Joining the Repeater 29er and Relay MX, is another ‘R’-named Transition e-bike, the new Regulator. 

• Best e-MTBs 2025 - top-performing e-mountain bikes for every situation
• How to store an e-MTB - storage solutions and best practices
• e-MTB items you never knew you needed

Transition’s Repeater and Relay are hard-hitting enduro e-bikes. However, the Regulator is configured for agility and lower weight builds, appealing to trail and all-mountain riders who value pedal assistance. The Regulator’s 29er front wheel slots into a 160mm fork, with a 150mm shock absorbing terrain inputs from that 27.5-inch rear wheel. 

LIT01687.jpg, by Liam Mercer

The frame design, kinematics and shock mounts are similar to other Transition e-bikes, with the Regulator featuring trunnion mount shocks. Transition is one of the few brands that’ve remained committed to trunnion shock-to-linkage mounts, believing in the benefits of easier packaging frame and suspension integration and reduced standover height offered by trunnion mounts.

Lighter Transition e-bike options

Providing the Regulator’s pedal assistance is Bosch’s proven Performance mid-drive motors. There are two motor options for the Regulator, CX or SX. 

LIT02157.jpg, by Liam Mercer

The Regulator CX has 85Nm of torque and draws energy from a 600Wh downtube battery pack, while the SX is rated for 55Nm and powered by a smaller 400Wh pack. All versions are compatible with Bosch’s 250Wh range extenders, and feature the Bosch system controller display and wireless mini remote function. 

The appeal of Transition’s new Regulator SX and its smaller battery, is lower weight and better on-trail agility. If you are the kind of rider who values being able to lean the bike and leverage that handlebar to immerse yourself into the descending singletrack experience, the lower weight of that smaller battery pack matters. 

The Regulator SX XT build, with Shimano’s M8100 drivetrain and TRP DH-R EVO brakes (with 203mm rotors), rolls DT Swiss XM 481 wheels and has an on-trail claimed weight of only 18.6kg. And that’s with proper Maxxis Assegai 3C EXO+ 2.5in front tyre and Minion DHRIII 2.4s at the rear, in the same casing. 

LIT01473.jpg, by Liam Mercer

Transition’s Regulator CX XT build comes in at purported 22.32kg with a similar drivetrain spec to the SX, but rolls DT Swiss H 1900 wheels, shod with 2.5in Schwalbe Albert Trail Evos, in the ultra-soft compound up front and the soft compound at the rear. 

Geometry on the Regulators is what you’d expect from a modern all-mountain bike with a 160mm fork. The core numbers are a 64.5-degree head angle and 480mm of reach (on a size large). On the Regulator CX, the lower shock mount flip chip slackens the Regulator to a 64-degree head angle. 

Launch prices for the Deore spec Regulators are £7,000, and XT builds are £8,500.

• www.transitionbikes.com (link is external)

You might also like:

• E-MTB geometry explained: how weight and geometry affect your ride
• Pivot Shuttle LT Pro XO e-MTB review
• Electric mountain bikes - everything you need to know