It's been almost 5 years since Christopher Walken
graced the mountain bike world with his presence, meaning it's been almost 5 years since the YT Jeffsy saw an update. This was arguably one of the more outstanding bike release videos we've seen, but at a certain point the bike has to live up to the hype. With a whole-cloth revamp the Jeffsy platform, YT aims to keep the train rolling and deliver a bike that will stay relevant and memorable for as long as that Walken edit.
The main theme of the Jeffsy is alive and well: a 29er trail bike that's meant to get along with just about anything you might encounter out there in the woods.
Jeffsy Details• Carbon or aluminum frame
• 29" wheels
• 145mm travel, 150mm fork
• 65° head angle
• 77.9° seat angle (size specific)
• 435-515mm reach, 475mm size L
• Size-specific chainstay length
• High-low flip chip
• Measured weight: 34.4lbs
• $2,799-$6,499 USD
•
yt-industries.com I'll be talking about the Large frame in Low mode, for now.
GeometryGiven the all-mountain/trail purview of Jeffsy, the geometry of the Low mode seemed a better fit for my terrain and preference. In time I'll try the High settings out, but for now the bike feels too good to change things up quite yet. The numbers for this new YT feel quite correct for the up and down nature of the bike, with a good mix of length and sharpness to keep stability and excitement in balance.
The 65° head angle is becoming pretty typical of bikes in this range of travel, and makes for something that is stable enough in steep terrain while still feeling lively on flatter sections. The actual seat angles vary depending on size in order to hit the 77.2° mark at the average saddle height for a given frame. This is a smart approach, taking actual rider dimensions into consideration, as opposed to simply achieving a given number on paper without factoring setup changes.
In the 5-size range, the smallest 3 get 437mm chainstays, with the larger 2 jumping up to 442mm. While not exactly a perfectly size-specific approach, it at least addresses the shift in balance from the smallest to the largest reaches in the range.
A note on sizing: based on the geo chart, I probably would have leaned towards the XL, but I find the Large fits me really well. Either size would work nicely, but for the terrain in Bellingham, I think the smaller wheelbase is more fun. If I were looking for all-out stability and a safer feel at speed, then I'd probably go with the XL.
Frame FeaturesIn keeping with the times, Jeffsy's third coming features a host of updates we're seeing on many recently released models, with some clever and clean integration by the YT engineers. The most noticeable is probably the in-frame storage, which has been implemented in a slightly different way to other designs on the market. Instead of being the plate that also carries the water bottle, the storage hatch on the Jeffsy stands alone above the bottle, eliminating the eventual loosening or rattling that might accompany the dual-duty designs. The hole is fairly small, but it's enough to get the two included ditty bags in and out, and can fit plenty of tools, snacks, and shiny pebbles.
Old Jeff now features a UDH dropout, which is convenient for both the Transmission compatibility and the increasing ubiquity of those aftermarket hangers. For those running cables, the frame features full tube-in-tube routing to make the job a whole lot easier.
Jeffsy Core 1 and 2 are the aluminum-framed options, and sadly those don't include in-frame storage of any sort, though they do feature all the same geometry and kinematics of the higher-priced tiers. Core 4 and 5 come with a Crankbrothers SOS plug tool and stash strap attached to the upper frame mounts, as you can see on my test bike.
There are nice finishing touches on the frames, like the rubber bumpers to silence any cable rattle that might occur from undersized cables for the through-frame routing. This is a frustration I have with other implementations of that design, as it can be quite noisy despite looking clean.
Though it looks a bit tight, there's plenty of room for a full-size water bottle in the frame, with potential to eek out a bit more room with a different bottle cage. As noted in the geometry chart, a quick trailside operation can take you from the Low to the High mode, serving as the only adjustment available on the frame.
Suspension DesignYT is sticking with their typical suspension layout for the Jeffsy, opting instead to tweak the points slightly to make the bike as well-rounded as they could. Sag is optimized around 30%, with anti-squat falling around 105% at that point. The bike is more progressive than its predecessor, without jumping the shark and going for a rate that loses predictability and support.
Build KitsWe talk a lot about the comparative value of brick and mortar bike shop brands versus the no-longer-new direct to consumer model, but with some of the most traditional brands out there opening direct sales channels, that comparison has gotten a bit murky. Suffice to say that a DTC brand like YT can still offer value that most shop model brands can't compete with, as is the case with the new Jeffsy. Topping out at $6,499 USD, Jeffsy lineup has 5 well-specced tiers that cater to a wide array of budgets, depending on price, experience level, and component preference.
Jeffsy Core 1 // $2,799 USD, €2,499. Aluminum frame.
Jeffsy Core 2 // $3,299 USD, £2,999, €2,999. Aluminum frame.
Jeffsy Core 3 // $4,299 USD, £3,999, €3,999. Carbon frame.
Jeffsy Core 4 // $5,499 USD, £4,999, €4,999. Carbon frame.
Jeffsy Core 5 // $6,499 USD, £5,999, €5,999. Carbon frame.
Ride ImpressionsI had an excellent first ride on the Jeffsy, and the positive feeling hasn't waned much since that day. From quick laps on my local favorites to longer, very technical rides, the bike has felt predictable, fun, and simply easy to ride. YT seems to have nailed the tricky balance of a bike that is easy to cruise on while still holding its own when pushed hard or thrown into more serious terrain.
Climbing feels supportive and efficient, without giving up too much grip, and remains active over technical terrain in and out of the saddle. Descending is intuitive and well balanced, with excellent cornering performance and great pop on jumps and jibs. The 145mm of rear travel is well managed, with only a few bottom-outs on some very serious hits. The bike has an active feel through chattery terrain, especially when you let off the brakes and push through the bike.
An immediate takeaway was just how quiet the Jeffsy is, with no rattles, creaks, or other annoyances developing over the past couple weeks of riding. Another rosy first impression is the dialed build kit - there's nothing I'd change out of the gate on my Core 4 test bike. The brakes, drivetrain, suspension, wheelset, and cockpit are all pretty close to what I'd choose for a bike of this ilk, so I'm more than happy to stick with the stock options.
Stay tuned for the long term review on the YT Jeffsy and a few other recently released trail bikes in the near future.
For more pictures of Jeffsy, head on over to the album
here.
Hard to do both…
The previous Jeffsy Core 2 alloy cost more than a Norco Fluid FS A1...
The all new Jeffsey Core 2 at MSRP is $400 less than the FSA1. Suspension is Performance vs. Factory/Perf. Elite on the FSA1, but all other components on the Core2 are higher value than what Norco put on the FSA1. Norco certainly cut a lot of corners on the FSA1 with no-name cockpit/wheels to get to the price point.
Plus, my wife would be far more agreeable to a $2,700ish purchase rather than a $4,600 purchase and i'll try to sell stuff to make money back.
Still, nice bike with good looking spec sheets for the price.
Plus frame storage and an actual proper sized water bottle (not that idiotic little thing on the previous Capra) means a nice looking all rounder bike.
Capra - 38 - enduro
Jeffsy - 35/36 - all mountain
Izzo - 34 - trail
Their lineup makes a lot of sense.
i understand why you wouldn't recommend the 27.5 rear wheel, but i do recommend it :-)
Because my alloy Stumpy Evo absolutely has a SWAT box.
I still have the bike with its original Acros headset and it work like new.
My 4 Giant's (Trance, XTC, Anthem, TCX) with pressfit haven't had any issues and have a total of 20y of use in them.
Also Canyon on road end is fuss free for 5y.
Problem is when poor manufacturing causes issues. BSA can also be an issue if poorly aligned, very quick bearing wear. BSA shell can also be unglued from carbon in some instances.
Anyhow, it is not a dealbreaker for me based on my experience.
I wanted a Capra core4 this year, I signed up to be alerted when they became orderable but never got an email. Missed the window and bought a competitors enduro bike instead. But I’m keeping that Jeffsy around too.
A friends 2023 Jeffsy -1 Wolf tooth angleset, and longer fork is a ripper, go do it.
YT still giving the people the best value in the business as far as I’m concerned.
160/160 with Fox Performance for $2000 was an amazing deal and would have made the perfect ride for his first full season of enduro racing next year!
Primus 27 it will be, with some upgrades…
(staying with Christopher Walken theme)
www.youtube.com/watch?v=gORawBY8vhU
I have ridden the stumpjumper for 3 years in fairly wet conditions without excessive water ingress due to the swat door. There is a draining hole at the bottom bracket in case (I guess it’s the case on most bikes). And the frame didn’t crack there neither.
But I have to say I never use the storage because I find it or too noisy or too difficult to take out if the content well packed not too rattle. And no frame storage makes for a cleaner tube.
So it will not be a selling point for my next bike
Also what the equation to figure that out?
The chart above looks like a change in leverage ratio from 3.3 to 2.25 which, according to that article I linked, is about 32% progression. I'm not sure everyone measures it the same way though.
I wish YT would jump on the 27.5, short travel playbike bandwagon and release a 140R/160F 27.5 Jeffsy.
us.yt-industries.com/products/bikes/jeffsy-primus/27/576/jeffsy-primus-27/#tech1
I’ve been toying with putting an angleset in my capra for funsies.
Stock wise, pickup some cheap RSC levers, a good bleed and they are killer!
Price difference is minimal, yet lever/brake feel is much better.
Don't agree with it as I prefer Shimano, but it is as it is.
Bleed them properly and there is no sponge at all.
I would easily understand if Dario was in between L and XL... but he's between XL and XXL.
I'm just trying to understand, it's tricky to pick up the right size when you buy a bike online.
REALLY??? How bad is your math that you think a 5mm difference in chainstay length can compensate between the 23/28mm differences in wheelbase between sizes much less the almost 100mm difference between the smallest and largest frame sizes!!!
It's like living in the 2010's
I'm happily employed, thanks for the offer. And from your attitude, I wouldn't work with someone like you anyway.
You put bolts on the underside of your top tube for tool/tube storage already...
This is most apparent when looking at frame bearing alignment. The big 3 (& better boutique companies) have perfectly aligned bearings. On modern multi link bikes, this is more difficult to do. It’s vital that all of the frame components align 100% perfectly to ensure proper bike performance, and to prevent bearing/shock/frame failures.
YT has an earned reputation for inconsistent alignments. If you get a good one, party on. It’ll probably run fine for years. If not, the bike will never *quite* ride right and will likely be plagued with premature bearing and rear shock wear.
Frame alignment doesn’t show up on a spec sheet, but I’d say it’s worh an extra $500 or so. Which ends up being what you “save” on a YT that likely isn’t built right.
These things are done with jigs. Experience has nothing to do with it.
Carbon plies are hand laid in molds-there is a LOT of error that can be introduced through poorly cut plies, incorrect resin application, incorrect mandrel (or other internal mold) alignment.
A lot of cheap rigid frames come out of the jigs crooked and have to be cold set (bent) into alignment.
Like I said before, there are multiple tiers of quality big bike manufacturers offer (usually good, better, best). Only frames coming off a best quality line are welded straight, or are perfectly aligned out of the molds.
It's a weird trend that everyone seems to be o.k. with.