Review: Jones Diamond frame and two forks

By Justin Steiner

Jeff Jones believes trail riding is best experienced with a direct connection to the trail, without the complexities of suspension. It’s the purity of the experience he’s pursuing, not outright speed. Karen reviewed the first round of Jones production bikes in Issue #141. The titanium, Merlin-made framesets cost $5,500. Since then, Jones has pursued over-seas manufacturing and steel to further propagate his vision with better availability and significantly lower prices—$750 for the Diamond frame and Jones unicrown fork (including EBB as well as geared and singlespeed dropouts).

The bike

The frame is constructed of 4130 chromoly. Both forks, also 4130, require a 135mm-wide front hub, so unicrown fork blades were drawn to Jeff’s spec to accommodate the additional width. Jeff chose to use a 135mm-wide front hub to maximize front wheel stiffness through wider flanges and an improved spoke bracing angle.

Additionally, Jeff has designed all of his forks to accommodate the new wave of fat “snow” tires ranging in size from 3.7” to 4.7”, including Surly’s new Big Fat Larry tire. All Jones frames accommodate a 2.5” 29er tire with ample room for mud and snow. Jeff prioritizes stiffness over weight, resulting in a 2,573g frame and 1,316g unicrown fork—that’s an 8.5lbs. rigid frame and fork. The Truss fork weighs a little less at 1,200g.

All of Jeff’s steel products are treated with an electro-deposition process called ED Black, which seals the frame and fork internally and externally before powder coating. This bike is built for the long haul and construction is top-notch.

There are rack mounts on the seatstays for bikepacking. Forks will include lowrider rack mounts (my early sample did not). Unfortunately not many racks on the market are tall enough for fatty 29er tires and fenders, though eventually the market will catch up. That said, touring on this bike is best executed in ultralight mode with frame, seat, and handlebar bags like those pictured from Carousel Design Works, which can be purchased directly through Jeff. With this setup you’re ready for any adventure.

The ride

Geometry and riding position of this workingman’s Jones frame is identical to that of the original Jones-made Spaceframe. Essentially, Jeff’s theory is to design a bike that’s extremely capable on technical terrain and very comfortable to ride. When paired with a Jones H-bar, you’re placed in a relaxed and upright position where you’re afforded a feeling of control when seated, and an athletic “attack” stance when standing. This standing position feels in line with many of today’s all mountain bikes, putting a majority of your weight on your feet, allow- ing your arms to focus on the task of steering and braking.

Swing a leg over a Jones bike and the first thing you’ll notice is how freakishly comfortable the riding position is. Initially it doesn’t feel as though the cruiser-like riding position would be conducive to gnarly technical riding, or to pedaling efficiency. Just a few miles of trail prove this initial reaction dead wrong.

Technical prowess is a product of Jeff’s unorthodox, 29er geometry. A tight 1066mm wheelbase keeps handling snappy, as does the increased fork offset—55mm versus the more common 48mm. With the 70° head tube angle, this geometry places the front wheel well out in front of the rider for stellar stability when braking and descending. Descending is further assisted by the short top tube and H-bars, both of which shift the rider’s weight over the rear of the bike, instilling confidence. The 292mm bottom bracket keeps he rider’s center of gravity low and makes for a wonderfully carvy bike in the corners. The short chainstays help to give the bike a playful ride, requiring moderate effort to manual.

I’ve traditionally preferred an old school, up-over-the-front-wheel, riding position. So I was a bit skeptical about the rearward-biased rid- ing position. To my pleasant surprise, I had no difficulty maintaining a neutral position over the pedals. In terms of efficiency, I felt no down- side to sitting upright, but rather found the riding position conducive to putting the hammer down when racing, at least at my back-of-the- pack speeds. Climbing while standing is stupidly comfortable, making this bike perfectly suited to singlespeed use.

This bike is poised and controlled, with very a predictable ride thanks to stiff wheels, a stiff frame, and stiff handlebar. Combine those attributes with the “crouching tiger” riding position and you’ve got a very capable bike in demanding situations. Strange as it may sound, this bike really is a zero-travel all mountain rig, both in attitude and aptitude. I found myself picking lines just like I would on a 6-inch all mountain bike, albeit at slower speeds.

Though Jeff ‘s claim of proper fit for riders 5’5” to 6’2” may seem dubious, I now believe it to be valid for the vast majority of people. As rider height increases the virtual seat tube slackens to accommodate taller riders, and conversely steepens for shorter riders. In conjunction with a longer or shorter stem, the rider’s fore-aft weight distribution remains similar, regardless of height. For perspective, Jeff designed this bike around his six-foot self.

With the Surly Larry 26×3.7” tire installed up front, this bike takes on a whole different attitude. At my preferred tire pressure of approximately 10.5psi “Larry” delivered a nice balance of bump absorption and traction. Any less pressure and Larry squirmed in corners, any more and he bounced a bit much for my liking.

From my experience, Larry is well-suited to slow speed rock crawling. At high speeds, this heavy—adding two full pounds of rotational mass—wheel/tire combo contributes stability due to increased gyroscopic inertia, but can get a bit bouncy.

Final thoughts

The Diamond frame makes an excellent all-around mountain bike for everything from bikepacking, to geared or singlespeed use. It makes a damn fine commuting bike, too. In many ways it’s the perfect rigid bike for riders of the trail/all mountain persuasion, due to its similar riding position and technical aptitude. There’s nothing like a capable rigid bike to sharpen your skills.

In my opinion, the $750 asking price for the Diamond frame and unicrown fork is a stellar value. The precision of the Truss fork is worth the upgrade if you have the coin. As for front wheels and tires, both have their merits. When I buy this bike, I’d like to have the 29” wheel for more sporting days in the saddle and keep Larry around for fun, rough, technical rides.

If you’re interested, simply give Jeff a ring; he’d love to talk you though the specifics and help decide which setup is right for you.

Bike stats

  • Price: Diamond frame w/ unicrown fork $750, diamond frame w/ Truss fork $1,100
  • Weight: 29.4lbs.
  • Sizes available: One size fits most, 23” top tube, recommended for riders from 5’5” to 6’2”
  • Country of origin: Taiwan
  • Online:

Tester stats

  • Age: 28
  • Height: 5’7”
  • Weight: 165lbs.
  • Inseam: 31”



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