KELLYS Theos RS50

KELLYS THEOS RS50: A strong trail player with modern technology

The KELLYS THEOS model series has been one of the most sophisticated e-bikes in its category for several years. The Theos RS50 variant is new for 2026 and targets demanding hobby riders and riders who want the most from an e-MTB - high performance, honest travel, modern geometry and advanced technology. And that's exactly what the RS50 offers in a surprisingly balanced package.

Robust frame and modern construction

The Theos RS50 is built on a full-suspension frame with Think Link® construction, which features high suspension sensitivity and minimal pedaling influence on rear-end performance. The combination of 160mm of travel at the front and 130mm at the rear can easily swallow technical trail, steep climbs and rocky descents.

The frame is made from durable 6061 T6 aluminium alloy and its fabrication benefits from robotic welding in Europe. This contributes to quality, stiffness and durability. Another interesting feature is the use of a mullet wheel combination - 29″ at the front and 27.5″ at the rear. This choice gives the rider stability on fast sections and also playfulness in tight corners.

Power that doesn't disappoint: Panasonic GXM MaxxPro

At the heart of the e-bike is the powerful Panasonic GXM MaxxPro mid-motor with up to 105 Nm of torque. This is a value that ranks among the highest on the market without hesitation. The motor excels in smoothness, refined performance and very low pedalling response lag, which you'll appreciate especially on technical rides.

It's complemented by a battery with a capacity of up to 820 Wh. That's a power reserve that allows for long day-long trips without fear of premature discharge. The battery is housed in the frame, well protected and relatively light thanks to carbon technology, which lowers the center of gravity and improves handling.

Component equipment for challenging terrain

On the RS50 we find equipment that matches its ambitions:

• RockShox ZEB Select fork - robust, stiff and ready for aggressive riding
• RockShox Super Deluxe / DebonAir+ rear shock absorber - excellent off-road sensitivity
• Shimano SLX M7120 hydraulic brakes - four-piston design with confident stopping power
• 11-speed drivetrain - reliable and suitably graded for different elevation profiles
• Fixed boost axles for maximum wheel stability.

Overall, these are components commonly found on significantly more expensive trail models.

Sport performance with support technology

The KELLYS Theos RS50 isn't just about the mechanical design - the software also plays a significant role. The e-bike is compatible with the Kellys Connect app, which enables:

• real performance and fuel consumption monitoring
• battery status monitoring and diagnostics
• oTA system updates
• ride logs and other useful features.

For riders who want to know everything about their bike, this is a great addition.

Who is the KELLYS Theos RS50 for?

This model is the perfect choice for:

• riders who spend most of their time on the trails
• bikers who want maximum power for steep climbs
• sporty users looking for all-day range thanks to the 820 Wh battery
• anyone who wants a modern e-MTB with very high stiffness, stability and technological features.

The KELLYS Theos RS50 is a robust, technologically advanced and powerful machine that can handle the most ambitious routes. It offers the perfect combination of power, long range, excellent suspension and components designed for real trail punch. If you're looking for an e-bike that can handle tough terrain and long trips while remaining a reliable partner for many seasons, the RS50 is one of the hot candidates.

KELLYS BICYCLES s.r.o. now offers a 5-year extended warranty. This extended warranty covers the frame of the e-bike and its claim when a manufacturing or material defect is proven to be the cause.

E-bike range calculator

Battery capacity: 500 Wh

300 Wh 600 Wh 900 Wh 1200 Wh

Rider weight: 75 kg

50 kg 80 kg 110 kg 140 kg

Assistance mode: 3

Min 2 3 4 Max

Route profile: Flat

Flat

Medium

Hills

The e-bike range is approximately

*Factors affecting total range include technical condition of the e-bike, battery age, ambient temperature, headwind, and riding technique

Motor Panasonic GXM MAXXPRO

MAXXPRO – a revolutionary new e-bike drive system. Designed to deliver full power without unnecessary weight. The GXM MAXXPRO motor, developed jointly by Kellys and Panasonic, has a torque of 105 Nm and weighs just 2.56 kg, with a special magnesium alloy casing. Optimized cooling and mounting. The combined motor and battery system weighs approximately 6.1 kg. Modular and modern electronics: Open architecture, over-the-air (OTA) update capability, and compatibility with various batteries via CAN bus (open system).

More information

Battery Kellys Maxxpro 820 Wh

Kellys, in cooperation with German battery manufacturer BMZ, presents a new series of batteries called Maxxpro, which excel in high energy density. Energy density is the amount of energy stored in a given amount of material, measured in Wh/kg. Carbon batteries are up to 20% lighter and offer higher capacity. The batteries weigh approximately 3.5 kg. To achieve low weight and high energy density, Kellys used an all-carbon battery body.

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PANASONIC GXM Center Display 501

A highly modern central display designed for e-bikes with Panasonic drives. This display provides a clear overview of all key information – from speed, range, and assistance level to navigation and connection to a smart app via Bluetooth® 5.0. Enables stable and fast connection to smartphones and Panasonic apps, including firmware updates and ride data transfer. Intuitive navigation. The display provides information on speed, range, battery status, assistance mode, and other bike functions. The display is resistant to water, dust, and vibrations, and is readable even in direct sunlight.

GXM Remote 501

A modern control unit located on the handlebars, designed for intuitive control of e-bikes equipped with Panasonic GX series drives. The controller allows quick and safe switching between assistance levels and control of additional functions. Designed to be easily accessible with your thumb, minimizing the need to take your attention off driving. Ergonomic design. Intuitive button layout. High durability. Fast response and precise control. Seamless integration with Panasonic GX and GXM series motors and displays.

Designing and manufacturing e-bikes is not just about putting mechanical components together. It's more than that. The purpose for which an e-bike is created is important, because it has a unique purpose in each person's life. This mission gives every KELLYS e-bike its reason for being. Thanks to modern technology, skilled designers and the best materials, the Kellys brand has some of the highest quality e-bikes.

We are specialists in KELLYS electric bikes. We offer full suspension and fixed mountain bikes, touring bikes, men's and women's electric bikes with an excellent price / performance ratio.

Contact: KELLYS BICYCLES CZECH REPUBLIC s.r.o., Havlickova 426, 753 01, Hranice, Czech republic, e-mail: infocz@kellysbike.com, phone: +420 581 698 810, web: https://kellysbike.com

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