Transition’s new Regulator comes with a Bosch Performance CX Gen 5 motor, or the lightweight SX, it gets 150mm travel, a full carbon frame and superlative RockShox Ultimate suspension.

Bosch’s new CX motor had a redesign last year, and amidst all the excitement about its clever use of power, rattle free ride and lighter weight, we almost missed one crucial detail: it uses the same two-bolt mounting pattern as Bosch’s Performance SX mid-power motor.

Transition didn’t miss the memo because it just launched a brand new e-bike, called the Regulator you can get it with the new Bosch Performance CX Gen 5 motor, or the lightweight SX. Same frame, same mounting points, but two different drive units, and two different riding bikes, Transition says.

Transition Regulator CX uses the latest Bosch CX motor, or the SX

I’ve put in a first ride review on the Transition Regulator CX XT e-bike to see how it compares to the current best electric mountain bikes. Skip over to see how it rides or keep riding for prices, sizing and spec on both.

Transition Regulator need to know

• Transition Regulator CX gets Bosch Gen 5 motor, 85Nm torque, 600W peak power
• Regulator SX uses Bosch SX, 55Nm torque, 600W peak power, saves 800g weight
• Carbon frame with 150mm travel rear wheel travel, 160mm fork, mullet only wheel setup
• CX gets a 600Wh battery, SX uses 400Wh: both can use 250Wh range extender (not included)
• Four-bar suspension design, similar to the Bosch powered Santa Cruz Vala
• Two models in each motor option, XT costs £8,499 with RockShox Ultimate suspension, Deore is £6,999
• Size specific chainstays, flip chip on CX bike only, magnetic charge port cover

I half expected the new Regulator to be powered by the DJI Avinox motor, currently only available on Amflow’s PL Carbon

Regulator rivals

The Regulator is not Transition’s first e-bike, that honour went to the Repeater, which came out in 2022 with a Shimano EP8 motor. The US brand got onto the SRAM Powertrain launch programme though so quickly switched over in 2023, and at the same time launched its first lightweight e-bike, the Transition Relay, have a look at my first ride review.

The new Regulator sits somewhere in the middle in terms of weight. I measured a size Large CX XT model at a really respectable 21.5kg, meaning it’s lighter than both the Santa Cruz Vala and DJI-powered Amflow, although both have larger batteries.

The Regulator is a mullet bike with 150mm travel, it gets a flip chip for geo adjust

Regulator CX details

Both new bikes get 150mm travel and a 160mm fork, the main difference is that the CX bike gets the new CX motor, of course. I won’t go into the details because you can read Danny’s review for that.

The bike comes in four sizes, from SM-XL, and the frame is carbon and mullet only. You do get a flip chip to adjust the geometry a smidge, but I don’t think there’d be enough room to get a 29er rear wheel in there, even if it didn’t mess with the ride height.

Transition went with a 600Wh battery, reasoning you can always top it up with a 250Who range extender

Transition’s gone for a 600Wh battery, which was something of a surprise to me when the 800Wh battery also came out at the same time. This approach saves some 900g and almost certainly drops the price of the bike. You can also buy a 250Wh range extender separately to increase the range.

There are more details (of hundreds) that I really like about the new bike. The first two are about protection, Transition has fitted a squishy new chainstay protector strip, and there’s also a mud flap between the two halves of the bike to stop those little stones grinding away at the swingarm moves.

The third is a self closing magnetic charge port cover. I really like this touch because it means you’ll never again forget to close it, and leave your internals exposed to water and mud. Sounds kinda rude! Check out Transition’s ride video…

Regulator CX builds and price

The Transition Regulator CX ticks a lot of boxes.

Regulator CX XT £8,499

The top end bike gets the same motor and battery, while the drivetrain is largely Shimano XT. There are short 150mm cranks here too, this time SRAM S1000. Suspension is top end SRAM, with a Zeb Ultimate fork and Super Deluxe Ultimate shock.

DT Swiss Hybrid 370 wheels, Schwalbe Albert Radial tyres, TRP DH Evo brakes, a OneUp dropper and bar and Anvl Swage stem round it out.

Regulator CX Deore £6,999

The Deore bike uses Bosch Performance CX motor with a 600Wh battery. It gets a largely Shimano Deore drivetrain and four-pot brakes, with the exception of the crank which is a Samox. Interestingly it’s incredibly short at 150mm, presumably to help with ground clearance.

There’s a RockShox Super Deluxe Base shock, Domain Gold RC forks, Race Face cockpit and WTB ST i30 rims. I’m not sure about the tyres as yet, the details are still being decided by Transition and UK importer Windwave.

Regulator SX details

The SX uses Bosch’s SX motor, with 55Nm of torque and 600W peak power it’s punchy but not in the same league as the CX bike. We’ve no idea about the weight yet but I’d expect it to be around 20.5kg, given the weight of the CX bike.

The SX is pretty much the same bike to all intents and purposes, with the same travel and close geometry. There’s no flip chip to change the geometry though, presumably to save weight and maintenance. The 400Wh battery is also not removable, unlike the Relay where the battery and motor could be removed and the bike ridden ‘naturally aspirated’.

Regulator SX builds and price

Regulator SX XT £8,499

Both SX builds get the Bosch SX motor with 55Nm torque and 600W peak power. They use the same drivetrain and brakes as the CX models, but the build is slightly lighter. That means the XT model gets a Lyrik Ultimate fork instead of a Zeb, and DT Swiss XM 481 rims

Regulator SX Deore £6,999

The Deore model gets a Lyrik Base fork, Super Dleuxe Select shock, the rest of the spec pretty much mirrors the CX bike.

Regulator CX geometry and sizing

I ran a tape measure over the size Large CX XT bike, in the low setting the geo looks like this…

• Head angle: 64.3º
• Seat angle: 74.8º
• Effective seat angle: 77.4º
• BB height: 339mm
• Chainstay: 446mm
• Front centre: 830mm
• Wheelbase: 1,276mm
• Down tube: 760mm
• Seat tube: 440mm
• Top tube: 615mm
• Reach: 485mm