They appeal with the promise of being particularly fast: Aero racers have been the latest hype on the road bike market for around two years. The fact that most amateur riders have little or no advantage from the usually rather uncomfortable speed machines - no problem! The streamlined frames look refreshingly new and good, and it is also clear that aerodynamics can be a race-deciding factor in top-level sport. For an ambitious manufacturer like Simplon, adding an aero model to its range is therefore a no-brainer - and as a sponsor of the German Team NetApp, which is set to become increasingly involved in international sport, it is almost a necessity.
The sharp tear-off edges on the seat tube, down tube and seat stays of the Nexio frame are striking - in aerodynamics, this design is known as the Kamm tail. It goes back to the German aerodynamicist Wunibald Kamm, who discovered more than 80 years ago that an aero profile does not necessarily have to be moulded to the end. If the end is cut off, the aerodynamic advantage is retained and weight can be saved. Scott, BMC and Trek have already adopted Kamm's idea for their aero models; another detail on the Nexio also looks familiar: The copyright for the three bottle cage threads on the down tube lies with the Canadian manufacturer Cervélo, who realised this idea on the Aero model S5. This means that two holder positions are possible: a higher one if two bottles are to be transported and a lower one, which is probably a little more aerodynamically favourable.
In addition to these eye-catching features, it is above all the small, well thought-out details that characterise the Nexio. Clever: The clamping area of the aero seatpost is roughened at the rear. This means that no high tightening torques are required on the clamping bolts to securely fix the post. Also good: the Acros headset, already familiar from other Simplon models. The bearing play can be adjusted from the outside using a small adjusting screw; the usual claw in the steerer tube is not required.
Aero with comfort?
The lab data is eye-catching: a frame set weight of 1,473 grams and a comfort value of 266 newtons per millimetre on the saddle are good values for an aero road bike. They indicate that the Nexio has other qualities than just being fast. Under the saddle, the bike is very responsive right from the start - a racy racing machine. What the lab results suggest is confirmed in practice: the bike doesn't ride as rough as some other aero racers, which hardly yield vertically due to the streamlined tube profiles. On the saddle you can feel the suspension comfort, which is partly due to the still passably flexible seat post and partly due to the pleasantly flexible cover of the SLR saddle. However, the Nexio's main discipline is fast, winding descents, which the bike masters with remarkable aplomb without the slightest sign of unsteadiness.
The test bike is built with an equipment package from Simplon's modular range. The lightweight Force groupset from SRAM is joined by Cosmic-Carbone-SLE wheels from Mavic with Exalith coating on the aluminium brake track. The deep grey roughened surface is said to be extremely abrasion-resistant and, in combination with special pads, offers particularly good braking performance. As previous Exalith wheels occasionally caused unpleasant brake squeal, especially during the running-in phase, Mavic has developed new pads with the specialist Swissstop to solve the problem. During initial test rides, this calculation seemed to work, but after a few hundred kilometres, at least the rear brake once again produced the familiar, piercing squeal of the pads on the rim. The new, slightly profiled Yksion Pro tyres from Mavic, on the other hand, left a positive impression, subjectively rolling easily and adhering well. However, it remains to be seen how puncture-proof and durable the tyres, which harmonise perfectly with the rims, are.
ConclusionThe Nexio is a good example of how it can pay off for a manufacturer to observe a trend for a while before reacting to it. The bike offers more convincing riding characteristics than many other aero racers and impresses with its good workmanship and harmonious appearance. In terms of price, the Nexio is on a par with the competition. The range starts at € 3,949 for the version with Ultegra groupset, while the tested version with SRAM Force is priced at € 4,349. In the next aerodynamics test, we will find out whether it actually cuts through the wind faster than other racers.
Price complete wheel 4,349 Euro
Weight 6.8 kilos
Reference/Info www.simplon.com
Frame sizes** 50, 5 3, 55, 57, 60 cm
Seat/steering angle 74,5°/73,5°
Seat/top tube/head tube 530/555/146 mm plus 18 mm headset cap
Wheelbase/caster 990/51 mm
Stack/Reach/STR*** 555/397 mm/1.40
EQUIPMENT
Steering bearing Acros, top 1-1/8, bottom 1-1/4 inch
Brakes/gears/bottom bracket SRAM Force (50/34 t., press-fit)
Wheels/tyres Mavic Cosmic Carbone SLE/Mavic Yksion Pro
Handlebar/stem Simplon ERG/Simplon ERO
Saddle/post Selle Italia SLR Monolink/Simplon Aero
MEASURED VALUES & INDIVIDUAL NOTES
Weight of complete wheel (without pedals) 6.8 kg
Frame/fork/steering bearing weight**** 1.025/322/90 g
Standardised weight frame set 1.473 g: 2 , 0
Steering head stiffness 97 Nm/°: 1 , 3
Lateral stiffness fork 50 N/mm: 1 , 7
Bottom bracket stiffness 65 N/mm: 1 , 0
Comfort frame 266 N/mm: 2 , 3
Comfort fork 96 N/mm: 5 , 0
The frame set accounts for 40 per cent of the overall score and the equipment for 60 per cent. Individual grades are included in these evaluations, only some of which are printed for reasons of space. The grades are calculated up to the final grade with all decimal places; however, for the sake of clarity, all grades are given with rounded decimal places.
** Tested frame size greased.
*** Stack/reach: projected vertical/horizontal measurement from the centre of the bottom bracket to the top of the headset; STR (stack to reach): Values between 1.45 and 1.55 indicate a sporty riding position, values below are race-like, above are comfortable.
**** Adjusted weight for frame size 57 cm and fork steerer length 225 mm.
