YT Jeffsy 29 - First Ride

The inspiration for the unique name has something to do with a legendary trail builder from the steep, wooded hillsides and valleys of South Wales. Although his actual identity remains anonymous, Jeffsy could just as well be a random name given to the authorities when inquiring about illegal trail building. When the team at YT heard about Jeffsy, they instantly drew a correlation between the idea of a selfless individual, real or not, who would work tirelessly so others could shred, and the bike they had in development. The name stuck, and soon Jeffsy was ready for its international debut.


Frame Design

The Jeffsy's overall frame shape bears a strong resemblance to the Capra, but there are a few notable difference, particularly when it comes to the rear suspension layout. The bike still uses YT's Virtual 4-Link System (V4L), YT's take on a Horst Link design, but the link that helps drive the shock is now mounted to the seat tube, rather than to a brace between the seat and down tube. This design opened up just enough room for a specially designed water bottle, one that holds exactly a pint of liquid, a measurement we're sure many of you are familiar with. The team at YT even created a unique bottle and cage combo especially for the Jeffsy that has rubber o-rings intended to hold a CO2 cartridge and an inflator. Unfortunately, this doesn't come in the box, but you can add one during checkout, as you do know that YT is a direct sales brand, right?



Aside from the internal routing for the Reverb dropper post and the gear cable, which neatly finishes its journey through the chainstay, the Jeffsy's cable and hose routing is a mostly external affair. This will no doubt please anyone who's struggled with internal routing during services or found the noise of rattling cables inside their frames a touch too annoying. Does it detract aesthetically? Perhaps, but considering how good Jeffsy looks, the sight of hoses and cables is easily offset.

Another potential surprise comes in the shape of no ISCG tabs. YT are keen to distinguish the Jeffsy from its bar brawling sibling, the Capra, and considering the chain retaining abilities of modern drivetrains, are they even needed, especially on a 140mm trail bike? There is however, the option to use the E-Mount tabs on the frame. And while we're on the subject, YT have three Jeffsy models that come with front derailleurs and 2x systems.




Out back a 148mm Boost rear helps add that essential element of stiffness that 29ers need, but does not accept 27.5+ wheels - will this come back to bite YT in the near future? It is a possibility, but considering the relative newness of 27.5+, perhaps YT are waiting for the kinks to be ironed out, especially in the tire and rim market, before jumping in. In the bottom bracket department, a BB92 shell means you're still faced with a push-fit interface, but this smaller standard does goes some way to improve compatibility with aftermarket cranks, especially over the BB30 option.



As far as geometry goes, the Jeffsy sports a relatively slack 66.8° head angle in the lower of the two geometry settings, with a 435mm chainstay length on the small and medium sizes, and 440mm on the large and XL. The reach numbers are in line with similar bikes in this category, and although YT could likely have stretched the front center measurements even further, what they've come up with is very reasonable. Overall there are few shortfalls in the geometry and little to poke at with some excellent numbers all round, most notably in the BB height, stack height and the generous amount of standover. Big wheels can sometimes require more input and direction from above and it's nice to see this that has been incorporated into the Jeffsy's makeup.






So, YT Industries now have a 29er. Did we see this coming? As a brand synonymous with the more 'dynamic' end of the sport, perhaps not, but then why can't a 29er be dynamic? The truth is they can and then some, but this concoction of big wheels and good geometry isn't new... It's certainly not old either and with a few other forward-thinking brands, namely Specialized and more recently, Evil Bikes, having previously proved the potential of such a machine, surely more will follow. Here at Pinkbike we've already suggested as much, so keep watching this space to see what else unfolds.

The ability for 29ers to achieve their full potential has taken some time, but it seems we've finally reached a point where both the technology and the ideas are coming together. We now have stiffer wheels and of course 'Boost', to offset the flex that 29" wheels can be prone to and a better understanding of geometry and how it relates to both the trail and the rider, especially with regards to building bikes with larger wheels. The transition to 27.5" wheels did more than just the obvious - it gave the engineers responsible for the bikes and gear we use the opportunity to explore how far they could push things. With that in mind, the Jeffsy joins a growing list of 29ers that mean business, combining solid geometry and dialed suspension with the raw speed and traction this wheel size is renowned for. The question we wanted to know was how fast, and more importantly, how much fun was Jeffsy going to be out on the trails?

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Residing 520 km to the west of the African coast and 1,000 km from the European continent (approximately a one-and-a-half hour flight from the Portuguese capital of Lisbon), the island of Madeira would act as host and home for the two days I would spend getting acquainted with Jeffsy. The topography of Madeira has done its part to shape a thriving mountain bike scene on the island, with a trail network that packs a punch for both its size and isolated location. After setting up the suspension with a good base setting for the coming days' activities, it was to the hills and into the mountains for a one-on-one with Jeffsy.

The first trail of the day, and coincidentally the last of the second day, was called the 'red trail', delivering everything from open piste and high-speed sections up top to jumps and drops with plenty of roots and tight corners under the tree canopy further down. After a few hours, something became very clear: I'd completely forgotten I was on a 29er. This bike is crazy fast, addictively so, and if you were to stick a Monarch Plus shock in the back and a stiffer Lyrik fork up front, well, you'd have a full-blown enduro bike, but let's not get ahead of ourselves.



Over the course of the two days, our guides introduced us to a host of trails, many of which we regrettably only hit once and blind as time was against us, but enough of a sampling to see how Jeffsy would fare in a variety of scenarios. One trail in particular, stood out. It was a slog to get to, with some climbing, gravel roads and the usual rigmarole involved with getting to a trailhead - a good test of Jeffsy's handling on less-than-aggressive trails, which thankfully it dealt with admirably. But this one trail - once we got into it - was fast, very technical, marginally steep throughout and pushed you into a gully packed with large boulders and debris from recent heavy rain storms that had taken their toll on the island. Following our guide, I simply let off the brakes and let Jeffsy come to life as I tried to keep up. Damn, this bike loves to open up, and as you find traction in places you would reconsider going to on a smaller wheeled machine, Jeffsy just holds the line and saves your ass.

Riding by the seat of your pants is a hell of a lot of fun, especially when you're in control, but there's far more to Jeffsy - it also offers both the means to explore and the ability to put the miles down like a good trail bike should. In short, if you like to disappear into the wilds with a view to smash and dominate what you find there, while simultaneously getting out and coming home unscathed, Jeffsy could be the bike for you.

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Visit the high-res gallery for more images.

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MENTIONS: @YTIndustries

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Reviews and Tech First Looks First Rides Yt Jeffsy