For those who are not familiar with the Jeffsy 29, it is a 140mm trail bike designed around 29-inch wheels with adjustable geometry using a flip chip that changes the bottom bracket height, head angle, and seat tube angle.

Cable routing is mostly external apart from the house for the dropper that enters the seat tube just above the bottom bracket junction and the rear derailleur cable which runs internally. Fortunately, the other cables run neatly on the top of the down tube with guides doing a good job of keeping them in place and minimising excessive rub.

As with their Capra and Tues, the Jeffsy makes use of a Virtual 4 Link suspension system.



The Build

YT is known for excellent value for money thanks to their direct to customer model and it shows on the CF Comp 1.

Such is the nature of the specification that, other than the saddle (which is a personal choice), the only thing I'm looking to change is the dropper post lever. To date, I have always run a right-hand lever on the left in order for it to sit below the bar. This makes pushing it easier as it requires less movement of the wrist. I will most likely replace it with RockShox's 1 x remote lever sooner rather than later.

Everything else is exactly what one would expect on a 140mm 29er aimed at slaying trails. Wide bars, short stem, beefy Onza Ibex tyres, a dropper seatpost, 1x drivetrain, and great suspension. All of which come from reputable brands that don't look out of place on a premium carbon bike.

The only component niggle to date was the Guide RSC brakes that suffered the same fate as the ones on Nick's Transition Smuggler and had to be warrantied. Thankfully turn around time was quick and they have been perfect since then.



On the Trail

With the dialed spec, confident handling and comfortable fit, it is easy to jump on and just get on with riding. There are no funny quirks to ride around. Some bikes are super stable at speed but need some muscle to get it around tight corners, others can turn on itself but sacrifice some confidence at speed - the Jeffsy exhibits none of these imbalances.

The YT Jeffsy has been nothing short of pure unadulterated fun on the trails and has quickly become one of my favourite longer travel 29ers. With their first effort, YT has managed to strike the perfect balance of agility and stability by blending the best on offer from 29" wheels with 27.5-like handling.

In the end

If you're looking for a fun trail and all mountain bike that will tackle the Enduro scene with confidence, then the Jeffsy could be the bike for you. YT Industries South Africa is currently selling this model for a ridiculously low R 53,500 (down from R 67,900) which makes it the deal of the century for a bike that will reward on every ride.

Keep an eye out for the full review later in the year.


Build Specification

  • FrameJeffsy Carbon 29"
  • HeadsetAcros AIX-326
  • Bottom BracketRACE FACE
  • Rear DerailleurSRAM X01
  • ShiftersSRAM X01
  • CassetteSRAM XG 1150
  • ChainSRAM PC1130
  • DiscsSRAM Centreline 200mm / 180mm
  • GripsRace Face Love Handle
  • WheelsetDT SWISS M1700 SPLINE
  • SaddleSDG Circuit
  • Actual weight13.23 kg including YT mudguard and Shimano SPD pedals