Just when you thought you understood mountain bike suspension, along comes another design. This time it's Trek’s new Supercaliber cross-country race bike, which has been raced throughout the 2019 World Cup season by Switzerland’s Jolanda Neff, albeit with a black cover over the top tube to keep us guessing at goings on below.
Now the cover is off, and the bike is available at four price points, and in a frame-only option, all with “just enough suspension” — 60mm rear wheel travel — and available in six sizes.
But the rear shock still remains somewhat of a mystery until you take a closer look.
What is the Trek IsoStrut?
The Supercaliber’s IsoStrut suspension incorporates the suspension structurally into the frame and limits the number of pivots and linkages, creating a simplified suspension system. This is all done in the name of reducing weight and increasing efficiency, key things in cross-country racing.
While similar designs have existed in the past, the Supercaliber’s system has a main pivot that sits in a relatively forward position above the bottom bracket.
Trek tried a similar idea 18 years ago with the STP. The new bike aims to eliminate the problems it found with that bike through the use of this main pivot and a fixed position suspension unit, which has been developed with Fox.
The IsoStrut itself is fixed in place at both ends, and the frame becomes part of the suspension, with the fixed tube (or 'carriage') at the top seatstay junction sliding over a stanchion housing the internal workings of the suspension.
As the carriage slides along this stanchion, it drives a shaft housed within it (with slide bushings running through a slot in the stanchion to eliminate twisting) and the rest happens exactly as it would with a normal shock setup.
The business end is at the front of the IsoStrut, and settings are adjustable externally just underneath the top tube. Remote lock-out is also featured, as is to be expected for a bike of this breed.
With no pivot in the seatstays, the design relies somewhat on frame flex in order to work.
The rest of the Supercaliber is, like any of Trek’s bikes, well thought-through and finished.
Key for marathon racers is that the frame design leaves room for two water bottles. It’s also feather-light at a claimed 1,950g including the shock, in an unspecified size.
The 29in wheels, 69-degree head angle and 74-degree seat angle are right on-the-money for the aggressive, technical riding the bike is aimed at. It certainly seems to have been working for Neff, who took second place on it at the World Championships in Canada last week.
All four build options come with Bontrager Kovee carbon wheels, which have a two-year breakage guarantee.
If it’s not already special enough, you can create a custom version with Trek’s Project One workshop.
2020 Trek Supercaliber range overview
All Supercaliber build options are based around an OCLV-level Mountain Carbon frameset.
It features a Knock Block to stop the forks hitting the straight down tube in the event of a crash, and Control Freak internal cable routing to facilitate any cockpit setup, including Di2.
That Trek makes specific reference to the fact the frame is Di2 compatible is notable, suggesting a new generation of Shimano's electronic mountain bike drivetrain may be around the corner.
The frame has Boost 148 wheel spacing, and travel is 60mm at the rear and 100mm up front.
Trek Supercaliber 9.7
- Sizes: S, M, ML, L, XL, XXL
- Shock: Trek IsoStrut, Fox Performance shock, air spring, DPS 2-position damper
- Fork: RockShox Reba RL
- Wheels: Bontrager Kovee Elite 23 carbon
- Tyres: Bontrager XR2 Team Issue
- Crankset: SRAM NX Eagle
- Derailleur: SRAM NX Eagle
- Brakes: Shimano MT501/MT500
- Price: £4,000 / €4,499 / $4,799.99
Trek Supercaliber 9.8
- Sizes: S, M, ML, L, XL, XXL
- Shock: Trek IsoStrut, Fox Performance shock, air spring, DPS 2-position remote damper
- Forks: Fox Performance 32 Step-Cast, Float EVOL air spring, GRIP 2-position damper
- Wheels: Bontrager Kovee Elite 30 carbon
- Tyres: Bontrager XR2 Team Issue
- Crankset: Truvativ Stylo Carbon Eagle
- Derailleur: SRAM GX Eagle
- Brakes: Shimano Deore XT M8100
- Price: £5,300 / €5,999 / $5,899.99
Trek Supercaliber 9.9
- Sizes: S, M, ML, L, XL, XXL
- Shock: Trek IsoStrut, Fox Factory shock, air spring, DPS 2-position remote damper, Kashima Coat
- Forks: Fox Factory 32 Step-Cast, Float EVOL air spring, FIT4 2-position damper
- Wheels: Bontrager Kovee XXX 30
- Tyres: Bontrager XR1 Team Issue
- Crankset: SRAM XX1 Eagle Carbon
- Derailleur: SRAM XX1 Eagle
- Brakes: SRAM Level Ultimate hydraulic disc
- Price: £8,200 / €9,499 / $9,499.99
Trek Supercaliber 9.9 AXS
- Sizes: S, M, ML, L, XL, XXL
- Shock: Trek IsoStrut, Fox Factory shock, air spring, DPS 2-position remote damper, Kashima Coat
- Forks: RockShox SID Ultimate, DebonAir spring, Charger 2 RLC damper
- Wheels: Bontrager Kovee XXX 30
- Tyres: Bontrager XR1 Team Issue
- Crankset: SRAM XX1 Eagle AXS Carbon
- Derailleur: SRAM XX1 Eagle AXS
- Brakes: SRAM Level Ultimate hydraulic disc
- Price: £9,200 / €10,499 / $10,999.99
Trek Supercaliber frameset
- Frame: Trek Supercaliber Carbon IsoStrut
- Shock: Trek IsoStrut, Fox Performance shock, air spring, DPS 2-position remote damper
- Price: £3,400 / €3,799 / $3,699.99
