Why the new Tarmac tops the Venge
The Tarmac SL7 squares the circle between light weight and aero, says Michelle Arthurs-brennan
Trickle-down technology is all well and good, until it makes the initial product obsolete. Arguably, that’s what’s happened to the Specialized Venge.
Every Specialized release of the last few years has taken notes from the aero road bike’s design. Now, in its latest guise, the lightweight all-rounder Tarmac is considered aero enough by the brand that it’s all but put the Venge out of a job.
The Venge will still exist as a frameset, but with this new Tarmac SL7 (affectionately called the Varmac by Cycling Weekly testers), we wave goodbye to it as a built bike. The Tarmac SL6 will continue to be available at Sport and Comp level, for those who prefer the old bike’s ride quality. And make no doubt about it: the ride quality of the new Tarmac is different.
A lot of the justification for the new, aero Tarmac SL7 comes from feedback from the pro ranks. They wanted the Tarmac to be stiffer, more stable and aero like the Venge, but to maintain the lively feel and climbing prowess of the Tarmac.
I had a lot of affection for the outgoing Tarmac SL6, so when I rode the Tarmac SL7 for the first time (ahead of any presentation or press literature), and messaged the brand manager to ask “have you made the bike stiffer?” – I wasn’t immediately bowled over. However, after over 300 kilometres on the new SL7, any reticence has ebbed away: I can confidently say that the Tarmac still holds a very firm place in my list of ‘favourite rides of all time’.
Aero treatment
The aero influence on this Tarmac is obvious, but it’s not touched all areas.
A redesigned seat tube, seatstays, head tube and fork blades help smooth air flow, as does the Aerofly II bar – seen on the Venge – and Roval Rapide CLX wheels. The result is that the new Tarmac is a reported 45 seconds faster over 40 kilometres at 50kph versus the old Tarmac SL6.
Look at the seatstays on the outgoing Venge versus the Tarmac SL6, and it’s clear that the new SL7 takes after the former. The head tube is also bulbous at the top and bottom, with a taper in the centre. The down tube looks near identical.
The handlebar is an obvious update, and the SL7 has a new ‘Tarmac Integrated stem’ that comes with an integrated computer mount. There are no split spacers, so if you want to lower the front end, you’ll have to chop down the steerer.
The SL7 also features an S-works carbon seatpost, with an integrated location for the Di2 junction box.
These changes make the bike more slippery against wind resistance, but beefing up the rear end has also made it stiffer. Product manager Cameron Piper confirmed: “The new Tarmac has a stiffness/ compliance balance that’s much closer to the Venge than the old [SL6] Tarmac.”
The new, disc-only Tarmac SL7 has clearance for tyres up to 32mm wide,
though it comes with 26mm rubber. All of the bikes use a threaded bottom bracket.
Weight
Brands have been able to make lightweight aero bikes for a while now.
A size 56 S-works Venge disc weighed 6.9kg, which is only 100g over the UCI weight limit of 6.8kg, while the last S-works Tarmac Disc we reviewed came in at 6.61kg in the same size.
The new S-works Tarmac frame, at the top level featuring the FACT12R carbon, now comes in at 800g, with a built bike a reported 6.7kg; the size 52 model we have on test weighs 6.6kg.
The SL7 Pro and Expert models come with a FACT10R carbon frame, at 920g,
Geometry
coming in at 7.3kg and 7.65kg for Ultegra Di2 builds.
The Tarmac’s geometry remains the same, so the bike retains its much- admired handling characteristics. Ditto the size range, with Specialized offering ‘rider first engineering’, with tube diameters adjusted throughout the range to ensure those on a size 49 enjoy the same experience as those on a 58.
The bikes are all unisex, with cockpit
swap options available, – something that’s worth bearing in mind considering the cost of the Aerofly II bars at £250.