Long-Term Test: YT Jeffsy CF2 29

The not-so-minor details


YT Jeffsy CF2 29


YT Industries






Rock solid construction.
Fast and engaging trail bike blaster.


Water bottle fitment is a pain.
Narrow rims are prime for an upgrade.

The ride

29er trail bikes of this kind of travel seem to often have the misconception hanging over them, that somehow the addition of big wheels morphs them into quasi-Enduro bikes. It ain’t the case – this bike is very capable all-rounder, a true trail bike, albeit with a lot of enthusiasm for the descents.

We’d have to rate the Jeffsy as one of the most engaging trail bikes we’ve ridden. A floater, not a flogger – it skims along, doesn’t get stuck down in its travel. It combines that supportive feel with a stiff frame too, so there’s never any vagueness about what the bike is up to. With 140mm front and rear, the bike was easy to balance, and we enjoyed the damping symmetry of the RockShox combo of a Pike up front and Monarch out the back.

We’d have to rate the Jeffsy as one of the most engaging trail bikes we’ve ridden.

The reach and overall length measurements of the Jeffsy are comparative moderate, it’s not a big boat to pilot, it’s sizing and geometry are such that it doesn’t require steep descents to come alive. In fact at the opposite end of the spectrum, on steep climbs, we were impressed too by both the climbing efficiency and the grip on offer.

The Jeffsy proved to be a great choice for our Ride High Country road trip in Victoria. It handled the varied trails brilliantly.
Popping along on Flowtown, Falls Creek.

We’re yet to get a creak or loose pivot bolt, despite nearly five months of regular use.

Its versatility was proven to us when we took the Jeffsy road tripping, hitting seven different destination across the Victorian High Country. On everything from flowing singletrack in Beechworth, to big climbs in Mt Buller, and some hefty jumps in Bright, the Jeffsy didn’t put a foot wrong. Nor has it required any maintenance, we’re yet to get a creak or loose pivot bolt, despite nearly five months of regular use. The assembly quality would appear to be top notch, and we like the mechanic friendly brake/dropper housing routing too.

Chunky, keyed hardware on the lower pivot. We’ve appreciated the creak-free ride.
YT aren’t buying into the idea of running 27.5+ wheels in a 29er frame. This bike is built solely for 29er wheels, so ditch any thoughts of putting a set of plus-sized wheels in here.

What did we change?

This particular model of Jeffsy is the only bike in the range that comes with a 2×11 drivetrain. We didn’t waste any time swapping it out for a 1×11 setup, as we’re sure many riders will.

The Jeffsy CF2 comes stock with a 2×11 drivetrain, but we went to a 1×11 straight away. The XT shifting has not missed a beat.

Over the five months of testing, we’ve fitted a number of other test parts too. This is not because the stock items on the Jeffsy needed changing, but purely because it’s nice to test parts on a bike that you’re familiar with. We’re currently reviewing the PRO dropper post and cockpit, and DT XM1501 wheels on the Jeffsy, along with the Industry Nine MatchStix fork axle/multi tool.

External cable routing for the dropper and rear brake line (and a continuous, sleeved route for the rear gear cable too) makes the Jeffsy one of the most mechanic-friendly bikes we’ve tested in a while.

The gripes?

Well, the fact you can fit a water bottle into this bike really appealed to us, as we like the freedom of riding without a pack. There’s a catch, however. The only bottle you can actually fit is YT’s own ThirstMaster, which at just 480ml capacity, can’t bust master of a thirst. YT also supply the bottle cage and it doesn’t have a firm enough grip, launching bottles into oblivion. We gave up on the YT bottle setup after a few rides and reverted to backpack.

This bike begs for some broader rims to give more support to the large 2.4″ tyres

As part of our long-term test we fitted some wider rims. The DT XM1501 wheels have a 30mm internal width. Highly recommended!

The Jeffsy’s narrow rims aren’t optimum either. This bike begs for some broader rims to give more support to the large 2.4″ tyres, as the stock setup restricts you from dropping the tyre pressures. As part of our long-term test, we fitted a set of 30mm wide DT XM1501 wheels to the Jeffsy and the transformation was instant. We could lower the tyre pressures by 5psi for more traction, but without any tyre roll. Wider rims really are the ultimate upgrade for this bike.

Left, the original DT M1900 wheels. Right, the XM1501 wheels we installed. As you can see, there’s a big difference in width.
The Onza Ibex tyres are great performers in the dry, but the hard compound is a bit lacking in the wet. They greatly benefitted from the use of wider rims as well, meaning we could drop the pressures and find more traction.

The wrap up

It’s hard to deny that a direct-to-consumer model like YT has some real appeal in terms of delivering a lot of bike for a reasonable price; the $5499 price tag nets you a full carbon bike of superb quality, top-shelf suspension and performance that puts the Jeffsy amongst our favourite trail bikes we’ve ridden.

Of course, for some riders, having the ability to communicate face-to-face with a salesperson and build a relationship with a local shop is paramount, and you just don’t get that with an online purchase like buying from YT. But if you’re happy with the sales approach, and you want a bullet-proof carbon 29er trail bike, then you’d be mad not to peruse the Jeffsy range from YT.


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