In the run-up to the CC World Cup in Albstadt, Cannondale presented its new race hardtail: the F-Si. The further development of the legendary "Flash" was developed by Peter Denk and his team with the aim of incorporating as much system integration as possible into the new race hardtail. The Cannondale developers even went so far as to design the frame around in-house parts such as the Lefty fork, OPI stem and Hollogramm crankset. The new frame, which is said to weigh 960 grams, features a number of innovations that should bring the handling of the 29er much closer to the old 26-inch versions.
The most important facts about the new Cannondale F-Si
- flatter steering angle (69.5 degrees)
- shorter chainstays (429 mm)
- more comfortable Save 2 seatpost (50 grams lighter)
- Greater fork pre-bending of the Lefty fork (55 mm; previously 45 mm)
- better handling downhill
- Better traction on steep climbs
The new F-Si, which Manuel Fumic and Marco Fontana rode for the first time at the last World Cup in Nove Mesto, no longer has much in common with its predecessor. The new Lefty fork with a larger pre-bend is designed to make handling significantly more manoeuvrable. However, in order not to lose any smoothness for fast downhills, the steering angle has been slackened slightly to 69.5 degrees. The manoeuvrable, controlled handling is noticeable on steep uphill switchbacks, for example, where many 29ers tend to tip over when turning sharply.
The best of two worlds combined
Chief engineer Peter Denk talks about three major weaknesses that 29ers have always had. Firstly, the somewhat sluggish handling, for example to avoid rocks in a flash on a downhill. Secondly, the often soft wheels and thirdly, the long chainstays, which made it difficult to get 29ers onto the rear wheel. These three points were the main focus in the development of the F-Si. Denk speaks of the result as follows: "We have finally combined the best of two worlds - the advantages of a 29er with those of a 26-inch bike." These are also the three main innovations on the F-Si:
New Lefty forks with larger offset
In order to overcome the sluggish handling, Cannondale has increased the fork pre-bend of the new Lefty forks from 45 to 55 millimetres. According to Denk, this comes very close to the handling of good 26-inch bikes. At the same time, the steering angle has been slackened to 69.5 degrees so as not to sacrifice the smoothness of a 29er. Anyone who now thinks that the F-Si is no longer agile enough is wrong. The Race 29er is super manoeuvrable, jumps through corners at lightning speed and accelerates extremely smoothly and aggressively when pedalling out of the saddle.
Shorter chainstays and chainline shifted to the right
With 429 millimetre chainstays, the F-Si has the shortest chainstays in the CC World Cup according to Cannondale. This ensures that you can easily lift the front wheel over obstacles and have great traction on the rear wheel when pedalling out of the saddle. In addition, so much tyre clearance has been taken into account that you can even ride 2.35" wide tyres. To prevent the front derailleur from rubbing against the tyre, the front derailleur, chainrings and rear cassette have been moved six millimetres to the right (outside). This maintains the chain line and the rear wheel is even stiffer thanks to the wider support of the spokes. This sounds like a new standard, but it is only partially so. Although the rear wheel has to be specially spoked (no longer asymmetrical), it can be realised with the same spokes, hubs and rims as a conventional wheel. Cannondale currently purchases such rear wheels from Mavic, Stan's and Enve.
Stiffer hubs with wider support
The wider support makes the wheels stiffer, which eliminates another 29er disadvantage. Cannondale also uses Lefty hubs at the front with wider support and a flatter spoke angle, which increases stiffness. "This allows us to achieve wheels that are at least as stiff as 26-inch wheels," says Peter Denk. This is reflected in super-direct handling on the trail.
You can find the Cannondale F-Si ride report here: First ride test of the Cannondale F-Si
