Rock solid, all-mountain ready and feels like a proper workhorse

Product Overview

Giant Reign E+ O Pro


Giant Reign E+ O Pro: first ride


The new electric Giant Reign E is brother to the successful enduro machine with the same name, and the brand’s first real foray into longer-travel e-bikes.

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Giant Reign E

Giant Reign E+ O Pro: first ride

Being electric means it targets wilderness trails as much as bike park riding and built to handle ‘steeper ups and downs than you thought possible’.

The chassis uses huge aluminium tubing profiles and a fully sealed composite design (with rubber downtube flap and integrated protector) to house Yamaha’s brand new motor. Three different models all share the same drive unit and battery and deliver 160mm rear and 170mm front travel.

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Giant Reign E

Reach measurements across four sizes are longer than the brand’s, shorter-travel, Trance E (475mm in size Large here), plus there’s a slacker 64.5° head angle and, significantly steeper, 76° seat angle. Fox 36 forks and Float X2 shocks are found throughout the range in various guises.

Giant Reign E

Battery and motor

Giant’s high-output battery was designed alongside electronics giant Panasonic and delivers 500w of power. The rating doesn’t sound that radical, but the motor claims significant efficiency and smoothness gains and we experienced excellent lifespan at the launch. This is in part due to special tuning and the use of six sensors in the intelligent ‘Smart Assist’ mode that interpret torque and power requirements on-the-fly.

While being much quieter than previously (around 15%), the new SyncDrive Pro motor also revs at a higher cadence, which increases the power bandwidth for smoother support and no tapering off around full power load scenarios.

The fully internal battery uses a wraparound aluminium casing for better heat dissipation, and also wider cell spacing that allows a higher amperage and better performance. Giant claims the battery will fast charge to 80% in one hour.

Giant Reign E

A unique Reign E feature is a 250w add-on ‘range extender’ that lives externally on top of the down tube and plugs into an external frame port. Unlike some aftermarket solutions, Giant’s extra cash power pack delivers the exact same output as the integrated battery (making for 750w total) and cleverly auto-shifts over for the 2.5kg extra weight you lug around.

Giant Reign E

Giant’s familiar RideControl One handlebar unit remains, and it can sync with any computer or Garmin with ANT+ protocols for battery and support levels and range.

Giant Reign E

The ride

We spent a full twelve hours blasting around Morzine on the top tier Reign E+ zero model using full electronic SRAM AXS kit and Giant’s own TRX carbon wheels clad in 2.6in Maxxis tyres. The 30mm inside hoops use DT Swiss internals with steel ratchets to reduce lag and get the power down, and proved stiff and tough enough (despite our scepticism) across a big group of journos in a lift-riding environment.

Giant Reign E

The new Yamaha motor is indeed smooth under power and long lasting, but also has a strange quirk of ‘revving’ or trembling while stationary if you rest one foot on the pedal seated. The lengthy (469.5mm) chainstays make the Reign E a superb climber, but less nimble and less ‘like an analogue bike’ than some new e-bikes in playful ‘berm and jump’ scenarios.

Giant Reign E


Overall, Giant’s electric enduro rig is rock solid, all-mountain ready and feels like a proper workhorse.


Frame:Giant ALUXX SL grade 160mm travel
Shock:Fox Float X2 Factory EVOL
Fork:Fox Float 36 Factory GRIP2 170mm travel
Motor:Giant/Yamaha SyncDrive1 80nm
Battery:Giant EnergyPak Smart 500
Drivetrain:SRAM XO1 Eagle AXS 12-speed, Praxis e-Carbon cranks, SRAM X-Sync Eagle 36t chainring
Wheels:Giant E-TRX 30mm internal. Maxxis Minion DHF EXO+ 27.5 x 2.6in F, Maxxis High Roller II 27.5 x 2.6in DoubleDown rear
Brakes:SRAM Code R 220mm rotor F, 200mm rotor R
Components:RockShox Reverb AXS, Giant Contact SL saddle, Giant Contact SL stem 50mm, Giant Contact SL 35 Trail bar 35x800mm
Sizes:S, M, L, XL
Size tested:Large
Head angle:64.5°
Seat angle:76°
BB height:343mm
Chain stay:469.5mm
Front centre:806.5mm
Down tube:725mm
Top tube:645mm