Is the FLYER a piece of fine Swiss engineering, or more of a blunt instrument for the rough stuff? FLYER enter our huge 2024 e-mountainbike group test with the revised version of their classic trail eMTB, the Uproc, which comes equipped with a Bosch Performance Line CX motor and generates 150 mm of travel front and rear. Retailing at € 7,999, it’s one of the most affordable competitors in this test. But how does the latest descendant of the Uproc dynasty perform on the trail?

FLYER Uproc X 8.70 | Bosch Performance Line CX/750 Wh | 150/150 mm (f/r)
25.1 kg in size M | € 7,999 | Manufacturer’s website

The Uproc range has long been an integral part of FLYER’s portfolio. The X suffix designates the all-purpose variant, which generates 150 mm of travel (f/r) and was designed to cut a fine figure in a wide range of scenarios, from long tours to Alpine crossings and descents in challenging terrain. For the latest Uproc X, FLYER ditched the Panasonic motor of the outgoing model, opting instead for a Bosch Performance Line CX drive system. While this move might detract a little from the bike’s exotic flair, the Swiss brand remains one of the most exclusive manufacturers in ZEG’s massive brand portfolio. The Zweirad-Einkaufs-Genossenschaft also includes BULLS, Pegasus and numerous other bike brands. Incidentally, the latest iteration of the Uproc X maintains the same mullet wheel setup as its predecessor. How did the FLYER fare in our huge 2024 eMTB group test, and can it push ahead of the competition with its new improvements?

For an overview of the test fleet head to the group test: The best eMTB of 2024 – 27 of the most exciting models in our comparison test

What sets the 2024 FLYER Uproc X 8.70 apart from the competition?

When you see the “Swiss Quality Assembly” slogan on the top tube, the expectations are high. But does the FLYER Uproc X 8.70’s manufacturing quality do justice to the sticker’s claim? The full carbon frame is painted in white, with grey accents in the main triangle and a grey swingarm. The latter is also made of carbon and, combined with an alloy shock link, brings the total weight up to 25.1 kg in size M. The FLYER Uproc X’s predecessor didn’t fare too well in last year’s big eMTB group test, but a few things seem to have changed on the latest iteration. The distinctive kink in the top tube is no longer part of FLYER’s design language and the extravagant Panasonic motor system, including the large remote and exposed display, have been superseded by a more elegant Bosch Performance Line CX motor system. This delivers 85 Nm of torque and is elegantly integrated into the frame, drawing its power from a Bosch PowerTube 750 Wh battery.

The ONZA Porcupine tires are named after the large rodent with a coat of sharp spines. In wet conditions and loose terrain, they lose grip easily, spinning out of control.
Trade-off: The FOX 36 Performance FIT Grip fork is easy to adjust for beginners, but lacks progression.
Swissembled: FLYER’s depth of production doesn’t do justice to the Made in Switzerland sticker. They are at least assembled in Switzerland.

However, this can not be removed from the side of the frame, and with the new version you’ll have to turn the bike upside down (or at least on its side) to remove the 750 Wh battery, which is secured with a bolt and slides out from the bottom of the down tube. The cover is firmly secured to the battery, forming a clean transition to the motor area. Moreover, the Uproc X is also compatible with Bosch’s 250 Wh PowerMore Range Extender. The motor is paired with a bar-mounted Bosch Kiox 300 display on the left of the stem with Bosch’s eBike Lock feature, which allows you to shut down the motor functions via Bluetooth, with the standard Bosch Connect module enabling a bike location service and thus allowing you to track down your bike if it gets stolen.

Centred! The charging port is easily accessible and not within the crank’s rotation range. This allows for light maintenance such as lubing the chain while charging.
Cable operated: The Shimano drivetrain isn’t electronic, and is only as intelligent as the person operating it. Under full load, the drivetrain makes a racket, especially when the Bosch motor is under full steam.

The FLYER Uproc X 8.70 relies on proven FOX suspension, consisting of a 150 mm 36 Performance fork with FIT Grip damper, which is simple and intuitive to adjust but offers fewer adjustment options than its superior GRIP2 counterpart. The fork is complemented by a FOX FLOAT X Performance shock, which controls 150 mm travel at the rear and, like the fork, only offers limited adjustment options with its rebound and compression dials and a lockout switch. At 150 mm, the KS LEV INTEGRA Vario dropper post offers less travel than the average in this test, and limits your freedom of movement on the trail. Shifting and braking is taken care of by a Shimano XT groupset. The XT 4-piston brakes are paired with 203 mm rotors front and rear, ensuring powerful and reliable deceleration, even on challenging descents. A 12-speed, cable operated Shimano XT drivetrain ensures smooth, precise shifting. For the cable routing, FLYER rely on a conventional internal routing system with cable ports on the frame, which makes it easier to service the bike. The cockpit consists entirely of in-house components, except for the small, integrated Granite multitool, which allows you to carry out basic trailside repairs. The MonkeyLink mount under the stem is compatible with several clip-on headlights, and is wired directly into the bike’s main battery. The DT Swiss H 1900 mullet wheelset is paired with ONZA tires, with a 2.4” Porcupine TRC at the front and a 2.6” GRC at the rear.What is the 2024 FLYER Uproc X 8.70 capable on the trail?

FLYER Uproc X 8.70

€ 7,999


Motor Bosch Performance Line CX 85 Nm
Battery Bosch PowerTube 750 Wh
Display Bosch Kiox 300
Fork FOX 36 Performance 150 mm
Rear Shock FOX FLOAT X Performance 150 mm
Seatpost KS LEV INTEGRA 150 mm
Brakes Shimano XT 203/203 mm
Drivetrain Shimano XT 1x12
Stem SATORI Ursa 35 mm
Handlebar FLYER Alloy 780 mm
Wheelset DT Swiss H1900 29"/27.5"
Tires ONZA Aquila GRC/50 2.5

Technical Data

Size S M L XL
Weight 25.1 kg
Perm. total weight 140 kg
Max. payload (rider/equipment) 115 kg
Trailer approval no
Kickstand mount no

Specific Features

MonkeyLink light holder

Tuning tip: Volume spacer in the fork to improve progression

What is the FLYER Uproc X 8.70 2024 capable of on the trail?

The FLYER places you in a comfortable, upright pedalling position, which, together with the efficient rear suspension, ensures a high level of long-distance comfort. The weight is evenly distributed between the front and rear, with a slight bias towards the rear, making it easy to tackle longer tours. Riding uphill, the suspension generates good traction, with the Bosch Performance Line CX motor providing powerful thrust even at low cadences. This makes it easy to tackle steep singletrack climbs without having to actively weight the front wheel, and allows you to hold your line with precision even on technical terrain with bigger steps and ruts. The Uproc X 8.70 is always easy and intuitive to ride, and doesn’t force you to actively shift your weight to find traction. For comparison’s sake, it outperforms bikes like the ROTWILD or the GASGAS.

While Catalunya’s dry rocks provide plenty of traction, in wet conditions the tires reach their limits quickly.
Enjoy responsibly. With big compressions, the FLYER’s fork tends to dive deep into its travel. We recommend cranking the compression dial all the way up!

When gravity takes over, the FLYER impresses with intuitive handling and makes you feel at ease right from the top – the entire test crew felt at home from the first few pedal strokes on the trail with the Uproc X. Like the FOCUS SAM², the FLYER isn’t easily perturbed, making it easy to shred your way back down into the valley with its intuitive, predictable handling. The FLYER is particularly great fun on flowing trails, but is slightly less lively than the firm Lapierre Overvolt GLP 3, for example. The suspension successfully bridges the bike’s touring and trail capabilities but isn’t tweaked towards performance. That said, it still offers a good mix of traction and support which makes the FLYER great fun on the trail, while the limited adjustment options make the initial setup easier. The rear suspension effortlessly filters out bigger hits but at the same time provides sufficient feedback from the ground. However, there’s one drawback: the fork clearly lacks end progression and tends to dive deep into its travel with bigger drops and compressions. Unfortunately, this robs you of confidence on steep, rough descents. If you’re familiar with suspension, you should add a volume spacer or two to increase the support. Moreover, the shallow-profiled tires tend to lose grip easily in muddy conditions and loose terrain – here the competition fares significantly better! As a result, the FLYER doesn’t perform well outside of dry, grippy conditions, but it makes up for this with good all-round qualities and an excellent feel-good factor. This is spoiled somewhat by the fork, which often forces you to pick the chicken line rather than sending it over larger gaps. Overall, the FLYER is more of a loyal road-trip companion than a two-wheeled motivational speaker encouraging you to get rowdy on the trail.

The FLYER isn’t a rowdy downhill bruiser but a fun, intuitive rig for all skill levels.

Size S M L XL
Top tube 567 mm 600 mm 632 mm 664 mm
Seat tube 400 mm 415 mm 450 mm 485 mm
Head tube 102 mm 110 mm 120 mm 140 mm
Head angle 64.5° 65.0° 65.0° 65.0°
Seat angle 77.0° 77.0° 77.0° 77.0°
Chainstays 460 mm 460 mm 460 mm 460 mm
BB Drop 31 mm 31 mm 31 mm 31 mm
Wheelbase 1,221 mm 1,229 mm 1,261 mm 1,292 mm
Reach 435 mm 445 mm 473 mm 495 mm
Stack 612 mm 622 mm 631 mm 650 mm
helmet Fox Mainframe Mips Helm | Hip Pack Thule Rail2
Jersey DHaRCO Womens Gravity Jersey Sunset | Pants ION Shelter 2L Softshell | Shoes Leatt 2.0 Flat | Socks Monserat TS03 | Gloves Endura FS260-Pro Nemo

Who should take a closer look at the 2024 FLYER Uproc X 8.70 and who should look elsewhere?

The FLYER Uproc is true to its Swiss roots, making its way to the top of the mountain without breaking a sweat. This makes it a good option for those riders who love to tackle technical singletrack climbs and flowing descents. The high feel-good factor makes it suitable for anyone who wants to enjoy some relaxed trail riding close to home, and isn’t looking to secure all of the local KOMs – with the spec being a limiting factor. The FLYER is the right choice if you’re looking for a fun riding companion but also want to use your bike on a daily basis, which is where the integrated light mount and Bosch’s software features really come in handy.

Riding Characteristics


  1. unbalanced
  2. coherent


  1. cumbersome
  2. clever


  1. flop
  2. top


  1. low
  2. high


  1. demanding
  2. intuitive


  1. boring
  2. lively

Intended Use

Gravel roads

Technical climbs

Flowtrail descents

Technical descents

Our conclusions about the FLYER Uproc X 8.70

With the Uproc X 8.70, FLYER offer an excellent overall package that appeals to a broad target group, simply delivering top Swiss quality with no nasty surprises. For € 7,999, you’ll get a well-rounded, beginner-friendly bike at a fair price. The FLYER is great fun without feeling challenging, whether it’s on tours, climbs or flowing descents. Although the Uproc lacks a touch of flair to secure Best in Test, it manages to keep in the midfield of this test.


  • Good allrounder
  • Beginner-friendly, intuitive handling and great feel-good factor
  • Integrated tool in the headset


  • Fork lacks end-stroke progression

For more information, visit

The test field

For an overview of the test fleet head to the group test: The best eMTB of 2024 – 27 of the most exciting models in our comparison test

All bikes in test: BULLS VUCA EVO AM 2 (Click for review) | BULLS SONIC EVO AM SX-I (Click for review) | Canyon Strive:ON CFR LTD (Click for review) | Canyon Torque:ON CF Roczen (Click for review) | CENTURION No Pogo SL R8000i (Click for review) | CUBE AMS Hybrid ONE44 (Click for review) | FLYER Uproc X 8.70 | FOCUS SAM² 6.9 (Click for review) | GASGAS ECC 6 (Click for review) | GIANT Trance X Advanced E+ Elite 0 (Click for review) | KTM Macina Scarp SX Prime (Click for review) | Lapierre Overvolt GLP3 (Click for review) | Merida eOne-Sixty 10K (Click for review) | Mondraker Neat RR SL (Click for review) | Moustache Samedi 29 Game 11 FOX (Click for review) | Orbea WILD M-LTD (Click for review) | Pivot Shuttle AM Team (Click for review) | Propain Ekano 2 CF (Click for review) | RADON RENDER 10.0 HD (Click for review) | ROTWILD R.X 1000 Ultra (Click for review) | Santa Cruz Heckler SL XX AXS RSV (Click for review) | SCOR 4060 ST (Click for review) | SCOTT Voltage eRide 900 Tuned (Click for review) | SIMPLON Rapcon Pmax Pinion (Click for review) | Specialized Turbo Levo SL Expert (Click for review) | Specialized Turbo Levo Pro (Click for review) | Spherik E-SMT XX AXS (Click for review)

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Words: Julian Schwede Photos: Peter Walker

About the author

Julian Schwede

Juli is used to dealing with big rigs. Besides working on his bike, he also tinkered and worked on buses after completing his training as a vehicle mechatronics engineer. Since the development of large-scale electric motors was too slow for him, he went on to study technical business administration while building carbon fibre tables on the side. Though his DJ bike is welded from thick aluminium tubes, his full-susser is made of carbon and it's already taken him to the top of numerous summits. Apart from biking, he likes climbing via ferratas or vertically on the wall. Nowadays, his personal bike gets ridden less as he tests the bikes that get sent to us, pushing them to their limits to see what they're capable of. In addition to bike reviews, Juli also takes care of the daily news and thinks of himself as the Daily Planet reporter Clark Kent.