When it comes to value for money, the YT Jeffsy Comp 29 is an absolute belter

Product Overview

Overall rating:

Score 9

YT Industries Jeffsy 29 CF Comp


YT Jeffsy 29 CF Comp review


Price as reviewed:

best full suspension mountain bike

Trail Bike of the Year in association with Alpinestars

Back to defend its Trail Bike crown is the YT Jeffsy 29 CF Comp 29. Revamped last year: a new carbon frame, adjustable geometry, top-quality spec.

>>> Trail Bike of the Year 2020

Most of that remains unchanged for 2020, but the price has dropped by £300!

yt jeffsy

YT Jeffsy 29 CF Comp review

The Jeffsy Comp 29 doesn’t just get a carbon front end; the seatstays, chainstays and rocker link are all carbon too. Surprisingly, this full composite construction doesn’t make it the lightest bike in its class. That award belongs to the Radon Slide Trail 9.0, but it does make it the stiffest. Not that this extra rigidity is welcome in every situation. On wet, slippery trails there’s not a lot of give in the frame, so it tends to step out more readily over roots and rocks, although some of that is the fault of the harder-compound tyres – more on that later.


Last year’s bike came with a 140mm-travel Fox 34 suspension fork, but we found it was a bit too flexible on such a stiff frame and recommended a Fox 36 instead. Twelve months on and YT has delivered. It’s only the Rhythm-level 36, but it now has 150mm-travel and it easily outclasses the Revelation on the Commençal.

The Jeffsy also gets the full 140mm of rear travel this year, which might be due to a change of shock – the Fox DPX2 replacing the DPS – or it could be down to a tolerance issue. Either way, the Jeffsy now feels more balanced both in terms of travel and stiffness. The upshot being that it also feels more like a proper trail bike rather than a jumped-up XC rig.


YT has made some positive changes to the specification too. The key one being that it has eliminated the three-position E13 dropper post and replaced it with its own 150mm Postman dropper that has infinite adjustment, a better lever and a smoother action. YT also fits different length droppers depending on the frame size and has increased the ream depth in the frame so you get a much wider range of saddle height adjustment.

Unfortunately, YT has persevered with the rock-hard SDG Radar saddle. It’s still a butt breaker, and not something that we wanted to sit on for longer than a couple of hours. The grips aren’t much better. YT has splashed the cash for genuine ODI lock-ons, but they are the hard-compound variety and have little in the way of cushioning.

Another big upgrade this year are the tyres – the E13 rubber is gone, replaced instead by our favourite Maxxis DHR II front and rear. Sadly, YT’s budget hasn’t stretched to the soft-compound 3C rubber. Yes, the harder dual-compound makes the bike fast-rolling, and the tyres last longer, but they are also pingy and nervous in rooty corners. Fitting our 3C Maxxis control tyres really calmed things down, so we’d recommend that, at the very least, you upgrade the front tyre straight off the bat.


The YT Jeffsy Comp 29 is an amazing- looking bike. The full carbon frame has stacks of standover and is incredibly stiff. It’s just not as fast in the turns or technical sections as the test-winning Radon Slide Trail 9.0.

We didn’t quite feel like we could carve a tight line or really hang it out fully on the Jeffsy. To be fair, the hard-compound 60a tyres didn’t help matters, which is why we swapped to our softer Maxxis 3C control tyres, but even then, the Jeffsy seemed reluctant to party.

So even though the YT Jeffsy Comp 29 is a better bike than the one we tested last year, the specification is a tale of what you haven’t got rather than what you have. Ultimately, we’d like YT to dial in a bit of frame compliance (call that flex if you like) so the Jeffsy offers a more forgiving ride, especially for lighter riders. With that single change, we’re convinced that 
the Jeffsy would have the ride quality to match the dialled geometry and first-class build kit.

yt jeffsy


When it comes to value for money, the YT Jeffsy Comp 29 is an absolute belter. Not only do you get a ton of top-notch clobber, YT has also ditched some of the duff components that prevented last year’s bike getting a perfect 10 rating; like 
the E13 dropper post, Shimano XT 11-speed drivetrain and spindly Fox 34 fork. The end result of all the updates is one bomber-solid, lightweight and fully loaded 140mm trail bike. We just had a bit more of a blast riding the Radon Slide Trail, and that’s the sole reason that YT takes the runner-up spot this time round.


Frame:Hi-Mod carbon, 140mm travel (143mm measured)
Shock:Fox Float DPX2 Performance
Fork:Fox 36 Float Rhythm, 150mm travel
Wheels:E13 TRS 110/148mm hubs, E13 TRS 27mm rims, Maxxis Minion DHR II 29x2.4in tyres
Drivetrain:SRAM NX Eagle 32t chainset, SRAM NX Eagle r-mech and shifter
Brakes:SRAM Guide R, 200/180mm
Components:E13 Base 780mm bar, E13 Base 50mm stem, YT Postman 150mm post, SDG RDR MTN saddle
Sizes:S, M, L, XL, XXL
Weight:15.23kg (33.58lb)
Size ridden:L
Head angle (low setting):65.9°
Actual seat angle (low setting):70.4°
Effective seat angle:76.7°
BB height (low setting):342mm
Front centre:786mm
Top tube:610mm
Down tube:739mm