First Look | The 2020 Trek Supercaliber has a new suspension design unlike anything we’ve seen before

When Trek launched the new 2020 Top Fuel back in May, it certainly raised a few eyebrows – for multiple reasons. Having moved up to 115mm of rear travel, with a bigger 120mm fork and a slacker 67.5° head angle to boot, the latest Top Fuel has certainly notched up the capability stakes, but it’s also taken a dramatic U-Turn away from its previous World Cup XC racing intentions. And with the Top Fuel having morphed into more of a lightweight trail bike, that’s left a bit of a gap in Trek’s lineup for a thoroughbred, fully-suspended race machine. A gap that’s just been filled by this svelte number that has been four whole years in the making: the 2020 Trek Supercaliber.

2020 trek supercalibre
The new 2020 Trek Supercaliber is here to fill the spot as Trek’s superlight XC race bike.

Supercaliber To The Rescue!

Filling the void between Trek’s Procaliber hardtail and the latest Top Fuel, the Supercaliber is a brand new model for Trek. The name isn’t new though. It’s actually drawn from one of Gary Fisher’s earlier XC race bikes, of which there were both hardtail and full suspension variants. The thing is though; the 2020 Trek Supercaliber isn’t exactly either of those things.

Using a sort of soft-tail design, the Supercaliber has just 60mm of rear-wheel travel that’s paired to a 100mm travel fork. Being a purpose-built World Cup XC race rig, it is only available in carbon fibre (specifically Trek’s OCLV Mountain blend), and it only comes with 29in wheels – all the way down to the Small size.

2020 trek supercaliber supercalibre
The Supercaliber combines 29in wheels with aggressive geometry, a 100mm travel fork, and 60mm of rear travel via the unique IsoStrut suspension system.
2020 trek supercalibre supercaliber
The IsoStrut design allows Trek to plonk two water bottles inside the mainframe – a big deal for long-distance marathon racers and XC riders.

The frame features some familiar Trek technologies. There’s the Straight Shot downtube, which is there to increase stiffness and reduce weight by taking the shortest route from the plump tapered head tube to the 92mm wide bottom bracket shell. You’ll also find the Knock Block headset, and Control Freak internal cable management system.

One unique feature of the Supercaliber though is its ability to fit two water bottles inside the mainframe – something that the Top Fuel has not been cable of. Running two water bottles is a big deal for XCO and marathon racers, and it’s a big reason why Trek have built the Supercaliber around an entirely new suspension system called IsoStrut.

2020 trek supercaliber supercalibre
The Supercaliber frame is made exclusively from OCLV carbon fibre and features an enormous Straight Shot downtube, Control Freak internal cable management system, and the Knock Block headset.

Let’s IsoStrut

IsoStrut is the name for the sliding suspension strut that sits underneath and parallel with the top tube. It’s a bit of a head-scratcher at first, but it’s actually a relatively simple and space-efficient system. And it looks like nothing else on the market – something that’s a bloody mission to do these days.

Bolted onto the frame is a round alloy rail – a bit like a fork stanchion. The carbon seatstays wrap around the seat tube and morph together into a carbon fibre carriage, which slides up and down this alloy stanchion. The carbon fibre carriage has two round bushings inside to keep it sliding smooth (again, just like a suspension fork), and there’s a wiper seal at each end to keep oil inside and crap outside (and again, just like a suspension fork).

fox kashima 2020 trek supercaliber isostrut
The carbon seatstays merge together into a one-piece carriage that slides up and down a single alloy stanchion.
fox kashima 2020 trek supercaliber isostrut
Sitting inside the top of the alloy stanchion is a concealed mini-shock. There’s adjustable air pressure, rebound damping, and a lockout too.

Hidden inside the alloy stanchion is a mini rear shock. And driving the end of the rear eyelet of the rear shock is a pivot bolt that runs through the outer carriage. As the suspension compresses, the carriage moves forward to drive the end of the rear shock.

Does It Twist?

No. Or at least, Trek says it doesn’t because the stanchion is keyed – a bit like a dropper post. The pivot pin that joins the carbon carriage to the end of the shock has two big bushings on either side of it, and these bushings slide along bores that are machined lengthwise in the stanchion. This stops the carriage from rotating freely around the stanchion, and is what turns the IsoStrut system into a structural member of the frame.

fox kashima 2020 trek supercaliber isostrut
Here you can see the end of the rear shock inside the stanchion. The carbon carriage bolts to the end of the shock, while the machined bores on either side prevent the whole assembly from twisting.

Moving further back on the frame, you’ll notice that unlike every other current Trek full suspension bike, the Supercaliber does not use an ABP pivot. Instead, Trek has employed very slender seatstays that are designed to flex throughout the rear travel. Those tubes are properly thin too, which means there’s likely a good bit of compliance beyond the bike’s mechanical travel, and also some vibration damping even when the shock is locked out.

2020 trek supercaliber supercalibre isostrut
That black bolt on the underside of the carbon carriage is the lower shock bolt.
fox kashima 2020 trek supercaliber isostrut
Stupendously slim seatstays are designed to flex and add further compliance to the chassis. It also negates the need for an ABP pivot at the rear dropout. So the whole swingarm is a one-piece carbon fibre structure.

Who Makes All This Wizardry?

While the IsoStrut design is all Trek, the engineering know-how has been brought to the table by Fox Racing Shox, which manufactures both the alloy stanchion and the mini-shock inside. It’s loosely based on a Fox Float DPS shock, so you’ve got adjustable air pressure, rebound damping, and a lockout. There are even volume spacers for adjusting the progression of the spring curve. The whole thing can be unbolted from the frame for servicing, and Trek says that Fox distributors will handle both servicing and warranty support for all the moving suspension parts.

The shock itself has just 32.5mm of travel, which, when translated through the linkage, creates 60mm of vertical travel at the rear wheel. Those doing the math will realise that this creates a very low 1.84:1 leverage ratio, which means operating pressures are likely to be quite low inside the air spring.

fox kashima 2020 trek supercaliber isostrut
Ooh, cutaway! Here you can see the mini shock that occupies the inside of the stanchion on the left. In the middle you’ll see two white bushings – these are what slide up and down the machined bores of the stanchion.

60mm Of Travel – Is That Enough?

Good question. And we’re not sure, because we haven’t ridden it yet.

60mm of travel isn’t a whole lot – especially when most brands have settled on 100mm for their full suspension bikes. Then again, for elite World Cup athletes who regularly flit between racing their hardtail or full suspension race bike, a super-short travel bike like this might be the mid-way point that helps settle that decision.

Jolanda Neff, Swiss mountain biking champion and Trek sponsored athlete, has been on the Supercaliber for most of the 2019 race season. “This has been that dream bike that I always wanted, but never existed until now,” said Neff. “I’ll be racing nothing else from now on.” Of course, she’s biased, but she seems to have gotten along with it pretty well, having earned a silver medal at the World Championships on the weekend.

fox kashima 2020 trek supercaliber isostrut
This photo shows how much the seatstays flex through to full compression with the shock bottomed out. So bendy!

It Isn’t As Light As We Were Expecting

Trek claims the Supercaliber frame weighs 1950g including the rear shock and hardware. Now that is light, but it isn’t the lightest full suspension frame on the market. That mantel still belongs to the Scott Spark RC, which has a claimed weight of 1779g. Very impressive given it was released over three years ago and has the full 100mm of travel.

For reference, here’s a few of the other bikes playing in the same zone as the new Supercaliber;

But – and here’s the big but – not all of those frames will take two water bottles inside the mainframe, which is a big feature for the Supercaliber. So if we’re comparing on that level, it’s really only the Oiz, Epic and Lux that tick that box.

2020 trek supercaliber supercalibre
Trek claims the Procaliber frame weighs 1950g including the rear shock and hardware.

Steep & Sharp Geometry

If you were expecting long, low and slack for a contemporary XC race bike from Trek, then you were wrong. Being a precision instrument for dissecting World Cup race courses, the Supercaliber is designed to be deadly sharp. As such, it gets a tight 69° head angle, a moderate 74° seat tube angle, and short 430mm chainstays.

One thing that does stick out on the geometry table is the fork offset, which is 42-46mm depending on the fork model. This is a turn-around for Trek from the previous 51mm G2 fork offset that it’s trumpeted for all the years that it (and Gary Fisher) have been making 29ers for. With most brands shifting back to a reduced-offset fork though, Trek has quietly followed suit with the new Top Fuel, Fuel EX, and now the Supercaliber too.

On the note of the fork, Trek does point out that the Supercaliber will accommodate up to a 120mm travel fork. We’re not sure how it would handle with double the travel up front compared to the back end, but hey, the option is there.

2020 trek supercalibre frame geometry
2020 Trek Supercaliber geometry.

What Bikes Is Trek Australia Bringing In?

There will be four 2020 Trek Supercaliber models coming into Australia later this year, starting at $6,500 for the Supercaliber 9.7, and going all the way up to $13,750 for the Supercaliber 9.9 XX1 AXS. There is a standalone frameset too, but that won’t be coming to our shores.

All of the Supercaliber models are running 100mm travel reduced-offset forks, wide-range 1x drivetrains, carbon wheels, and speedy 2.2in Bontrager tyres. One thing you won’t find on any of them though is a dropper post, which seems a bit of a shame given that more XC racers are choosing to run them. Dropper whinging aside, here’s a closer look at each of those bikes.

2020 trek supercalibre 9.7
The entry-level Supercalibre 9.7 uses the same OCLV carbon frame as the 9.9 model. It’s rolling on carbon Bontrager wheels, and you’re also getting SRAM NX Eagle shifting and a RockShox Reba fork for your hard earned cashola.

2020 Trek Supercaliber 9.7

2020 trek supercalibre 9.8
How stealthy is this grey-on-black 9.8? Trek upgrades the Supercaliber 9.8 with carbon cranks, a Fox 32 Step-Cast fork and Deore XT disc brakes.

2020 Trek Supercaliber 9.8 GX

2020 trek supercalibre 9.9 xx1
Stepping up the bling factor, the Supercaliber 9.9 matches the Factory-Series fork with a Kashima-coated IsoStrut stanchion and a gold XX1 cassette. Suave!

2020 Trek Supercaliber 9.9 XX1

2020 trek supercalibre 9.9 xx1 axs
If you must have the best, then Trek have this bike for you – the AXS-equipped Supercaliber 9.9, which features wireless shifting and superlight Bontrager XXX wheels.

2020 Trek Supercaliber 9.9 XX1 AXS

So there’s our first look of this new high-performance XC race bike from Trek. At the very least, we have to applaud Trek for coming up with something that’s genuinely different. When a lot of full suspension bikes are merging towards just two or three general frame shapes and suspension designs, it’s impressive that Trek has been able to pull off something so radically different.

Enough of what we think though – tell us your thoughts! We’d love to hear your opinion of the new Supercaliber, and if you’ve got any questions, drop those into the comments too.

And if you’re still frothing on a bit of XC tech, make sure you check out our head-to-head test of the latest Giant Anthem 29 vs Specialized Epic – it’s a doozy that one!

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