3T Mercurio 60 LTD - First look

Plus first ride of Garmin-mount Integra

Back in May, BikeRadar reported on 3T’s latest wheelset, the 60 LTD. This weekend we had the opportunity to go out to Italy to try the hoops, and see a couple of extras, with cycling legend Francesco Moser.

While 3T’s wheel line has been in the offing since 2011, it’s only now that the first sets are due to be delivered. As with all 3T’s ranges, they’ll be split into Limited (top end), Team (performance level) and Pro (basic) models.

Tubular wheel systems have been first to appear from the brand, called Mercurio and available in 40, 60 and 80mm rim depths. The carbon/alloy clincher line is named Accelero and available in 40 and 60mm sizes.

Both sets are a first project for 3T’s technical director, Richard McAnish. He was previously employed as head of composites at Scuderia Ferrari – in his own words, he was  “in charge of making all the red bits”. This means he’s arrived in the bike industry with a knowledge of advanced carbon design and technology, from the cutting edge of Formula 1 motorsport.

For the development of the wheels and the ongoing design and production of 3T’s core bar, stem and seatpost lines, McAnish has recruited a staff of four engineers. He’s also invested in CFD (computational fluid dynamics) as well as high-end machinery and tooling.

McAnish now believes that, with the calibre of staff and resources available, 3T could engineer an F1 car: “We couldn’t do it in six months as was possible at Ferrari, but we definitely could do it.”

The development of the wheel line started with an assessment of the state of play. McAnish cites the excellent work that Zipp have done in the past, and explains the independent research 3T did on Zipp’s products (three thesis papers, peer-reviewed academic studies and more). Again, this feeds back to McAnish’s time in F1, where if the competition had the technical edge, hundreds of man hours followed to find out why.

3T suggested that the current crop of aero wheels, which are chasing ever-lower drag numbers rather than stability, is the way to go. In fact, McAnish is in favour of more research into wheel aerodynamics for bikes. In his opinion, it’s still a relatively new area of study compared to the long-established aero work being done for the aviation and motorsport industries – that and you’re dealing with much lower speed conditions, too.

So the design and engineering brief for the Mercurio project was to concentrate on weight, inertia, strength and aerodynamics, all closely interlinked factors. The finalised design featured the unique spoke ‘pocket’ idea – keyed slot holes in the rim that hold the spoke, removing the need for nipples at the rim end.

One of 3T’s spoke pockets in action – note the lack of rim nipple

In 3T’s opinion, just drilling a carbon structure isn’t a good idea, as shearing fibres can mean fatigue issues further down the line. The second reason for eliminating the rim nipples was to lower weight at the outer edges of the wheel. McAnish claims that a reduction of 30g over a standard design was achieved.

The rim’s structure is defined by the use of aerospace standard composite design software. Once your parameters are defined, the software will aid you in working out the ideal layup of the fibres. Further software recommends the optimum products to use, and how to minimise amounts to create strong light structures.

The internal fibre layup reinforces the rims at every spoke hole, with a suspension bridge-like design anchoring and stiffening the spoke beds to the outer rims. McAnish said that, while this setup looks outwardly simple, it’s been a huge manufacturing challenge as the design relies upon the correct layup for its strength.

The idea has the benefit of putting plenty in the structure, with spoke tension being the highest of any similar wheel on the market. The 60mm deep rim has a claimed weight of 380g (+/- 10g), which is light for a deeper section model.

The reverse spoke design meant the need for a hub with threaded flanges. The patent for that was held by Cane Creek, but a chance meeting at Interbike led to 3T acquiring the rights for use, enabling them to produce a specific hub for their new wheel.

This hub has seen 12 months of development, as early models didn’t benefit from the right engineering tolerances, leading to some issues. With the tolerances checked, tightened and adhered to, the latest generation of the hub is where 3T want it to be.

You might think that the pockets would have an effect on the wheelset’s aero properties, but independent tests with the holes both open and taped over showed no impact on the overall figures.

Bearing quality and braking performance are obviously important to the end user, and again 3T have done things differently. The bearings might be standard (but high quality) but particular care has been taken with the fit tolerances in relation to the hub, to get the most out of the bearing units.

We tried the new Mercurio wheels on an Eddy Merckx EMX-5

The braking surface is a treatment developed at Ferrari to coat the underside of F1 wings, where the surface needs to be as smooth but tough as possible (chips and marks can compromise aero quality). Having a super-hard, smooth brake surface actually creates more bite with the paired SwissStop Yellow carbon pads, making for impressive stopping power.

Riding the Mercurio wheels

We got the chance to ride the wheels over fast, flat terrain, climbs and descents, at the sort of speeds you can only achieve on long mountain roads.

What’s most impressive on the Mercurios is the pick-up from slow speeds, with little of the inertia you usually feel with a deep rim. The Mercurios have a much more instant feel, which we think is down to the combination of a lower rim weight and super-stiff structure.

Changes in tempo and sharp attacks of acceleration felt more rapid than with most wheels, too. All of this sharp stiffness has a downside, though – the wheels descended and turned brilliantly, but over short sections of pavé and white road they didn’t give, making for a bit of jolting.

As we’ve said, braking was impressively powerful, but because we were riding fresh wheels and pads we noticed a lot of noise until everything had bedded in. The other limitation was that, while bite was excellent, it all kicked in quite a way through the levers’ travel.

As a first attempt at a high-performance wheel, 3T have hit the mark. And that it’s so full of innovation certainly bodes well for the future of the company’s hoops. In McAnish’s own words, “Remember, with our ongoing development program, that these wheels will be the worst ones we ever produce!”

Integra stem

3T also shipped a production version of their new Integra stem to Trento, especially for us to try out.

If we’re honest, we had some doubts over the relative stiffness of the alloy internal clamp in relation to the carbon body on the prototype. However, we’re glad to say that these worries were put aside when we got a chance to ride the stem.

The full carbon structure has been designed by the same team as are in charge of the wheels, and with the same structural analysis software. It’s impressively rigid, and the clamp is actually wider than on most stems on the market. This makes for a solid connection, free of any movement, creaks and groans.

3Ts Integra stem is innovative for its integrated Garmin computer mount

The real benefit, though, is the integrated mount, developed with Garmin to fit one of their GPS computers. The shroud cover integrates the mount some distance in front of the stem clamp. And because the head unit is a couple of inches further forward, it’s constantly in your eyeline – perfect for scoping while you ride and train.

Initially, the Integra will only be available in the Limited spec. That means it will be pricey, though 3T have announced an alloy Pro version that should be available by September.

New bars

3T’s highly shaped, anatomic drop Ergonova bar design has proved popular. But some pro cyclists riding with 3T’s partner teams have asked for a bar with the same shaped top and ovalised profile matched to a more traditional round and deep drop, similar to the company’s classic Rotundo.

3T have produced the new Tornova bar to meet those exact requirements. The bar will be available in alloy Pro, carbon fibre Team and high-modulus carbon LTD models.

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