VITUS SUBSTANCE SRS 1
£1599.99 British steel for big adventures
The Substance SRS 1 combines modern all-road geometry with classic, skinny Reynolds 725 steel tubing to create a bike that majors on versatility without compromising off-road performance. The design combines a road-bike style 73.5-degree seat angle with a slightly relaxed head angle of 71.5-degrees. The fork offset of 43mm and the big 47c tyres create a 69mm trail figure (see p35). The usual trail for a fast handling road bike is around 57mm, so at 69mm the Vitus boasts handling that is more relaxed than a road bike, making for great off-road stability, though it’s not as relaxed as either the Bivi or the Ragley with their more overt mountain-bike influences.
This makes the SRS a truly excellent allrounder. On dirt it inspires confidence with handling that’s nicely balanced between stability and swift reactions and it feels particularly at home when traversing technical singletrack.
The SRS comes with an off-road-ready 1x SRAM Apex groupset, combining a 40-tooth chainring with an 11-42 cassette. The super-low gear makes off-road uphill traverses a breeze. Even when traction is an issue I always found the right gear to make progress. Braking comes from SRAM’s Apex (1). With bags of power and plenty of feel, they’re less vocal than Shimano’s hydraulics but did become a little screechy when wet and mudcaked. And I did experience a little rotor scraping at the rear after riding on muddy sections.
Vitus has stepped away from the full SRAM group by using a SunRace RX8 cassette. This looks swish with its red anodised carrier and glossy black sprockets. Looks out-do the performance as compared to the understated GRX on the Bivi and Ragley, or the smart Force unit on the Felt, as the Vitus has a little more chain chatter and vibration.
The finishing kit all comes from the Vitus stable with the cockpit (2) a particular high point. The gravel bar combines 16-degree flare with a flattened, almost aero-shaped top section that makes for a great hold when you’re grinding along on the flat at speed. The ride position, with its low 577mm stack and mid-length reach of 391mm, makes for a ride that feels rapid off road and is no slouch on it.
The Prime Kanza wheels (3) (the alloy version of the carbon Primes that so impressed us on the Substance GRX, issue 370) are stiff laterally; the WTB Venture tyres have a low textured grip through the central section and prominent knobs on the shoulder. This makes for a fast-rolling tyre (for its size) on tarmac and one that offers plenty of cornering grip on dirt. That said, while the less-prominent tread’s excellent in the dry, it struggles in wet mud compared to the Senderos on the Ragley, but then so does every bike in the test compared to the mountain-bike style treads that are the Trig’s secret weapon.
Like the Ragley and Felt, the 650b wheel choice has its benefits when it comes to off-road cushioning and traction. Sadly, it shares the selfsame downsides when it comes to matching the speed of a 700c set-up on mixed-surface rides. You’ll beast big-wheeled rivals on the really rough stuff, but on tarmac, you’ll exert yourself to stay on the wheel of big-wheeled brethren.
Ride comfort is seriously impressive with the Substance; the skinny-tubed Reynolds steel frame offers the lively spring indicative of quality steel pipes and the full carbon fork, with its generous rake, nulls vibrations. It’s all wrapped up with the suspension-like cushioning offered by the huge tyres. The Vitus saddle is the only chink in the SRS’s formidable armour. The flat shape is okay, but the hull feels overly stiff and that’s only compacted by the minimal padding.
Overall, the Vitus is a superb modern gravel machine. It hits all the high points – handling chops; versatile with fixtures and fittings for racks and mudguards; 1x and 2x drivetrain options; 650b and 700c compatibility – though the carbon fork lacks mounts for the fully-loaded bike-packing brigade. It’s well-priced with it and the ride will impress too.