Introducing the 2023 BMC Fourstroke AMP LT – All the details about the new light eMTB and its TQ HPR 50 motor

More traction, more power, more trails. That’s what BMC promise with the 2023 Fourstroke AMP LT, featuring the TQ-HPR 50 motor and available in four variants. Thanks to a weight of just 15.9 kg, revised geometry, and a new suspension system, it should allow you to have even more fun on the trails. Read on for all the details.

As we predicted, 2022 marks the beginning of a new generation of light eMTBs. Lightweight eMTBs with somewhat less support are all the rage. There are several exciting systems currently available from FAZUA, TQ, and Maxon, as well as variants of the Shimano EP8 motor such as on the ROTWILD R.E375. After Trek‘s exclusive launch partnership with TQ’s new motor, we’re now seeing other eMTBs follow suit, relying on the most natural feeling and promising system for experienced riders: the TQ HPR 50.
Grüzi, as the Swiss like to greet. The BMC Fourstroke AMP LT comes at us straight outta the Alps and is based on the analogue BMC Fourstroke 01 LT ONE, which is a capable xc bike suitable for use on fast trails with lots of climbs as well as more downhill-oriented terrain. This is BMC’s area of expertise, but friends of bigger hits and gnarlier descents are better off with the sister brand SCOR, as we found out for you in our review of the 4060 Z. By the way, the LT on the Fourstroke doesn’t stand for “light” but for “long travel”, providing 120 mm travel, which is 20 mm more than the previous version.

The new suspension system is intended to provide improved traction, which should make the most of the motor’s support on the climbs. The new HPR 50 motor from TQ is designed to provide just the right amount of assistance, extending, and even improving your trail experience. It’s a great option for experienced riders who would like a bit of assistance on tours, keeping up with friends on their gravel bikes, or for athletes who want to stick to their training plan or do a recovery ride even when they’re out and about in mountainous terrain.

The 2023 BMC Fourstroke amp LT in detail

As you can see, it’s almost indistinguishable from its analogue sibling. It’s just the slightly beefier down tube and the motor peeking out through the bottom bracket that give it away. The TQ HPR 50 is seamlessly integrated into the frame and delivers 50 Nm of torque – well-hidden power! The Fourstroke AMP LT comes with a 360 Wh battery and the option of a Range Extender, which gets mounted on the down tube. In that case, however, you’ll have to sacrifice one of your water bottles, since, without it, frame sizes M and up have enough room on the down tube for two 550 ml bottles. Even the size S comes with four bottle cage bosses, accommodating one 550 ml bottle and a smaller 350 ml version.

Efficiency is key for the AMP LT. Accordingly, the size M carbon frame and its light components tip the scales at a total of just 15.9 kg, according to BMC. Moreover, BMC have tried to combine plenty of traction with a high degree of pedalling efficiency in their APS (Advanced Pivot System) suspension, providing 120 mm travel at the rear together with a 120 mm fork. The four model variants are available in four sizes each and will set you back from € 6,899 to € 13,999.

The build variants of the 2023 BMC Fourstroke AMP LT in detail

The Fourstroke AMP LT LTD comes equipped with a FOX FLOAT 34 Factory fork in the weight-optimised step-cast version, while the other three models rely on variants of the RockShox SID model. The shocks are specced correspondingly. While the flagship model comes with wireless RockShox components for the dropper post and drivetrain, the other models have to make do with mechanical alternatives. Unfortunately, the SRAM G2 Ultimate brakes on the range topping model must rely on 180 mm rotors. The components of the AMP LT are similar to those of the analogue Four-stroke, but they limit the potential of its electrified counterpart. Pairing the same components with more power from the motor and the added weight that brings limits the bike’s capabilities and can’t do justice to the intended purpose. We’d like bigger rotors and a beefier fork, for example, providing increased stopping power on steep descents while offering more suspension reserves. In addition, the Fourstroke AMP LT is not meant for heavy riders, as the bike has a maximum permissible weight limit of just 110 kg (ONE, TWO) or 120 kg (THREE, LTD).

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The geometry of the 2023 BMC Fourstroke AMP LT

In general, the geometry is based on the DNA of the previous Fourstroke family. However, the geometry of the AMP LT follows the trend of progressive XC bikes, leaning more towards trails and technical terrain. A relatively slack head angle of 66.5° should improve the bike’s downhill capabilities and the slightly longer travel should offer the rider more reserves when things get rough. The concept could work with the appropriately capable components, but, unfortunately, BMC chose not to spec even the flagship bike accordingly.

Size	S	M	L	XL
Top tube	574 mm	597 mm	620 mm	644 mm
Seat tube	420 mm	430 mm	470 mm	490 mm
Head tube	90 mm	102 mm	113 mm	125 mm
Steering angle	66.5°	66.5°	66.5°	66.5°
Seating angle	77°	77°	77°	77°
Chainstay	435 mm	435 mm	435 mm	435 mm
BB Drop	40 mm	40 mm	40 mm	40 mm
Wheelbase	1,157 mm	1,178 mm	1,202 mm	1,227 mm
Reach	437 mm	457 mm	476 mm	496 mm
Stack	594 mm	605 mm	615 mm	67 mm

Our conclusion on the BMC Fourstroke AMP LT

With the Fourstroke AMP LT, BMC continue to fuel the XC ebike niche, outfitting their analogue racing machine with a motor. The HPR 50 motor has been neatly integrated, but there is still room for improvement regarding the spec and the low maximum permissible weight limit. While the electric motor does increase the bike’s versatility, it can only do so with the right components. We’ll have to wait until we can get out mitts on the BMC Fourstroke AMP LT to see how it fares in practice.

For more information, visit bmc-switzerland.com.

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Words: Gabriel Knapp Photos: BMC