At the heart of the JEFFSY 27 AL is a high-quality aluminum frame which is based on the JEFFSY MKI version. With its downhill-oriented geometry, low BB height and slack headangle it is one of the more aggressive all-mountain bikes on the market. As is the YT way, with the JEFFSY 27 AL Base you’ll ride faster and be more playful and creative on your bike. Setting up the bike is child’s play thanks to simple and reliable components that both beginners and experienced riders will enjoy.
With 150 mm of travel, the FOX 34 Float Rhythm fork and FOX Float DPS Performance shock are always ready to get rowdy while the low standover height, the generous reach and the compact chainstays ensure optimal handling. For a perfectly balanced bike, the chainstays of the XL and XXL frame sizes are longer. The result: JEFFSY lets you truly redefine your riding style.
Setting up the JEFFSY 27 AL Base is child’s play thanks to simple and easy-to-use components that both beginners and experienced riders will enjoy. The 150 mm FOX 34 Float Rhythm fork was developed for aggressive trails and provides plenty of travel for almost any terrain. The FOX Float DPS Performance shock transmits enough feedback from the ground to let you know what’s going on, while remaining both compliant and sensitive – 3 preset positions let you tune it to almost any conditions.
SRAM’s NX Eagle drive train is reliable and precise and with 11–50 teeth on the cassette you’ll always have enough gears to take on your next adventure. The 4-pot calipers of the SRAM T brakes were developed together with downhill riders for reliable braking performance, while the butter-smooth action of the SDG Tellis dropper post puts you in the right riding position both on the way up and down the hill.
FrameJEFFSY ALLOY 27,5"
hydro-formed aluminum frame, V4L Virtual 4-Link rear suspension, 148x12mm DT Swiss QR Thru axle, seat stay/chain stay protection
WheelsetDT Swiss M 1900 SPLINE
27,5“ x 30mm | 110x15mm | 148x12mm
HandlebarRace Face AEFFECT R 35
20mm Rise | 780mm
ColorDEEP BLUE / MAGNESIUM WHITE
DEEP BLUE / MAGNESIUM WHITE
CONCRETE GREY / BLACK MAGIC
Front TireMaxxis Minion DHR II
27,5" | 2.40
StemRace Face AEFFECT R 35
Travel front/rear150mm / 150mm
Rear TireMaxxis Minion DHR II
27,5" | 2.40
GripsODI Elite Motion
V2.1 | Lock On
Frame SizeS / M / L / XL / XXL
CranksetSRAM NX Eagle
175mm | 32T | DUB
Weight*13,8 kg / 30,4 lb
* Weight measured without pedals in frame size S. Due to manufacturing tolerances of the individual components the bike weight may differ +/- 5%
Rear DerailleurSRAM NX Eagle
31.6mm | 125mm / 150mm Drop
ForkFOX 34 Float Rhythm
27,5“ | 150mm | 15QRx110 | 44mm Rake
ShifterSRAM NX Eagle
SaddleSDG FLY MNT
YT Custom | White | Grey
ShockFOX Float DPS Performance
3pos | Evol LV | 230X60mm
CassetteSRAM PG-1230 Eagle
11-50T | 12-Speed
BrakesSRAM Guide T
ROTOR CENTERLINE | 200mm / 180mm
ChainSRAM GX Eagle
Bottom BracketSRAM DUB Pressfit
Pedalsincluded / inklusive
The included pedals were not made for demanding trails or racing. That is why we also offer you quality pedals at an attractive price in the shopping cart.
Tool KitIceToolz Set
Torque Wrench (3NM-10NM; 3-6mm, reset) | Shock Pump (330psi/20.6bar; pressure relief valve) | Allen Key | Anti-Slip Paste
Progress means change. In the case of the new JEFFSY 27, the changes are relatively small but the improvements are still noticeable. For an even better ride, we have given the new JEFFSY 27 longer reach and a slacker headangle. This has a calming effect on the bike and gives you more control when things get steeper and faster, the long reach helping JEFFSY stay on track and making sure even taller riders can sit “in” the bike.
To apply YT’s Tailor Made concept also to the new JEFFSY, we’ve significantly shortened the seat tube and introduced an XXL size. This gives you the choice between two or even three frame size in order to adapt the reach measurement to your riding style and preferences. To ensure consistent handling across the frame sizes, we’ve made the chainstays longer on the XL and XXL, while the integrated Flip Chip lets you further adapt the bike’s geometry to suit your technique and terrain. Run it in the low position to slacken the headangle and lower the BB for fast and rough terrain, or switch to the high position to raise the BB for better clearance and more fun on the climbs.
|A Toptube length||573 mm||602 mm||625 mm||648 mm|
|B Reach||415 mm||440 mm||460 mm||480 mm|
|C Stack||584 mm||597 mm||611 mm||620 mm|
|D Seattube length||410 mm||450 mm||480 mm||520 mm|
|E Chainstay length||430 mm||430 mm||435 mm||435 mm|
|F Headtube angle||66,5 / 67 °||66,5 / 67 °||66,5 / 67 °||66,5 / 67 °|
|G Seattube angle (eff.)||75,0 / 75,5 °||75,0 / 75,5 °||75,0 / 75,5 °||75,0 / 75,5 °|
|H BB Drop||15 / 9 mm||15 / 9 mm||15 / 9 mm||15 / 9 mm|
|I Wheelbase||1138 mm||1169 mm||1200 mm||1224 mm|
|J Headtube length||95 mm||110 mm||125 mm||135 mm|
|K bb height||341 / 347 mm||341 / 347 mm||341 / 347 mm||341 / 347 mm|
|standover height||708 mm||737 mm||752 mm||782 mm|