The F-SI is the top-of-the-line hardtail cross country bike in Cannondale’s MTB range, which has recently been completely revamped to provide more speed and better handling. Apart from the advancements in frame technology, the American brand has also developed a new fork called the Lefty Ocho, which many now consider to be the best XC suspension on the market. So we have a flagship frame paired with an extraordinary fork, a fine recipe for special ride experience!
The F-SI was launched at the XCO World Cup event at Albstadt earlier this year, where BikeMag was kindly invited. We watched the race but unfortunately could not take part in the test ride due to the unfavorable weather conditions. All that remained is to some product pictures, and return home with painful craving. In order to lessen our sense of deprivation, Aspire Sports – the distributor of Cannondale bikes – offered us another occasion to test ride the 2019 F-SI and other newly introduced bikes in the Czech Republic. (We’ve previously reported on our ride experience on board the new SystemSix from this test camp.)
Most have probably noticed that this is not the first time we bring you news about the F-SI. In a previous write-up we listed all the new features of this leading carbon hardtail bike.
Instead of repeating the cited article, I’ll simply cover the main specs. The new revamped F-SI model inherited all the conspicuous features of the 2015 model version, including the OutFront frame geometry, where the 69 head tube angle is paired with a fork with a slightly longer offset. The result is a bike geometry which lends itself to faster descending on challenging cross country trails without compromising climbing efficiency. The other main feature the designers transferred to the new F-SI is the asymmetric rear frame triangle (AI). This means that the complete rear end is shifted 6mm to the drive side, thereby providing more room for the cogs and the tires, shortening the chain stays for a more nimble handling, while also increasing stiffness. It seems like a win-win scenario. The third main heritage is the BallisTec carbon layup structure which allows for more comfort while preserving stability and decreasing weight of the frame. All in all, the engineers managed to cut 80 grams weight for the new F-SI compared to the former generation.
The F-SI accumulates all the top-level technologies Cannondale brought to the world of mountain bikes. It was developed with a perfective approach, no corners were cut, enabling the rider to enjoy all the modern advancements in bike technology. This manifests in every detail of the new bike, including straightforward aspects like the hidden cable routing, the thru-axle wheel attachment, the integrated seat post clamp and the flat-mount brake calipers. Looking at the bike gives us great satisfaction in every aspect.
The F-SI is available with several build levels, the Carbon 3 on this test could be considered mid-level within the range, on the other hand, the frame and fork are definitely top-tier.
The F-SI Carbon 3 received the newly developed Lefty Ocho fork, which is a milestone in the 20 year history of Cannondale’s single-legged “Lefty” fork technology. What separates it from the previous versions is the single crown design, but then again the internals have also been overhauled. The stanchion slides on three rows of Delta Cage needle bearings and the rebound dampening cartridge has also been reengineered. The latter has a self-gassing air valve design with heat compensation and separate compression and rebound dampening adjustment. This is way ahead in terms of technology compared to conventional “two-legged” forks on the market.
Our test bike comes with the most modern 1×12 shifting, employing a single chainring in front and 12 cogs at the back, comprising of a SRAM GX Eagle rear mech and shifter paired with a lower-tier SRAM NX Eagle cog set and a Truvativ Stylo crankset. It’s evident from the component choices that Cannondale wanted to keep cost down while provide a stellar frame and fork for the rider. Fortunately the shifting performance doesn’t suffer as a result of this marketing strategy, the 1×12 system is fully up-to-date, ridden in top level professional racing. Finally breaking duties were handed to the SRAM Level T hydro disc units with 160mm discs both front and back.
The wheels on the bike are the renowned Stan’s Crest MK3, which leave little to be desired for cross country riding. The front hub is obviously adapted to the Lefty fork, the rear to the 12×148 AI system, hence both bear a non-standard Cannondale-specific design. They are topped with the Schwalbe Racing Ray – Racing Ralph tire duo, plenty fast and trustworthy choice for a performance-oriented cross country bike. They can easily be converted to tubeless, or substituted with something else based on rider’s preference or trail conditions.
We have been accustomed to seeing Cannondale’s house brand accessories on all the bikes offered by the American specialist. The top-tier F-SI carries on this trend. The handlebar, stem and seat post all bear the Cannondale logo, the latter is a carbon model utilizing the well-known SAVE technology to provide more comfort for the rider.
Unsurprisingly the test ride brought no surprises. The F-SI proved to be a top class act, something we have come to expect from the brand. It’s truly an excellent XC bike, extremely efficient, accelerates like no other bike I have ridden, pedals well uphill and descends like a demon when the trail heads downward. There is absolutely no kink in its armor. Hopping on the saddle, you’ll quickly come to the conclusion, that this is the XC rig you always longed for. Mind you, the test trail in Czech Republic was quite rocky with rooted sections, not exactly what I’d categorize as classic cross country terrain. More like what most MTB riders would term “trail riding”. Nonetheless, this hardtail XC bike was able to cope with the challenges, and handling was just fine even on the most technical sections. The seat post employing SAVE technology did a fine job at attenuating the bigger hits, so I was happy with overall comfort. Climbing is naturally the bike’s main forte: it’s insane how efficiently it can be pedaled when the trail points upward. The rear wheel tracks rough ground surprisingly well, soaking up most of the chatter.
And to finish off a list there is the Lefty Ocho! It’s not easy to declare a bike components to be best available, but in this case I have little hesitation in saying exactly that. For me Lefty Ocho is a game-changer, probably my favorite part on this bike, and the best fork I’ve ever ridden. It’s difficult to describe in words what makes it so special. The travel is buttery smooth to start with. In fact, I’ve ridden an older generation Lefty during one of the test rides, and the improvement is quite noticeable. I believe the Ocho deserves all the accolades it received from the media and the industry in general.
To sum up my experience on the Cannondale F-SI, it’s a bike tailor-made for XC racing, making it an ideal choice for those who take part on XCO competitions or even in marathon events. But beware: if you ride an F-SI, you’ll never again be able to blame your result on the bike!
Recommended retail price: HUF 1,169,990.