Ribble Ultra SL R Enthusiast review

The Ribble Ultra SL R is one of the most progressive aero road bikes to launch in recent years.

Revealed in August 2021, it generated a huge amount of interest for its aggressively optimised frameset and innovative ‘wake-generating’ handlebar.

After a long wait to test one, we’re finally able to answer the inevitable question – was the hype justified?

In short, yes. The Ribble Ultra SL R is a very fast bike.

The only caveat is the uncompromising pursuit of speed results in the Ultra SL R occupying a highly specialised niche.

Shortlisted for our 2023 Aero Road Bike of the Year award, it's a race bike in the truest sense of the term. There has been no attempt from Ribble to make it an ‘all-rounder’.

If going as fast as possible on a drop-bar road bike is your highest priority, there are few options as compelling as the Ribble Ultra SL R, especially for the price.

Ribble Ultra SL R frameset

Having started with a brief to “make the most aerodynamically advanced frameset in the world”, Ribble spent three years developing and testing the Ultra SL R in CFD (Computational Fluid Dynamics), the wind tunnel and the real world.

The result is an array of deep truncated aerofoil tube shapes throughout, with a narrow head tube, a wide, bladed fork and, most notably, the futuristic integrated handlebar up-front.

According to the brand, the sum of these features is an “11.6-watt saving at 22mph across the average of 5 and 10 degrees of yaw” over Ribble’s Endurance SL Disc road bike.

Ribble says that makes it “75.1 seconds quicker over 40km”. That’s hardly a marginal gain, but it’s one that’s easy to believe just by looking at the differences between the two bikes.

The Ultra SL R is constructed using Ribble’s premium carbon fibre blend, which features a mix of Toray T1000 and T800 carbon fibre.

Ribble says an increased use of T1000 fibres results in a painted, size-medium Ultra SL R frame (1,050g) being a claimed 150g lighter than the cheaper Ultra SL version (1,200g).

Overall, my size-medium test bike weighs 8.31kg.

Even once spec differences are accounted for, that’s a little heavier than some competitors, such as the Giant Propel Advanced SL, Canyon Aeroad CFR or Scott Foil RC.

Unlike those bikes, though, the Ribble Ultra SL R doesn't make any concessions to weight or all-round performance. The frameset, front end and build are entirely aero-focused, down to the smallest details.

It also compares well to other similarly hyper-aero bikes, such as the Cannondale SystemSix Hi-Mod and Cérvelo S5, both of which are significantly more expensive, yet only marginally lighter overall.

At 7.69kg, Trek’s Madone SLR 7 is just over 600g lighter than the Ultra SLR (in a comparable spec). Given it costs £10,200, though, the weight saving comes at a significant premium.

Ribble Ultra SL R geometry

In terms of geometry, the Ultra SL R is racy, as you’d expect.

The riding position is long and low, with 545mm of stack and 392mm of reach.

The 73-degree head angle and 45mm fork offset combine for a trail figure of around 58mm with the included 700 x 28c tyres, which measure just over 30mm wide at 60psi / 4 bar. This translates to responsive handling and a nimble ride feel.

The seat tube angle is relatively steep at 73.5 degrees, which helps put you forward over the bottom bracket for an efficient pedalling position.

At 410mm and 985mm respectively, the chainstays and wheelbase strike a good balance between responsiveness and stability at speed.

Ribble Ultra SL R build

I tested the Enthusiast build, with Shimano’s excellent Ultegra Di2 R8170 groupset.

This sits in between the top-spec ‘Hero’ build (£7,999 with Dura-Ace Di2 R9200) and cheaper ‘Sport’ build (£4,799 with 105 Di2 R7150).

There are no SRAM- or Campagnolo-equipped builds in the range, but if you have a groupset and wheels, an Ultra SL R frameset (which includes the showpiece Ultra handlebar) can be purchased separately for £3,299.

In its standard guise, with Level DB56 Sport carbon wheels and Schwalbe Pro One TLE tyres, the Enthusiast build costs £5,599.

Showcasing its Bike Builder customisation programme, Ribble supplied my test bike with a couple of upgrades – a set of Zipp 404 Firecrest wheels and Continental GP5000 S TR tyres (set up tubeless).

This brings the total cost to £6,599, which although expensive in absolute terms is competitive compared to the competition. The only notable omission from the build was a power meter.

All builds come with Ribble’s Ultra handlebar, which takes a radically different approach to handlebar aerodynamics.

Instead of slim aerofoil tops and round drops, the Ultra bar uses large truncated aerofoils in the central portion of the wing-like tops to influence the airflow over the rider behind it.

The drops are also shaped to fit the palm of your hands more effectively than a standard design. The bar is intended to be used without bar tape, too, for an additional small aero gain.

Adding bar tape creates a little extra frontal area, which marginally increases drag. Given how stiff the bar is, though, I would wrap the drops for a little extra comfort, if this were my bike.

Ribble claims this handlebar alone makes the Ultra SL R “20.5 seconds quicker over 40km at 22mph” compared to the Ultra SL and its Level 5 integrated aero handlebar.

In order to create such a deep aerofoil shape at the brake hoods, Ribble has also ditched the traditional brake lever band clamp in favour of a direct-mount design. The design retains scope for adjusting the position and tilt of your brake hoods.

My only gripe is that parts of the rubber grommets, which are used to fill in any gaps between the shifter body and clamping area, tended to stick out from underneath the brake hoods on my test bike. This doesn't affect performance, but does look a little messy.

Leaning fully into the aero theme, the Ultra bar is available in only three narrow widths – 33, 36 or 38cm (centre to centre at the brake hoods – the drops flare out by 2cm on either side).

My test bike came specced with the most extreme 33cm version, which is paired with a 140mm effective stem length.

The 36cm version is available with 80 or 100mm stem lengths, and the 38cm version with 120 or 135mm stem lengths (38cm/120mm is the default option on a size medium).

Any of these can be chosen at the point of purchase via Ribble’s online Bike Builder tool, but those are the only choices available. If you want something different, it’s not an option here.

Unfortunately, having only five size combinations available means the scope for finding the exact front-end setup you want is limited.

Though the range of handlebar widths offered wouldn’t be an issue for me, my preferred bar width and stem length combination (120mm/36cm) isn’t available. It’s fair to say broader riders might also find the selection too narrow for an optimal bike fit.

Limited adjustability is, of course, an issue with many bikes with integrated handlebar systems.

It’s true that some brands offer a wider array of stem-length and bar-width combinations for their integrated cockpits, plus the option to swap in a non-integrated setup if desired.

However, these are often only available as after-market upgrades at additional cost.

The stock saddle is a Selle Italia SLR Boost. Its short shape is a good match for the Ultra SL R and I had no issues with it during testing.

I did find the saddle clamp a little frustrating, however. The front adjustment bolt (which determines the saddle tilt/angle) requires the use of a small spanner, and is a little fiddly as a result. It’s also not a tool you’re likely to have on a multi-tool for mid-ride use.

The seatpost clamping bolt and frame insertion area would also benefit from a rubber cover to help protect this area from road spray and grime.

Ribble Ultra SL R ride impressions

Given the highly optimised frameset, handlebar and build, it’s no surprise the Ribble Ultra SL R feels like an absolute rocket on favourable terrain.

It’s easily comparable to the fastest road bikes I’ve tested, such as the Cannondale SystemSix and Cervélo S5.

The rate at which it picks up speed on descents is particularly addictive, for example, and I found myself setting some personal records on downhill Strava segments during testing.

Though the bike is heavily optimised overall, the specific cockpit setup likely makes a big difference in this regard.

At just 33cm wide (at the brake hoods) and paired with a 140mm stem, the resulting position on the bike is exceptionally long and narrow, and clearly very aerodynamic.

As someone experienced with narrow handlebars, the bar width felt great and didn’t compromise handling. The reach felt excessive, though, and while the position was sustainable for short rides it isn’t ideal for longer days in the saddle.

Still, though, tucking down into a tight aero position and powering along on flat or rolling roads feels fantastic (for as long as you can hold the position).

Curiously, the default chainring spec on the Ultra SL R Enthusiast is 50-34t (paired with an 11-30t cassette at the rear), which often felt too small.

This can be remedied by switching to the 52-36t option in the Bike Builder, but rarely has a compact crankset seemed as out of place as it does here.

As I alluded to in the introduction, the laser focus on aerodynamic efficiency means compromising on other characteristics.

Thanks to the Zipp 404 wheels, which have a 23mm internal rim width, the Continental tyres plump out to around 30.5mm wide at 60psi / 4 bar.

Despite this, though, the massive overall stiffness of the Ultra SL R means the ride quality can tip into being juddery on broken roads.

The slightly heavier overall weight and narrow handlebars also make it more of a ‘sit in and spin’ climber than something to attack mountains out of the saddle with.

It will get you over the climbs, of course, and potentially make up for any time lost coming down the other side, but it isn’t a natural mountain goat.

Inevitably, the chunky frameset tubes and 58mm-deep rims are more difficult to handle in windy conditions, compared to bikes with less aggressive frameset shaping and shallower wheels, such as the latest Giant Propel.

This could be something lighter or less experienced riders find unnerving. However, fitting a shallower wheelset, such as the Zipp 303 Firecrest (also available via the Bike Builder) would likely help mitigate this somewhat, at the expense of a little flat-land speed.

Ribble Ultra SL R bottom line

For those concerned with getting from A to B as fast as possible on a road bike, the Ribble Ultra SL R is an almost perfect tool for the job.

It shares the same spirit as a dedicated hill climb bike or time trial bike – near-impractical for everyday riding, but fantastic at the specific thing it’s designed to do, and addictive to ride on the right terrain.

As a consequence, it may be too specialised for many riders. It makes few concessions to comfort or practicality, and the Ultra handlebar’s limited size range makes no effort to cater for ‘regular’ riders or riding styles.

This is intentional, though, and an honest consideration of your riding style and requirements will help you decide if this is the right bike for you, or whether a less extreme alternative might suit your riding better.