Do you know what a "fuselage frame set" is? No? We didn't know either - until a few weeks ago. When the Hessian bike manufacturer Storck announced its "Fascenario 0.7 IS" as the lightest "fuselage set" on the market to date, we too initially stumbled over the term, which originates from aircraft construction. It refers to what Cannondale once introduced to the cycling world as "system integration": frames that form a technically harmonised unit with the fork, headset and bottom bracket. There is a simple reason why more and more high-end suppliers are adopting this design approach. Weighing between 800 and 900 grams, today's best racing bike frames such as the "R3SL" from Cervélo, Scott's "Addict" or Storck's "Fascenario 0.7" have long been on the edge of what is technically feasible. To make their models even lighter, manufacturers almost inevitably have to focus on the periphery of the frame, i.e. the fork, headset, bottom bracket and cranks. There is still potential for optimisation here.
This was Storck's main motivation in developing the "Fascenario 0.7 IS", which is technically based on the "Fascenario 0.7" introduced in 2006. At 865 grams, the "IS" is extremely light, although not significantly lighter than the "Fascenario 0.7" (886 grams) last tested in TOUR 3/08. The two models are also only separated by a blink of an eye in terms of set weight including fork and headset ("0.7 IS" 1,197 grams; "0.7" 1,203 grams). The main difference is the bottom bracket, which is part of the frameset on the "IS". The "Powerarms SL" carbon cranks developed by Storck alone, which weigh just 558 grams including chainrings and bottom bracket, save more than 200 grams compared to a similar bike with Shimano Dura-Ace cranks. This includes the fact that the IS frame does not require bearing shells because the bearings are inserted directly into the housing.
At first glance, it seems that the bottom bracket area with the housing widened to 86 millimetres for the power arms is the only thing that distinguishes the two Fascenarios. However, company boss Markus Storck mentions further differences. Because new production moulds had to be built anyway due to the special cranks, the fibre layup in the headset area was optimised once again. At 110 Newton metres/degree, the steering head stiffness of the "IS" is around ten percent higher than that of the "Fascenario 0.7". The "IS" is therefore not only top in terms of weight and price, but also in terms of the STW value, which puts frame weight and steering head stiffness in relation to each other and is a measure of the design intelligence of a frame. An impressive 125 Nm/°/kg is likely to remain the top mark for some time to come.
Whether the frameset therefore has to cost 7,000 euros (including cranks and ceramic headset) remains to be seen. However, if the manufacturer is to be believed, there are enough racing bike freaks for whom their hobby is so expensive. According to Storck, it has already sold 68 of the "Fascenario 0.7 IS", which is limited to 100 units worldwide.
So how does this marvel ride? The biggest compliment you can pay it is that it not only looks like a full-blown racing bike, but also rides like one. Not a trace of compromise at the expense of function. The difference to "normal" bikes is most striking when pedalling: thanks to the featherweight, the bike, which weighs 5.9 kilos including pedals, accelerates phenomenally. High steering precision and the geometry, which is not too stretched, contribute to the positive riding impression, as does the astonishing fact that, apart from the wheels, only tried and tested mass-produced parts have been used.
The only point of criticism are the "PRO VT-1" wheels from the US manufacturer LEW. The joy of the crazy acceleration behaviour of the full carbon wheels, which weigh 840 grams as a pair, was dampened when we had to brake the bike from higher speeds for the first time. Unpleasant rubbing of the pads made the front brake in particular difficult to control. Our initial suspicion - uneven brake flanks - was not confirmed on closer inspection. Something else is visible to the naked eye: The manufacturer has obviously pushed the material of the rims to the limit so that the brake flanks buckle under the pressure of the pads - no chance for a clearly defined pressure point and evenly controlled braking forces. Although the 4,300 euro wheelset is a perfect match for the "IS" in terms of weight and design, it completely counteracts the impression that the frameset is suitable for everyday use without any problems. But that can be changed.
*Test wheel frame size greased;
**Projected dimension from centre of bottom bracket to upper edge of head tube-saddle-head tube elevation at 75 cm seat height (centre of saddle frame-upper edge of head tube);
***Adjusted weight for frame size 57 and fork steerer length 225 mm;
**** The score includes further individual scores that we have not included for reasons of space.
Photos: Daniel Simon
