Far out or nothing – JEFFSY® is our first trail bike, and it represents our very own definition of trail riding. Just like your best friend JEFFSY inspires you to all new performances: together you climb the highest mountains, discover the most remote locations, and shred the trail on the way back down – JEFFSY and you make an unbeatable team. With gravity DNA, JEFFSY is the most aggressive all-mountain bike on the market, the YT amongst trail bikes, the perfect buddy for all those of you who want to ride a tad faster, more aggressive and more creative than the mainstream. And with its incredible propulsion JEFFSY and you will conquer the steepest climbs. Whatever life throws at you – JEFFSY has your six.
SIZE DOESN'T MATTER
When picking the right wheel size, your personal preferences, riding style, and last but not least the terrain you ride all play an important role in your decision. With JEFFSY 29 you get the most aggressive and agile 29er on the market, full stop. The large 29“ wheels compliment the compact frame‘s silhouette perfectly, and are also responsible for the significant amount of BB drop - leaving you low in the sweet spot of the bike, feeling right at home and perfectly in control of even in the wildest situations. Thanks to the super slack head angle and the big wheels JEFFSY 29 rolls incredibly fast and stable and makes quick work of rough terrain. While the larger tire contact patch provides outstanding grip and unheard-of propulsion.
The JEFFSY 27 is for those who prefer an even more agile and playful bike. So that you won’t have to back down in rough terrain, and because you might want to take it off a jump or two, we’ve given JEFFSY 27 a bit more suspension travel. This means you can relax when things get gnarly, and it also means that JEFFSY 27 is the right choice when it comes to dropping the hammer in your next enduro race. But no matter what people say, it’s not about the size. Because at the end of the day it’s never about numbers. It’s about the rad time you had. And that glorious satisfaction after a day of pushing hard, scoring flowy curves. Letting loose on juicy corners. Go for the all new JEFFSY 27 or its big brother JEFFSY 29. Whatever wheel size you believe in: Size doesn’t matter – it’s what you do with it.
As a YT, JEFFSY’s mission is to be the most gravity-ready bike of the entire trail bike segment. Therefore, we equipped it up with our award-winning Virtual 4 Link suspension technology which combines excellent off-the-top sensitivity, ample mid-stroke support and a progressive ending stroke. V4L does not only give you the confidence you’ll need for big gaps and rugged terrain but also makes pedaling super efficient and JEFFSY a very effective climber.
The frame scores points with a compact silhouette, an undoubtedly downhill-oriented geometry and one of the most aggressive headtube angles to be found on any trail bike today. The low stand over height, distinctive reach, wide riser handlebar and compact chain stays ensure optimal handling. At YT, we don’t accept any compromises, therefore the length of the rear triangle comes optimized for each frame size. Whether you’re railing turns or hammering through a rough section you’ll feel right at home.
For our Enduro-Freeracer Bryan, JEFFSY 27 is the perfect weapon when prevailing in Enduro World Series runs that come with a lot of pedaling . Light, agile, and playful – and with enough suspension travel for when things get rowdy. From the very first time Bryan rode it on Canada’s steep and rough trails it was clear that he would make room for JEFFSY 27 in his racing stable.
Thanks to the Flip Chip, the frame’s geometry can easily be adapted to your riding style. In the low position, the head angle is slacker and the BB drop more pronounced, for better stability when pinning it in rough terrain. In the high position, the steeper head angle and higher BB position make for easier climbing and more agility on tighter trails.
Perfectly integrated polyurethane shields help protect the frame from rock impacts and scratches. Additional protectors on the chain and seat stays keep drivetrain noise to a minimum, leaving you to enjoy that other sound that we all love so much – braaaaap!
All bearings are sealed against water and dirt. This protects the bearings and extends their service life.
Chainsuck Plate Protection
Should things get a little rough, the inconspicuous chain suck plates protect the frame from damage caused by a dropped chain. This keeps sensitive areas out of harm’s way and helps prolong your frame’s lifetime.
The headset bearing surfaces are shaped directly into the carbon itself. This allows for homogeneous material distribution in the headtube which creates the optimal relationship between weight, reliability, and performance.
Internal Cable Routing
Internally routed cables give your bike a clean look. Integrated cable guides at the entry and exit points protect both the frame and the cables from premature wear.
V4L / Virtual Four Link
Our award-winning suspension technology offers a very sensitive response, with good mid-stroke support and significant end-stroke progressivity. This does not only provide stability and safety in rough terrain, it also helps make pedaling more efficient.