Cannondale Synapse Carbon LTD RLE review

The Synapse is a certified endurance bike classic. It has earned multiple awards (including our own Bike of the Year back in 2014) and, in this updated guise, takes the endurance bike title in our 2022 Bike of the Year showdown.

As well as proving popular with everyday riders, the Synapse has also had major successes at WorldTour level over the years. It has won Gent-Wevelgem and taken sixth spot at Paris-Roubaix underneath an emerging superstar (Peter Sagan).

Cannondale’s Synapse formula was always to make an endurance road bike with racing DNA and a UCI certification. The new 2022 Synapse, however, retires that way of thinking and is a bike that’s all about usability for you and I, rather than the lofty whims of professionals.

That change in direction was immediately apparent upon testing the Cannondale Synapse Carbon 2 RL when it launched. However, I’d proffer that this RLE LTD model shows the Synapse’s new direction in its optimal – and most versatile – guise.

Out have gone the two-tier carbon fibre levels across the range, with a standard high-grade frame used throughout. In comes a bike that’s equipped not only with integrated daytime-running lights, but also an integrated battery system, a speed sensor and Garmin’s brilliant Varia radar technology.

That might suggest the Synapse has gone soft, but be safe in the knowledge that Cannondale has kept the same geometry as its race-ready predecessors, albeit with a slightly longer wheelbase to accommodate larger tyre clearances. It now ships with 30c tyres across the standard-range models.

However, even that is upped to a 32c tyre on this limited model. The frame and fork have clearance for 35c tyres (with 6mm of clearance either side), and the bike can even run the standard 30c tyres with full mudguards without issue.

The details on the Synapse are all about making it an easy bike to live with.

The aero-benefiting, yet intricate internal routing found on both the SuperSix EVO and SystemSix are replaced with a simpler system.

This sees the brake hoses exit the bar at the SAVE stem, channel down through the fork and then through a single port in the down tube that also channels the Di2 cables and the wiring for the front light down to the central down-tube mounted battery.

Elsewhere, there’s the practicality of top-tube mounts for a bag, triple bottle mounts, proper mudguard mounts and even removable extension inserts for the thru-axles to make the Synapse smart-trainer compatible.

Also out goes the fiddly integrated seat clamp of the previous Synapse, replaced with a simple old-school ring binder wrapped around a slotted seat tube.

Perhaps the biggest surprise in this new ‘practical’ offering, however, is the switch from Cannondale’s signature lightweight BB30 bottom bracket standard shell, replaced by a threaded BSA bottom bracket shell.

The frame also adopts the dropped-stay design from the EVO, SystemSix and CAAD13, and gets Cannondale’s ‘proportional response construction’.

This method of creating carbon frames means each individual frame size has its own construction, including tube diameters. It ensures that the largest 61cm frame size and the smallest 48cm share the same ride quality.

I’d have expected the addition of a bunch of extra mounts, larger clearances and a heavier bottom bracket shell standard to add a lot of weight.

So, it’s impressive to find out that the new Synapse chassis weighs in at just a few grams more than its slimmer UCI-ready 2018 predecessor at 1,035g compared with 1,015g, most of which comes from the extra hardware (four more bottle bolts and end caps on the thru-axle).

Cannondale Synapse Carbon LTD RLE specifications

The LTD RLE, for me, is the pick of the range.

There is a higher-spec model, the 1 RLE, at £9,000. This gets you Shimano Dura-Ace Di2 with its extra sprocket, an SL version of the KNØT 45 wheels (which come with lighter hubs, but the same rim and construction) and skinnier road tyres.

The LTD comes with KNØT 45 wheels, Vittoria’s chunky any-road Terreno Zero 32c tyres and the 2x version of Shimano’s adventure/gravel-focused GRX Di2 groupset.

The front end uses Cannondale’s slick, clever HollowGram Save SystemBar and stem.

The aerodynamically optimised pairing doesn’t use a traditional round clamp between bar and stem; instead it’s a cradle that the bar sits on (the bolts thread through the bar). It creates a much more aerodynamic shape, which saves a claimed nine watts of energy over a standard setup.

The interface still offers eight degrees of pitch adjustment, so you do have plenty of scope to tune to how you like your bars set up.

The stem comes in 80 to 120mm options and Cannondale dealers should have a stock of different lengths to help you get the right fit.

At the back, there’s a standard round 27.2mm post, albeit one designed to integrate the SmartSense light/radar package and a Di2 battery. It’s topped by the ever-dependable Fabric Scoop saddle.

The KNØT 45 wheels come tubeless-ready with a bang-up-to-date 45mm-deep rim and broad 21mm (internal) width. The hub internals and spokes both come from DT and past experience has shown the KNØT to be a tough and fast wheel.

Finishing off the LTD’s build is a bunch of smart tech not usually found on off-the-peg bikes.

First, there’s the smart wheel sensor, which is now common to all Cannondales. This small unit, designed with Garmin, gives more accurate speed and distance data than GPS alone.

The Cannondale app comes next, with bike registration, servicing and maintenance tips, quick spares identification and Strava-style ride recording.

Finally, there are integrated lights and a Cannondale-specific iteration of Garmin’s clever Varia radar.

Powering the SmartSense system is a down-tube mounted power pack with a claimed five-hour run time on standard mode. I’ve been getting around four hours, 25 minutes (down to two hours, 45 minutes on its highest setting, or 20 hours in battery save mode).

The power pack charges fully from a USB-C source in three hours and will remain topped up on standby for 150 days. The battery can also be used as a USB-C power source off the bike.

The Foresight front light (built for Cannondale by Lezyne) sits underneath an integrated mount on the bar that can also hold either a GPS unit or the included Garmin Varia display. It packs 350 lumens and comes in a non-flashing StVZO-approved specification for mainland Europe and a flash-mode enabled version for international buyers.

In the UK, initial bikes are being shipped with StVZO, but long-term it’s going to come with the international lights – giving potentially longer run times than the always-on StVZO standard.

A button on the rear of the front light will scroll through the modes on the light. With StVZO, you can set it to no front light (for daylight running) or ambient light sensor, so it turns on automatically when the evening draws in.

The international version has a multitude of flash modes and lots of setting adjustments too. It also makes the most of the Varia tech, changing from flashing to solid as another road user approaches.

Varia is a rear-facing radar system that detects vehicles from up to 140 metres behind. The bike comes with an LED Varia display fitted to the out-front mount, with 15 LEDS that light up from green to red as vehicles behind close in. It has an audible warning too.

You can connect the system to a Garmin GPS. This replicates the approach signals by using the colour display, showing approaching vehicles with the edges of the display switching from the standard colour (white during the day, black at night), to green and red, and making use of the Edge’s backlit screen.

A strip on the right-hand side of the screen also tracks a large dot from the base of the screen to the top, showing vehicles approaching and their speed.

The rear light also brightens as vehicles approach, with the front light providing a secondary warning.

Cannondale Synapse Carbon LTD RLE geometry

The Synapse's geometry is a true case of ‘if it’s not broke, don’t fix it’, with this 2022 issue sharing the same 610mm stack height and 392mm reach as the previous models.

The wheelbase has been eked out by 11mm to take into account the increase in tyre clearance, now up to 35c. The new-shaped fork’s trail is a shorter 56mm.

These subtle changes in wheelbase and trail combine to give the Synapse the quick, yet controlled feel that’s been the signature of the bike for its last two generations.

Cannondale Synapse Carbon LTD RLE ride impressions

The new Synapse is, quite simply, a wonderful place to spend multiple hours riding.

The endurance geometry hits the sweet spot of being at once comfortable and not too stretched, with enough room to get down in the drops and go for it without feeling cramped, as can happen on more relaxed endurance-shaped bikes.

If anything, the handling is a little quicker than on the older bikes. I love the way in which the steering reacts snappily when I want to quickly make a correction mid-corner or navigate a pockmarked road, rut, hole – or even gravel surface.

The chassis and wheels feel compliant. The KNØT 45s have a bit of give in the rim that combines with the chunky Vittoria tyres to provide a plush feel. The tyres, with their slick centre strip, roll fast enough on tarmac, while the shallow studded edges provide a bit of bite should you ramble off-road.

That’s where the gravel-capable LTD, much like BMC’s Roadmachine X, differs from established endurance bikes.

On one of my longer test rides, I took it over a section of Salisbury Plain’s Imber Range path and it impressed, feeling as fast as some of the lighter gravel bikes I’ve tested on the same terrain.

I’m in no way suggesting the LTD is a bike I’d choose to take on singletrack trails or more technical terrain, but for the occasional excursion onto wide byways and fire roads, it’s more than up to the job.

With those points in mind, the Shimano GRX Di2 drivetrain seems like an outlier choice for a road bike, with its 48/31 chainring pairing and 11-34 cassette. In use, though, I found the more compact range of gears ideal.

IsThe spread is great for climbing, with a proper low gear for the steepest slopes, and while I may have found myself hitting a high cadence when descending on longer, faster roads, I wasn’t spinning out.

It also means you get GRX’s brilliant ergonomics, with the lever offering the best brake feel from the hoods of any current groupset. It’s worth noting that when riding big miles endurance-style, you’ll be spending the lion’s share of your time on the hoods.

Di2 shifting is, as ever, impeccable, and the GRX Servo Wave braking results in subtle increases in pressure at hand, meaning I braked more efficiently and maintained more speed. The brakes never emitted a squeak, screech, or rubbed throughout my test rides in all weathers.

Cannondale Synapse Carbon LTD RLE bottom line

The new Synapse takes performance endurance bikes to a new and exciting all-road space. Bikes such as Specialized’s Future-Shock equipped Roubaix and Trek’s IsoSpeed-sporting Domane arguably pushed open the door to a new go-anywhere style of road riding. The Synapse in this LTD guise has smashed it wide open.

I love that this bike has been created without the influence of the pro tour.

Don’t get me wrong, I love the tech in the pro tour rider’s arsenal, but the needs of a professional athlete who rides around 30,000km / 18,640miles annually are much different to even the keenest recreational rider.

The Synapse LTD has tyres and gearing not quite as speedy as on lightweight performance bikes, but none of those feathery, flighty bikes could handle a byway excursion or a bridleway blast shortcut.

If you’re the sort of rider, like me, who loves a bit of exploration along with your big-mile rides, then the Synapse LTD RLE should be on your shortlist.

As endurance bikes go, this is an exciting glimpse into the future of this genre of bike.

The fact that it’s practical and has enhanced safety features doesn’t make it dull. The Synapse rides with huge panache, and stays exciting when you want to mix it up. It’s a superb achievement, making it not only the best iteration of the Synapse to date but just maybe the best example of an endurance bike.