YT goes back to their Young Talent roots with a new Jeffsy Primus for shorter mountain bike riders. Scaling down their ever-popular all-mountain Jeffsy trail bike once more, the new Primus model goes full send on smaller 24″ & 26″ wheels, offering a shred-worthy ride with much lower standover height.
YT Jeffsy Primus alloy 24″ 130mm & 26″ 140mm MTB trail bikes
![YT Jeffsy Primus youth MTB trail bike, alloy aluminum, all-mountain enduro trail bikes, 24in 130mm, 26in 140mm](https://bikerumor.com/wp-content/uploads/2020/02/YT-Jeffsy-Primus-youth-MTB-trail-bike_alloy-aluminum_all-mountain-enduro-trail-bikes_24in-130mm_26in-140mm_Harry-Schofield-custom_photo-by-Isac-Paddock_angled-front.jpg)
A few years ago YT already added a 27.5″ option to the popular 29er Jeffsy trail bike to make it more accessible to more riders. Now they go two big steps further, bringing back the 26″ mountain bike, then an even smaller 24″ wheeled addition to last year’s latest incarnation of the Jeffsy.
YT calls it a “Dream Bike for Short Shredders!”
Having recently signed young & talented, now 10-year-old British BMX & MTB rider Harry Schofield, YT needed to get him a trail bike, hence a good excuse to engineer a 24″ Jeffsy.
![YT Jeffsy Primus youth MTB trail bike, alloy aluminum, all-mountain enduro trail bikes, 24in 130mm, 26in 140mm, Harry Schofield custom, photo by Isac Paddock](https://bikerumor.com/wp-content/uploads/2020/02/YT-Jeffsy-Primus-youth-MTB-trail-bike_alloy-aluminum_all-mountain-enduro-trail-bikes_24in-130mm_26in-140mm_Harry-Schofield-custom_photo-by-Isac-Paddock_berm.jpg)
“We are not toying around with this bike. We wanted to create a real performance mountain bike for the Young Talent out there. Creating a bike of this sort has been something we have been eyeing up for some time. After developing the custom bike for Harry and seeing how well he got on with it we knew we were on the right path and it is great to see this project become a reality.” – Markus Flossmann, YT CEO
Primus – Geometry
Shorter trail riders (not just younger ones) need a good fit before you can start to look at modern trail geometry. So YT started with a rider height of 135cm-150cm (4’5″-4’11”) Â for the 24″ bike, and 145cm-160cm (4’9″-5’3″) for the 26″ version.
From there, the Jeffsy Primus gets a proper aggressive stance, with slack angles, (relatively) long frame reach & tiny stems. Each wheelsize gets its own single alloy frame size, with both Jeffsy Primuses still getting the Flip Chip at the lower shock mount to give some geometry adjustably.
Swap between a slack 65.5°/66° head angle and 76.5°/77° effective seattube angle. Go High for more ground clearance and improved climbing , or Low for faster rougher trails & race tracks.
Primus – Tech details
Of course, smaller riders are generally lighter too. And while YT couldn’t really build super light while keeping price under control, they did make sure to get custom suspension tunes so the small riders will get the most out of the bike possible. What started out as a prototype project bike for Harry, became a smaller alloy trail bike that went through the same complete development & testing process as all other YT bikes.
The JPs use the same Virtual Four Link suspension design as the big Jeffsy for balanced all-mountain to enduro suspension kinematics, with extra sealed full complement pivot bearings. The Jeffsy Primus features internal cable routing, stealth dropper compatibility, a 160mm brake post mount, tapered headtube, and ISCG tabs.
The alloy frames integrate downtube rock protection, plus seatstay, chainstay & anti-chain suck protectors. And they are Boost 12x148mm spaced, but the accompanying forks keep standard 15x100mm spacing.
Jeffsy Primus – Pricing & availability
![YT Jeffsy Primus youth MTB trail bike, alloy aluminum, all-mountain enduro trail bikes, 24in 130mm, 26in 140mm](https://bikerumor.com/wp-content/uploads/2020/02/YT-Jeffsy-Primus-youth-MTB-trail-bike_alloy-aluminum_all-mountain-enduro-trail-bikes_24in-130mm_26in-140mm_24inch.jpg)
The new Jeffsy Primus doesn’t skimp on build quality, taking advantage of the recent crop of top-spec 24/26″ suspension & tires available just like their 27.5/29″ counterparts.
The 1900€ alloy Jeffsy Primus 24 gets a 130mm Manitou Machete Junit fork, McLeod air shock, SRAM NX 1×11 drivetrain, SunRinglé Duroc 30mm internal tubeless wheels wrapped in Maxxis Minion DHRII 24×2.3/2.4″ tires, plus youth-specific SDG Slater/Fly Jr bar, stem, grips, seatpost & saddle… at a claimed weight of 12.6kg / 27.8lb.
![YT Jeffsy Primus youth MTB trail bike, alloy aluminum, all-mountain enduro trail bikes, 24in 130mm, 26in 140mm](https://bikerumor.com/wp-content/uploads/2020/02/YT-Jeffsy-Primus-youth-MTB-trail-bike_alloy-aluminum_all-mountain-enduro-trail-bikes_24in-130mm_26in-140mm_26inch.jpg)
The 2000€ alloy Jeffsy Primus 26 gets a 140mm Manitou Machete fork, RockShox Deluxe Select+ air shock, SRAM SX Eagle 1×12 drivetrain, Duroc 30mm internal tubeless wheels wrapped in Minion DHRII 26×2.3/2.4″ tires, plus E13 Base cockpit, ODI Elite Motion grips & a SDG Radar saddle… at a claimed weight of 14.2kg / 31.3lb.
Both will start hitting the trail in Europe at the start of March and arriving in the United States about two weeks later in mid-March.