YT’s award-winning Jeffsy gets an overhaul for 2019

YT has launched an updated version of its Jeffsy trail bike, with 29” and 27.5” wheeled carbon bikes ready to buy, right now!

The YT Jeffsy CF Pro Race - YT Industries / Johan Hjord

The 2018 YT Jeffsy CF 29 was our Trail Bike of the Year - not an accolade that comes without competition, it beat over 20 similarly priced and specc’d bikes in the process. That generation Jeffsy, technically, wasn’t the best bike in the test. However, the test team, myself included, simply found it the most fun bike on test - and if a trail bike has to be anything, it’s fun.

It's definitely a fast bike, and super capable on a wide range of terrain - YT Industries / Johan Hjord

Criticisms were fair though - the frame wasn’t ‘up to date’, the geometry was relatively conservative, and its climbing performance was unlikely to put many KOMs under stress. The latest iteration of the Jeffsy has tackled these ‘issues’, and you can find my first impressions of how the bike rode in my YT Jeffsy First Ride.

2019 YT Jeffsy Key Features

29” (140mm) and 27.5” (150mm) versions
‘Pro Race’ models get extra 10mm travel front and rear thanks to longer stroke forks and shocks
Currently carbon frame only
Significant increases in reach figures
Slacker head and steeper seat angles
Increased anti-squat
Stiffer head tube area

Updates to the 2019 YT Jeffsy

I rode the new Jeffsy in Portugal to get a taste of the new bike - YT Industries / Daniel Roos

YT has released the new Jeffsy with both 29" and 27/5" wheels, though it feels that the 29er has had the most attention from the team, and this mirrors our experience and attitudes towards trail bikes - 29ers, on the whole, make a lot of sense on the trail. It is also the version of the Jeffsy that has a more radically different shape to the previous generation.

The headline figures for the bikes’ geometries show that YT doesn’t want to be left behind, geometrically. The reach in a size large grows from 445mm to 470mm, with the seat tube sat at 77 degrees (formerly 74.5 degrees). Head angles drop from 67 to 66 degrees, while the seat tube shortens by 45mm to 435mm - giving much more room for longer droppers, or smaller riders to ‘size up’ their bike. YT will also now offer the Jeffsy in five sizes - Small to XXL.

The headtube area has been beefed up - YT Industries / Johan Hjord

The 27.5” bike has a 460mm reach, 65.5 degree head angle and 76 degree seat angle.

The geometries above are for when the Jeffsy is in its ‘super low’ position - you could, in theory, use the flip-chip to raise and steepen the bike a touch, though we can’t think of many situations where we’d bother.

You can change the geometry a little with this flip-chip, though it's arguable as to how necessary that would be - YT Industries / Johan Hjord

Both wheel sizes get three carbon models, and an alloy model remains from the previous generation of the frame.

29” bikes get 140mm of travel front and rear, and the 27.5” bikes are 150mm. YT now uses Metric length shocks in their bikes. The top-end Pro Race Jeffsy gets a longer stroke shock, and longer forks, however, boosting them to 150mm (29”) and 160mm travel (27.5”).

YT also claims that they have increased the anti-squat figures for the Jeffsy by around 30% through the suspension’s stroke. This gives the bike a much more pedal-friendly nature, both on climbs and on pedally sections of trail, in theory.

Another new feature of the Jeffsy comes from their Tues DH bike. YT’s mechanics wanted a set of pivot bolts that could all be accessed from one side of a bike’s work-stand, to save continually moving around the bike during strip-downs. YT designed their pivots (save for the drive-side horst-link pivot) to all be strippable from the non-drive side, and this can now be found on the Jeffsy.

All the pivots can be serviced from one side of the bike (except the drive-side horst-link pivot) - YT Industries / Johan Hjord

It’s only a small feature, that many may not appreciate, but it keeps the driveside looking smooth, and will make maintenance easier. Speaking of which, YT has also apparently improved sealing for the bearings, and are using radial bearings from Acros in the Jeffsy.

This ‘liveability’ has also taken the form of increased, and smoother mud clearance for the back-end, with more room and less ‘shelves’ for mud to collect on - ideal for us in the UK, at the very least!

YT says that there's less places for mud to collect - YT Industries / Johan Hjord

There is a glass-fibre downtube protector present, and YT bolts it on, as they found glue doesn’t work so well in wetter conditions. There’s also a PU material protector on the seatstay, which merges seamlessly around the mech hanger - this is said to prevent the chain rubbing on any carbon and should keep the bike quieter.

Cables are routed internally along internal tubing, and they’re only clamped in place at one place on the frame. Finally, there’s room for a specific 600ml YT designed bottle in all frame sizes, using the Fidlock system. This bottle will be available aftermarket, also.