2017 YT Jeffsy 29

2017 YT Jeffsy 29

Size Tested: Large

Geometry: (Here)

Build Overview:

  • Drivetrain: Shimano XT
  • Brakes: Shimano XT
  • Fork: Rockshox Pike RCT3
  • Rear Shock: Rockshox Monarch RCT3

Wheels: 29”

Travel: 140 mm rear / 140 mm front

Blister’s Measured Weight: 28.7 lbs (13.01 kg) without pedals

Reviewer: 5’9”, 155 lbs.
Test Location: Moab, UT

MSRP: $3,999

Noah Bodman reviews the YT Jeffsy 29 for Blister Gear Review
YT Jeffsy 29


We swung through Outerbike in Moab several weeks ago to hang out, ride some bikes, and partake in the good times that happen when bike people gather together in the desert.

If you don’t already know about Outerbike, you should; it’s a great opportunity to demo new bikes on some great trails. There are three Outerbike events throughout the year — Moab in the spring; Crested Butte in the summer; and Moab again in the fall. Each event lasts 3-4 days, and you can get more information at outerbike.com.

So we had three days to ride some of this year’s new bikes on a smattering of Moab’s best trails. And while it was a great opportunity to learn a good bit about a number of new bikes (including the one reviewed here), we only rode these bikes for a few hours each, so keep in mind that this isn’t our normal full-scale review.


YT has been making waves with their direct-to-consumer sales model and bikes that offer some pretty stellar deals. And while they started with a more downhill- and enduro-focused lineup, the addition of the Jeffsy 29 and the new (but as yet unavailable) Jeffsy 27 expands YT’s offerings into the realm of trail bikes.

I’ve spent a fair amount of time on assorted 29ers in the past few years, and I’m generally a fan of how they ride. When the geometry and suspension is dialed, they’re tough to beat when it comes to carrying speed on rough singletrack, and the better options still manage to stay reasonably maneuverable and fun.

Noah Bodman reviews the YT Jeffsy 29 for Blister Gear Review
Noah Bodman on the YT Jeffsy 29.

The Jeffsy 29 certainly seemed like it checked the right geometry boxes for that perfect blend of chunder-crushing prowess that’s still fun in corners, so I was pretty excited to get one out for a spin in the Mag 7 area in Moab.

The Build

The Jeffsy 29 build options have changed a bit for the new model year (the new version is essentially a Sram X1 build), but the frame remains the same. I rode the carbon frame, which was kitted out with a Rockshox Monarch RT3 rear shock and a Pike RCT3 Fork, both set at 140 mm travel. Both of those are top of the line suspension options, so no complaints there.

Shifting and braking were handled by Shimano, with XT components except for some Raceface Turbine cranks. All of those bits have well-earned reputations for durability and performance. My only minor gripe is the big jump on the XT cassette; shifting from second gear to first gear is a big jump, is a bit clunky, and also feels unnaturally large on the trail.

DTSwiss M1900 Spline wheels are a quality performer, and have held up well every time I’ve ridden them. They’re not the stiffest wheel I’ve ever ridden, but for most people, they’re certainly stiff enough. (I do, however, dislike the terrible engagement in DT Swiss hubs, which is particularly annoying on the techy climbs of Moab.)

Fit and Geometry

The Jeffsy is fairly middle of the road among modern trail bikes in terms of sizing. YT recommends a Medium for people from 5’4” to 5’10”, and a Large for people from 5’8” to 6’2”. At 5’9”, I fall into the overlap, but I ended up on a Large.

With a reach measurement of 443 mm, the Jeffsy 29 is a pretty average Large, and at my height, the bike fell roomy but not overly stretched out. The top tube length comes in at 616 mm for the Large (again, fairly average), but the actual seat tube angle is somewhat slack. So the top tube might feel a bit longer for those with a lengthy inseam and a high seat.

The bike’s geometry can be adjusted via a flip chip at the lower shock mount, which slackens and lowers the bike. I rode the bike in the “low” mode, which yielded a 67° degree head angle, 32 mm of bottom bracket drop, and an 1178 mm wheelbase for the size Large. This puts it right in line with other bikes in this category, like the Specialized Stumpjumper 29 and the Santa Cruz Hightower.

Noah Bodman reviews the YT Jeffsy 29 for Blister Gear Review
Noah Bodman on the YT Jeffsy 29.

One noteworthy aspect of the geometry that I think YT should get a lot of credit for is that the chainstays get longer on the larger sizes. Small and Medium Jeffsy’s have 435 mm stays, while Large and Extra Large Jeffsy’s have 440 mm stays. This makes a ton of sense, yet very few companies do it.

NEXT: The Ride, Bottom Line

10 comments on “2017 YT Jeffsy 29”

    • Hey Brian,

      I’d give the Following the edge on climbs, mostly by virtue of it having less travel. And I’d give the Jeffsy the nod on descents, again, largely because it has a bit more travel. But the Jeffsy was a decent climber, and the Following is a really good descender, so the difference isn’t huge.


      • i had the same experience. jeffsy is a bit better climber. depends on what you prefer, though both do well either way.

  1. Awesome read. Love the breakdown and photos. Outerbike sounds like a super cool way to test some bikes, can’t believe we hadn’t come across them yet. Looking forward to getting out to Moab and hitting some trails. Thanks for the inspiration!

  2. The Jeffsy doesn’t climb very well with the stock 32 tooth chainring. A 30t or smaller helps this bike out significantly!
    More antisquat, less pedal bob, less pedal kick-back, and higher bb when mashing! Also, because the rear-suspension curve is so progressive by itself, removing bottomless bands or tokens from the rear shock helps with off the top sensitivity and suppleness. Switching the flip chip to high makes it stupid-efficient, but less stable for everything else. I’ve left mine in the low position with the the other changes I mentioned. More than stoked with my YT, after some tweaks.

  3. The Jeffsy has longer chainstays than all of it’s contemporaries. I know that we’re not supposed to care about such passe things anymore but it seems like that should matter (at least a little) for this class of bike. Everyone keeps saying how “poppy and playful” the bike is so that probably means it doesn’t matter in this case? Does the front wheel comes up easily or is it noticeably harder and “poppy and playful” applies when you have the assistance of a trail feature?

    • Hey Scott,

      I’m not sure that’s accurate. Here’s a non-exhaustive list of bikes that are more or less comparable to the Jeffsy 29 that have the same length or longer chainstays than the small / medium size: Santa Cruz Hightower, Specialized Stumpjumper, Yeti SB 5.5, Transition Smuggler, Rocky Mtn. Instinct, Ibis Ripley LS, Intense Carbine, and Niner WFO. I’m sure there are others that aren’t springing to mind.

      But yeah, the Jeffsy’s chainstays aren’t excessively long. I didn’t notice that it was any harder to get the front end up on the Jeffsy than any other 29er that I’d put into the “poppy and playful” category.


  4. watching trail peek rides his new jefsy and i wouls say this bikes has lots of pop
    then again, dude can manual any bike all day

  5. How would you compare it to the Django 29er? That’s my current ride and I just put a 150mm DVO up front and have been happy with the results so far.

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