Felt’s Z4 Disc is an endurance road bike through and through, with compact, upright geometry, a compliant, buzz-absorbing frame, SRAM’s spin-happy WiFli gearing, and that new must-have sportive bike feature: hydraulic discs.
Picking an endurance bike over a race machine was something of a careful choice, because frankly, as I stood astride the Z4 for the very first time at the start of the Lionheart Sportive in Wiltshire, it wasn’t only the magnificently grand Longleat House casting a large shadow over me. I'd been rather less diligent in my trainer sessions over last winter than in previous years. The sight of the chilly start line of my first sportive of the season seemed to drain away the false confidence I’d carried up to that point by convincing myself that cross training would see me through.
On the plus side, I was tackling the 100km (62-mile) route, rather than the 100-mile option that I'd previously completed. In that longer iteration I had suffered badly towards the end, riveted to my Garmin as each 0.1 of a mile crept interminably by.
This year, the element causing the most pointed dread was also the most pointed mark on the route profile: the wall-like ascent up to King Alfred’s Tower near the gorgeous National Trust estate of Stourhead, which climbs 158m over a 2.3km stretch that starts easily enough, but ramps up to 19 percent in places.
- The course: The Lionheart Sportive (100km distance) with 1,460m of climbing
- The equipment goal: See how disc brakes, endurance geometry and SRAM WiFli gearing fare on a hilly season-opening leg tester
- The horse: A Felt Z4 Disc completely stock plus Time Xpresso 2 pedals, Garmin Edge 800
After a briefing that hammered home the difficulty of the Alfred's Tower climb, our wave was off, with more than 1,000 riders already up the road ahead of us. The course began by whipping around Longleat’s grounds, famous for being home to one of the UK’s biggest safari parks. I took it as a good omen that the monkeys weren’t screeching eerily through the cool morning air this year.
The Felt floated over cattle grids without hint of peril. The SRAM hydraulics gave a sense of braking power that bordered on overconfidence. The brakes weren’t as sharp as the fly-over-the-bars-twitchiness I’d been expecting, but proved strong and easily modulated. The transition from lifetime rim-brake user to being completely comfortable with the discs took at most five minutes. Then it was on to enjoying the extra speed that can be comfortably held coming into bends.
It was a chilly start to the day as I clicked through the gears on the first climb away from Longleat House
All too soon, the first big climb reared up – a long, varying gradient from the Longleat grounds up onto the roads of the idyllic surrounding countryside. My then-cold legs began to burn inside from the sudden effort. If I’d already fallen in love with the discs, I was equally – and as quickly – smitten by SRAM’s WiFli drivetrain, which offered 34t on the front and 32t on the back.
I know what you’re thinking. ‘What kind of self-respecting roadie would degrade themselves with such a wide ratio?’ I might once have been similarly sceptical myself, but the thing is, I wasn’t thinking that as I climbed that first hill. Instead I was smiling to myself in a self-satisfied way as I overtook dozens of cyclists grinding away (their knees) with ‘proper’ gears, while keeping a sprocket or two in reserve should I need it later on in the climb.
Lungs heaving at the sudden heart rate spike and legs now heated in a hollow way like microwaved frozen meat, the next several miles of the ride were spent getting to know the Felt a bit better. That WiFli gearing continued to impress on steep climbs, but also proved really useful on the flats, where the wide cassette meant less changing out of the big ring. The downside is a definite gap between the 'churning' and 'spinning' cogs, occasionally making finding a comfortable cadence irksome.
The combination of compact carbon frame and 25mm tyres at 90psi did a good job of absorbing the jangling staccato of British country roads. While it didn't filter out all the buzz on rougher roads, any muted road noise that made it through the tyres, wheels and frame wasn't enough to affect handling.
And the Z4 handles beautifully, responding instantly to steering input without being twitchy, and enabling mid-corner line changes without fuss.
There was plenty of time to enjoy the scenery and the Z4's comfy ride
As the climbs mounted up, it became increasingly obvious that though the Z4 is made for endurance comfort, there’s no noticeable concession made in terms of stiffness when climbing. Each laboured turn of the cranks is translated into forward speed without loss.
The Mavic Aksium ONE Disc wheels aid the climbing despite their chunky brake-track free looks, contributing to that overall stiffness. In the lulls between climbs, they rolled well, held reassuringly onto speed and accelerated speedily out of the corners. Occasionally I did get some slight disc rubbing after sections of dusty, gravelly road, but that was silenced by lightly feathering the brake levers, then releasing. On the subject of the levers, the fact you can't change gear while braking, as you can with Shimano, is still less than ideal when descending fast towards a foot-down junction.
Despite usually preferring cut-out style saddles, in the interest of a fair test I left the Prologo Scratch 2 T2.0 in place. I expected numbness and discomfort but was astounded that neither appeared, especially considering there’d been no time to test-ride the saddle before the event. It perfectly balances the line between squishy comfort and firm support.
It might give you an upright, all-day friendly position, but the Z4 can really race when the need for speed overtakes. In fact, it could well be that comfortable, contortion-free fit that saw me fly past the overstocked feed stations in search of a PB. You can’t get low and flat like on a race bike, but I found the overall ride experience quite satisfying.
As a spring sun appeared to warm the glorious rural locations the Lionheart enjoys, the Z4 and I faced our biggest challenge – that steep ascent to King Alfred’s Tower. It's a place where grown men and women shriek with pain as they zigzag to the top of the narrow lane, and where event signage asks the steady line of participants pushing their bikes up to keep left.
Even those wide gears didn't make 19 per cent seem too easy
As you can tell from the picture above, the Felt Z4 didn’t flatten the hill to an easy spin, but I was certainly glad of the WiFli gearing, the stiff frame and upright positioning as I stayed sitting down and grimaced my way to the top – while my heart rate hit 185. Though it was hard work, there wasn’t a moment’s doubt that the Z4 would see me conquer the hill. Spinning back down the gears at the top, I was soon back into the Lionheart’s well-judged mix of rolling terrain, climbs and descents.
The remainder of the event with the Z4 went by companionably, my fondness for the bike only increasing as its comfortable, smile-inducing ride overcame tiring legs, hunger and aching lungs, urging me to push on, enjoy being out on the road and roar towards a 27-minute PB on the course to finish in 3:47. I’m convinced the bike did more of the work than I did. Packing the Z4 away, I was utterly content with the day, fulfilling as it did those two facets of what cycling’s all about – a great ride on a great bike, or rather a great horse for a great course.