Bike Test: Cannondale Topstone Carbon Lefty

For decades now Cannondale has been known as a bike brand not afraid to push the limits with new innovation. Sometimes the pushiness has paid off, sometimes not. Things like their radical Lefty suspension fork have proven themselves over time, but it definitely took a while for it to truly get dialed in. As with the rest of the industry, the explosion in popularity of the gravel segment has brought a new willingness to approach bike design and technologies differently, with suspension proving to be the ultimate arbiter of possibility.

Back in 2015 we saw the first version of a drop-bar Cannondale using a Lefty suspension fork on Tim Johnson’s factory cyclocross race bike. A few months later Zap wrestled the bike away from the multi-time national champion and used it to race at Dirty Kanza.

A few years later Cannondale went big and introduced the Slate as a hybrid road/gravel bike that rolled on 650b wheels with a Lefty fork upfront. To be honest, it was one of our least favorite bikes to date. The fork was good, the frame was nice, but combined with the wheels, none of it ever seemed to work in harmony. In spite of its less-than-ideal characteristics, Cannondale team rider Ted King showed its detractors up by using one to win Dirty Kanza in 2018.

Well, it looks like Cannondale stayed inspired enough with the overall concept of the Slate to introduce a new, fully suspended version of their Topstone gravel bike that they introduced last year.

THE FRAME

Still using their proprietary Kingpin rear suspension, the new Topstone frame is pretty much unchanged from its predecessor. It has the same geometry and size run as the bike we tested last year. Cannondale claims 30mm of travel as a system, but in our testing, that seemed a bit far-fetched, as most of the “travel” was found in the seatpost and less at the axle. And as oversold as the benefit of the Kingpin at the pivot point is, it has never suffered from any problems in testing.

The Topstone Carbon is Cannondale’s most endurance-oriented geometry with a 57.9cm stack and 38.5cm reach on our size-medium test bike. A 103cm wheelbase matched with a 41.5cm chainstay, offering room for 47mm, 650b tires. Internal routing keeps things tidy and the BB30 means there are plenty of crank and spindle options.

THE PARTS

The big news for the 2020 Topstone is the addition of the Lefty suspension fork, now called “Oliver,” that provides 30mm of rear travel. The Oliver is similar to their most recent mountain bike version with a single crown, but the damping and travel have been fine-tuned for gravel and all-road use. The fork has no negative air chamber, making it significantly more supportive and stiff on the top with a fairly progressive tune. This makes it stiff and supportive for most riding, but supple enough for the rough stuff.

The fork is offered in either a carbon or alloy version. Cannondale claims the carbon fork weighs 1340 grams, while the aluminum version is 1610 grams. Both have the same internals with a large lockout lever on the top of the single fork leg that, when closed, still offers a blow-off. The fork uses a flat-mount caliper but has a new tool-less quick-release feature to remove the caliper. This is useful in removing the front wheel as it exits off the side.

The fork stock fits 650x47mm tires on all bikes, but can be modified to also fit 700x45mm; however, you will have to take it to your local bike shop for the fix. The Oliver fits the Lefty 50 hub that has been on the market for many years. This makes wheel upgrades and availability a bit easier.

At $3,750, our Carbon 3-level bike is just shy of a whopping $4000 less than the higher-end Carbon 1 version. The new suspension bikes both roll on 650b WTB alloy rims mounted with a mixed set of tubeless-ready WTB tires—a 47mm Byway in the rear and a 47mm Venture upfront, which keep things fast and efficient for their size.

Gearing is left to Shimano with their GRX mechanical 1x drivetrain. The Cannondale alloy 40t crank is matched to an 11-40 cassette. In-house Cannondale-branded alloy bars, stem and carbon seatpost all help keep the price down.

THE RIDE

Our mid-tier bike is a good value for what it delivers. On the tarmac the bike is buttery smooth, and the suspension is very stiff and supportive, which makes for a pleasant and rewarding ride. As we head to the roads less traveled, the minimal suspension is appreciated, even when we are just doing some light off-road exploring.

Heading for the hills is where our budget build starts to show its shortcomings. The alloy wheels are fairly robust, which makes the rotational weight heavy. Add to that the big knobby tires and it makes for a lot of work to keep things rolling uphill. Since our bike also has the heavier alloy version of the Oliver fork, this, too, brings added weight. The Carbon 3 hits the scale at 23.31 pounds, and you feel it on the climbs.

Once you get to the top and point the bars downhill, you almost instantly forget about the effort it took to get there. The bike is responsive and, like many of the other suspension-equipped drop-bar bikes, you can fly downhill with complete confidence. The Oliver does a great job of supporting you at the top of the stroke while eating up the terrain. Suspension dive is nearly nonexistent, and there is almost too much rebound adjustment, making it easy to fine-tune the return speed.

As expected, the Shimano GRX shifts are flawless, but owing to the bike’s added weight, we wished we had a bit lower gearing for the climbs. Cannondale did spec the hoods on this model to include the dummy left lever, so if you want to switch to a 2x system or maybe a dropper post, you will need to replace it.

With the mention of a dropper post, sure the Topstone is compatible, but in our opinion you would not only be adding weight but also sacrificing the in-saddle compliance brought by the flex of the 27.2mm carbon post, which does most of the work.

THE VERDICT

When it all comes down to it, the Topstone is fairly unchanged for a majority of the riding. The crown-to-axle on the rigid fork and Oliver is the same, making it handle the same when things are smooth or locked out. The large 47mm, 650b tires are slightly smaller in total diameter, but the added weight of our build makes this the first place we would consider an upgrade. New, lighter 650 wheels or even a set of light 700c wheels would top our list of modifications.

To make the bike more climbing-friendly, our next change would either be a smaller chainring or an aftermarket cassette that offers a wider range of gears on the same system.

Overall, the Topstone is a fun bike. Yes, a tad on the heavy side, but with some slight changes could be made lighter. The alloy fork weighs almost a pound more than the carbon version, but it would perform just the same in normal riding conditions.

While Cannondale still offers a family of Topstone models that don’t use the Oliver fork (starting at $2,750), clearly the world of drop-bar bikes is evolving, and this version of the Topstone just adds to the growing list of options available for those willing to explore new routes and new technology.

PUNCH LINES

• Suspension brings weight and fun
• Same great platform
• Upgrades are sure to be plenty

STATS

Price: $3750
Weight: 23.31 pounds
Sizes: XS, S, M (tested), L, XL
www.cannondale.com

THE GEAR

Helmet: Poc Omne Air
Jersey: Champion System RBA
Bib: Gore Wear
Shoes: Specialized S-works 7
Socks: Sock Guy
Glasses: Rudy Project Defend