Cannondale just released the latest version of the F-Si, the brand's top-end carbon cross-country hardtail, which features an updated frameset and a whacky new Lefty fork, the Ocho.
The bike is incredibly efficient, and yes, the Ocho looks weird, but it works well, tracking precisely through hard corners, remaining active in chunky terrain while still offering that legendary excellent small-bump sensitivity.
- Everything you need to know about the Cannondale Lefty Ocho
- A year of hard riding on the Cannondale Scalpel Si Team
So what about that fork?
I’m sure you’re all itching to learn what the deal with thank funky new fork is. There is lots to talk about, so I’ve put together a separate article on it.
You guessed it; it’s lighter!
In terms of weight, Cannondale claims to have shaved 80g off the previous generation of the bike. That 80g doesn’t sound like a lot but bear in mind that represents just under nine percent of the total weight of the new frame.
The top-end World Cup build, which is built around an XX1 Eagle groupset, ENVE wheels and all manner of fancy carbon finishing kit comes in at a seriously impressive claimed 8.4kg / 18.5lb.
For context, this build is 90g lighter than the Specialized S-Works Epic, a similarly minded, top-end XC hardtail.
You guessed it; it’s more comfortable!
The new F-Si has dropped the traditional seat clamp of old in favour of an integrated clamp, which is accessed via a 4mm bolt that sits just about flush with the tubes inside the main triangle.
This layout allows more seatpost to be exposed, increasing deflection, thus improving comfort. The layup of the frame has also been altered, resulting in an overall eight percent increase in deflection.
As you would hope of a modern carbon bike, the layup and profile of the tubes are altered throughout the size range to ensure the ride quality of the bike remains consistent. This is fairly standard practice these days, but it’s still reassuring to know that brands are considering those at the upper and lower ends of the size spectrum.
In a similar vein, the size small through XL frames come with 29in wheels and the XS ships with 27.5in. All bikes have clearances for 2.35in tyres out back.
Cannondale has always been pretty progressive with its XC bike geometry and the new F-Si is no different.
The bike features Cannondale's signature OutFront Geometry, which on the F-Si, pairs a 69-degree head angle — which is slack by XC standards — with a longer-than-average 55mm offset fork (50mm on a size XS).
In theory, this slack head angle should improve handling in steep and gnarly terrain with the 55mm offset keeping things snappy and nimble in twisty technical areas.
The reach is also fairly long by XC standards, coming in at 440mm in a size large. This is comparable to similarly progressive bikes (like the aforementioned Epic).
In a further nod to progressivity (which I’m delighted to discover is a word I haven’t just made up), all bikes in the F-Si range will ship with 760mm bars.
The bike features Cannondale’s AI (Asymmetrical Integration) system out back. In short, this pushes the whole drivetrain 6mm out to the right, improving tyre clearance and allowing riders to run a front derailleur if they wish, all while keeping the chainstays short (427mm), improving stiffness and keeping the handling nimble.
This setup requires that the rear wheel is dished 6mm off to the left to compensate for the asymmetrical shape. However, it’s worth noting that as the rear end is built around a regular 148mm Boost standard hub, it will almost certainly be possible to re-dish a regular wheel to make it compatible with the new F-Si.
Speed Release thru-axle
Removal of the rear wheel has also been made significantly quicker with the new Speed Release thru-axle.
With this system, an open slot is moulded into the non-driveside of the dropout that allows a skinnier stepped-down section of the thru-axle to drop out once the threads are disengaged from the driveside.
This is genuinely easy to use and quick solution to one of the most common complaints with thru-axles for racing.
Builds for all budgets
The F-Si comes in seven different builds, ranging from the affordable Carbon 4 (€2,799) rising to the lofty Hi-MOD World Cup (€8,499).
It’s worth pointing out that the F-Si Carbon 5 — the cheapest bike in the range (pricing TBC) — ships with standard forks. All bikes above this ship with either a carbon or alloy version of the Ocho.
Cannondale F-Si Hi-MOD World Cup edition first ride review
Myself and BikeRadar videographer and XC machine, Joe Norledge, spent a day riding around the Albstadt World Cup course getting to grips with the new bike.
We were both spoilt with a top-end Hi-MOD World Cup build, which is built around an XX1 Eagle groupset, ENVE M525 wheels, SRAM Level ultimate brakes and all manner of fancy carbon finishing kit.
This build comes in at 8.4kg / 18.5lbin the size large we tested.
This low weight and the impressive stiffness of the frameset makes for an incredibly efficient bike on the climbs. Matched with the solid lockout on the Ocho fork, it feels more like a road bike than anything else when climbing out of the saddle.
For seated climbing, I was really pleased with the zero-setback seatpost. Personal preference plays a part here, but this makes it easier to get your weight over the front wheel on steep climbs.
The previous generation of the Lefty was impressively stiff and the Ocho is no different. The front of the bike feels very accurate in rough terrain and is super responsive in hard corners. Even hopping off little drops into really chundery chutes, the fork remained active throughout the entirety of its travel, never binding or stuttering.
Small-bump sensitivity is impressive. It’s captivating to glance down on a seated climb and watch how active the fork is over small bumps.This sensitivity would really come into its own on longer fireroad climbs or in marathon race where reducing fatigue is key.
As a fastidious fettler when it comes to suspension, I was surprised by how satisfied I was with the stock setup of the fork after just setting up sag.The fork is very supportive and ramps up nicely through the travel, coping very well throughout repeated bouts of out of control high-speed abuse on the gnarlier descents.
It of course has no bearing on performance, but the aesthetics of the fork will obviously be a deciding factor for some. In the flesh, there’s no denying that the design does look pretty whacky at first, but I honestly can’t say I paid it much attention as soon as I was on the bike. Whether or not you vibe with it will be up to you.
The simple mechanical lockout worked perfectly throughout our stupendously muddy ride, though the action is a little counterintuitive at first (pushing the lever in unlocks the fork).
There’s enough room to move about on the bike in steep terrain and I felt far less pitched over the front compared to similar XC bikes I’ve ridden. Make no mistake, though; this is a true XC race bike. It’s a super-responsive ride and a bike that is best enjoyed ridden at the ragged edge.
Having spent more time on trail bikes in the last few months, I also couldn’t help but find myself desperately stabbing my thumb in hope of finding a dropper lever. No bike in the F-Si range comes stock with a dropper, but the frame is compatible with stealth-routed droppers.
The bike ships with Schwalbe’s all-new Racing Ray tyre up front and an updated Racing Ralph out back. I have no doubt these will be perfectly competent tyres for fast, dry summer riding, but they could not have been a more inappropriate choice for the conditions of the course.
I won’t dwell on these too much as it wouldn’t be fair to draw any conclusions given the conditions, but it’s safe to say I’d be immediately swapping these out for something more suited the damp climes of my native UK.
Joe — a far more competent, experienced and faster XC rider than I — noted that he felt the front end of the bike a bit high for his tastes.
Cannondale was happy to admit that this is a fairly common complaint from its pro riders, but that the majority of consumers prefer — and often benefit from — a slightly loftier front end.
Of course, this is more of a spec issue than anything else as it’s always possible to a fit a different stem if you want a more aggressive fit.
Likewise, the Eagle-eyed (get it?) will note that all of the bikes in the F-Si range ship with SRAM’s own cranks. Due to the Ai integration out back, this means that Cannondale has had to spec the F-Si with cranksets with an unusually high Q factor.
Last year, Joe — who has hips narrow enough that I often worry he’ll fall through a crack in the floor — found this to be an issue on his Scalpel test bike (which has the same AI integration) and swapped the stock cranks for Cannondale’s own Hollowgram cranks, significantly reducing the Q factor.
If you want to reduce the Q factor on the new F-Si, you’ll have to go down the same route.
I must stress this is a small point that few will have to worry about, but bears mentioning given the typically obsessive nature of XC racers.
Cannondale F-Si Hi-MOD World Cup early verdict
The new F-Si is kind of what we expected of the new bike, but is no less impressive for it. It’s a refinement of an existing and much-loved platform that is matched with a seriously impressive and totally unique fork.
There’s a handful of spec issues I’d want to sort from the off and I’d want to spend some more time on the bike before drawing any solid conclusions, but I think it’s safe to say that those looking for a super-fast and well-composed modern XC bike are unlikely to be disappointed by the new F-Si.