Cane Creek Invert CS review: all the gravel fork you need – just don't mention the price

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The Cane Creek Invert CS gravel fork is, as the name suggests, an upside-down suspension fork.

It compares starkly to the traditional stanchions and sliders of established designs such as the Fox 32 TC and RockShox Rudy, along with most of the best gravel suspension forks.

It is the lightest telescopic fork available, simple to set up, has excellent small-bump response, and is stiff and flex-free under pressure.

Cane Creek claims this dedicated design has advantages over the competition thanks to its lighter weight, simple setup and performance on gravel.

However, it's an expensive option at £1,199.99 / $1,199.99.

Cane Creek Invert CS details

The Invert CS is the longer 40mm-travel version of the Invert design (it's also available in a lighter-weight 30mm option).

The CS stands for ‘climb switch’, which is a button on the top of the left-hand side of the carbon-fibre crown.

This isn’t a full lock-out – a press of the button firms up the fork to reduce any bobbing when riding out of the saddle, sprinting on tarmac or climbing.

This test fork comes in light at 1,250g with an uncut steerer and thru-axle in place. That’s lighter than both the 50mm-travel Fox 32 TC (1,320g) and the 40mm-travel RockShox Rudy XPLR Ultimate (1,300g).

The carbon-fibre steerer and crown blend smoothly into aluminium legs, which telescope in and out. The lower stanchions are black hard-anodised and 30mm in diameter.

The minimal looks are complemented by the matt finish, brake-mount covering plate and simple hose routing.

The thru-axle is a standard 12x100mm size, the disc-brake mount is flat-mount standard, and a brake caliper mounts directly to accommodate a 160mm rotor – or 180mm with an adaptor. Tyre clearance is 50mm for a 700c wheel.

The axle-to-crown distance is 435mm and the offset 45mm, with a 1-1/8in – 1.5in tapered carbon steerer.

It’s a great-looking design that suggests a fork specifically for gravel bikes rather than a scaled-down mountain bike fork – a criticism often levelled at more established designs.

The inverted design means the individual (lower) stanchions can rotate freely once you’ve removed the wheel and thru-axle. That can make wheel replacement a bit tricky.

That’s a symptom of the fork’s simplicity – Cane Creek says building in fittings to stop this rotation would add weight and complexity.

Why upside-down?

The claimed benefits of this design are threefold. Firstly, it has improved fore-aft stiffness.

That’s because as forces act on a fork, the largest flex point is at the crown/top of the stanchions.

Thanks to this design, despite the high levels of leverage on this area of the fork, there’s little in the way of flex. This is a positive in terms of performance because flex can cause the fork to bind as it compresses, resulting in a sticky, harsh feeling.

Secondly, this design reduces the unsprung mass. While the sprung mass refers to any part of the bike supported by the suspension, the unsprung mass includes components such as the wheel, tyre, brake caliper, rotor and – in this case – lower legs of the suspension (because these cycle in and out of the fixed upper legs, which are part of the sprung mass).

Thanks to the lower inverted design, the narrower lower legs help reduce this weight. A lower weight helps improve bump sensitivity – something that's key when considering the trail buzz and chatter likely to be encountered on a gravel ride.

Lastly, it is claimed that an inverted fork stays better lubricated for longer, therefore improving sensitivity.

That’s simply because the oil within the fork naturally sits at the bottom of the fork leg. On a conventional fork, that means the stanchions dip in and out of the lubrication as the fork moves.

In an inverted fork, those all-important seals and bushes are constantly bathed in lubrication, effectively keeping them smoother for longer and hence better at bump sensitivity because they don’t dry and bind after extended use.

Inverted history

The Invert isn’t the first bicycle fork design to embrace inverted telescoping designs. Back in the early days of full-suspension mountain bikes, the legendary 1993 Mountain Cycle San Andreas came with an inverted fork – a design used in the world of motocross for many years.

Sunn Bicycles, under the guidance of Olivier Bossard, had some serious success with an inverted downhill fork, as did the former Cannondale team throughout the late 1990s, while the Manitou Dorado continues to be a World Cup regular, proving the design can work well.

However, getting it to do so isn’t easy, especially with the rigours of mountain biking and the lateral strains it can put a fork under.

In 2015, RockShox tried with the RS1, but it failed to gain traction for these exact reasons.

Creating a fork light enough for use on cross-country bikes, but still able to deal with the huge lateral forces, proved a step too far in this instance and is why you’ll see RockShox XC racers using the SID Ultimate fork instead.

Like the Dorado, Cannondale’s iconic single-sided Lefty fork is still going strong.

Cane Creek Invert CS setup

The fork’s carbon steerer has an integrated 36-degree crown bearing race moulded in. As standard, it includes a Cane Creek ZN40 52mm bearing, which should be compatible with most gravel framesets.

However, my Cannondale Topstone frame requires an MH-P16 (40x52x7mm – 45/45) bearing, which Cane Creek is happy to supply when ordering the fork.

The brake hose routing is simple, and I like that with a 160mm rotor you can mount the brake caliper directly to the fork without the need for an adaptor.

A neat cover plate over the brake-mount hardware keeps the aesthetics clean and slick too.

My only niggle is the brake-hose retainer on the front of the fork. Its ovalised shape enables the hose to move naturally and it stays in place. The same can’t be said of the rubber insert.

After 400km of testing, while it had stayed put, it required checking after every ride because it twists and compresses as the hose shifts.

On my most recent outing, which included a twisty, technical singletrack descent, this insert found its freedom somewhere along the way.

A replacement was ordered, and it feels as if it's made from heavier material. It has stayed in place perfectly since.

Cane Creek's advice is to run fork pressure at 95 per cent of your rider weight (you and your ride kit, weighed in lb) as a starting point.

For the record, my own 93kg/203lb weight, with helmet, shoes and spares in my jersey, equates to 193psi.

After a bit of experimentation and a few rides, I’ve settled on 195psi. That gives around 10mm of sag and the fork feels active but doesn’t bottom out (or is that ‘top out', because this fork is inverted?).

Home servicing is limited to keeping the fork clean and inspecting it regularly, with an oil service after 50 hours of riding.

This should be a simple procedure in a home workshop – you loosen the two rings at the bottom of the upper fork legs (using a standard bottom bracket tool), drain the 5ml of 15wt fork oil and refill it. You then replace the stanchions and tighten them.

Cane Creek recommends an annual full rebuild service, including the air spring. This is certainly something best left to the experts.

Cane Creek Invert CS ride impressions

The Invert CS impresses on the trails, particularly in its stiffness. There is no discernible fore-aft flex and it’s a match for the equally impressive Cannondale Lefty in that respect.

On washboard ruts and choppy tractor tracks, the bump response is excellent. It takes the edge off and eliminates jarring knocks that can put you off balance. In short, the Invert helps you flow and hold your line.

It’s also impressive at reducing the fatiguing vibrations of gritty gravel and poor road surfaces.

Even when you engage the climb switch, which greatly stiffens the fork, it remains active – it makes for a smooth-riding, no-bobbing companion on tarmac between gravel sections.

On climbs, with the switch engaged, it again takes the edge off but has the solid, stiff feel of a rigid fork, yet with a welcome smoothing edge when dealing with gritty tarmac buzz.

The button-shaped switch is quite firm to engage and release, but it has a defined click, which eliminates any vagaries.

On bigger hits, drops and larger exposed roots, the Invert CS fork copes well, although it doesn’t have the hit-crushing smoothness of Fox’s 32TC or the bottomless-travel smoothness of the RockShox Rudy XPLR.

It doesn’t come unstuck on dips, wallows or chunky roots, and it progressively ramps up resistance on big hits.

On a few occasions, though, I got through the fork travel and met an abrupt bump stop until I’d dialed in the pressure on the fork.

My advice is to spend plenty of time experimenting to get the feel right on the fork. So be prepared to ride a few times with a shock pump onboard.

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Cane Creek Invert CS bottom line

I’m hugely impressed by the Invert CS; its simplicity will be welcome to technophobes who just want to ride, and not fettle endlessly with settings.

The only niggles are the wayward hose clamp insert and that when you remove a wheel (and the axle), the individual stanchions can rotate freely – which makes wheel replacement somewhat fiddly.

Overall, the Invert CS is a great gravel fork. It’s the lightest telescoping gravel suspension fork available, and its performance on trail and tarmac is impressive.

The minimal looks are more aesthetically pleasing than the scaled-down traditional mountain bike designs favoured by the competition.

The downside is the $1,199.99 / £1,199.99 price. That's £199 / $250 more than the Fox 32 TC Factory and a huge £320 / $300 more than the Rock Shox Rudy XPLR Ultimate.

It is £200 cheaper than Cannondale’s similarly inverted single-sided Lefty Oliver, and that fork requires a dedicated wheel build.

If you like the minimal understated looks and don’t think you’ll need the climb switch, the lighter Invert SL with 30mm travel will set you back £1099.99 / $1099.99.

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