Cube Acid 240 Hybrid Rookie Pro
The Cube Acid 240 Hybrid Rookie Pro is the Pro 400X, a 24-inch Bosch-assisted hardtail that helps a younger rider join longer, hillier family rides and moderate unpaved or gravel routes.
- Bosch Performance Line SX: Pedal assistance up to 20 km/h, so a younger rider can stay with the family on the hills
- 400 Wh CompactTube battery: Integrated power for longer outings, with a 2 A charger included
- 24-inch child-proportioned hardtail: Wheels and contact points scaled so a younger rider can handle the bike
- 80 mm Suntour XCT fork: Suspension for moderate gravel and unpaved surfaces
- Shimano Cues 1×9, 11–46T: One shifter and a wide spread of gears, including a low gear for family climbs
- Shimano hydraulic disc brakes: Hydraulic disc brakes for mixed family routes on a child-sized hardtail
Cube Acid 240 Hybrid Rookie Pro Deals
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Bikesy's Verdict
The Acid 240 Hybrid Rookie Pro suits a child who can already ride and still gets left behind when the family route turns hilly. Bosch Performance Line SX assistance and a fixed 400 Wh battery add help on those climbs, up to 20 km/h, while the pedalling stays with them. The 24-inch hardtail is specified for leisure miles and for CUBE's 2Y brief of moderate unpaved and gravel routes, with drops up to 15 cm. At a £1,999 suggested retail price this is the Pro, leaving the SLX's air fork and dropper to families who want that trail kit. It is a poorer match near the 50 kg rider limit, worn kit included, or if lifting 17.6 kg with a fixed battery will be a regular job.
Pros
- Bosch pedal assistance up to 20 km/h helps a younger rider stay with the group on longer, hillier family rides
- A single 24-inch size with a kids' saddle, 160 mm cranks and pedals fitted
- 80 mm of travel, an 11–46T cassette and hydraulic discs for moderate unpaved and gravel routes, with drops up to 15 cm
- Compatible with a separate 250 Wh range extender, plus mudguard and carrier mounts, if family days grow more ambitious
Cons
- 17.6 kg with a battery fixed in the frame, so lifting the bike and charging it away from its parking spot is awkward
- A 50 kg rider limit, including worn equipment, can shorten the useful years as a child grows
The Acid 240 Hybrid Rookie Pro is for the child who can ride the flat miles and still fades when the family route heads uphill. It is a 24-inch hardtail with pedal assistance, built so longer leisure rides and moderate gravel can stay a shared outing. The current UK model is the Pro 400X, and its particular appeal is keeping a younger rider in the group.
Assistance that keeps the group together
The drive is a Bosch Performance Line SX, the BDU31, and it assists while your child pedals. Help runs up to 20 km/h. Past that, the motor stops adding power and any extra speed is down to them. The component specification is 55 Nm. CUBE also describes the assistance as up to 60 Nm, which Bosch makes available through an SX performance update. Whether a particular bike has that update is not stated in the specification.
The battery is a Bosch CompactTube 400, fixed and integrated in the frame, with 400 Wh of capacity. A Purion 200 handles the display and the controls, and a Bosch 2 A charger is included, so charging happens where the bike is parked. If a longer day needs more capacity, a Bosch PowerMore 250 Wh range extender is compatible as a separate accessory. CUBE gives no ride-distance figure for the 400 Wh battery on its own, or with that extender added.
CUBE lists the bike at 17.6 kg. With the battery staying in the frame, a flight of stairs or a lift into the car is a proper carry, and you will want a socket near the usual parking spot.
One size, and a 50 kg ceiling
CUBE offers this Pro in a single 24-inch size, with a published height and inseam band that it presents as general guidance. The contact points are made for a younger rider: a CUBE Kids saddle, 160 mm cranks and a rigid seatpost, with pedals fitted.
Maximum rider weight is 50 kg, including worn equipment. Maximum system weight is 80 kg, and the two limits are separate. The 50 kg rider figure is the one that can shorten how long the bike stays suitable as a child grows.
Moderate gravel and family miles
CUBE classifies the bike as 2Y, covering moderate unpaved and gravel routes, with drops limited to 15 cm. That is the shared riding it is specified for: leisure miles, gravel and unpaved paths, and small drops inside that limit. Harder trail categories sit beyond the classification.
An 80 mm Suntour XCT DS fork supplies the suspension for those moderate surfaces. Shimano Cues 1×9 gearing, with an 11–46T cassette, gives a wide spread and a low gear for the climbs, all from one shifter. Stopping is handled by Shimano BR-MT200 hydraulic discs, and the tyres are 2.1-inch Schwalbe Rocket Rons.
A kickstand is already fitted, which makes a stop on a ride simpler. The frame also has mudguard mounts and SIC 2.0 carrier mounts, and it is dropper-seatpost ready. Mudguards, a carrier and a dropper are separate additions. If you fit a compatible carrier, its maximum load is 10 kg.
Which Pro you are buying
The current bike is the Pro 400X, officially the ACID 240 HYBRID ROOKIE PRO 400X. A 2026 or 2027 label on an offer still describes this Pro 400X equipment: Bosch Performance Line SX and Shimano Cues on the 24-inch hardtail. The earlier Pro 400 is a previous build, published with different geometry and a 60 kg rider limit. Those older figures belong to that build. For this bike, use the 50 kg rider limit and the geometry published for the Pro 400X.
CUBE's suggested retail price is £1,999. That is the list price, and an offer can sit either side of it. The Cube Acid 240 Hybrid Rookie SLX 400X is a separate model at a higher suggested retail price, with an air fork, a fitted dropper and 1×11 gearing, for families who want that trail equipment. The Pro makes sense when the reason for buying is those shared hills and moderate gravel days, with your child still doing the pedalling.
Key Features & Benefits
- Bosch Purion 200: Display and assistance controls are built in, so there is no separate computer to fit
- Kickstand fitted: The bike stands on its own at a stop, without an extra accessory to buy
Geometry
Pro 400X, standard hardtail
These measurements apply to the current Pro 400X only. The earlier Pro 400 was published with different frame geometry.
| Build | Frame | Size | Wheel | Reach (mm) | Stack (mm) | Effective top tube (mm) | Head angle (degrees) | Seat angle (degrees) | Chainstay (mm) | Wheelbase (mm) | Seat tube (mm) | Head tube (mm) | BB height to hub (mm) | Protrusion height minus 80 mm (mm) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pro 400X | Standard hardtail | OneSize / 24-inch | 24-inch | 357 | 555 | 506 | 67 | 75 | 420 | 1032 | 335 | 100 | -50 | 668 |
Alternatives to Consider
Cube Acid 240 Hybrid Rookie SLX keeps the 24-inch Bosch Performance Line SX and 400 Wh platform and fits different trail equipment. The SLX has an 80 mm Suntour Raidon air fork, a dropper post, Shimano Cues 1×11, Magura MT Thirty brakes and 2.35-inch tyres. The Pro has a Suntour XCT fork, a rigid post, Shimano Cues 1×9, Shimano BR-MT200 brakes and 2.1-inch tyres. The SLX is the one when that air fork, dropper and 11-speed gearing are the point of the purchase. The Pro is the one when Bosch assistance, the simpler fork and the 1×9 are what the family riding needs.
Full Specification
Pro 400X build
ACID 240 HYBRID ROOKIE PRO 400X. Suggested retail price £1,999.
| Item | Detail |
|---|---|
| Frame and wheels | Aluminium Superlite hardtail; 24-inch wheels; Boost 148 rear axle; UDH hanger |
| Motor and assistance | Bosch Performance Line SX (BDU31); component specification 55 Nm; pedal assistance up to 20 km/h. CUBE's prose says up to 60 Nm; Bosch documents an available SX performance update. Delivered-bike update status is not specified. |
| Battery | Fixed, integrated Bosch CompactTube 400, 400 Wh |
| Controls | Bosch Purion 200 integrated display and control |
| Charger | Bosch 2 A charger, included |
| Range extender | Not fitted. Compatible with optional Bosch PowerMore 250 Wh range extender. No ride-distance claim is supplied for this build. |
| Suspension | Suntour XCT DS fork, straight steerer, 80 mm travel |
| Drivetrain | Shimano Cues 1×9: RD-U4000-GS derailleur, SL-U4010 shifter, CS-LG300 11–46T cassette; ACID MTB Hybrid Pro 38T crankset; KMC eGlide chain |
| Brakes | Shimano BR-MT200 hydraulic discs. CUBE specifies rotor sizes as 160/180 mm without identifying their front/rear order. Replacement rotors are permitted only in the original sizes for the particular bike model, series and model year. |
| Tyres | Schwalbe Rocket Ron Kevlar, 2.1-inch |
| Rims | ACID ZX20, tubeless-ready. Tubeless-ready rims do not establish that the supplied tyres are tubeless-ready. |
| Contact points and fitted accessories | 590 mm handlebar with 19 mm diameter; 160 mm cranks; CUBE Kids saddle; rigid 31.6 mm seatpost; pedals; flat-mount kickstand fitted |
| Use | Pedal-assisted family rides, leisure riding and moderate unpaved or gravel routes. CUBE 2Y classification: moderate unpaved and gravel routes, drops limited to 15 cm. |
| Mudguards, carrier and dropper | Mudguard mounts and SIC 2.0 carrier mounts; dropper-seatpost ready. Mudguards, a carrier and a dropper are not fitted. Maximum carrier load 10 kg only if a compatible carrier is fitted. |
Weight, limits and warranty
| Item | Detail |
|---|---|
| Bike weight | 17.6 kg |
| Maximum rider weight | 50 kg including worn equipment |
| Maximum system weight | 80 kg |
| Warranty | Two-year manufacturing-defect warranty from sale for the original purchaser, with claims directed through the selling dealer. Additional aluminium-frame breakage guarantee of six years for frames from model year 2012 onwards, subject to CUBE's warranty terms. |
CUBE warns that supply-chain circumstances may cause delivered components to differ from the published specification, so compare the bike itself with this list when you are weighing an offer.