First Look Review : Pete’s YT Industries Jeffsy Core 3.

Pete has taken delivery of the mid-range YT Industries Jeffsy Core 3 model and gives his opening thoughts on the 150mm 29er.

A slick, wet day is just as good as any to get a new bike dialled in, and that’s exactly what Pete did with his latest test whip, the YT Industries Jeffsy Core 3.

Photos by Pete Scullion.

Key features:

  • Fox 36 Performance Elite 150mm fork
  • Fox Float X Performance Elite shock
  • SRAM GX Eagle 12-speed drive
  • SRAM G2 R brakes
  • Crankbrothers Synthesis Enduro alloy wheels
  • YT Postman dropper
  • £3,799.00 RRP


The Jeffsy Core 3 is available in S, M, L, XL and XXL.

Reach on the Medium (tested here) is 450mm with a seat tube at 415mm. Head angle is 66.5 degrees in high and 66 in low, courtesy of the flip chip. Head angle is similarly adjustable to 77 or 77.5 degrees. Chainstays on the Medium are 435mm with a wheelbase of 1196mm.

Opening moves.

Sitting in the middle of the Jeffsy Core range, below the 2 and above the 4 in terms of price and spec, you get the lighter of the two carbon frame offerings, this one being the UM carbon that offers up 150mm rear wheel travel. 29″ wheels are the only option when it comes to the Jeffsy.

Damping is handled by a pair of Fox Performance Elite units, a 36 out front and Float X out back. The latter being one of the rolling changes to spec updates, replacing the DPX2 listed on the website. Drive train and brakes are all SRAM units. GX Eagle 12-speed drive handling the gears and G2 R brakes on anchor duties. All solid and reliable.

Merida OneSixty Leaderboard 2023

Another rolling change is the Crankbrothers Synthesis Enduro alloy wheels, replacing the DT Swiss M1900 Spline wheels. These are shod with Maxxis Minion DHR IIs front and rear, EXO flavour, 2.4″ width. E13 finishing kit, a YT Postman dropper, SDG Bel Air 3.0 saddle and ODI grips round everything out spec-wise.

Setup was the usual affair, get sag right to start, wind the levers in to suit and get them nice and close to the inner lock ring of the grips. With rebound dialled in thanks to the external dials on both dampers we were off.

My previous experience with the Capra had left me feeling slightly underwhelmed in terms of experience, mostly that the bike went about its business with almost too much skill and left the ride a little lacking in fizz. Any thoughts I had that this might happen with the Jeffsy were soon disabused.

With a short sighting run to heat cycle the pads, we headed to Dunkeld’s Craigvinean Forest for some steeps. The opening laps saw the bike a little low on rear wheel grip and the front end a little firm. Slowing the rebound on the shock and opening the low speed compression soon worked wonders, with low speed compression opened on the fork a touch, the bike would be off like a rocket.

Only a slight rise in the brake lever angle was required after that to get my weight a little more central and off the hands that bit more. From then I’d be trying to calculate the rate at which the trail was coming at me. Whilst the Capra might have lacked the X-Factor, it seemed that the Jeffsy found it and brought some more to the party.

I’m looking forward to getting my head in front of the speed this bike is capable of going at in just a few rides, with a bit more time underneath me, hopefully it’ll be another bike I definitely don’t want to have to give back.

You can check out the YT Industries Jeffsy Core 3 over on their website here.