Cannondale Jekyll 1 review

It’s all change for the latest iteration of Cannondale’s Jekyll, a bike that’s remained largely untouched since it was revamped in 2017.

The new Jekyll has been toiled over for close to three years now and sports a radically different frame to the old bike. But what exactly does all that R&D time equate to on the hill and could this be the dawning of a new era for the brand that once frequented the podium at Enduro World Series events?

After covering every aspect of the frame in detail when the bike first launched, it’s now time to get the full low-down on exactly how it behaves on the trail.

Cannondale Jekyll 1 frame and suspension details

At the core of the new carbon Jekyll is its suspension. The latest bike moves to a high pivot, four-bar linkage design and boasts 165mm of rear-wheel travel.

Cannondale explains the reasoning behind this is the benefit of the rearward axle path that comes with the high pivot design. This helps the rear wheel to move backwards and up out of the way of the obstacle, which should help sustain momentum, along with the bike maintaining a more constant wheelbase because both wheels cycle through their suspension travel.

The Jekyll’s rear wheel doesn’t move as far backwards as some designs though, with the rear wheel axle moving, at most, around 12mm (from full extension) when the bike is sat at around 100mm into its 165mm of travel.

Tuning the suspension

As you’ll probably be aware, high pivot suspension designs need a carefully positioned idler pulley to help mitigate pedal kickback, the biggest drawback associated with this type of system.

Using an idler pulley helps to eliminate chain growth caused by the rearward axle path and, in turn, helps to prevent pedal kickback.

In simple terms, pedal kickback is caused by the distance between the chainring and cassette growing as the suspension compresses. With the chain under tension, this 'growth' can cause the chain to pull back on the chainring, spinning the cranks backwards and creating pedal kickback – there’s more to it than that but in brief, these are the basics.

Cannondale actually combines its idler pulley with a small chain guide (called the ‘Guidler’). The pulley doesn’t sit directly on the main pivot, though, it's positioned just behind and attached directly to the mainframe in a bid to better tune the anti-squat values (how much the suspension resists pedal bob), which sit at around the 105 per cent mark at sag – though these do vary slightly across the different frame sizes (anti-squat is closer to between 110 and 115 per cent when the bike is unweighted).

Creating less drag

Cannondale has done its homework and minimised drag (something commonly associated with high pivot, idler-equipped designs) and claims when it’s clean and properly maintained it's just 1 per cent less efficient than a non-idler-equipped bike.

In theory, at least, Cannondale also says that idler wear should be roughly in line with that of the chainring.

Frame and suspension designed for every rider

Where the Jekyll (and a number of other Cannondale frames, including the Scalpel and Habit) differs from much of the competition is with its Proportional Response treatment.

What this means in terms of the suspension is that as the frame size increases, the suspension layout is tweaked accordingly – different pivot locations, leverage ratios, anti-squat and anti-rise as well as axle paths.

This ensures every frame rides the same, so every rider, tall or short, should get the same ride experience. Those differing factors don’t stop there, though.

Low-slung shock placement

In a bid to keep the bike’s centre of mass as low as possible, the engineers at Cannondale decided they wanted to sink the shock as low in the bike as possible.

That meant rather than bolting it on top of the down tube and right down by the bottom bracket, they instead put it inside the down tube, making their own lives very tough indeed.

The shock is enclosed inside the ‘GravityCavity’ where it’s visible from above but is protected from trail debris and muck by a plastic guard that bolts to the underside of the down tube.

You can still tweak most of the Fox Float X2 adjusters without too much hassle, but due to Fox redesigning the layout of the X2 while Cannondale was developing the Jekyll (which included Fox shifting the location of the high-speed rebound adjuster), getting in and adjusting the high-speed rebound damping is really rather tricky.

Like other bikes from Cannondale, the Jekyll uses its Ai Offset Drivetrain system.

This design employs an offset rear triangle that shifts the drivetrain 6mm over to the right, helping to sit the rim more centrally between the hub flanges (instead of centring it between the hub end caps) in a bid to improve spoke angle and therefore wheel stiffness.

It’s worth noting then, that should you want to swap over to a favourite set of wheels you already own, you’ll need to get the rear wheel re-dished in order to fit the frame.

Finally, unlike a lot of modern enduro bikes, the Jekyll doesn’t use SRAM’s Universal Derailleur Hanger because Cannondale just couldn’t get the hanger to work with the chainstay pivot placement.

Cannondale Jekyll 1 geometry

The Jekyll is offered in four different frame sizes (small to extra-large) and comes with 29in wheels only. There’s currently no option for using a smaller, 650b rear wheel to create a mixed wheel size set-up.

It’s also designed around a 170mm travel fork up front.

In terms of numbers, the Jekyll boasts measurements and angles that are bang up to date when compared to its contemporaries, including the likes of the Trek Slash 8, Nukeproof 290 Alloy Pro and Whyte G-180 RS 29 V1. My medium test bike had a reach of 450mm, a slack head angle of 63.7 degrees and a decently steep seat-tube angle of 77.5 degrees.

I measured the bottom bracket to sit at 342mm off the ground, which is lower than Cannondale states in its geometry chart, though this is no bad thing and impressively low for a bike with this much travel on tap.

The Proportional Response treatment doesn’t just apply to the suspension layout, but to the frame sizing, too. As frame size increases, so does the rear centre (also known as effective chainstay length, measured from the centre of the bottom bracket to the centre of the rear wheel axle).

The medium sports a 435mm rear centre (the XL’s is 450mm). Effective seat tube angles are identical across all sizes too, also in a bid to give every rider, no matter what size bike they ride, the exact same ride feel.

Thanks to short seat tubes (it’s just 410mm on the medium), running a longer dropper post isn’t an issue and I think Cannondale could have gone even longer than it has. While the medium comes with a 150mm travel post, the large and extra-large both get 170mm posts.

Cannondale Jekyll 1 specifications

Cannondale offers two different Jekyll builds, both of which use the same frame. The pricier Jekyll 1 will set you back £6,500, while the lower-specced Jekyll 2 is £4,500.

All that cash not only covers a frame that’s clearly been toiled over for years, but also a host of (mainly) top-tier kit.

A Fox Factory 38 fork up front boasts 170mm of travel and offers masses of external adjustment (high- and low-speed compression and rebound damping). It’s also easy to tweak the spring volume with the spacers that Cannondale provides. This is matched with a Factory X2 rear shock with the same external adjustments.

SRAM’s X01 Eagle drivetrain takes care of the Jeykll’s gearing needs and comes complete with the massive 10-52t cassette, which is a real blessing for those steep climbs when you’re properly fatigued.

It’s not the full X01 Eagle drivetrain though, Cannondale has used a GX Eagle shifter and NX Eagle chain.

SRAM's top-tier Code RSC brakes have been wisely specced with 220mm front and 200mm rear rotors for ultimate stopping power.

Cannondale has also made the smart move of speccing the shorter 165mm SRAM X1 Eagle cranks, which means more ground clearance and less chance of smacking pedals.

Considering the cost of the Jekyll 1, it’s a little surprising that Cannondale has opted for the WTB wheelset seen here.

While the WTB KOM Trail i30 rims are thoroughly decent, I’d have expected them to be laced onto slightly fancier hubs than the Formula (front) and SRAM MTH700 (rear) chosen.

There’s no grumbling about the tyres though, the formidable combination of the 2.5in Maxxis Assegai MaxxTerra compound up front and 2.4in Maxxis Minion DHR II at the rear (both of which use the EXO+ casing) is one of my favourites.

Fabric supplies the saddle and grips, while Cannondale takes care of the dropper post and bar.

The carbon bar is certainly worth a mention here, featuring some careful profiling to help create a more forgiving ride and, so far, I’ve been really impressed with the feel.

Cannondale Jekyll 1 ride impressions

I’ve been riding the Jekyll in a number of different locations, from steep, technical wooded descents to high-speed, rocky bike park trails, in a bid to get a good idea of the bike's strengths and weaknesses.

I also rode the Jekyll back-to-back with a few different enduro bikes, including Nukeproof’s Mega and the Giga to try to get the best measure of the bike possible.

Cannondale Jekyll 1 setup

Getting the Jekyll set-up requires a little attention in order to get the most out of the bike. Luckily, Cannondale says it's able to supply all the details you’ll need to get you going when it comes to sag numbers and base suspension settings.

After a bit of tinkering, I settled on just under 25 per cent sag for the rear shock, with both compression dials and the high-speed rebound damping dial fully open.

Reaching the high-speed rebound adjuster is a bit tricky and quite involved – it’s not something you’ll want to do out on the trail. After removing the shock protector from the underside of the down tube, I then had to coax the dial around with a small, 1mm Allen key. It’s not easy, but once I found the settings I liked, I’ve not had to repeat the process.

During the test process, I was going back and forth with Cannondale about what I was feeling on the bike, some of which didn’t quite tally with its experience. It was discovered that the shock tune I had on the early sample bike I was testing wasn’t quite right, so Cannondale got the shock tweaked (switching to a lighter compression tune) and then the bike returned to me.

Cannondale Jekyll 1 climbing performance

Despite Cannondale's claims that the Jekyll has a descending bias, it’s still more than comfortable on the climbs.

For starters, I felt like I had more than enough room when seated thanks to the 608mm effective top tube coupled with the 35mm stem. This meant I was neither too cramped nor uncomfortably stretched out.

The steep effective seat angle also contributes here, helping to sit you up over the bottom bracket. This proved a real plus when tackling especially steep climbs.

At no point did I use the low-speed compression lever on the shock to firm the back end up. That’s was down to how composed the bike pedals when you're sat down and spinning a gear, with very little in the way of pedal-induced suspension bob.

Leaving the rear suspension open to work away as you climb has its benefits. I found that the rear wheel was able to inch its way up and over rock steps or roots without really disturbing my pedalling rhythm, and traction was impressive when the trails became dry and dusty.

Drag-free climbs to the trailheads

When it comes to noise and drag from the idler pulley, I was impressed by just how quiet the Jekyll is, with no notable additional friction compared to a non-idler equipped bike.

That’s not to say it’s completely silent, though. When using the biggest 52t sprocket, the noise and feel when pedalling is comparable to that of a non-idler equipped bike with an upper chain guide mounted (although as the chainline straightens out on these bikes, the noise tends to drop off).

In fact, I’ve ridden some bikes with upper guides (and no idler pulley) that are noisier when using the biggest sprocket. When climbing on rough, loose terrain, this noise from the idler is easily drowned out by the sound of the tyres crunching over gravel.

Of course, get the bike caked in mud and the noise through the drivetrain does increase – but, even then, I’d be hard-pressed to say this had a dramatic effect on efficiency. So it’s well worth staying on top of cleaning and maintenance to get the most out of the Jekyll.

Cannondale Jekyll 1 descending performance

The Jekyll has been designed with descending in mind, and as I’ve already mentioned, getting the sag set is really important to get the most out of the bike.

I dabbled with running 30 per cent sag (and ventured as far as 35 per cent) and while the bike felt fast in a straight line on steep, rough terrain, it didn’t give much back to the rider when pumping and trying to build or maintain speed.

At the prescribed 25 per cent sag (which works out at around 16mm of shock stroke and around 40mm of total travel), the Jekyll feels far more dynamic, and I was able to really drive my weight through the bike when working my way through undulating terrain.

Mid-stroke support is great too, giving you a really stable platform to work from when it comes to properly attacking corners.

And it’s through the turns that I really started to appreciate the low-slung weight of the bike and the bottom bracket height, which just helped to add to cornering confidence and overall stability.

It helps that the Maxxis tyre combo is truly superb, with both tyres eager to bite into the dirt and feeling equally predictable when traction does start to drop off.

While the rear wheel moves back by around 12mm in total (up to around the 100mm of travel mark), it’s only travelling rearwards by around 5mm from sag before the axle continues upwards and begins to arc forward. As these aren’t exactly dramatic numbers, the bike felt totally predictable and easy to handle through the turns.

All-round suspension performance

The supple suspension – which improved following the shock's re-tune – helps to keep the tyres tracking the terrain too, and I always felt more than comfortable with how the suspension behaved as I loaded it from turn to turn.

When it comes to faster, rougher high-speed sections of trail, the Jekyll manages to handle square-edge hits really very well, soaking them up with relative ease and always with an impressive air of serenity.

I’ve got a rather nasty root spread on one of my preferred test tracks that can be hit at speed. The uneven, protruding, criss-cross nature of this section can be a real momentum sapper, but the Jekyll managed to spit me out the other side time and time again, and always with a decent amount of exit speed.

A little like the Trek Slash 8 that won our Enduro Bike of the Year award in 2021, the Jekyll manages to maintain masses of chassis stability as you pelt through rock gardens at pace, with next to no pitching back and forth as the wheels work away beneath you. But the Jekyll feels a little less frenetic than the Trek – potentially some of this is down to the rear suspension design and the difference between how RockShox and Fox suspension behaves.

Generous geo

This sensation means you can stay neutral on the Jekyll, poised ready to react to the trail, rather than having to counter what the bike is doing as you get bucked around.

I felt relaxed on the bike and well-centred between the wheels, never needing to over-exaggerate my movements and just doing enough to keep the bike doing what it needed to do – a real plus on longer descents.

It helps that at 172cm (5ft 8in), I felt really comfortable on the medium frame. It’s stable when it needs to be but still easy to manoeuvre and throw around when you want to.

On slower, steeper, chunky terrain, I’d argue the Nukeproof Giga feels plusher, but it doesn’t feel quite as composed as the Cannondale. The Jekyll offers a more direct, racy ride, muting rather than totally erasing these types of hits. Running more sag on the Jekyll does boost comfort but erodes its dynamism, making it harder work when pumping through undulating terrain.

That means, in some situations, there’s a little more feedback through the bike, but it’s not uncomfortable and doesn’t disrupt all-important line choice or flow.

While it’s all been really positive up to this point, I do have a couple of issues with the Jekyll.

Wheel woes

First up, the wheels. I’m not looking for the most flash set of carbon hoops by any means, but I’d prefer to see a £6,500 bike with a tougher wheelset than what’s here.

The hubs seem just fine for the most part, but the pick-up on the SRAM rear hub isn’t particularly rapid.

And the WTB KOM Trail rims might help to create a great tyre shape thanks to their 30mm internal width, but they’re relatively easy to ding when riding rocky terrain (and lose air, though these did seal pretty quickly).

It’s also worth mentioning that I’ve had to re-tension the rear wheel a couple of times during testing after noticing a number of the spokes loosening off quite dramatically.

When you consider I’ve been riding other bikes on the same trails for even longer without needing as much as a twiddle from a spoke key, it is a little disappointing when you consider the asking price.

Something to keep your eye on

My other niggle is with the GravityCavity.

Admittedly, this has only happened on two occasions, but nonetheless, I’ve had rocks flick up and get in behind the plastic guard, rattling around right next to the shock.

Removing them is easy enough, but to prevent what could be expensive shock damage, it's best to stop as soon as you hear that distinctive rattle to get the problem sorted immediately, even if it’s mid-run. Adding some kind of moto foam to plug those gaps on either side of the base plate could solve the issue. Maybe…

High-performing parts

Those were my only real bugbears, though. Otherwise, the spec is hard to fault.

As I’ve already mentioned, I’m a big fan of the tyres, and the addition of the massive disc rotor up front combined with the beautifully controlled SRAM Code RSC brakes is a real plus when it comes to battling hand fatigue on steep, long trails.

The decision to go for 165mm cranks is another smart move and I’ve had no issues with clattering my pedals into the ground, despite the reasonably low bottom bracket height.

Then, of course, there’s the Fox suspension, which offers loads of tuning potential and is great if you like to fettle (there are fewer things to tweak on the Jekyll 2).

This all helps to create an incredibly balanced ride – I settled on two tokens in the 38 fork up front, even though Cannondale recommends three – and further bolster that calmness, which really shines through.

Overall, the new Jekyll 1 is a seriously fast, composed and highly capable bike.

Cannondale has done a great job in creating a machine that feels stable and very controlled, even when riding the fastest, most terrifying trails.

Yes, the wheels could be better and it’d be good to see some more protection around the shock, but it’s clear that the new Jekyll could be a seriously formidable enduro race machine in the right pair of hands.

Cannondale Jekyll 1 bottom line

Cannondale’s clearly spent a lot of time and money overhauling the Jekyll and, thankfully, it’s paid off. The new suspension design, geometry and well-considered (for the most part) spec sheet has delivered a bike that’s clearly eager to go fast and feels incredibly calm and stable when you most need it to.

Considering the price, it’d be great to see some better wheels, which could elevate its performance even further. Otherwise, the Jekyll feels well-balanced, incredibly capable and very composed. I really like it.