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The Helium is Belgian company Ridley's flagship race bike, a bike that's been ridden to victory in many professional races, in the mountains, in sprint finishes and on pavé. The updated SLX is lighter than the SL it replaces, and puts in a great ride with enhanced performance, pinpoint handling and impressive comfort.
While the reduced weight is obviously a good thing (a claimed 750g frame weight, compared with 790g for a medium SL), it hasn't been achieved at the expense of handling and performance, which is a marginal improvement of the already very good Helium SL.
The Helium SLX draws on the Belgian company's years of racing pedigree and is a highly impressive bike, a very refined and competent all-rounder, at home on mountain climbs or battling the cobbles. I tested the range-topping model with the latest Shimano Dura-Ace R9100 mechanical groupset, costing £4,899.99 and weighing just 7kg.
First impressions are certainly good. It's a very accomplished race and high-performance bike. Ridley has got the handling and steering dialled to perfection with the Helium, and the new SLX draws on the same geometry as the previous model so there's no great surprise in the way this new bike rides.
It's clearly a fast bike, that's something you notice immediately and was a theme that continued through the test. Of course, it's going to be fast on the hills, as any bike weighing just 7kg is going to be, and even the cheap Fulcrum wheels don't hold it back all that much. Go from a 9-10kg bike to one weighing 7kg and you really do notice the lighter weight on climbs, whether long and fast, steep and slow, or anything in between.
Comfort is an area where the bike impressed too. I rode the Helium SLX on a 215km audax out of Bristol a couple of months ago on a fast, rolling route with some cheeky climbs, and – apart from some saddle discomfort – the bike was smooth, controlled and composed over all manner of road surfaces.
The geometry helped with its all-day comfort, as it's far from the most aggressive race bike. Typically a 56cm race bike will have a 150-165mm head tube but the Helium SLX's is a rangey 175mm, which places the handlebar quite high, even if you remove all the headset spacers from below the stem. It does have a stretched-out position, though, with a longish 565mm top tube.
To put those numbers into some sort of context, the stack is 573mm and reach 390mm (stack and reach are the vertical and horizontal measurements from the centre of the bottom bracket to the top of the head tube), which compares to 567mm and 393mm for a 56cm Cannondale SuperSix Evo. It's taller in comparison, not by much admittedly, but if you are trying to replicate a low front-end position it's something to consider.
Back to how it rides, and the handling is precise, the steering well weighted, with just the right level of feedback through the contact points to inform you of the surface under the tyres. This makes it easy to judge traction in a range of conditions. It flatters you through the corners, being very stable and predictable, and is a good bike for descending fast, with the wheels and their aluminium braking surfaces providing plenty of purchase for the Dura-Ace callipers.
Carbon frames have developed a heck of a lot in the last decade, and improvements are getting harder to achieve with current materials and processes. As such, the revisions to the new Helium's SLX frame and fork are fairly minimal compared with the previous iteration, but do add up to a small but noticeable improvement in the overall ride quality when you really look closely for the differences. If you already own an SL it might not be enough reason to upgrade, but if you're new to Ridley be assured it's a fine handling bike.
The Helium SLX frame carries roughly the same outline as the previous Helium SL, a reasonably classic look with mostly rounded tubes and little in the way of extraneous curves and lumps. The seat tube transitions from round at the top to a square section at the bottom bracket, the chainstays are asymmetric and flat, and the seatstays as skinny as it's possible to get.
But it's lighter and stiffer, the design brief behind it being to focus on the best stiffness to weight ratio. It's not trying to be the lightest or stiffest – that's a battle Ridley leaves other bike manufacturers to contend with – instead it's going after that all-round appeal, a bike that performs and flatters in all arenas of high-performance cycling.
The removal of excess material helped to contribute to a claimed lower frame weight of just 750g (for a size medium, from a claimed 790g), while a refined and upgraded carbon fibre layup (60, 40 and 30-ton high-modulus carbon) has also helped not only in the battle against weight but increased stiffness, as much as 15% according to Ridley. The fork has also been redesigned, with a much more slender stance, and weighs 300g.
Ridley is also offering the Helium X this year, a more affordable frame that uses a lower grade of carbon fibre for a 150g weight penalty, with a claimed 900g frame weight. It gets the same fork as the SLX.
The frame has fully internal cable routing, the rear brake going inside the top tube and the gear cables into the down tube, with neat plastic plugs at the entry and exit ports.
A slim 27.2mm seatpost, almost standard on top-end race bikes these days, points to a desire to provide a measure of comfort. A regular seat clamp makes saddle height adjustments easy, no fumbling with fiddly internal clamps here.
A press fit bottom bracket is also another common feature on top-end race bikes and has allowed Ridley to enlarge the seat tube, down tube and chainstays at this junction, providing the maximum possible stiffness.
Finally, as we're seeing increasingly on race bikes, tyre clearance has been improved. Ridley says the Helium SLX will take 28mm tyres, and the bikes are supplied with 25mm tyres.
Opt for this £4,899.99 model and you get a full serving of Shimano's latest Dura-Ace R9100 mechanical groupset, with a semi-compact 52/36 chainset driving an 11-28t cassette. The sharpness of the latest Dura-Ace takes it to another level, with front derailleur shifts noticeably quicker and smoother. And thanks to the excellent calliper brakes you'll be able to make very quick stops.
While the new Dura-Ace is a lovely thing to have on a road bike, the Fulcrum Racing 5 LG CX wheels look a bit out of place on a bike costing nearly £5k. The explanation is sheer economics and Ridley being a relatively small company – the frameset costs £2,600 and the groupset is £1,900, which doesn't leave much space for posh wheels.
There's nothing actually wrong with the Fulcrum wheels – they're not all that heavy at a claimed 1,645g, reasonably stiff and certainly reliable with the double sealed bearings – but they do look out of place on an otherwise top-drawer build and the ride quality isn't as refined as more expensive wheels.
So it's a bike crying out to be treated to lighter and stiffer climbing wheels or faster aero wheels to exploit its full potential. Looking around at other bikes from big manufacturers at this price reveals that speccing similarly sensibly priced and tough wheelsets is common, so Ridley is certainly not alone in keeping costs down with the wheels.
Then again, you do get carbon climbing wheels on the £4,499 Giant TCR Advanced SL 1, though the groupset is downgraded to Ultegra Di2. If you want bang for buck, direct sales brands are hard to compete with: Canyon will sell you an Ultimate with the same Dura-Ace groupset and Mavic Cosmic Pro Carbon wheels – a £1,000 wheelset with superior aerodynamics. And, I think, looks.
Another frustration is the fitting of the Continental Ultra Sport tyres, the cheapest in the German tyre company's range. While I applaud the on-trend 25mm width for improved cushioning, they're not as fast, grippy or durable as the better Conti offerings, and they don't have the puncture resistance layer so flat prevention is low.
Otherwise, the finishing kit is all good stuff. It's from the company's own 4ZA brand (nearly all bike companies lean heavily on their own-brand equipment these days) and covers the carbon handlebar (nicely shaped with compact reach drops), aluminium stem (too short for me), carbon seatpost (easy to adjust) and saddle (extremely uncomfortable for me on longer rides but easy enough to swap).
On the scales, the bike comes in at 7kg (15.43lb), so that UCI 6.8kg weight limit is within reach with a wheel, tyre and maybe saddle upgrade.
I've always found that Ridley bikes ride extremely well, particularly so the Helium with its competent all-round appeal, and Ridley has pulled off a nice update with the SLX. Its updated frame and fork serve up a very controlled and well-damped ride, allowing it to deal with rough roads and remain composed at all times. It does everything well and just gets on with the task without much fuss or drama.
For all-out value for money, Ridley simply can't compete with the direct sales brands when it comes to the best equipment. But the new Helium SLX is more than the sum of its parts, and while the wheels are an obvious blight on its scorecard, they can't mask what is a beautifully handling bike.
For sure it flies under the radar when compared with more mainstream offerings such as the Specialized Tarmac, Cannondale SuperSix Evo, Trek Emonda and Giant TCR Advanced, but if you're prepared to look away from those relatively safe options, the Helium SLX is highly commended. Just save up for some better wheels and you've got a high-flying race bike on your hands.
Light, fast and great handling race bike but let down by the wheels
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road.cc test report
Make and model: Ridley Helium SLX
Size tested: Medium
About the bike
State the frame and fork material and method of construction. List the components used to build up the bike.
From Ridley distributor Madison:
Blended 60T UD carbon combined with 40T and 30T carbon to provide the right balance of weight, comfort, rigidity and road feel
Oversized round tube shape offer the best stiffness to weight ratio
Carbon rear dropouts with a reinforced steel plate for increased durability
Specially designed oversized PF30 bottom bracket offers a very high level of stiffness for maximal power transfer
Tapered 1 1/8 - 1 1/4 head tube with angular contact bearings
Flex seat stays provide comfort without sacrificing stiffness
Straight blade fork is lighter and offers improved road feel
Compatible with electronic and mechanical shifting
Tell us what the bike is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about the bike?
Ridley says: "Superlight race bike of approximate frame weight ca. 750g. The oversized tube shape is engineered with the use of extremely high modulus carbon. This results in a very light bike, without compromising stiffness. The dual purpose internal cable routing uses the same holes for mechanical and electronic shifting, resulting in a very clean design without excess holes. Flex seat stays increase vertical compliance for additional comfort, without reducing lateral stiffness. This Ridley's lightest racer offers the best combination for stiffness, low weight and all day comfort. Brutal Belgian pave and Tour de France hors category climbs are no match for the Helium SLX."
Frame and fork
Tell us about the build quality and finish of the frame and fork?
It's been made to a very high standard and details such as the cable ports are nicely finished.
Tell us about the materials used in the frame and fork?
A mix of 60, 40 and 30-ton high-modulus carbon.
Tell us about the geometry of the frame and fork?
It's on the aggressive side, as you'd expect for a race bike, but it's higher at the front than most bikes in this class.
How was the bike in terms of height and reach? How did it compare to other bikes of the same stated size?
Out of the box, it's higher than I'd like for a race bike but is comfortable for more leisurely rides. A few component changes created the position I prefer.
Riding the bike
Was the bike comfortable to ride? Tell us how you felt about the ride quality.
The new carbon frame and fork, despite the increased stiffness, are supremely comfortable. It's smooth even on rough roads, as a 215km audax proved.
Did the bike feel stiff in the right places? Did any part of the bike feel too stiff or too flexible?
The beefed-up frame stiffness is noticeable when you put the hammer down in a sprint, or when climbing at max effort on steep gradients.
How did the bike transfer power? Did it feel efficient?
With impressive efficiency.
Was there any toe-clip overlap with the front wheel? If so, was it a problem?
How would you describe the steering? Was it lively, neutral or unresponsive? Responsive with just the right amount of liveliness.
Tell us some more about the handling. How did the bike feel overall? Did it do particular things well or badly?
The handling is where the Helium SLX really shines, it's so competent in all situations, nicely stable and planted, with a crispness to the steering.
Which components had the most effect (good or bad) on the bike's comfort? would you recommend any changes?
The wheels removed some of the shine, and posher wheels would untap more of the Helium SLX's potential.
Which components had the most effect (good or bad) on the bike's stiffness? would you recommend any changes?
I changed the saddle from the start; I just didn't get on with it. I liked the handlebar – a nice shape – and the carbon adds a bit of extra smoothness at the front.
Which components had the most effect (good or bad) on the bike's efficiency? would you recommend any changes?
Only the wheels, as previously mentioned.
Wheels and tyres
Tell us some more about the controls. Any particularly good or bad components? How would the controls work for larger or smaller riders?
I didn't get on with the saddle. I liked the shape of the bar but had to swap the stem for a longer one with negative rise.
Anything else you want to say about the componentry? Comment on any other components (good or bad)
New Dura-Ace R9100 continues to impress. The difference from the previous generation Dura-Ace is small but noticeable.
Did you enjoy riding the bike? Yes
Would you consider buying the bike? Maybe
Would you recommend the bike to a friend? Yes
Use this box to explain your score
Ignore the cheap wheels and the new Helium SLX is a thoroughly commendable bike, but as a package it doesn't quite shine next to some better-specced bikes.
About the tester
I usually ride: My best bike is:
I've been riding for: 10-20 years I ride: Every day I would class myself as: Expert
I regularly do the following types of riding: road racing, time trialling, cyclo-cross, commuting, touring, mountain biking
David worked on the road.cc tech team from 2012-2020. Previously he was editor of Bikemagic.com and before that staff writer at RCUK. He's a seasoned cyclist of all disciplines, from road to mountain biking, touring to cyclo-cross, he only wishes he had time to ride them all. He's mildly competitive, though he'll never admit it, and is a frequent road racer but is too lazy to do really well. He currently resides in the Cotswolds, and you can now find him over on his own YouTube channel David Arthur - Just Ride Bikes.