The name says it all: Specialized emphasises the comfort aspect of the "Roubaix SL2". The geometry, components and special elastomer inserts are designed to make the racer fit for rough, bumpy tracks. In the US manufacturer's product hierarchy, the model is on a par with the "S-Works Tarmac SL2", making it one of the most expensive models in the American manufacturer's range of road bikes.
Externally, the two high-end carbon fibre racers are not immediately distinguishable. Only at second glance do the design differences become apparent: The head tube of the "Roubaix" is longer than that of the "Tarmac", and the lower end has a 1-3/8 inch bearing instead of a 1-1/2 inch bearing, while the upper end measures the usual 1-1/8 inches. Elastomers in the seat stays and fork blades promise comfort. Black, red and silver dominate the look, and the designers have not skimped on brand logos and type designations. Shimano's new Dura-Ace groupset and the latest "Ksyrium SL Premium" wheels from Mavic form the high-quality equipment basis, while the remaining components come from the Specialized range.
The racer completed its practical test at the TOUR-Trans-Austria in September 2008, on a course 650 kilometres long with 15,000 metres of altitude. During the week-long tour through Austria, we liked the relaxed riding position. The slight elevation from saddle to handlebar is easy on the back and shoulder girdle on long distances, the comfort on the saddle is noticeable, the peaks of hard impacts are noticeably softened by the compliant seat post. The effect of the elastomer bumpers called "Zertz", on the other hand, is beyond judgement. However, Specialized sees the inlays less as suspension and instead ascribes them vibration-damping properties. However, these cannot be isolated from the overall comfortable riding impression. If they are imperceptibly involved - all the better.
Beyond this comfortable design, the "Roubaix SL2" is a thoroughbred sports bike. On Austria's mountain passes, the bike always remained controllable on fast and winding descents, the test bike followed steering corrections unerringly, even at 85 kilometres per hour, and there was no trace of the dreaded frame flutter. The very good brakes on the new Dura-Ace also stood out in this test. The handlebars with their flat top bar cross-section and small height difference between the top and bottom bars feel good in the hands. The only thing to criticise was the slanted Specialized saddle, the frame of which was not precisely straight.
The test results from the laboratory largely confirmed the practical experience: In particular, the stiffness values for the frame are good, which can certainly be attributed to the material used - the "Roubaix SL2" weighs 200 grams more than the "Tarmac SL" for the same size. The measured comfort value of the frame is very good, the slim seat post with a diameter of 27.2 millimetres makes a decisive contribution to this. The fork, on the other hand, doesn't quite match the otherwise comfort-orientated design of the frame. It has virtually no suspension at all, is more compliant laterally than competitor products and, at 400 grams, is not particularly light. On the other hand, the "Roubaix" scores points for its impact-resistant paint finish and impeccable workmanship.
PLUS: unique design; good workmanship; stable ride; high comfort value on the saddle
MINUS: Relatively heavy and less laterally stiff fork, hardly any spring effect
*Test wheel frame size greased;
**Projected dimension from centre of bottom bracket to upper edge of head tube/seat tube height at 75 cm seat height (centre of saddle frame-upper edge of headset cover);
***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;
1) At the time of going to press, the results of the laboratory and practical tests for the new Dura-Ace 7900 were not yet available (you can find them in our Component test from the February 2009 issue).
Photos: Uwe Geißler, Matthias Borchers
