Endurance SL vs CGR SL – Tarmac or Off-Road?

If you are in the market for a high-performance carbon frameset the Endurance SL and CGR SL certainly tick all of the right boxes. Advanced carbon construction-check, aero efficient tube profiles-check, dropped seat stay geometry-check. So, why should you choose one over the other and why? To find out just what the differences are, we thought a little head to head comparison was in order. Here then is ‘Endurance SL vs CGR SL‘.

The CGR SL is pictured on the left in it’s 650b guide but also takes 700c like those pictured on the Endurance SL in the right hand image.

Below we will explore the differences between the Endurance SL vs CGR SL. With one a thoroughbred endurance road bike and the other a highly capable ‘all-road’ machine.


As we alluded to in the intro, both framesets benefit from the very latest advancements in frame building construction and techniques. A carefully selected blend of Toray T1000 and T800 carbon fibres are layered to an exacting specification using an advanced monocoque mould technology.

These strands of carbon are intricately layered over an EPS inner core system that ensures complete consistency of the structural integrity of the carbon fibres. Consequently, this also eliminates any of the excess material that you can expect to find on the inside of entry-level carbon frames. In summary, it allows us to produce a lighter frame that still retains the same strength as a heavier construction.


Aerodynamics played an important part in the development of the SL Carbon Series of frames. In fact many drag saving features have been incorporated into the design and these include:

  • Truncated aerofoil downtube.
  • Aero fork blade profile.
  • Truncated aerofoil seat tube and seat post.
  • Internal cable routing.
  • The option to fit the LEVEL 5 one-piece aero cockpit enables all the cabling to be completely hidden. Giving the bikes their sleek aesthetics while generating 28.5% less drag when compared to a traditional handlebar & stem setup.

Dropped seatstay geometry

Whilst a fairly recent innovation in bike design, dropped seat stays offer distinct advantages over the more traditional design. Firstly, moving the stays further down the seat tube creates improved vertical compliance. The longer length of the seat tube/seat post assembly allows for a little more flex. This helps combat the effects of road vibrations (or road buzz as it is often referred to).

The dropped stays also result in a more compact rear triangle. This has slight implications to aerodynamic efficiency but it also enhances lateral stiffness. Improved lateral stiffness equals better power transfer. Meaning that more of the power generated through the pedals is transferred to forward motion with little wasted effort.

Endurance SL

The Endurance SL is a specialist high-performance endurance road bike, designed exclusively for riding on paved surfaces. As such, it allows riders to experience that feeling that you only get from a high-end race bike. Albeit, one with geometry and a fit designed to achieve as comfortable and efficient a riding position as possible for those long days in the saddle. In doing so, it helps to keep you fresher for longer.

For a ‘pure’ endurance road bike it does have a surprisingly generous tyre clearance. The disc brake version, for instance, boasts clearance for tyres up to 32mm without mudguards. With mudguards in-situ, this drops to 25mm.


The Endurance SL makes short work of the miles.


The CGR SL is an extremely versatile platform, the very embodiment of the ‘one-bike-to-do-it-all philosophy. When fitted with slick road tyres it’s more than capable of keeping pace on any group ride. However, there’s also the capability to fit 700c or 650b wheels with tyres up to 45mm or 47mm.

It’s this inbuilt versatility that makes the CGR SL so supremely suited to all-road adventures big or small. It opens up the possibility to divert off-the-beaten-track and explore that road or side trail that you’ve always seen but never had a bike that’s up to the task. On the CGR SL, you have the freedom to explore where you want, whenever you want, unlimited by terrain or ambition.

Using the level of customisation available through the Bike Builder tool you can fine-tune the spec of the CGR SL to perform on-road, off it. Or opt for an all-rounder package that’s capable of excelling on both.


The ultra-versatile CGR SL in full off-road ‘gravel’ mode.


When perusing bikes on our website there are essentially 2 options available to you. The first being our ‘choose a popular build’ which are essentially ‘off-the-peg’ bikes. if you select one of these builds you are then transferred into the Bike Builder. In Bike Builder you can simply choose to add the bike to the basket and purchase as specified. However, if you wish to make any changes to any of the components you can do so whilst in the Bike Builder.

The second is to select the build your own bike option. This is thoroughly recommended if you have a particular build spec in mind and it is not a default option in the recommended builds. Bike Builder offers you an almost unlimited selection of components, wheels and finishing kit options to customise the bike exactly how you want it.


CustomColour in Bike Builder allows you to get creative with your bikes design. To experiment with changing colours, adding gradients or mixing fades to create your perfect bike, one that’s unique to you. Your Bike. Your Way.

Wheel options

Wheels are a massively important core component of any bike and can literally make or break a ride. The most important features of any wheelset above all else must be reliability, performance and durability. This is why we offer LEVEL and Mavic wheelsets which certainly tick these boxes.

Endurance SL

Default Wheelset

The Endurance SL comes equipped with Mavic’s Aksium Disc wheelset which has been around forever in one form or another. One of the reasons it has been around for so long is its superb reliability and durability. In the sub £200 category it has few peers.


Upgrading to a mid-tier wheelset like LEVEL’s 20 Alloy or Mavic’s Ksyrium SL wheelset offers you the same ‘bombproof’ reliability and durability of the default wheels but with improved build technology and construction materials. Resulting in lighter wheels with enhanced performance, acceleration and compatibility with tubeless tyre systems.

Carbon Wheels

To maximise weight savings and performance nothing beats a carbon wheelset. Deep section carbon rims carve through the air with greater efficiency and their low inertia results in rapid acceleration and while reducing rolling resistance.


To maximise the off-road potential of the CGR SL there are builds centred around Shimano GRX or SRAM 1x gear systems. Similarly to the Endurance SL, the default wheel selection is the ever-reliable Mavic Aksium wheels. However, thanks to the mammoth tyre clearance of the CGR SL there’s also the option to select 700c or 650b wheel sizes. If you are not too familiar with the differences let us explain.

When measured across the wheel from rim bed to rim bed a 650b wheelset has a smaller diameter than a 700c wheel. This enables the fitting of big air volume tyres that when fully inflated equate to a 700c wheel with a narrower tyre. These tyres can be run at low pair pressures for improved shock absorption from the lumps and bumps experienced when riding off the beaten track.

It is worth noting that the 700c version of the Aksium wheels that are supplied as standard are not tubeless-ready.

Endurance SL Tyre Options

With the Endurance SL being an endurance road bike, the tyres available are all for eh slick, tarmac specific variety. They offer the best possible combination of rolling resistance, grip and puncture protection. The default tyres are rigid Continental Ultra Sport 3’s, a slick and durable race/training tyre with good puncture resistance. Upgrades are available to folding tyres which offer amongst other things improved puncture protection, faster rolling speeds and grip.

Continental Ultra Sport 3 are a wire bead tyre for training / racing.

Continental GP5000

The GP5000’s carry on where their predecessor the GP400 left off. Namely being one of the fastest tyres on the planet! This is in no small part due to their Black Chili and Vectran construction. The patented Black Chili compound is extremely fast-rolling and offers supreme levels of grip. Vectran is Conti’s puncture protection belt and offers seriously impressive year-round reliability for what is essentially a racing tyre. If speed is all-important, these are some of the fastest, grippiest and most reliable tyres around.

The latest iteration of Continentals top-tier tyre, the GP5000 can be found on Pro team bikes and are exceptionally fast.

Continental Grand Prix 4 Season

As the name suggests, the GP 4 season tyres offer exceptional all-season, all-weather performance. They offer similarly impressive features as their siblings the Gator Skins but with an emphasis on performance. They roll faster, are lighter and offer exceptional puncture protection by way of a dual Vectran protection strips incorporated into each tyre. Not only are they puncture-resistant, but they are also extremely durable thanks to the Duraskin compound. This compound has been tried and tested by UCI World Tour teams in such events as the gruelling cobbled classics of Paris-Roubaix, Tour of Flanders etc.

GP4 Seasons are almost a fit and forget style of tyre, offering impressive year round performance and durability.

CGR SL Tyre Options

The CGR SL is supplied with the excellent Schwalbe G-One Allround 700x40c tyre which is a great all-rounder. Tubeless-ready, they feature a small pimple tread for traction on hardpack and gravel. Yet the tread is not severe enough detrimentally affect on-road speeds to any great extent. A wide selection of tyres to suit all terrains and surfaces is available in Bike Builder .

Challenge Gravel Grinder

The Gravel Grinder is a fast-rolling and durable multi-surface clincher tyre. The 38mm diameter improves comfort and makes it a great choice for gravel, cyclocross or adventure riding. The central section provides better traction on hard-pack surfaces and the knobs on the shoulders enhanced grip when cornering.

The Gravel Grinder is a fast-rolling and durable multi-surface clincher tyre. The 38mm diameter improves comfort and makes it a great choice for gravel, cyclocross or adventure riding. The central section provides better traction on hard-pack surfaces and the knobs on the shoulders enhanced grip when cornering.

WTB Riddler

Built for speed over a wide range of surfaces the Riddler is a tubeless-compatible tyre with exceptional cornering grip in mixed conditions. Equally at home on gravel rides, cross circuits or towpaths and byways. 

Built for speed over a wide range of surfaces the Riddler is a tubeless-compatible tyre with exceptional cornering grip in mixed conditions. Equally, at home on gravel rides, cross circuits or towpaths and byways. 


So in summary, which is best for you purely depends upon what style of riding you prefer. If you are looking to concentrate solely on road the Endurance SL is clearly the better option. It’s lighter and slightly more efficient on the road. However, if you want the added flexibility of being able to detour off-road and explore fire roads, trails, gravel tracks and the like, then the CGR SL is definitely the right choice.

Torn between disc brake and rim brake and left wondering which is better? read our blog here.

Do you have access to a cycle to work scheme? Find out how they work and the savings you can make here.


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