With the introduction of the new Trek Farley full suspension fat bikes, they also introduced a lot of new components to out fit them and the rest of their line, including trail and cross country mountain bikes.

Starting with XC, the new Kovee XXX carbon wheels started out as an experiment to see if their pro racers (like Emily Batty) would like a wider rim. They tested various widths and heights, and ended up at a 29mm internal width, but a shallow 27mm height to give it more compliance and save weight. They also used Impact Specific Resins, which they’ve implemented in more aggressive wheels, but switched to lighter weight carbon fibers to create their lightest-ever MTB rim…


To properly finish the Kovee’s story, we need to switch to the new Line XXX wheel. They’re the direct replacement for the Rhythm Pro, which was Bontrager’s carbon all-mountain/enduro wheelset. Inspired by the Aeolus road wheels, the new Line XXX Carbon rims are wider, lighter and 70% stronger than the Rhythms. They measure in at 29mm wide internally and 29mm tall, a height they say is a balance between being tall enough to offer good impact resistance, but not so tall that they’re too rigid for good traction and comfort. Combine that with the custom “Impact Specific Resins” and you get a wheel that’s ready for most anything without slowing you down on the climbs.

They come in at a claimed 435g per rim (29er), available in Boost configurations only. That weight is without their TLR rim strip, which adds about 60g per wheel and about 0.55mm to the bead channel’s height. It’s not required, but they designed it to make tubeless setup more consistent and far easier than just using tape. Complete wheelsets are laced to Boost DT 240 hubs with 6-bolt rotor mounts and weigh in at 715g F / 820g R for 27.5″ and 760g F / 865g R for 29er. Retail is $1,225 front and $1,275 rear.

Micro Hooks make for better tire retention at low pressures without compromising impact resistance.

At those weights, the Line XXX could have been an XC option, but they wanted something lighter for their pros. So, they tested various iterations, but ended up at the same 29mm internal width. The difference came in the height and fiber layup, which brought the rim weight all the way down to 375g for a 29er.

Why go so wide for XC? It lets you run lower tire pressure, which provides better traction and ends up decreasing rolling resistance because it saves energy over the chatter. And with tires designed around that width, traction and cornering were improved even further.

They tested hookless designs, which allow easier manufacturing and typically a stronger sidewall, but found that “micro hooks” offered better air retention and tubeless performance without affecting rim strength or impact resistance.

The Kovee XXX wheels are built with DT Swiss 240 Boost Center Lock hubs and get claimed weights of 640g F / 750g R. Both the Line XXX and Kovee XXX are designed for Bontrager’s 2.2 – 2.35 tires, but will work up to about a 2.5. Both are also OCLV carbon rims that are hand made in Waterloo, WI, at Trek’s HQ. Both get the custom 54-tooth star ratchet system that’s exclusive to Trek.

Below it will be a Kovee Pro that gets a lot of the carbon rim tech from the outgoing Rhythm Pro, and is actually pretty similar, but gets lighter Center Lock hubs to bring the weight down on both the rim and the complete wheelset. It’s also stronger. Options include standard and Boost hubs on two wheel sizes:

  • Kovee Pro 27.5″ – 679g F / 898g R
  • Kovee Pro 27.5″ Boost – 689g F / 904g R
  • Kovee Pro 29er – 727g F / 951g R
  • Kovee Pro 29er Boost – 737g F/ 937g R

Claimed weights are without rim strip. Retail is $530 front, $670 rear, making it a very affordable carbon wheelset.


Moving up to wider tires, the all-new Line Pro 40 (39mm internal) takes the OCLV carbon, DT Swiss 240 hubs and 54-tooth engagement but designs it for wider tires.


Trek says they’re good for about 2.55 up to 3.0, and that you could put wider on there, but you might get tire roll issues at low pressures.


This one is hookless, and they opted to make it work best with the included 21mm wide tubeless tape rather than their TLR rim strip because at this width, the strip would add too much rotational weight. At launch, it’ll only be available in a Boost 29er, but others are likely to follow. Wheelset weight is claimed at 845g F / 985g R, and retail is $680 F / $820 R. All of these new wheels come standard with SRAM/Shimano 10-11 speed freehub bodies, and XD Driver bodies are available.


With wheels improved, they turned to tires. New SE4 / XR4 tires get faster rolling and improved traction thanks to new tread block shapes.


Increased ramp angles on the center knobs and a slightly firmer 61a compound help it roll a little faster. The shoulder knobs get a dual knob design and siping with 50a rubber. It’ll come in a 2.4 x 27.5 that’s already out and a 29 x 2.4 starts shipping this summer. Coming later in the year will be a 29 x 2.55 size, with a 27.5 x 2.55 possibly following in 2017.

The XR4 uses their Inner Strength two woven nylon inserts on the sidewalls provide extra protection without making it too stiff, so it still rides well but is less susceptible to pinch and tear damage. The SE4 gets Core Strength, which adds a third nylon insert under the center of the tread to further improve puncture protection while maintaining a single ply construction’s flexibility.

The SE4 Team Issue TLR comes in at $74.99 with a 60tpi casing. Claimed weight is 845g for the 27.5 x 2.4. The XR4 upgrades to a 120tpi casing and comes in at $69.99 and 745g for 27.5 x 2.4. Weights for the 29er versions aren’t available yet.


The Barbegazi, which gets spec on Trek’s new fat bikes, uses a 62a/60a dual compound and 120 tpi casing and is designed to run as low as 2psi in a tubeless environment.


The tread pattern is designed to work well on everything from dirt to ungroomed backcountry snow trails. Weight is 1,240g and retail is $119. It’s only available in a 27.5 x 4.5 size. Oh, and the name? It refers to small white-furred, long-bearded men with enormous feet of Swiss folklore.


The Drop Line dropper post was designed to work across all temperature ranges, something that’s important when spec’ing it on their new fat bikes. It’s an air-sprung, hydraulically locking cartridge with infinite adjustment through its range.

With so many dropper posts on the market these days, we had to ask what makes this one special? Several things, actually. First, it can be opened up with a common multitool and rebuilt (or just lubed or cleaned) in the field. Inside is a keyed system to prevent rotation, and they spent a lot of time designing a dual locking pin system on either end of the cartridge, which prevents binding when being lowered with your weight on it (we’ve requested internal images, will update as we get them).


The lever sits under the bar and controls the dropper via standard mechanical cable and allows you to modulate the post’s release and return speed. To make it super user friendly, the cable’s barrel nut is captured at the bottom of the post, not at the lever, which makes removing it from the frame very quick and easy. It also means the cable is pinched at the lever, so it’ll stay in place and in adjustment if you have to pull the post out.

The Drop Line will come with a 1x under bar lever, but a second universal (over/under mount) lever will be available separately to work with 1x systems or 2x. Available June 1 for the 100mm and 125mm travel lengths, the 150mm will follow shortly thereafter. Retail is $199, available only in 31.6mm diameter and internal routing. Claimed weights and total lengths are 100mm (350mm, 565g), 125mm (400mm, 599g) and 150mm (440mm, 642g).


Finishing off the new Line Pro collection are new 35mm oversized handlebars and stems. They were plumped up because the larger diameter let them drop weight from comparable 31.8 parts. They tuned them to be stronger, too, but not stiffer, so they’ll have the same ride feel as their 31.8 parts.


The handlebars provide both cut marks and lines near the brake and shifter lever mounting locations to help you line things up evenly. Options include a Pro and standard level bar and stem:

  • Line Pro 15mm Riser Bar – OCLV carbon – 750mm & 820mm – 202-222g – 179.99
  • Line Pro 27.5mm Riser Bar – OCLV carbon – 750mm & 820mm – 222-243g – 179.99
  • Line 15mm Riser Bar – Quad butted 7050 T6 – 750mm & 820mm – 294-312g – 79.99
  • Line 27.5mm Riser Bar – Quad butted 7050 T6 – 750mm & 820mm – 298-314g – 79.99
  • Line Pro Stem – 3D forged 6061 T6 alloy – 40-80mm – 144-178g – $39.99
  • Line Stem – 3D forged 6061 T6 alloy – 40-80mm – 151-184g – $39.99

Both stems are 0º, grow in 10mm length increments and have laser etched marks on the sides of the faceplate to help you line things back up once you’ve dialed your position. The Pro stem essentially just gets a little more polishing to shave a few grams and upgrades to steel bolts.


The new Line Pro Pedal has been in testing with their pro gravity riders and uses sealed cartridge bearings and has a concave, beveled 6061-T6 alloy platform with replaceable and adjustable pins.


Pin height can be adjusted, letting you customize just how sticky they are. Available in black or orange, they’re shipping now and retail for $99.99. Claimed weight is 365g.


  1. Those XC rims are w i d e. Wide Lightning wide. Is casing exposure a concern at those widths?

    Really like the cable arrangement of the dropper post w/ cable end at bottom of post. It’d be awesome if KS changed to the same.

    • KS used to do that on their LEV integra and the cable came out of adjustment if you changed the seat post height. They changed to how they do it now and it is much better.

  2. Wow. $1200 for carbon wheels with 240 hubs and a functioning $200 dropper with a good lever design? Bontrager killing it with this release.

    • I stand corrected. After checking Trek’s website there is mention of a 3-paul system indicating the Kovee Pro line does not share hub internals with 240s. Still probably a pretty good cheap option though.

  3. I am really sick of Trek coming up with whatever standards they feel like because it suits their engineers. I have a top fuel frame sitting next to me that I can not build up because there everything boost is sold out. Send trek a message and don’t buy these bars.

  4. The DT 54 tooth star ratchets are not exclusive to Trek. All the Roval Traverse SL wheels have them and you can buy them from DT and QBP as an upgrade for your 350 and 240 hubs.

  5. 27.5×4.5? Wow!!! I can’t imagine that fitting any fat bikes but I’d otherwise love to try it. I’m guessing that’s a 3.5?

  6. Lotsa cool stuff. Made in USA carbon rims! I’m not currently in need of wheels, but I’ve already told my LBS that I’ll take the first set of XR4s in 29 x 2.55. Current version kills it, already.

  7. Let’s see how long these wheels last. Or if they will blow up like the rest of Bontragers wheels

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