2011 Scott Foil
By Tom Demerly.
Scott Bicycle’s new Foil series of four road bikes enters the market to combine two previously conflicting design themes: Frame stiffness and aerodynamics. Previous model offerings from Felt and Cervelo separated these two categories: The aerodynamic road bike, such as Felt’s AR and Cervelo’s S series; and the ride quality or stiffness bikes with the Felt F series and the Cervelo R bikes. Scott’s new Foil road bikes attempt to combine stiffness and frame aerodynamics into one package.
On one account they have succeeded, on the other, I can’t tell.
The Scott Foil road bikes include four models, Foil Premium, Team Issue, R1 and our test bike, the Ultegra equipped R2 at $3699.95. The bikes use a new frame shape to provide both a (claimed) aerodynamic and stiffness benefit. This new frame family shares the Scott catalog with their previous Addict road bikes.
The basis of the aerodynamic claims made by Scott for the Foil design is the recent “truncated” air foil theme we see from Trek and others. This is different from the wing-cross section airfoil from Cervelo. The shape or section of the “wing” is chopped off about half way back with an abrupt flat surface. There is no sharp trailing edge. The argument is; the flow of air surrounding the frame at speed, the boundary layer, detaches with less drag and more smoothly at the trailing edge.
Scott’s promotional video for the Foil development process shows a lot of CFD development, Computational Fluid Dynamics. CFD is a computer modeling process for testing and developing fluid mechanics in a virtual setting. You can do “virtual wind tunnel testing” with CFD on a computer screen. You don’t have to go to the wind tunnel with a real set of prototypes. Scott used the Mercedes-Benz Formula 1 development wind tunnel for verification of the CFD developed Foil design, a sexy marketing association with F1.
The truncated wing shape of the Scott Foil is also compliant with the UCI’s technical rules for a 3 to 1 ratio of tube depth to tube width. If you look at Cervelo’s aero bikes they achieve UCI compliance with the 3 to 1 ratio by being quite narrow in overall width. The Scott bike is much wider. To be UCI compliant with the 3 to 1 rule they simply had to cut the tail off. This achieves other design agendas as well, mostly frame stiffness.
Does it work to reduce drag? There is likley no way to verify this short of an independent wind tunnel test. VeloNews Tech Editors Caley Fretz and Nick Legan conducted a ground breaking, independent wind tunnel test of four road bikes for the April 2011 edition of VeloNews, but the Scott Foil was not one of the four tested. If you subscribe to Former President Ronald Reagan’s dictum of, “Trust… but verify” we’ll have to wait for verification of Scott’s claims about the drag reducing concept used on the Scott Foil. Scott claims the FO1 concept- the developmental name of the Scott Foil aerodynamic concept, “showed the best competitive results of six competitors’ bikes” in a promotional video. They did not name the six competitors’ bikes.
Stiffness. It is your first impression of the Scott Foil. From front to back the lateral stiffness is superb. The only bike I can compare this level of lateral stiffness to is Cervelo’s previous R3SL. That may be no coincidence since Cervelo and Scott have shared composite vendors.
Ride quality- how much you feel the bumps, is often related to stiffness and the Scott Foil is not exempt. In exchange for the incredible stiffness you are going to feel some bumps- some, but not all, and it is a reasonable exchange for such great lateral rigidity. The minor road irregularities I rolled over at speed. The heavy hits: hang on. So much of your ride “feel” or sensation of the road comes from your wheel and tire choice the Scott Foil’s edgy ride quality could be tamed with a pair of mushy Michelin 25 mm tires as opposed to the stiff, precise riding 23 mm Continentals that came on our test bike.
The anomaly of the Scott Foil’s ride is the rear end. With a bike this stiff I expected it to explode forward with an out of the saddle effort. It doesn’t, and that’s odd. I couldn’t get back to the geometry chart fast enough to see what was going on. I just came off a road test of the BH G5 road bike. The rear end on the BH G5 is one of the most superbly designed rear triangle geometries I’ve ever ridden. When you do five hard pedal strokes out of the saddle the BH G5 responds with splendid and attentive acceleration- despite having a rather sedate mid-section and front end. The BH uses a slacker 72.5 degree seat tube angle and short 40.2 cm chainstays. The Scott Foil has a 73.3 degree seat tube angle in front of 40.5 cm chainstays. Do 1.2 degrees of seat angle and only 3 millimeters of chainstay length make a tangible difference in ride quality? By themselves, maybe not. It is the combined effect of slightly longer chain stays, slightly steeper seat tube angle and the seated stiffness of the unusual triangular seatpost on the Scott Foil– along with other frame features including the invisible influence of carbon lay-up that provide angry stiffness in the saddle, but less response out of the seat. It’s an odd contradiction.
The Frame and Fit.
Geometry across the chart on the Scott Foil tracks with the Scott Addict road bikes. My company bike is a Scott Addict. I like the head tube height, top tube length and overall fit. With the high-ish head tube on the Scott, 140 millimeters on a 54cm frame, I run a low stem and no spacers. The front end stays stiff and precise.
The new design of the frame is striking in appearance. The seatpost binder bolt is integrated into the frame and cable routing is internal, entering the frame early for less exposed cable housing on the outside of the bike. The rear derailleur cable doesn’t emerge until you get to the end of the right chainstay. Headset is tapered from 1&1/8” to 1&1/4” on the lower race. The frame uses press fit bottom bracket cups, like most current frame designs. The seatpost itself is an unusual shape, not round, that makes rotational adjustment impossible and has a minimal set-back, steepening the effective seat tube angle range. The saddle clamp adjusts infinitely with one 5 mm bolt from the right side, an elegant and convenient design.
A feature that caught my attention in one of the promotional videos for the Scott Foil was a faired-in water bottle holder that attached to the bottle braze-ons. This aerodynamic integration idea has been used on the Cervelo P4 and the Trek Speed Concept 9 Series but is a new idea on road bikes. I hope Scott releases this bottle carrying option for the Foil.
The Foil R2 we tested was a Shimano Ultegra 6700 series bike with the option of a compact 50/34 crank or a full size, 130 mm bolt pattern 53/39 crank. Brake calipers continued the Ultegra spec. Furniture on this bike was a Scott labeled original equipment saddle and a Scott alloy stem and bar, both of which I like. The bike rolls on Mavic Cosmic Elites with 20 bladed spokes front and rear over the Continental 700 X 23c Ultra Race tires.
If Scott set out to build an attention getting frame with superb looks, remarkable stiffness and an arguable aerodynamic case the Foil achieves those agendas. I wish they had fortified their rear end geometry to match their racy lay-up, but the case for Scott’s Tour de France proven geometry is well established. That case, combined with the new frame design of the Foil bikes, makes for a tangibly different and compelling introduction from Scott. If you’re looking for a professional level race bike the Scott Foil belongs in your survey.