairs with
- The named pack
- Wheel price
- Maker list
There is no charger in the Maker list wheel offer. Budget Maker list for the charger that belongs to the pack you add.
Read the build notes
Wheel, controller, pack and charger are four lines. Cytronex only covers the first two.
07
Sensor
Cadence on the crank
- Type
- Cadence
- Magnet
- On the crank
- Lead
- To the bar unit
- Torque
- Set with the build
A cadence sensor and magnet ship with Cytronex. The pickup sits at the bottom bracket, the magnet on the crank, and the lead runs forward to the controller in the bar bag.
Read the build notes
Assist starts when the cranks turn. There is no torque reading on this configuration. Hills are handled by the bike’s gears plus the 250 W at the front hub.
08
Brake
Rotor and lever
- Mount
- Disc
- Rotor
- Move or replace
- Cut-out
- Lever sensor
- Wheel
- 700c, 26, 27.5
The motor wheel needs a rotor that matches the hub’s mount. If the bike already runs that rotor, it moves across. If it does not, a rotor is on the required list.
Read the build notes
Motor cut-out from the brake lever is part of a careful install. The lever that ships, or the sensor that clamps the existing lever, has to actually open the circuit when you brake.
Install
Order of work
Workshop install, in this order.
- 01Confirm the fork will take a hub motor and that the axle is 100 mm quick release.
- 02Fit the Cytronex wheel with its washers and torque arm.
- 03Move or replace the rotor. Check the caliper clears the arm.
- 04Mount Included controller. Run the cadence lead to the crank.
- 05Add the named battery and charger as their own purchase. Do not borrow a pack by voltage.
- 06Check brake cut-out, steering clearance and the first assist.
In depth
Read Cytronex before you book it.
Front hub · 25 km/h · United Kingdom. The numbers below are the ones on this configuration, not the family in general.
The offer
What Cytronex actually is
Cytronex is one configuration from Cytronex, made in United Kingdom, filed here as a front hub. The family is Kit, generation Catalogue. British front-hub system. The motor is built into a wheel for the bike you already own. 250 W, about 198 Wh.
In the box, as this record has it: Front motor wheel, Battery, Charger, Control. Still required before the bike moves under its own assist: Fork clearance for the wheel, A workshop fit is the usual path. A cheaper advert for the same family name is not this list. If the battery, the charger or the throttle differs, it is a different configuration and it gets a different page.
250 W continuous and a 25 km/h assistance cut-off.
The price on the card is the maker’s published figure in GBP, or Maker list when no figure was published. Allowances for a missing pack, a charger and workshop time sit in the complete-cost band. They are not a second product and they are not a promise that a random pack will talk to this controller.
The bicycle
The frame this motor is asking for
Cytronex lists Cytronex against Road, Hybrid bicycles, for Commuting, Leisure. Wheel sizes on the card: 700c, 26, 27.5. The mechanical interface is 100 mm quick release. Brakes are disc.
A front hub asks the fork to hold a heavier wheel and the reaction of the axle. Steel and aluminium forks with a 100 mm quick-release are the usual yes. A carbon fork is not given a pass from the product name. Steering, brake hose length and mudguard stay clearance are checked with the wheel in, not from a tyre size.
Pedals stay. This configuration is a bicycle with assistance, not a motorcycle conversion. Sensor on the card: cadence. Cut-off on the card: 15.5 mph. Throttle: not fitted.
The numbers
250 W is not the whole story
Continuous rated power for Cytronex is 250 W. Claimed peak is not stated separately from the continuous rating. Torque is not published as a crank or hub figure. Manufacturer stated. Motor mass is not published. System mass, once the named parts are on the bike, is Front motor wheel, Battery, Charger, Control.
Peak is a short claim. Street rules, including the Great Britain check on this site, use continuous rated power and the speed at which assistance stops. A controller that can be unlocked does not change the record of the motor as sold. Cytronex is filed in the 25 km/h class: 250 W pedelec class used across the EU, Great Britain and Australia.
In this class the useful comparison is torque and mass, not a bigger watt sticker. A 250 W torque-sensing mid-drive and a 250 W cadence hub do not feel alike, and neither of them becomes legal somewhere else just because the sticker matches.
Pack and charger
The pack is part of the kit
Cytronex pack is 198 Wh at 36 V. Lithium-ion The charger is Included charger.
Nominal watt-hours are voltage times amp-hours when both are known. That is stored energy on the label, not usable energy, and not a mileage promise. Cold, load, hills and how full you dare to run the pack all move the distance. Any range sketch on this page shows the watt-hours per kilometre it assumed.
Charge this pack with the charger named for it. The same plug on a higher-voltage brick is the wrong part. A swollen, hot, hissing or sharp-smelling pack is a stop: do not open it and do not keep charging it.
Front hub
How Cytronex uses this layout
Front hub. The motor is the front wheel. Cytronex leaves the chain, the cassette and the bottom bracket alone, which is why it is the usual first conversion on a hybrid or a folder.
The fork takes the extra rotating mass and the axle’s reaction. A torque arm is how that reaction goes into the dropout instead of into a skewer nut. Brake type is built into the wheel: a disc wheel is not filed into a rim fork with a wish.
Steering feel changes because the wheel is heavier. On a small folder the change is obvious. On a 700c hybrid it is mostly a longer moment when you flick the bar. Neither is a reason to skip the fork check.
The workshop
A workshop path, written as a sequence
Cytronex is a workshop install in this record. Doing it yourself does not rewrite the path into a pass. It means the documented route was not the one you took, and the result stays conditional until someone competent has seen the bike.
Warranty as published: Maker warranty. Term is on the invoice.. Labour in the cost band is separate from the offer. A brake service the bike already needed, a new chain, or a hanger alignment is not folded into Cytronex’s price to make the total look neat.
The sensible order is measure, then mount, then connect, then the first assisted roll in the stand. Connectors are keyed for a reason. The torque arm, the axle nuts and the connector boots are one inspection at the end, not three trips.
After it is on
The first month, and the parts that wear
Spoke tension on a motor wheel is part of the service, especially in the first few hundred kilometres while the wheel beds in. A ticking torque arm is a loose bolt, not a personality. Check axle nuts after the first week.
Keep Included charger with Cytronex pack. Store the pack cool, part-charged if it will sit, and not in a hallway that is your only exit. Cytronex’s display, if one is included, is paired to this controller generation. A screen from the next family is not a spare.
My Garage on this device can hold the configuration, who fitted it, and what was still open. That note is for you and for the next workshop. It is not a certificate. If a later notice lands on this configuration, the record is where it should show.
Read next to it
From the library
- What a conversion kit actually includesA motor wheel and a complete system are not the same product. The page should say which one you are looking at.
- Watts, torque, and the sticker that does not mean rangeContinuous watts, peak watts and newton-metres describe different moments. Mixing them is how a listing looks twice as strong as the motor you will live with.
- Speed classes, from 25 km/h to off-roadThe class is a property of the kit as sold. The road you may use it on is a property of the country, and sometimes of the state or the canton.
- Torque arms, dropouts and why the skewer is not the planA hub motor tries to rotate its axle in the frame. The torque arm is how that force goes into steel instead of into a nut.
- Wheel sizes, and why 700c is not a moodThe motor wheel is built for a diameter and a brake. The tyre you like does not retcon the rim.
Specification
Published figures for this configuration.
- Drive
- Front hubDocument reviewed
- Sensor
- cadenceManufacturer stated
- Continuous rated power
- 250 WManufacturer stated
- Claimed peak power
- UnknownNot verified
Not used as the continuous rating.
- Nominal voltage
- 36 VManufacturer stated
- Torque
- UnknownNot verified
Manufacturer stated.
- Motor weight
- UnknownNot verified
Front motor wheel, Battery, Charger, Control
- System weight
- UnknownNot verified
Front motor wheel, Battery, Charger, Control
- Controller
- Included controllerDocument reviewed
- Wheel sizes
- 700c, 26, 27.5Document reviewed
- Axle
- 100 mm quick releaseDocument reviewed
- Brakes
- DiscDocument reviewed
- Bottom bracket
- Not applicableDocument reviewed
- Assistance cut-off
- 15.5 mphDocument reviewed
- Throttle in this configuration
- NoDocument reviewed
- Warranty
- Maker warranty. Term is on the invoice.Manufacturer stated
Complete cost
Uncertain lines stay labelled. Shipping and import charges are not estimated.
| Kit offer | Maker list | Listed price |
|---|---|---|
| Battery | Included | Cytronex pack |
| Charger | Included | Included charger |
| Required accessories | Maker list | Allowance |
| Installation | Maker list–Maker list | Workshop band |
| Shipping | Not estimated | Ask the seller |
Estimated complete Maker list–Maker list
Nominal energy
198 Wh
Stated on the pack.
Range sketch
About 13 km at 12 Wh/km, using 80% of nominal energy.
Easier roads, 8 Wh/km, about 20 km. Hills, 18 Wh/km, about 9 km.
Included
- Front motor wheel
- Battery
- Charger
- Control
Required as well
- Fork clearance for the wheel
- A workshop fit is the usual path
Battery and charger
- Battery model
- Cytronex packDocument reviewed
- Charger model
- Included chargerDocument reviewed
- Chemistry
- Lithium-ionManufacturer stated
- Capacity
- UnknownNot verified
250 W continuous and a 25 km/h assistance cut-off.
Seller offers
Published offers in Great Britain.
Cytronex
Maker list
United Kingdom · Front motor wheel. Battery. Charger
List price not published in the source used. Ask the maker.
Source documents
- Published specificationManufacturer stated
Cytronex is a UK front-hub conversion at 250 W with a pack of about 198 Wh. List price was not in the source used.
Change history
- 17 Oct 2026
Entered from a published maker or press specification.