Focus Thron Impulse review

Haters look away – it's an e-bike

Our rating 
3.5 out of 5 star rating 3.5
GBP £2,999.00 RRP

Our review

Easy to use and easy to ride, the Thron helps you keep up with far fitter riders
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You’d think e-bikes were wired KGB-style straight to the haters’ nipples, such is the fury of their denunciations, but the reality is that some – this Focus Thron Impulse, for example – are very capable trail bikes.


Frame and equipment: the familiar and the lesser-known

The familiar bits are the 120mm travel frame, 650b wheels, RockShox suspension and Schwalbe Nobby Nics. Despite these and a steepish 68.5-degree head angle, our Large is very stable at speed and over rough ground, thanks in part to its long-ish 450mm chainstays and 1181mm wheelbase. But only in part. The other part is the 36V battery pack and Impulse II motor, which contribute to a massive 22kg (48.5lb) weight.

The thron’s 36v battery pack and impulse ii motor help swell its weight to a bruising 22kg:
Russell Burton

The Thron’s 36v battery pack and Impulse II motor help swell its weight to a bruising 22kg

The RockShox 30 Gold TK RL fork reacts well to small bumps and feels plush and controlled for a budget unit. The QR axle is a disappointment, and leg flex is enough to work the QR loose; be sure to clamp it firmly. At the back a 12x142mm axle and RockShox’ Monarch RT keep things more solidly under control, and both ends have lockouts (the front via remote) though we never felt the need. They reduce traction, and who needs extra efficiency when you’ve got a motor?

A Shimano Deore shifter and clutch derailleur mean shifting is solid, and as the motor senses shifts and backs off there’s no undue strain on the chain. With a huge 38T front ring it initially feels overgeared, but responds to slow torque better than rapid spinning. 

Ride and handling: impressive performance with a few worrying issues

The Thron is easy to use. It takes five-six seconds to start up, and after that the thumb switch on the left bar deals with power levels. The readout is clear and gently backlit, and constantly displays the battery level plus a slightly laggy speedo.

Under power you forget its weight until you get it in the air, and it flicks from side to side quickly too. If the bike’s off, a single button press displays its status, and judicious use of Eco(nomy) mode gives a range over 70km.

A clear bar-mounted readout displays power levels and speed:
Russell Burton

A clear bar-mounted readout displays power levels and speed

We suffered some nasty creaking from the bottom bracket, and checking Focus’ bolt-on cranks needs either a socket set or careful spannering, but worse is the nest of fine cables beneath the BB – they’re vulnerable. Our bike failed for 10 very wet minutes before reviving, and we suspect these wires.


The Thron works its lowly spec impressively hard. The electric assistance makes the climbs easier and faster, while the sheer weight adds stability, compliance and confidence to the descents. If you don’t mind the complexity – and the wrath of the e-bike haters – this bike will make you faster.

Product Specifications


Name Thron Impulse (14)
Brand Focus

Weight (kg) 22
Year 2014
Weight (lb) 48.5