Vitus Zenium SL Disc

Vitus has expanded its disc braked range for 2016 and with that comes a new, lighter, more comfortable frameset for the Zenium SL over the pretty damn good VR model I rode last year. Offering a Shimano 105 groupset, full-carbon fork, TRP Spyre mechanical disc brakes and a Fulcrum Racing 5 wheelset, there is a lot to like for your £1,299.99 outlay.

When I reviewed the Zenium VR (which has dropped 50 quid for 2016) back in February 2015, I was impressed with its racy nature and responsive ride. It was quite harsh, though, which won't be for everyone, but this SL (super light) model has tamed that just a little bit.

The SL does still have a stiff ride, and I like it. It feels purposeful, a kind of 'this is what I am, deal with it' type of thing. With a lot of bikes these days trying to be a bit of an 'everything' option, it's good to get on board something that can just be smashed about a bit and ridden hard.

Don't get me wrong, the Zenium isn't uncompromising – you can ride 100 miles on it at a steady pace, ride a sportive, or a long club ride – but it responds to a bit of aggression, an out-of-the-saddle effort up that short, sharp climb, the sprint for the village sign, nailing that Strava segment, that sort of thing.

Frame and handling

The Zenium SL has an aluminium frame made from a 6066-T6 alloy, as opposed to the lower priced models in the range which use a 6061-T6 grade. The 6066-T6 offers a higher strength to weight ratio, which means Vitus can cut a bit of weight from the frame by using less material for the same stiffness. It also seems to be a little more forgiving, but we're talking tiny benefits here which are only noticeable if you've ridden the two side by side.

Each tube is triple butted which, if you haven't come across this before, means the wall thickness changes from the end to the middle in, as you've no doubt guessed, three stages. It's thicker at the end where stiffness is required, thinning out in the middle to allow a little give in the tube for comfort.

What all this means out on the road is that the Vitus has a kick; stamp on those pedals and it'll respond through the head tube and bottom bracket junctions, those places where you want stiffness and total efficiency.

Up front it has a tapered head tube, increasing the cross sectional area and allowing a larger diameter down tube to be used, as well as creating a larger weld area for stiffness. The bottom of the seat tube flares out for the same effect.

You notice the oversize head tube in the bends, as the steering is spot and direct. And you can feel that front end stiffness when you really haul on those anchors too, you don't get any chatter or diving from the full-carbon fork.

The Zenium's geometry is slightly more relaxed than Vitus's Vitesse Evo race bike but only slightly, with a 145mm head tube, 73-degree seat and head angles, and a 545mm effective top tube still making for a pretty sporty position.

What you get from this, and the stack of 552.2mm and reach of 376.2mm (the vertical and horizontal measurements from the centre of the bottom bracket to the top of the head tube), is a bike that's responsive to the more experienced rider really pushing it, but also surprisingly neutral for those who are new to the game.

The Zenium SL feels really positive under foot, very forgiving and a pleasure to ride, with the Continental Grand Sport Race tyres offering plenty of grip in the wet and dry to inspire confidence in the bends.

The fork is stiff and you certainly don't feel any understeer when really pushing on technical descents or under heavy braking. Vitus has gone for a 15mm thru-axle on the fork, and while it certainly doesn't hamper the braking, from a personal point of view I just don't think it's a setup needed on road bikes – I've yet to suffer from any issues with discs and a conventional quick release. Just putting it out there.

When the road starts to head upwards, you soon notice that despite the superlight SL monicker it isn't exactly the most svelte at 8.84kg. It certainly lays down the power, though, climbing well considering its weight, helped by the now pretty much standard Shimano setup of 50/34 front and 11-28 rear ratios giving a large spread of gears. It's a full Shimano 105 drivetrain, too, which is nice to see.

Wheels and finishing kit

When I first took a look through the kit list I couldn't see much of a difference between this and the VR model for the sake of the extra £300 on the RRP, but the SL shaves off nearly half a kilo by speccing slightly lighter wheels. That might not sound a lot, but in the real world it makes a massive difference – this being another of those times when you can't judge a bike by its paperwork.

The Fulcrum Racing 5 DBs here are much more responsive and more comfortable than the Fulcrum Sport DBs on the VR model. They have a wider rim profile over the standard rim braked versions, which makes fitting 25mm tyres easier and also spreads the tyre's profile a little, meaning the 25s actually measure nearer 27mm when fitted.

We're seeing ever more bikes with hydraulic disc brakes since Shimano brought in its 105-level models, but if you have to go mechanical then TRP's Spyres are what you want, as they use the same dual-pivot design as hydraulic systems, with both pads squeezed in at the same time rather than just one pushing against the other.

The set on the Vitus did take a bit of a bedding in to get the best out of them, and I don't think I quite achieved it as they still weren't giving off the performance I've come to know from other test bikes, but the test period was surprisingly dry – they normally need a good couple of wet rides and a bit of grit to sort the abrasion out.

The rest of the componentry is marked up Vitus, and while not being massively exciting it does a good job and to be honest you never feel the need for anything better.

The aluminium compact handlebar provides all the hand positions you need while also making it easy to drop into the bends without too much strain on your back, and the stem is plenty stiff enough.

The alloy seatpost could probably be changed for a carbon one to add a bit of comfort, and would probably be negligible in terms of value for money. Vitus's own saddle is a well proportioned mix of padding and stiffness, which helps to take the sting out.

Value

Value for money is always a tough one, and on paper the Vitus looks quite expensive for what it is. But the ride you might expect when reading a spec list doesn't always transpire, and in reality the Zenium SL is quick and responsive. Yes, it's maybe a touch on the harsh side, but if you're the sort of rider who likes to go hard, as if you're racing without actually signing on, plus you want the all-round advantages of disc brakes, look no further.

The Zenium is a bike that can be smashed about a bit as you reach the end of that segment with your tongue hanging out and your vision going blurry. It's a proper race bike that isn't a race bike.

Verdict

Very good semi-race bike that responds well to hard efforts