Long-Term Test: YT Jeffsy CF2 29

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.



After the intensive training session in Italy, we headed off to Spain (we were up with the sun!). Ahead of us, a 10-hours drive. It’s a long way to go and a long way from home, but we were rewarded with incredible views of the many beautiful landscapes along the journey.  When we arrived, we arranged to meet up at La Poma Bike Park, which was buffed out to a shine. After a few hot laps, it was time to check out the home of Bienve, Adolf, and Andreu.Catalocos_Bikebuildup_Erik_by-Ralf-Schupp Catalocos_by-Ralf-Schupp Catalocos_Shuttle_by-Ralf-Schupp

The guys showed us their local riding spots on their CAPRA and TUES. We had a great time together, and we also took the opportunity to build up two fresh new TUES for Andreu – not forgetting to enjoy the odd evening beer or two. All in all it was a great trip with awesome weather, excellent food, and good training for the upcoming season.Catalocos_Lacondeguy_by-Ralf-Schupp Catalocos_Bikebuildup_by-Ralf-Schupp

I would like to thank Andreu, Bienve, Luis, Adolf, Lisa and all the other locos who came to hang out. I appreciate your hospitality very much!”.

Flow’s First Bite: YT Jeffsy CF Comp 2

The bold, brash YT Jeffsy.
The bold and brash YT Jeffsy.

The direct-to-consumer brand released the Jeffsy mid last year amongst much fanfare  with the 140mm trail bike being the first 29” offering from the gravity oriented Germans. Given the brand’s image, a 29er was certainly a surprise move, but YT acted fast to make sure everyone knew this was a bike that was still built to shred, by pumping out one of the best launch videos of the year. Watch it below.

The Jeffsy is YT's first foray into the world of 29" wheels.
The Jeffsy is YT’s first foray into the world of 29″ wheels.

What’s the YT Jeffsy all about?

Before releasing the Jeffsy, the YT line up consisted of the 27.5” Enduro focused Capra (read our review here) a couple of dirt jump bikes and the Tues downhill bike, so the Jeffsy filled the hole for the type of bike many riders are buying these days, a 140mm trail bike, something that shines on the climbs and descents equally. We’re pretty stoked about this also, as the 120-140mm travel range is also pretty spot on for most Australian conditions.

It won't be hard to remember the Jeffsy's name.
It won’t be hard to remember the Jeffsy’s name.
The Jeffsy packs 140mm of travel front and rear.
The Jeffsy packs 140mm of travel front and rear.

Despite being the bike with the least amount of travel in the YT line up, it’s clear the Jeffsy is a 140mm bike that wants to throw any stereotypes off a bridge. A burly frame is the first sign of this bike’s eager intentions, and geometry numbers like the slack 67.6 degree head angle and a long front centre tell you the Jeffsy doesn’t want to be treated gently out on the trail.

The Jeffsy has a flip-chip on the shock that allows the rider to switch between two head angle and bottom bracket options. We’re starting the review in the slacker head angle position, but will be alternating between the two positions throughout the course of testing to see how the geometry adjustments change the ride.

The Jeffsy has two geometry positions available courtesy of two shock mounts.
The Jeffsy has two geometry positions available courtesy of a reversible shock mount.

Is that a full carbon frame?

It sure is! YT are clearly confident in their carbon layup, as you see many brands going for aluminium rear triangles and chainstays in this travel bracket. The frame’s construction is beautifully finished, with smooth carbon lines throughout, chunky pivot points and well thought out frame protection. The frame is the only carbon you’ll find on this bike, but even still the complete bike weighs respectably smack on 13kg.

The Jeffsy CF frame is entirely carbon, including the stays and linkages.
The Jeffsy CF frame is entirely carbon, including the stays and linkage.

A regular shaped water bottle won’t fit in the frame, but YT offer their own “Thirstmaster 3000”, which is a custom water bottle and cage combo for the Jeffsy, with the bottle holding exactly one pint of liquid (an American Pint that is- 473ml). Whilst the inability to fit a regular sized drink bottle in the Jeffsy and the $100 price tag for the Thirstmaster 3000 is a slight annoyance, we believe every trail bike should have somewhere to put a bottle, so we appreciate YT giving riders the option rather than forcing them to wear a pack.

YT's "Thirstmaster 3000" i specifically designed to fit in the Jeffsy frames.
YT’s “Thirstmaster 3000” is specifically designed to fit Jeffsy frames.

If I don’t pick up this bike assembled from a bike shop, is the bike easy to build out of the box?

We covered YT’s shipping process and what you can expect as a consumer in our review of the Capra last year, and building up the Jeffsy was very simple. As we covered in out article on the Capra, YT really do make the process fairly straightforward, and the boxing of the bike is excellent.

YT's website has clear instructions on how to assemble your bike from the box.
YT’s website has clear instructions on how to assemble your bike from the box.

What’s the spec like?

Across their range of bikes, it’s clear that YT put a lot of time into speccing their bikes with parts that are up to the job. They don’t skimp on components in one area to bolster another, and the direct to consumer sales model keeps the pricing keen.

The RockShox Pike RCT3 is impressive value at this price point.
The RockShox Pike RCT3 is impressive value at this price point.
This is lots of bike for $5499!
This is lots of bike for $5499!

The Jeffsy CF Comp 2 is no exception, and the $5499 price tag represents a favourable dollars to shiny parts ratio. The suspension is handled by Rockshox front and rear, and the top of the line Monarch shock and Pike RCT3 fork are pretty hard to beat as far as suspension goes. The drivetrain is a normally a 2×11 XT arrangement with RaceFace Turbine cranks on this particular model, but we converted the bike to 1×11 before we’d even left the workshop.

Brakes are Shimano XT, with a whopping 200mm front rotor paired with a 180mm rotor out back.

More power than a Russian weightlifter.
More power than a Russian weightlifter.

The wheelset is DT Swiss’s M1700 Spline hoops in their narrow guise, coming in at 22.5mm internally. This is the only component we’re feeling a little dubious about, just because we’ve become such fans of wider hoops over the past 12 months.

The narrow DT Swiss wheels gives the Onza tyres quite a rounded profile.
The narrow DT Swiss wheels give the Onza tyres quite a rounded profile.

The Onza Ibex tyres strongly resemble Maxxis’ Minion DHR II tyres, which are a great option for the aggressive trail rider, and they match the intentions of the Jeffsy perfectly. They’re a big 2.4″ front and rear.

Onza's Ibex tyres strongly resemble the Maxxis Minion DHR II.
Onza’s Ibex tyres strongly resemble the Maxxis Minion DHR II.

It’s funny how the little things can really help a bike make a good first impression – the RaceFace grips instantly meshed with us, and the SDG saddle’s narrow nose works for us too.

The RaceFace grips are a real winner.
The RaceFace grips are a real winner.

How many models are there in the range?

YT bring three carbon Jeffsy models into Australia as well as three alloy models, so there’s plenty of choice. Prices range from $3299-7499, so there’s a good spread for a wide variety of budgets.

The Jeffsy AL is insane value for money at $3299.
The Jeffsy AL is the entry point in the range, at $3299.

Where are we going to ride the YT Jeffsy? 

We’ve just had a trip to some of Victoria’s finest trails, to get to know the Jeffsy, before returning to our home base of Sydney’s rocky, rugged trails. We know one particularly fast local shredder aboard a Jeffsy who pilots it around some technical trails pretty quickly, so we’re interested to see how far we can push the limits of the Jeffsy’s 140mm of travel.