The Cannondale Topstone Carbon Lefty 1 has a premium build and features the all new Lefty Oliver suspension fork.
Editor's note: This review was originally published on Roadbikereview.
Cannondale is adding a full suspension model to its gravel bike arsenal. The Topstone Carbon Lefty features an all-new Lefty Oliver fork and knobby, high-volume 650b tires intended to increase the Topstone's appetite for adventure.
Cannondale Topstone Carbon Lefty Highlights
- Lefty Oliver fork features 30mm of suspension travel
- KingPin flex suspension system provides up to 30mm of travel
- Carbon frame shared with standard Topstone
- Three trim levels available
- Price range: $3,750 - $7,500
- Available now
- Visit https://www.cannondale.com/ for more information
Ahead of the curve
Cannondale was years ahead of the suspension gravel trend. Decades, in fact, if you want to go back to the late 1990s when the company introduced the Headshok-equipped XS800 cyclocross bike. But it was the Slate set the stage for a number of different suspension systems that followed in recent years. When it was introduced in 2015, the Slate was unlike anything else on the market. With 650b wheels and the 30mm-travel Lefty Oliver fork, the Slate was hard to pin down for some riders at the time. Despite this, it went on to claim the men's victory at the 2016 Dirty Kanza (with a little bit of help from Ted King, of course).
The Slate was notably absent when Cannondale launched its 2020 gravel collection last summer. The company's new gravel bike, the Topstone, featured a soft-tail rear end that uses vertical frame flex around the KingPin pivot on the seat tube to provide up to 30mm of travel at the rear axle, but alas, no front suspension. The new Topstone Carbon Lefty picks up where the Slate left off.
Lefty Oliver suspension fork details, weights and pricing
The Topstone frame with the standard carbon suspension fork and 700c wheels alongside the Topstone with the new Lefty Oliver and 650b wheels.
The Topstone Carbon Lefty uses the same carbon chassis as the current Topstone. It's built around a new single-crown version of the Oliver that takes design cues from Cannondale's cross-country fork, the Ocho. This single-tined fork uses the same needle bearing internals as the Ocho with a damper that has been specifically tuned for the needs of gravel riding-firm under pedaling with a nearly rock-solid lockout.
The Oliver is compatible with both 650b and 700c set-ups. Swapping in a longer air piston is required to achieve the proper ride height with 700c wheels. According to Cannondale, the maximum tire clearance with 650b wheels is 47mm. Clearance with 700c wheels shrinks slightly to 45mm-wide tires.
The Oliver is offered in a version with a carbon chassis with a claimed weight of 1,350g, as well as an alloy version that comes spec'd on more budget-friendly builds. The alloy Oliver has a claimed weight of 1,610g.
Cannondale is offering the Oliver Carbon (tested here) for aftermarket purchase for $1,500.
Cannondale Topstone Carbon Lefty pricing and availability
Cannondale is rolling out three versions of the Topstone Carbon Lefty. The top-end Topstone Carbon Lefty 1 features a SRAM wireless AXS drivetrain and carbon wheels and retails for $7,500.
The more affordable Topstone Carbon Lefty 3 and Women's Topstone Carbon Lefty both feature Shimano GRX 1x drivetrains with alloy version of the Oliver and retail for $3,750. All three builds are available now.
Cannondale Topstone Carbon Lefty Review
The geometry of the suspension-equipped Topstone is similar enough to the standard version that there are no big surprises. The bike is agile and more willing to respond to small rider inputs than most gravel bikes. This can be attributed to very short rear end. Measuring at just 415mm, the Topstone's chainstays are 15-20mm shorter than many of its competitors.
The Lefty Oliver is an excellent fork. Steering precision is on point and it rations its 30mm of travel very well. The fork's air spring is designed to ride without sag, so handling isn't markedly different than the Topstone with a rigid carbon fork. Right away I was able to tell the fork had a lot of compression damping. It's quite firm and there's very little unwanted movement when grinding up climbs with the fork fully open.
I spent most of my time riding with the fork open, but would toggle the lockout on for long stretches of pavement. The lockout is firm and features a blow-off valve in the event you encounter a large impact. When pavement turns to rough gravel, or to singletrack, the unsagged ride makes the Oliver feel like it has more travel than it actually does. I appreciated this feeling on many of my test rides that linked sections of singletrack with gravel roads.
The top-end Topstone Carbon Lefty 1 tested here features a SRAM 1x "mullet" drivetrain with Force AXS controls and crankset with and SRAM XO1 Eagle AXS rear derailleur and cassette. While I wouldn't run anything other than a 1x drivetrain on a mountain bike, I'm not sold on 1x on all gravel bikes. The steps between gears are often too large to keep a consistent tempo on long gravel rides. The wide range SRAM 10-50t cassette does exacerbate this to an extent. But, given amount of time I spent testing this bike on singletrack, the 1x drivetrain made perfect sense. I was glad to trade smaller steps between gears for a wider range.
The Topstone frame features all the proper mounts for gravel bike needs including bolt-on feed bag mounts and three pairs of water bottle bosses.
Overall, I came away with a mixed impression of the Topstone Carbon Lefty. The ride quality is excellent and the Lefty Oliver works as advertised. But despite the addition of a suspension fork, this bike still leans toward the road end of the gravel bike spectrum. The short wheelbase is an asset if you favor agility over stability, but the short chainstays also seemed to hinder traction on steep climbs covered in loose gravel. In these situations, I found that my weight was further behind the rear axle. As a result, the rear tire was more apt to break loose. I confirmed this by swapping a 650b wheelset with the same 650b x 47mm WTB Sendero tires onto a Niner RLT 9 RDO (which has longer, 430mm, chainstays) and climbing traction was noticeably better.
The Hollowgram carbon wheelset helps to keep the Topstone Carbon Lefty 1 to a very respectable 21-pounds.
Maximum tire width was another sticking point for me. The Topstone maxes out at 700c x 40mm tires or 650b x 47mm. Many of this year's gravel bikes can fit 700 x 50mm tires or true 27.5 x 2.0-2.25 mountain bike tires. This limited tire clearance will put the Topstone at a disadvantage in some situations. Not every ride or race will call for tires this large, but many do. Even if you opt to run a narrower tire, the additional mud clearance in these frames is a godsend in many situations. (See the photos from this year's Mid South for reference.) Suspension isn't a solution for limited tire clearance-quite the opposite. In my opinion, suspension doesn't negate the need for larger tires; it increases it. Suspension expands how the Topstone can be ridden and tire width needs to increase to match this increased scope.
Last but not least, given Topstone Carbon Lefty's increased aptitude for rowdy riding, I would have preferred to have a dropper come stock on this bike.
Cannondale Topstone Carbon Lefty Verdict
The Topstone Carbon Lefty 1 is more capable than the rigid version, but more tire clearance would be a great addition.
Despite my reservations about tire clearance and the ultra-short chainstays, I have been having a lot of fun on this bike. In thinking about the times we live in right now, riding close to home is often the best option. I've created several loops from my front door that link together bike paths, roads, gravel, and singletrack. I've enjoyed rides on the Topstone that would have been boring on a mountain bike and a bit treacherous on a rigid gravel bike. If this sounds like your kind of adventures, then the Topstone is worth a try.
A few more words on the Oliver: I feel strongly that suspension-in its many forms-has a place in the future of gravel bikes. The Lefty Oliver is the most refined gravel suspension fork currently on the market. This one-sided slider is light, stiff, and supple when needed without undue movement when the road doesn't require it. I wouldn't hesitate to run this fork with 700c wheels at gravel events such as Grinduro or the Dirty Kanza.
What do you think?
Share your thoughts in our Gravel Bike Forum.