Tried and tested at Unbound Gravel, the new Parcours FKT ushers in the world’s first wheelset optimised entirely around aerodynamics and the rigours of gravel racing. FKT is an acronym for Fastest Known Time – a gravel racing/adventure term used to validate the Fastest Known Time across a specific segment of trail. 

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Parcours FKT gravel wheels, by Aaron Borrill

With the FKT, Parcours looked at the entire wheel system rather than focussing on the rim and tyre as separate entities. The company also looked at gravel racing and what it represents in different regions such as the UK, EU and United States – all to achieve the fastest known gravel wheelset.

Here’s everything we know about the company's best gravel wheelset

Parcours FKT gravel wheels, by Aaron Borrill

Refined and premium aesthetics

The Parcours FKT wheels adhere to the brand’s design style guide and utilise a matte rim finish with ‘raised’ Parcours wordmark and FKT logos in gloss black, adding a tactile quality. The unidirectional carbon fibre looks premium and the feel is elevated by a new Frontier Workshop graphic located on the valve end. The Frontier Workshop joins the Aero Lab nomenclature to differentiate Parcours’ off-road range from its road portfolio. It’s a great concept and the refined graphics help elevate the visual merit of the wheels. As it currently stands, the Frontier Workshop comprises the Parcours Alta and FKT wheelsets.

Parcours FKT gravel wheels, by Aaron Borrill

Design philosophy and technical details

The design parameters and constraints of creating an aerodynamic gravel wheelset are far more complicated than a regular road-going wheel. Attributes such as gravel tyre size, tyre compatibility, rim depth and internal rim width are big factors and play a vital part in the wheel system aerodynamics.

Parcours looked at learnings from motorsport and Trek’s Kammtail Virtual Foil to find a balance. Early FKT prototypes used 29mm internal rim widths and Kammtail contouring to create a truncated virtual foil but the company soon learned it was not just a case of making the rim wide but deeper, too. This led to truncating the rim depth, which helped manage air flow from the wider tyre and pronounced gravel tread. 

The biggest challenge, however, came in the form of the hookless architecture and tyre security. Tyre security was a major concern given the variable speeds and dynamic surfaces that comprise gravel racing – so Parcours ensured the FKTs complied with ETRTO and ISO standards.

This meant tweaking the rim design somewhat and bringing the edge of the rim inwards – the result was a 47mm rim depth, 40mm external and 27mm internal rim width. These measurements proved the ideal balance as turbulent air on the rim edge only starts to reattach further down the rim. The wheel is designed to play nicely with tyre widths ranging from 35 and 45mm but is optimised around a 40mm Panaracer Gravel King X1 tyre.

Parcours FKT gravel wheels, by Aaron Borrill

With a 40mm Panaracer Gravel King X1 fitted, the FKT has a virtual foil of over 120mm owing to the optimisation of the rim and tyre and airflow pattern coming off the tyres. Testing revealed that the Panaracer Gravel King X1 is an appreciably aerodynamic tyre combined with the FKT rim architecture.

As mentioned above,  the FKT wheels feature a 47mm profile, 40mm external and 27mm internal rim width, and the complete wheelset tips the scales at 1,500g. The drive mechanism uses the same six-pawl freehub and 44T ratchet as the road hubs – this was decided for their quicker engagement and lighter weight than what is used on the Alta wheels. The spoke count measures 24 front/rear and is laced in a two-cross pattern.

While the wheels were tested in a wind tunnel for validation, the entire design was done using CFD. To accurately carry this out, a physical Panaracer Gravel King X1 tyre was mounted to 3D-printed wheel and scanned in for modelling. The CFD numbers matched the wind tunnel data and significant aerodynamic savings were seen compared to the Parcours Ronde and Zipp 303 Firecrest wheelsets across the full range of yaw conditions. (Pre-FKT, Parcours athletes used Ronde wheels for gravel racing owing to the aerodynamic benefits, hence the comparison).

Contrary to the Parcours road wheel range, the FKT don't use an asymmetrical wheel profile. This was tested using ultrasonic anemometers on the front and rear axles, which showed that, for gravel riding, the yaw angle between the front and rear wheels is on average 0.4 degrees (the yaw angle at the front wheel was on average 1.5 degrees higher than at the rear wheel for the road wheel equivalent). This is likely due to the low speeds and more sheltered ride environment associated with gravel riding.

Parcours FKT gravel wheels, by Aaron Borrill

Parcours FKT gravel wheels - Riding impressions

I was sent a pair of Parcours FKT gravel wheels to test ahead of the local launch. The wheels came pre-fitted with Pananracer Gravel King X1 tyres complete with sealant. Initial testing was carried out on a technical route I reserve for cross-country mountain bike tests and the wheels performed well. I initially had the tyre pressure set quite high (60psi front and rear) as this test route comprises long sections of hardpack and some Tarmac. Despite this, the wheels performed well and tracked accurately over bumpy terrain and singletrack. I did get bogged down on some sandy sections but this was expected with such tyre pressures – dropping the pressure to 35/40psi front and rear (which is still not super-low) radically transformed the ride quality, compliance and grip levels.

The biggest standout during my testing was the speed of the wheels and their ability to soak up road imperfections and corrugations. There's a certain level of compliance built into the rims which helps iron out these imperfections – something that improves with lower tyre pressure. During my testing, I found my average speed over two hours increased by roughly 1.5km/h without much extra effort on the pedals. Not only was this a result of the faster speeds achieved in the open gravel sections but also the added levels of adhesion and trust from the front end in loose gravel and sandy corners.

I also got to test the wheels with a fellow journalist from Rouleur and Parcours founder, Dov Tate, on the local launch in the Surrey Hills. The wheels performed impressively well over the undulating and terrain-varied test route. I decided to go lower than usual and opted for 25/30psi front/rear pressure arrangement. This unlocked a whole new level of feel and feedback but was perhaps a little too low for the speed at which we were going at some points, as I felt a lot more detail coming through the wheel system. However, the lower pressure did save me from going over the bars when I collided with a sniper root on a gravel track descent.

The speed of these wheels is undeniable. In fact, I'm inclined to say these would work pretty well paired with slick road tyres during winter, such is the speed, control and comfort, not to mention the immediate hub engagement afforded by this aero gravel wheel setup. 

While I'm still deep into my testing, initial thoughts are very positive and the wheels do everything promised by Parcours and more – a rarity in post-pandemic cycling marketing where Kool-Aid is handed out and downed without question. A detailed review will follow in the coming weeks.

Parcours FKT gravel wheels, by Aaron Borrill

Pricing and availability

The Parcours FKT gravel wheels are priced at £1,199 / $1,599 / €1,559 and are available for pre-order through the Parcours website.

Tech specs: Parcours FKT gravel wheels

Price: £1,199 / $1,599 / €1,559
Weight: 1,500g
Disc layout: Centrelock
Spoke count: 24 front/rear
Rim depth: 47mm
External rim width: 40mm
Internal rim width: 27mm

• www.parcours.cc

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