When YT re-launched the Jeffsy this year, it made quite the impression. Not only did the German brand add big wheels, they brought in Christopher Walken to introduce your “new best friend.”
So, what is so great about the Jeffsy that YT was willing to shell out for a big budget Hollywood star? After spending some time with this 140 mm-travel trail bike, it’s not hard to see why they were excited. To stick with the “best friends” theme, Jeffsy is your well-mannered friend that’s easy to get along with, but is also the first to say “yes!” to a party. It’s mix of characteristics that makes it good for riders looking to build confidence in their trail riding, or for experienced riders looking for a trail bike that they can have all sorts of fun on. Add in a very competitive price, and the Jeffsy is a bike that should attract the attention of a wide range of riders.
YT Jeffsy 29 CF
At a balanced 140 mm travel front and rear, Jeffsy is YT’s mid-travel trail bike. Add big 29” wheels, and it is happy rolling for fast long rides and epics, or carrying speed over roots and rocks. YT gives the bike a carbon fibre front triangle and aluminum rear triangle, for a relatively svelte weight of 29.5 lbs. (size Small). Combined with an efficient pedaling suspension platform, updated for 2019, it’s a capable bike that is happy putting in the work climbing to get to those long, fun descents.
For 2019, YT also added an XXL size to the range, which now runs from Small to XXL. Each frame has excellent stand-over clearance, allowing riders to choose between more sizes. My XXL actually had better standover than some comparable Large size frames. This makes it so you can choose between different sizes based on your individual preferences instead of feeling tied to one size. The new frames are a step in the longer-lower-slacker direction, so being able to size up or down should make the Jeffsy more appealing to a wider range of riders.
Bolt on downtube protectors shield the carbon fibre front triangle from errant rocks
Generous rubber protection keeps the rear end safe
Improved internal routing, and weather protection on cable ports, should keep the Jeffsy running clean through foul weather.
A recessed water bottle cage leaves room for a 600 ml bottle, whether you use your own cage or YT's own Thirstmaster 4000 fidlock twist sytem.
Other notable features are longer, size specific chainstays (XL and XXL get longer 440 mm stays, vs. 435 mm for the rest of the range), improved weather sealing for bearings and internal cable routing ports. There’s room for a full 600 ml water bottle across the size range. Last, there’s bolt on frame protection for the downtube, and generous rubber on the chain and seat stays.
The Jeffsy 29 CF Comp comes in the concrete grey / black magic colour shown, or a more eye catching ember orange / night blue option.
Parts and spec: Jeffsy 29 CF Comp
YT specs the Jeffsy 29 CF Comp with a smart range of parts that is different than the standard all-Shimano/SRAM build. Highlights include swanky Renthal Fatbar 35 bar/ Apex stem combo, and a mix of e*thirteen parts, along with the Fox Float Performance Elite-level 34 fork and DPS shock and four piston SRAM Guide R brakes.
Shimano XT parts drive an 11-speed e*thirteen cassette. You don’t lose anything on the range, though, as the 9-46 range still gives a 511 per cent gear range. E*thirteen also supply the wheels and rubber, using its aggressive TRS+ tires. These give you some indication how YT thinks the bike could be used. Paired with faster rolling rubber, though, the Jeffsy can be a fun companion on more chill terrain and longer rides.
An e*thirteen TRS Plus dropper post provides solid range, but not infinite travel. In place of the usual infinitely adjustable post is a four-position post. It can feel unfamiliar at first if you’re used to a standard dropper post, but worked flawlessly throughout the test, and took minimal getting used to.
e*thirteen / shimano mix drivetrain
e*thirteen's TRS Plus dropper isn't infinitely adjustable, but it's been durable so far
The e*thirteen dropper remote lever is nicely shaped, and has a textured paddle for grip in the wet
SRAM Guide R brakes
On the Trail
The original Jeffsy built a reputation for being a very playful ride that liked getting sideways, and throwing its weight around in corners. With longer chainstays and 29” wheels, the new Jeffsy adds some stability at speed into this mix for a more balanced feel. But it’s still a bike that likes to party. With a low BB and slack 66.5-degree HTA, the Jeffsy accelerates out of berms, and hugs the ground in flat corners. Get airborne, and it’s quite happy pulling shapes, or just moving around on the trail while you’re wheels are still on the ground.
Pick up more speed, and you start to feel the benefits of those slightly longer chainstays. The Jeffsy is stable, and confidence inspiring bouncing through rough terrain.
With a reasonably light weight and good pedaling platform, the Jeffsy balanced out the fun on the descents with efficient climbing. It’s not a whip-fast XC bike, but it does reward any effort you put in. There’s a lockout lever on the Fox Float DPS but I only found myself reaching for it on extended smooth or paved climbs. A steep 77.5-degree STA keeps your weight forward enough that you stay on top of the 514 mm (XXL) reach. At 1266 mm the wheelbase is still long enough that you have to pick your line through tight switchbacks with care.
Direct to consumer
One aspect that contributes to the Jeffy’s excellent value, along with its parts build, is YT’s direct-to-consumer distribution. Since that’s part of any riders purchase experience, My test bike arrived in the box, ready to build.
The first thing you see when you open the box is the instruction manual and tool kit. The Jeffsy ships with everything you need to assemble the bike, including a torque wrench. The instructions were clear, and easy to follow. If you’ve already got your set-up dialed, YT’s order form includes everything from suspension settings to brake lever angle and seat height, so you can pull the bike out of the box with all the small details ready to go.
The first thing you see when you open a box from YT
Instruction manual, with simple to follow assembly steps
And a set of tools, including shock pump, torque wrench and pedal wrench.
I still managed to make on important mistake though. The derailleur comes set up, ready to go, you just need to bolt it on. I managed to twist the derailleur the wrong direction, creating a knot in the chain. In retrospect, it was a silly mistake. Everyone has off days, though, and it gave me the chance to talk to YT’s very helpful customer service. They were quick and clear in describing how to fix the problem, which they said – hopefully not just for my benefit – is one of the more common missteps in assembly.
Beyond that, the set up was easy. If I hadn’t got tangled in the chain, it would have been assembled in 15-20 minutes. Wheels come ready to go and pedals just need to be threaded in. The most complicated part of the process was attaching the Renthal bar to the stem. YT recommends keeping the box, for use when travelling, or should you need to ship the bike back to them for service. There’s easy to follow instructions and diagrams for re-boxing. Like any good friendship, the hardest part of wrapping up the Jeffsy at the end the test period with the Jeffsy was saying good-bye.
The Jeffsy is an impressive mix of fun and confidence inspiring stability. It’s easy to get along with, making it a great choice for riders looking to get into trail riding with a bike that will grow with them as they develop. For more advanced riders, it rewards the effort you put in with speed through corners, fun through the air, and stability when pushing at high speeds.
As a trail bike, there are limits, though. It is still a 140 mm bike so, while it might feel confident on big features, really aggressive riders may eventually want to step up to the Capra. That said, I reached the end of the fork well before the rear wheel travel, and I never felt a harsh bottom out of the rear suspension.
In the low setting, the bb is quite low. This has its advantages and drawbacks. While it makes the Jeffsy fly through corners, I did clip pedals occasionally when pedaling through rough descents. If you ride frequently in this sort of terrain, switching to the “High” go setting will help. That should also make the bike more agile if you’re frequenting routes on the more XC end of trail.
Last, the TRS plus dropper isn’t infinite adjust, which can take a bit of getting used to. It’s reliable, though, and some riders won’t mind having the four-position post.
Still, those are minor and specific limits for what is overall a very fun bike, and one that is comfortable in a wide range of terrain. Add in the attractive $4,600 price, and it’s easily a winner. It’s confident and fun on a wide range of terrain, from easy flowing trails to very technical, steep advanced runs, and is a bike that will grow with you, instead of you growing out of.
YT Jeffsy 29 CF Comp
Sizes: S, M, L, XL, XXL
Colours: Concrete Grey / Black Magic or Ember Orange / Night Blue