CTO Stefan Willared and his team put in the work of three years to develop JEFFSY. When they started the design for a new bike, it was not their goal to develop a 29er. Their main questions were: What does the perfect Trail Bike even look like? And what is Trail Biking, the YT way? At the beginning, nobody would have thought that they would come up with a 29” bike but they were open to all sorts of different concepts. The guys had one mission on their schedules: Developing a true trail-rocket which is comfortable and smooth to ride on, ready for you to shred hard and still has looks to kill for.
After countless tests and variations, they quickly realized that the larger wheels definitely fit in brilliantly with YT’s gravity genes. However, what does this actually mean?
The Virtual 4 Link suspension technology, which has already proven itself on the TUES and CAPRA is also equipped on JEFFSY’s rear end. The frame has a downhill-capable geometry and JEFFSY already had observers doubting if they are actually looking at a 29er.
The 66,8° head tube angle is one of the most aggressive ones of the Trail Bike category. The low bottom bracket lets you sit directly in the sweet spot of the bike. With the equipped Flip Chip technology, the rider has the option to either ride JEFFSY in a high or low position, the latter responsible for a bigger BB drop and a more aggressive head tube angle. The low stand over height, the wide riser handlebar and the compact chain stays ensure optimal and completely atypical handling for a 29er. YT doesn’t accept any compromises; therefore, the length of the rear triangle is optimized for each frame size. Sounds like JEFFSY is the perfect all-round bike out there.
JEFFSY’s voluminous but light full carbon frame and its compact silhouette already have some observers doubting whether they are actually looking at a 29er. With its aggressive headtube angle, low standover height and compact chainstays JEFFSY is a player among trail bikes, ready to go fast and get loose in the roughest of terrain. The length of the rear triangle comes optimized for each frame size and ensures a completely new and atypical handling for a 29er.
Thanks to the flip chip technology, JEFFSY’s geometry can be perfectly adapted to different terrain and to your style of riding. The low position gives you a more aggressive headtube angle and a bigger BB drop – perfect for quick and grimey downhill sections. The high position provides a smaller BB drop, so you can blast trails and tight turns with more ground clearance. Our prized Virtual 4 Link suspension technology is present on JEFFSY as well; sensitive, progressive, with lots of mid-travel support. This does not only give you the confidence needed for big gaps and rugged terrain but also makes pedaling a lot more efficient. The tube walls are thicker in critical areas to make sure the frame can handle the abuse, and integrated protectors keep the downtube and chainstays out of harm’s way when the action heats up.
YT Jeffsy CF Pro Spec's
The standout highlights of our top of the line model are the DT Swiss carbon wheels and the FOX suspension components consisting of the FOX Float DPS Factory shock and the FOX 34 Float Factory fork. The 780mm wide carbon handlebar and carbon cranks complete this high end build. With SRAM’s X01 transmission you shift precisely, easily, and silently, and should things get a little hectic, the Guide Ultimate brakes slow you down with authority. The JEFFSY CF Pro is the no-holds-barred bike for riders who accept no compromises.
YT Jeffsy Geometry
JEFFSY CF Comp 1
YT’s gravity background runs deep in the specs of the JEFFSY CF Comp 1: RockShox’ PIKE RCT3 fork and Monarch RC3 shock are ready to smoothly take on any root nest or rock garden. The wide RaceFace cockpit provides a maximum of control on wild descents and SRAM’s Guide RSC brakes provide ultimate stopping power. The 1x11 drivetrain calmly shifts into next gear.
JEFFSY CF Comp 2
With the JEFFSY CF Comp 2, YT offers a Trail Bike with prime specs. The 2x11 drivetrain allows a wider range of gears to shift through, so there are no excuses for the next uphill section. This carbon bike comes equipped with an entire Shimano XT group that is snappy and reliable, as well as a wide RaceFace cockpit, a RockShox Reverb Stealth, and sturdy 2.4” Onza Ibex tires.
JEFFSY AL Comp 1
The aluminum version, JEFFSY AL Comp 1 also gets a full load of dependable parts. RockShox’ Pike RCT3 and Monarch RT3 get riders through gnarly sections with ease and have your back for racing as well. SRAM’S GX 1x11 drivetrain ensures smooth shifting and the Guide RS brakes slow any rider down when things get out of hand. The 2.4” wide tires by Onza not only look good, but also deliver when it is time to send it through the rough stuff. At 13.5 kg the JEFFSY AL is a weapon for any trail and there are still some bucks left for the next bike trip.
JEFFSY AL Comp 2
For anybody looking for a wider range of gears, the AL Comp 2 with its 2x11 drivetrain is the right choice. The RockShox Pike RCT3 and Monarch RT3 keep things smooth even in the roughest terrain. When it comes to shifting gears and braking, Shimano’s XT group ensures precise shifting, optimal chain line and excellent reliability. Onza’s 2.4” tires are puncture resistant and offer great traction. Naturally, the RockShox Reverb Stealth is part of the stock JEFFSY AL Comp 2 build.
The JEFFSY AL is the entry level trail bike available for a killer price: Even with this model, riders can expect top quality specs: Armed with the RockShox Pike RC and Monarch R the bike is ready for the next adventure. A 2x10 drivetrain has a full range of gears to choose from and Shimano’s SLX brakes bring you to a safe stop when needed. The stock build also includes a RockShox Reverb Stealth, a wide RaceFace cockpit, and tough, reliable Onza Ibex tires.
JEFFSY is the perfect choice for long trips through the woods, alpine and blocked terrain and rough descents. The 29” wheels and their immense drive let you conquer the steepest mountains with ease. Obstacles are a piece of cake due to the larger wheel diameters- uphill as well as downhill.
Hence, JEFFSY is born to rule any trail and offers a whole lot of gravity potential for riders to get wild and rowdy.
Of course we have also achieved high levels of stiffness and reliability during the development of our carbon frames. Using a monocoque production technique, the tube walls have been given extra thickness where required to stand up to the strong forces generated in critical areas. The carbon frames weigh significantly less than their aluminum counterparts, and form the basis for our PRO models, which also feature the finest components.