Transition Regulator CX

The Transition Regulator CX is for trail and all-mountain riders who want serious climbing assistance without the heaviest, most battery-dominated feel. A carbon chassis, Bosch power, a 160mm fork and 150mm of rear travel make extra laps, steeper local climbs and longer hilly days realistic, while you still get a dedicated mixed-wheel bike that corners and changes line like a trail bike.

This is the current UK model, sitting above the Regulator SX as Transition's full-power Bosch option and short of the longer-travel Repeater PT.

Transition Regulator CX prices and current UK offers

Official original UK RRPs are £6,999 for Deore, £7,499 for Eagle 70, £8,499 for mechanical XT, £8,899 for Eagle 90 and £9,899 for XT Di2. Drivetrain, suspension, brakes, wheels, display and cockpit all change between those packages, and a mechanical XT bike is not the electronic XT Di2 build.

Deore is the lowest-priced way onto the shared carbon frame and Bosch system. Eagle 70 is the one to want if durable cable-operated Full Mount shifting is the priority, mechanical XT is the more significant suspension and wheel upgrade, and Eagle 90 or XT Di2 only make sense if you specifically want those drivetrains and their premium kits.

What is the latest Transition Regulator CX?

The latest Transition Regulator CX is the first-generation carbon chassis: GiddyUp suspension, a Bosch Performance Line CX smart system and a 600Wh battery inside the downtube. Current enabled motor settings are advertised at up to 120Nm of torque and 750W peak, though delivered output depends on Bosch software and the modes you actually run. Higher output can eat range and add wear, so treat those peaks as available performance rather than an all-day default.

Every stock build uses a 160mm fork and 150mm of rear travel with a 205mm x 60mm trunnion shock. A compatible 205mm x 65mm shock can create a 160mm rear-travel setup, but that is an aftermarket change rather than factory equipment.

Carbon frame, Bosch power and mixed-wheel ride character

The carbon frame carries an integrated top guide, frame protection, a main-pivot debris guard and conventional cable ports outside the headset, so you are not fishing housing through the head tube. GiddyUp is designed around a 27% progressive leverage curve: supple at the start, supportive in the middle and resistant to harsh bottom-outs once sag is set correctly. A high/low chip lets you run a slightly higher, steeper stance for clearance and agility, or drop it for a more planted feel. Large and X-Large also get longer chainstays than Small and Medium.

Wheels are a dedicated mixed-wheel format - 29-inch front, 27.5-inch rear - and Transition rules out a 29-inch rear conversion. The smaller rear wheel is there for easier direction changes and body clearance, with a 27.5 x 2.6-inch rear tyre as the published guideline. That layout will not suit a rider who specifically wants a full 29er.

For a full-power eMTB it feels comparatively light and lively. Mike Kazimer's Pinkbike test, run on original Bosch output settings, found easy line placement, a centred and upright descending position and strong technical climbing. Short 150mm cranks on most builds (155mm on XT Di2) and steep effective seat angles help on awkward climbs. It stays capable on rough ground, but the geometry and travel are there for involved all-mountain riding rather than a downhill-first 170mm-plus platform.

Which Transition Regulator CX build should you buy?

All five packages use the carbon frame, Bosch Performance Line CX system, 600Wh battery, mixed wheels, 160mm fork travel and 150mm rear travel. The money changes the controls, suspension and rolling stock.

Regulator CX Deore (£6,999) uses mechanical Shimano Deore M6100 with a 10-51t cassette and 34t ring, a RockShox Domain Gold RC fork, SuperDeluxe Base shock, four-piston Deore M6120 brakes on 203mm rotors and WTB ST i30 rims on Novatec hubs. Maxxis Assegai 2.5 and Minion DHR II 2.4 tyres, a Race Face Chester bar and a size-specific SDG Tellis dropper keep the kit straightforward. Claimed weight is 22.25 kg in Medium, with Bosch's System Controller and Wireless Mini Remote.

Regulator CX Eagle 70 (£7,499) keeps that Domain and SuperDeluxe Base suspension and the same WTB/Novatec wheel tier, then adds cable-operated SRAM Eagle 70 Full Mount Transmission (10-52t) and Maven Base brakes on 200mm rotors. Tyres stay Maxxis, with MaxxGrip on the front Assegai and MaxxTerra on the rear DHR II. This is also where the Kiox 400c display appears. Transition has not published a final weight.

Regulator CX XT (£8,499) pairs mechanical Shimano XT M8100 with a ZEB Ultimate fork, SuperDeluxe Ultimate shock, TRP EVO Pro brakes on 203mm rotors and DT Swiss H 1900 wheels. You also get Schwalbe Albert 2.5 tyres, a OneUp carbon bar, a 40mm ANVL stem and a size-specific OneUp dropper. Claimed Medium weight is 21.31 kg, and the display remains the System Controller with Wireless Mini Remote.

Regulator CX Eagle 90 (£8,899) combines cable-operated Eagle 90 Full Mount Transmission (10-52t) with the ZEB Ultimate and SuperDeluxe Ultimate pairing, Maven Silver brakes on 200mm rotors and DT Swiss H 1900 wheels. A size-specific Race Face Turbine bar and OneUp dropper sit up front, with Maxxis Assegai and Minion DHR II tyres and a Kiox 400c. Claimed Medium weight is 21.84 kg.

Regulator CX XT Di2 (£9,899) is the flagship: electronic Shimano XT Di2 eMTB shifting, a Fox 38 Factory Grip X2 fork, Fox Float X2 Factory shock, TRP EVO Pro brakes, DT Swiss HX 1700 wheels with an anti-kickback rear hub, and Schwalbe radial tyres. You also get a size-specific Race Face Era bar, Fox Transfer Factory dropper and Kiox 400c. Cranks are 155mm E*Thirteen Helix Race rather than 150mm, and Medium is claimed at 21.86 kg. That package is for riders who specifically want the electronic shifting and Fox/DT Swiss kit; the same frame and motor are already on the cheaper builds.

UK maintenance, charging and long-term ownership

The 600Wh battery is fixed inside the downtube and is normally charged on the complete bike. Removing it means taking out the drive unit and other parts, so treat that as workshop work. You'll want a secure indoor storage spot within reach of a socket before you buy, especially in a flat or a shared shed with no nearby electricity.

Medium, Large and X-Large frames can take an optional Bosch PowerMore 250Wh extender, with the correct 150mm cable and mounting kit, taking total nominal capacity to 850Wh. It cannot power the bike on its own if the main battery is flat, and size Small cannot use it at all. On Small, conservative support modes and planned charging are the practical answer. A Kiox 400c can also be added to compatible lower builds with the correct adapter if you want richer ride data without jumping to Eagle 70 or above.

Winter ownership is ordinary eMTB cleaning and lubrication plus a closer look at the charging port, motor cover, pivots and the main-pivot debris guard. The stock soft-compound, reinforced tyres suit wet, technical UK riding, but they'll wear faster and cost more to replace than lighter trail rubber. Firmware, diagnostics and Bosch warranty work are best done through a Bosch-certified workshop within a realistic travelling distance.

Transition covers the frame with an original-owner lifetime warranty, and the Bosch system has separate two-year cover. Rear rotors can grow to the published 223mm frame maximum with the right adapter if you want more to lean on during long, steep descents.

Pick the Transition Regulator CX when you want Bosch-level climbing help and a mixed-wheel trail-bike character in the same carbon chassis, then spend up only as far as the suspension, wheels and shifting you will actually notice. Deore already gets you on the bike that matters; the dearer builds polish the edges. Get the size right around reach as much as height, plan the charging, and the payoff is more technical climbs, extra laps and hilly days that still feel like mountain biking.