YT JEFFSY BASE 29
£1,999 + shipping YT’s cheapest Je sy is a veritable bargain shredder
This gravity-hungry trail bike appears to o er exceptional value few brands can match. The base model in the four-bike Je sy range, does it cut the mustard?
The frame
Built from aluminium tubing, the frame has internal routing for all the cables for a clean finish, and boasts integrated down tube and seatstay protectors as well as the more usual chainstay guard. Singlesided access to the pivot hardware makes tightening bolts and servicing the bike easier. YT claim they’ve improved the pivot sealing too, to help lengthen maintenance intervals. Je sy-specific bottle mounts adorn the down tube.
The Base 29 is, unsurprisingly, built around 29in wheels. A 650b Base 27 model is also available, with the same spec (except it has 160mm of rear wheel travel). All the Je sy 29ers have 150mm of progressive travel, delivered by YT’s V4L (Virtual 4 Link) system. This four-bar Horst link set-up uses a chainstay pivot, just ahead of the rear wheel, to tweak the axle path and reduce the e ect of braking forces on the suspension.
As for geometry, the 77-degree seat angle is much steeper than most other brands’ o erings, which helps with climbing. The head angle is 66 degrees; a flip-chip lets you steepen both by 0.5 degrees and raise the BB from 32 to 24mm, should you so wish. The large size we tested has a spacious 470mm reach, short 435mm chainstays and a relatively long 1,226mm wheelbase.
The kit
Up front is a RockShox Yari RC fork with 150mm of travel and Motion Control damper. This isn’t as smooth as the Charger 2 cartridge in their top forks, which is most noticeable over smaller chattery bumps. The SX Eagle 12-speed drivetrain works fine, but the shifter and brake lever lack MatchMaker clamps and we couldn’t get them into a position on the bar where we could use both comfortably. The Guide T brakes themselves feel good, with the big 200/180mm rotors giving plenty of bite, although on tougher descents they did begin to fade. Maxxis Minion DHR II tyres are a solid choice, and you get YT’s own Postman dropper.
The ride
The steep seat angle is a real performance highlight on the climbs, where it helps keep your weight relatively central on the bike, especially if you slide the saddle forwards a little too. We found this improved control, comfort and grip, because we weren’t having to stretch forwards over the bar or constantly battle against the bike to keep our weight from being pushed over the back wheel. This makes ascending a comfortable a air, although the Je sy doesn’t have much urgency and we felt every kilo of its 15.49kg weight – if you’re looking to zoom to the top, you’ll want to put the Base on a diet. Thankfully, the lowest 32x50t gear combination is fine for winching up the steepest gradients.
There isn’t a huge amount of pedal bob, and we didn’t feel like the shock
drastically needed a lockout function. This solid pedalling platform results from the combination of a welldamped rear shock and the frame’s own suspension kinematics, joining forces to provide excellent support. The suspension isn’t hugely active over small bumps, but it does a good job of ironing out the harshest of hits.
The Je sy’s heft is less of an issue on the descents. There, the chassis’s weight helps give a sense of stability and smoothness even over particularly rough terrain. This makes it easy to pick up speed on flatter sections, control the bike on steeper bits of track and choose lines precisely. Again, this composure is partly due to the shock tune and kinematics, but the long-and-low geometry also contributes.
There’s amazing support from the rear suspension throughout its travel, which let us corner confidently. In fact, the harder we pushed through turns, the more the bike seemed to come alive, never getting overwhelmed by bodyweight shifts or the terrain. We could generate speed without feeling like the bike was wallowing beneath us.
Even at the edge of its limits – for example, through deep, successive holes – bottom-out was virtually imperceptible.
The geometry is impressively coherent too. We found the front-toback ratio on the size we tested made it easy to tackle terrain we wouldn’t normally have considered on a 150mm bike. There was loads of space to move around, and we didn’t find ourselves hanging o the back on steep drops or leaning massively over the front to maintain grip in the turns. The Je sy doesn’t quite hit enduro bike levels of capability, but this ceiling on performance could just be down to the Base model running bottom-ofthe-range dampers – we certainly didn’t find it lacking in terms of frame geometry or kinematics. ALEX EVANS www.yt-industries.com