By The Takeaway: The Cannondale Topstone Carbon Lefty 3, despite its small wheels, fat tires, and full suspension, is a surprisingly agile and lively bike on both dirt and pavement.
- 30mm of front and rear travel
- Compatible with 27.2mm internally routed dropper posts
- Shimano GRX 1x11-speed drivetrain
Price: $4,250
Weight: 24.3 lb. (L)
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Despite having 47mm-wide tires on 650b wheels and 30mm of suspension front and rear, this burly bike is surprisingly agile and lively on pavement and dirt. It comes with a Lefty Oliver fork and has the same frame as the other Topstone Carbon bikes in the line, one that touts rear suspension without the weight and complexity of a shock and linkages. A thru-axle pivot in the seat tube allows the entire back of the frame—rear stays, seat tube, even the rear of the top tube—to flex like a series of connected leaf springs to provide comfort and traction on rough terrain while retaining pedaling efficiency.
The single-pivot design is an evolution of the compliance that’s been engineered into other Cannondale frames, said Sam Ebert from the Cannondale Product Team. It’s a style of suspension that’s popular on short-travel mountain bikes, and endurance road and hardtail mountain bikes have boasted measurable compliance in the rear triangle for several years now. But when the Topstone Carbon rolled out in the summer of 2019, it was the first time we saw the two concepts blended together.
Shimano GRX
The bike blends a GRX 800 derailleur with GRX 600 shift levers.
Remote Lockout
A quick flip of the lever makes the bike feel more efficient on pavement.
Rear Suspension
The leaf-spring design adds 30mm of travel without heavy shocks or linkage systems.
Lefty Oliver
The single-sided fork offers up to 30mm of front wheel travel.
1x Drivetrain
It's hard to argue with the simplicity of a single ring for off-road riding.
There is one important distinction to make. Typically, travel is measured at the rear wheel. In the case of the Topstone Carbon (and Lefty) frames, only 25 percent of the travel happens at the axle. The rest is measured at the saddle. But because each size uses slightly different tube shapes and carbon layups to achieve the same ride quality, precise travel varies by size.
Why measure travel at the saddle? That gets to the magic of this frame design. The suspension is active only while seated. When standing up on the pedals, the only noticeable compliance comes from the tires and the small amount of flex in the chain stays. That translates to a ride that feels extremely lively and efficient when accelerating out of the saddle, yet comfortable and compliant when seated. It offers amazing rear-wheel traction on steep climbs and rough terrain without the bouncing and bobbing that can come from plush suspension. Despite the efficiency of the frame, on the gravel bike continuum, the Topstone Carbon Lefty 3 far resides at the more adventurous end. If you’re looking for a speedier bike, the Topstone Carbon is its faster, more race-oriented counterpart, utilizing 700c wheels and a rigid fork.
Despite the impressive off-road chops, the lack of copious mounts for extra gear make it less well-suited to multiday adventures than other bikes I’ve ridden. Whereas the Salsa Warroad is covered in eyelet mounts for all the gear you could possibly want, the Topstone Carbon Lefty 3 can carry only three water bottles on the frame and a top tube bag. The rear triangle will take a fender but not a pannier rack. It is, however, compatible with 27.2mm internally routed dropper posts.
That somewhat limits the primary use of this bike to single-day adventures and light bikepacking trips. But within that realm, this bike boasts amazing versatility on account of its ability to transition between pavement and dirt.
Style Gravel
Material Carbon
Wheel Size 650b
Fork 30mm Lefty Oliver
Travel 30mm
Drivetrain Shimano GRX 600 shift levers, GRX 800 rear derailleur
Cranks Cannondale 1
Chainring 40t
Cassette 11-42
Brakes Shimano GRX 400 hydraulic disc
Wheels WTB ST i23 TCS, tubeless ready
Tires WTB Venture 47 TCS Light (front), 47mm WTB Byway 47 TCS Light (rear)
Saddle Fizik New Aliante R5
Seatpost Cannondale 2, carbon
Handlebar Cannondale 3, aluminum, 16-degree flare
Stem Cannondale 2, aluminum
Tire Clearance 650b x 47mm
Topstone Carbon Lefty Family
There are five Topstone Carbons from which to choose, but only two that are equipped with the Lefty fork. The bike that’s the subject of this review is the cheapest of the two. The Topstone Carbon Lefty 1 ups the ante with carbon Hollowgram wheels and a SRAM Force AXS 1x drivetrain, but it will set you back $8,500.
Cannondale also makes two versions of this bike with electric pedal assist, the Topstone Neo Carbon Lefty 1 ($10,000) and the Topstone Neo Carbon Lefty 3 ($6,300).
Middle-of-the-Road Fit Accommodates Most Riding Positions
The geometry favors a neutral riding position. Our size-large test bike has 394mm of reach and a stack height of 610mm. The standard 1⅛-inch steerer tube and round handlebar with a 31.8mm clamp diameter make it easy for riders to swap stems to best suit their desired handlebar height. Riders who prefer a short, upright, and comfortable position as well as those who like a more aggressive, stretched-out fit should be able to get what they need on the Topstone Carbon Lefty 3.
Pros
- Carbon frame with 30mm of front and rear travel
- Shimano GRX 1x11-speed drivetrain
Cons
- Doesn't have many eyelet mounts for extra gear
A Great Blend of Off- and On-Road Performance
This bike walks a fine line in the gravel world: rugged enough for big adventures while remaining pleasant on smooth roads. It floated over gravel with ease, and let me aggressively dig into singletrack. I found the quick and responsive low-speed handling to be a bonus on tight trails. The balance between out-of-the-saddle efficiency and plush pedaling was also very apparent in the woods. The rear wheel stayed planted remarkably well on steep, chunky climbs, and the firm pedaling platform was most welcome when I needed to stand up to power over obstacles and challenging segments. The bottom bracket height also felt appropriately balanced between low enough to provide stability and high enough to allow for adequate pedal clearance on uneven terrain.
As well as the Topstone Carbon Lefty 3 performed off-road, where I expected it to excel, it surprised me the most on pavement. Frankly, I didn’t have high hopes for stellar road performance from a 24-pound fully suspended bike with small wheels and fat tires. Boy was I wrong. I never anticipated using words like lively and agile to describe pavement performance, but that’s what it was. It’s not uncommon for bikes that are most at home off-road to lose their luster when they leave the trail, but that wasn’t the case. I enjoyed a speedy and exciting ride and was able to lean the bike into high-speed turns with confidence. The Lefty Oliver fork has an easy-to-reach lockout lever on the crown, and a quick flip of that lever was all it took to transform the trail-eating machine into an efficient road cruiser.
It Left Me Wanting More
Off-road performance was so stellar for a drop-bar bike that I found myself pushing farther and harder into terrain best suited for mountain bikes. The Topstone Carbon Lefty 3 handled it all with aplomb, as far as gravel bikes are concerned, yet I came away from those sessions disappointed because it wasn’t a mountain bike. But that’s not a fair judgement.
In that regard, the bike is a victim of its own success. I was riding a Salsa Warbird on a lot of the same trails and paths when I had the Topstone, and despite the bone-jarring (and slower) ride on the most technical terrain that I rode on both, I was never disappointed with that bike’s off-road performance. I think that was largely due to the fact that I had no unrealistic performance expectations of a rigid drop bar bike. The Topstone Carbon Lefty 3, however, let me ride so much harder it felt like I had transcended gravel bike capacity and was knocking on the door of the world of mountain bike capability. I was getting teased with that ability but not able to go all-in. In that context, I understood where the disappointment was coming from, and came to be impressed that a gravel bike elicited that feeling. The Topstone Carbon Lefty 3 is far from a quiver killer, but it’s a super option for riders who like the feel of a drop bar bike while also venturing into terrain where you’re more likely to run into mountain bikes than gravel ones.
