For one month, the Forchheim-based direct mail order company YT Industries the mountain bike scene was put on tenterhooks. Under the hashtag #IHATEJEFFSY, social networks and the Jeffsy microsite There has been wild speculation about what is behind this ominous Jeffsy. Now it's out! The Jeffsy is the new 29-inch all-mountain from YT with 140 millimetres of suspension travel.
YT Industries and All Mountains: the history
The Jeffsy is not the first all-mountain that the young mail-order label has welcomed into its range, but the second touring bike. Back in 2009, YT already had a genuine all-mountain in its programme with the Wicked. Now the Jeffsy range follows with three carbon and three aluminium models. YT is currently better known to gravity bikers: the downhill bike Tues and the enduro Capra have a firm place when it comes to downhill sport on two wheels. But YT Industries wants to remain true to its philosophy with the Jeffsy. It has the typical genes of the German gravity label.
A trail rocket: the new YT Jeffsy
Chief developer Stefan Willared and his crew have spent more than two years fine-tuning the new Trail 29er, testing various concepts and prototypes and working on detailed solutions. "At the start of development, we hadn't yet decided on a wheel size. We tried 27.5, 29 and 27.5+ inches," says Willared at the presentation in Madeira. A light, playful trail rocket that is comfortable to steer was the specification for the new bike. The result is something to be proud of: The Jeffsy embodies the latest generation of long-stroke twentyniners. Despite the large wheels, you can feel the freeride genes. In addition, all YT Jeffsy models rely on a modern geometry with a short reach, short stems and wide riser bars. "The cockpit is very important to us. We have equipped the bikes as we would like to ride them ourselves," explains Willared.
Technical data of the YT Jeffsy
With 140 millimetres of travel at the front and rear, YT places the 29er in the classic all-mountain sector. If that's not enough for you, you can also pimp the suspension with a 150 mm suspension fork. A virtual four-link suspension system is used, which YT calls "V4L". The clean carbon fibre chassis of the three carbon models weighs just 2100 grams (without shock & thru-axle), while the aluminium frame of the Jeffsy AL models weighs 3.0 kg. The flip chip in the shock rocker promises more versatility and customisability. The geometry can be changed using the two aluminium inserts: If you ride the Jeffsy in the LOW position, the bottom bracket sits eight millimetres lower (BB drop 32 mm) and the head angle of 66.8 degrees is one of the slackest we have ever seen and ridden on an all-mountain bike. However, those who climb a lot will prefer the HIGH setting. This is because the seat angle steepens up to an effective 75.3 degrees. This benefits the rider on steep ramps. And even in the HIGH position, the steering angle remains at a relaxed 67.6 degrees.
Boost at the rear, not at the front: To create more space between the chainring, right-hand chainstay and tyre, the Boost standard is used on the rear wheel and crank. But not on the front wheel hub. "We don't see any advantage there," says developer Willared. Although most Jeffsy models are supplied with single drivetrains, a front derailleur can be fitted to all bikes using an E-Type mount for Shimano sideswing models. To ensure that the elegant carbon frame does not suffer from chain slap, a damping plastic guard protects the chainstays and the chainsuck plates in the bottom bracket area are attached with epoxy adhesive.
As touring riders need a water bottle on long tours compared to freeriders, YT has developed a special gimmick: a dedicated bottle cage with a 0.5 litre bottle. The small bottle leaves the holder from the side and fits perfectly into the size M frame.
YT Jeffsy 2016: the models
There will be a total of six models of the YT Jeffsy. The entry-level aluminium model costs €1999 and comes with a Rock Shox Pike fork, 22-speed Shimano SLX drivetrain and Reverb dropper post. As on all Jeffsy bikes, the Jeffsy AL is fitted with 29x2.4 inch Onza Ibex tyres with dual compound. The Jeffsy CF Pro, which comes in a box for 4499 euros, is the end of the line. In contrast to all five other models, the suspension on the Pro version comes from Fox. The high-quality factory components with Kashima coating, a carbon crank (Race Face Next SL) and carbon wheels (DT Swiss XMC1200 Spline) reduce the total weight to under twelve kilograms. This means that the trail-loving 29er from YT is at the top of the trail bike league and can also be used for long tours or Alpine crossings.
However, only the CF Pro version of the Jeffsy relies on Fox suspension, with all other Jeffsy models using a Rock Shox Pike and a Monarch shock to work their way through the suspension travel. Incidentally, all shocks do not require a reservoir. According to Willared, the "small" Monarch shock, whose volume can be adjusted using spacers, is better suited to the rear suspension system. After two days on the Jeffsy, we can only agree with that. We didn't miss the Plus version of the Monarch anywhere.
First test: How the YT Jeffsy performs on the trail
We were able to test the new YT Jeffsy for two days on the jungle trails of Madeira. And the Jeffsy lives up to its promise! Our test bike, the Jeffsy CF Comp 1 for 3599 euros, weighed 13.2 kilos with pedals. For a 29er with 140 mm travel, which is in the same class as a Cube Stereo 140 and BMC Speedfox, this is a convincing figure. With a tester height of 1.80 metres, the carbon model with 1x11 Sram X01 drivetrain, DT M1700 wheelset and 150 mm Reverb dropper post (150 mm) in size L just about fitted. If you are 1.80 metres tall, you can also choose the M frame. But with a reach of 445 mm, the bike was an ideal fit.
After the first few metres on the muddy trails, the aha moment: man, the Jeffsy doesn't ride like a 29er! And it's great fun on technical terrain. Atypical for a 29er, the steering is very manoeuvrable, the playfulness is impressive and its direct handling is hungry for fast berms and small jumps. We only replaced the 60 mm stem with a 50 mm model. The super cockpit with Race Face Turbine riser bar appealed to us straight away and matches the successful geometry of the Jeffsy. A little later, when the suspension really hits its stride, it quickly becomes clear how potent the suspension is - especially in the mid-travel range. In addition, you sit nicely nestled between the large wheels. In short, the YT Jeffsy is a really good all-mountain bike with freeride genes that doesn't hold back on enduro race tracks either. And uphill? The Jeffsy climbs quite well in the LOW position, but not outstandingly so. If you want to chase the bike over the Alps, for example, it is better to mount a slightly longer stem and turn the flip-chip to the HIGH position. The rear suspension pumps very slightly in low gears. But only very minimally! For ramps in the double-digit percentage range, simply switch to platform mode and the suspension is quiet.
Test summary of the YT Jeffsy
Playful handling, lightweight carbon frame, successful geometry: the YT Jeffsy is a versatile, long-travel all-mountain bike with freeride genes. The 29-inch wheels paired with the super-slack head angle and modern geometry guarantee fun on trails and in technical terrain.
