The Substance is Vitus’s latest foray into gravel, but unlike a lot of gravel bikes that aim to be adaptable to the road this is a much more focused machine.
The 2020 carbon frame in this great-looking metallic brown finish is built from Toray’s T-700 carbon fibre, a high-modulus unidirectional weave that’s a premium material that brands the calibre of Pinarello use exclusively.
For those who want long days away, or even just some weather protection, the Substance frame has bosses for mudguards, fork-mounted bags and a third bottle boss on the underside of the down tube, making it a viable option for expedition riders and bikepackers.
The specification of fat (47c) tyres and 650b wheels, along with generous clearances front and rear, give the Substance mountain-bike-like appeal – even if the geometry is more drop-bar-biased with my XL test bike having a sporty 609mm stack and short 383mm reach.
The 72-degree head angle and 72.5-degree seat angle are endurance-bike compatible, while the wheelbase is a generous 1,041mm.
The sub-9kg weight for my XL test bike is impressive for a gravel bike at this price, particularly one with very large volume 47c tyres.
The frameset is compatible with 700c wheels, so there is the option down the line to add a second set of wheels into the mix should you prefer that larger wheel size, or want to make some gearing adjustments. The ratio at the moment is quite off-road focused but you can turn it into a capable all-rounder.
The 1x drivetrain comes from SRAM’s mid-range Rival group with a non-group affiliated S-Series chainset. The simplicity of DoubleTap shifting, where both up and down shifts come from the lever set behind the right-hand brake lever, is great and is quick and accurate to shift.
The gearing choice of a 40-tooth ring combined with a broad 10-42 cassette is perfect for off-road. With a lowest gear of less than 1:1 (40/42) you feel like you can ascend anything and on some particularly muddy test riding the ultra-low gearing was an absolute boon for low-traction climbs, while the high-cadence, spinny nature of the gears really suits riding off the beaten track.
Like its more expensive siblings, the Rival rear mech comes equipped with a roller-bearing clutch so when you’re bouncing over rocks and roots the chain is tensioned so it doesn’t slap the chainstay or get bounced off the chainring.
SRAM’s disc brakes also offer bags of feel at the lever and the disc rotors’ open design keeps contamination from dirt and road spray low, which in turn prevents noise from the rotor scraping the pad down, though in the wet I could hear a few squeaks now and again.
The Substance’s rock-solid frame feels rapid and reacts well to pedalling input but the downside to this is on the road. With the 40-tooth chainring I all too often found myself spinning out the available gearing before I’d reached close to the limits of what the frameset could do.
Even with the big-volume treaded WTB Venture tyres you soon find that you’re at the bottom of the block turning a 40/10 gear, giving you a 105-inch gear. With a pro compact that would be the equivalent of riding a 52/13, so it feels slightly lacking at the very top end. It becomes most prevalent on long, fast descents where you’re spinning out a little too soon.
For dedicated, pure gravel riding, however, it makes plenty of sense.
Vitus has put together a great package with the Substance. The cockpit uses Vitus’s own alloy gravel bar with a nicely shaped 16-degree flare held in place by a neat Prime alloy stem.
The Vitus saddle has titanium rails for a bit of extra spring in the seat, although the back end is pretty firm with the alloy post – a carbon upgrade down the line wouldn’t go amiss.
The wheels are certainly a stand-out feature on the CRX and I’m not too shy to admit that I’m a fan of brands that put money into parts that matter and really make a difference.
The carbon Prime wheels here are gravel gold: tubeless ready (they come set-up) with a broad 32mm wide external and 24.5mm internal width to the 30mm deep rim, and weigh in at just 1,570g a pair, which helps with the CRX’s impressive sub-9kg weight and the huge WTB tyres fitted.
Even with the chunky WTB Venture tyres in place the Substance feels flighty and superbly manoeuvrable, both on and off road. There is a lot to be said for lighter wheels if you want to give a bike a lively feel.
Vitus Substance CRX overall
The Substance is an absolute blast off the beaten track. It has true mountain-bike character when it hits dirt and I loved throwing it around some local singletrack spots and woodland tracks alongside the usual gravel byways.
In this guise and with this specification it’s a very focused off-road machine at a great price, and if you’re already sorted with a good road bike and you are looking to broaden your horizons then the CRX offers real substance and bags of value too.
Vitus Substance CRX geometry
- Sizes (* tested): XS, S, M, L, XL*
- Seat angle: 72.5 degrees
- Head angle: 72 degrees
- Chainstay: 435mm
- Seat tube: 580mm
- Top tube: 575mm
- Head tube: 190mm
- Fork offset: 50mm
- Bottom bracket drop: 68mm
- Wheelbase: 1,041.4mm
- Stack: 608.9mm
- Reach: 382.9mm