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by James Huang
August 29, 2019
Photography by James Huang
Cannondale debuted its new Topstone Carbon gravel bike a little more than two months ago, and the initial impressions were very favorable (if you want to refresh your memory on what the Topstone Carbon is all about, you can check out all the nitty-gritty tech details here). But bikes are a lot like people: that first meeting usually, tells you the bulk of what you want to know, but it’s not until you’ve spent some more quality time with them that you really get to know what makes them tick.
Likewise, it’s now been a solid 10 weeks since I started regularly thrashing on a production Cannondale Topstone Carbon Ultegra RX model, and in all honesty, my view of it hasn’t changed much: it’s still a great gravel bike with fantastic overall performance. However, not everyone is going to be willing to put up with some of its idiosyncrasies in order to get there.
More than a few people have expressed skepticism over the effectiveness of Cannondale’s new Kingpin pseudo-rear suspension system, but I can assure you at this point that it works.
In concept, Kingpin is a lot like Trek’s IsoSpeed system in that it allows the seat tube to flex more over bumps than it otherwise would without some sort of mechanical pivot in place. It also takes advantage of the inherent ride quality advantages of dropped seatstays, so in some ways, it’s almost as if Cannondale took the best parts of IsoSpeed and merely improved on it. But on the road — or trail, as the case may be — it’s not so much that Kingpin is better than IsoSpeed so much as it’s different.
The Cannondale Topstone Carbon is a superb all-around carbon gravel bike, but it’s not without a few compromises.
I personally find the IsoSpeed system on the Checkpoint to be more, well, isolating in how well it levels off the ground beneath you, but that’s not necessarily a positive depending on your preferences. It’s an incredibly effective system in terms of how well it erases road and trail chatter, but especially for larger and/or heavier riders, or riders that run more saddle setback and have jerkier pedal strokes, IsoSpeed can also be prone to unwanted movement even when the road surface is perfectly smooth. The newer, adjustable version of IsoSpeed largely addresses all of that, but at least for now, the Checkpoint is still outfitted with the standard non-adjustable design.
In contrast, the rear end of the Topstone Carbon still offers up a distinctly muted and composed feel on bumps, almost as if you employed a helper to run ahead of you on the trail and round off all the sharp edges. But the overall ride quality is firmer and a little more communicative. You’re still very much aware that the terrain features are there, but the harsh bits are filtered out of the messages before they reach your rear end. Think BMW vs. Buick.
There also seems to be a higher threshold of activation on the Kingpin relative to the Checkpoint, in the sense that the former feels like it leaves all the little stuff for the tires to handle; the frame movement doesn’t kick in until you run over something a little more significant. Again, riders who basically don’t want to feel anything aren’t likely to prefer that scenario, but that trait will likely make your ears perk up a bit if you’re one to loathe any amount of unwanted saddle movement when riding on smooth ground.
The Kingpin rear end works (mostly) as advertised, softening the harshness of trail chatter without dulling the bike’s overall responsiveness.
Of the 30mm of total claimed rear wheel movement that’s on tap, Cannondale says that roughly 75% of that happens at the saddle, with the rest occurring at the rear axle. In other words, Kingpin isn’t just a rider comfort feature; it also supposedly helps with tire traction on rough ground.
Was any of that noticeable on the trail? Nope, at least not to me. That’s not to say that Cannondale is lying, mind you, but rather that any effect simply wasn’t perceptible by me. Tricky climbs that I usually clean on other gravel bikes, I cleaned on the Topstone; and likewise, ones that frequently elude me eluded me just the same.
One other key element of the Topstone Carbon’s admirable ride quality is the shaped carbon fiber seatpost. It’s well-established at this point that small-diameter seatposts with lots of exposed shaft contribute greatly to ride comfort, and it’s no different here. You can legitimately see the seat tube flexing when you push down on the saddle of the Topstone Carbon, but you can also see the seatpost independently flexing rearward a lot, too.
For the sake of experimentation, I swapped the stock seatpost for a Thomson Elite aluminum one — known to be one of the stiffest available for a given size — and, as expected, the ride quality turned noticeably more firm. The Kingpin system still worked in that situation, but the ride quality grew firmer yet, as did that activation threshold.
Cannondale doesn’t point this out explicitly, but the seatpost certainly contributes a lot to the Topstone Carbon’s comfortable ride.
“As specced with a SAVE post and under the saddle height and loading conditions in our tests, about 60% of the vertical displacement at the saddle is due to the Kingpin features in the frame,” said Cannondale media relations manager Joe Mackey. “That said, the behavior of the frame and seatpost can’t be completely separated from one another.”
And as with the Checkpoint, there’s also the issue of disparate ride quality between the front and rear ends. On the flagship Topstone Carbon model I rode at the bike’s debut in Vermont, it wasn’t quite as much of an issue. That bike was equipped with Cannondale’s similarly flex-happy SystemBar semi-integrated handlebar and stem, which matched pretty well with the firmer ride of the Kingpin rear end.
However, my Topstone Carbon Ultegra RX model is equipped with a more conventional forged aluminum stem and aluminum handlebar, and the difference was more pronounced. I wouldn’t quite characterize the ride quality up front as harsh — the bike still rides on 37c tires, mind you — but that huge down tube and head tube area flex about as much as you’d expect.
That all said, Kingpin is pretty darn cool.
There are lots of gravel bikes out there with ultra-long wheelbases, ground-scraping bottom bracket heights, and super slack front ends, all in the name of confidence-inspiring stability.
The Topstone Carbon is not that bike.
Riders coming off of traditional road bikes that prefer similarly responsive handling, however, will find a lot to like here (myself included).
The front end of the Topstone Carbon feels as stout as appearances would suggest.
Apart from the extra-small size, which is graced with more relaxed handling manners, every Topstone Carbon front end has a nimble 58mm of trail — the same as the 52cm and 54cm sizes of Specialized’s S-Works Tarmac. But before you write off Cannondale’s engineers as crazy for going with something that quick, it’s important to note that that quoted figure is a theoretical number when the bike is fitted with road tires. Gravel-sized tires bring that number up to 62mm, which is still plenty quick for a gravel bike, and more inline with Cervelo’s new Aspero.
In addition to the responsive steering geometry, the chainstays are short at just 415mm, and the bottom bracket is relatively tall with just 59-69mm of drop, depending on size.
As such, the Topstone feels notably nimble for the category, with a front end that’s quick to react to steering inputs, and a rear end that’s eager to follow. That slightly taller bottom bracket doesn’t lend quite as much confidence when the tires start to slide, but it nevertheless makes for an overall sensation that’s more eager puppy than lazy lap dog.
There’s no noticeable rear-end wag when you put down the power.
That road bike-like feel extends to how the Topstone Carbon behaves under power, too.
The insanely big down tube, the wide-and-flat seat tube, and the broad spaced chainstays all suggest a stout backbone when you start mashing the pedals, and in this case, looks aren’t at all deceiving. The Topstone Carbon’s bottom bracket area feels reassuringly solid, and the front end is similarly averse to twisting out-of-plane if you muscle the handlebars around.
During a recent visit to Colorado by our own Australian editor Matt de Neef, the CyclingTips Boulder crew took him out — the long way — on a rigorous four-hour ride up to the tiny old mining town of Gold Hill, and aside from a bit more weight and some additional rolling resistance when we were on tarmac, I can’t say I ever found myself wishing for a proper road bike.
The down tube is a massive rectangular thing. Aero, schmero.
But had I wanted one that day, all I would have needed to do is install some narrower and faster-rolling rubber — and, indeed, when I did on the Topstone Carbon, its handling and overall feel rivaled plenty of high-end carbon road bikes I’ve ridden in recent years.
Gravel is what Cannondale primarily designed the Topstone Carbon for, though, and the frameset is appropriately equipped with a plethora of accessory mounts that lend the chassis ample versatility.
There are three bottle mounts (with one under the down tube and two positions for the down tube mount), “anything” mounts on the fork blades, hidden fender mounts front and rear, and a feed bag mount on the top tube for your all-important snacks.
Tire clearance is very good, but perhaps not incredible depending on how adventurous you want to be.
The Topstone Carbon is well-equipped in the clearance department, too. There’s enough room for single- or double-chainring cranksets, and despite the stubby 415mm-long chainstays, Cannondale officially approves the Topstone Carbon for 700x40mm or 650x48mm tires — and that’s with a minimum of 6mm of room, so you can likely go bigger depending on your risk tolerance for rub.
That amount of clearance won’t suit more adventure-minded riders who are looking to go really big, but it’s clear from the geometry that that’s not the crowd Cannondale was going for here. And while Trek says the Checkpoint will take a 700x45mm tire out back, that’s only with the adjustable dropouts set to their longest 440mm chainstay length.
But speaking of gearing, Cannondale nailed this one.
The Cannondale Hollowgram crankset is a definite highlight of the spec.
The ultralight Cannondale Hollowgram hollow bonded aluminum crankarms are fitted with a 46/30T one-piece machined Spidering chainring, which is matched to a Shimano 11-34T cassette. Taken in total, there’s ample range for anything other than fully loaded bikepacking, and shift performance is outstanding all around.
Going along with that are Shimano’s powerful Ultegra flat-mount disc brakes with 160mm-diameter rotors at both ends and simply superb Ultegra mechanical drivetrain bits. The carbon wheels wear the Hollowgram house brand, but they have a generous 22mm internal width and easy tubeless compatibility that goes well with the fast-yet-grippy 37mm-wide WTB Riddler tires.
The Shimano Ultegra RX rear derailleur shifts superbly, and the clutched pulley cage keeps things quiet on rough ground.
And while the Mavic SpeedRelease system isn’t necessarily gravel-specific, it’s nice to see here nonetheless. To remove a wheel, all you have to do is undo the thru-axle enough so that the threads are disengaged, and then drop the wheel out. There’s a necked-down portion of the axle that passes through a similarly-sized slot in the dropout, and there’s no need to remove the axle entirely.
Surely at this point, you’re wondering about the catch. There always is one, after all, and the Topstone Carbon is no different.
Cannondale was able to work that magic with the drivetrain and tire clearance only by resorting to its asymmetrical Ai concept, which pushes the entire drivetrain outward by 6mm. The rear hub spacing is the same 142mm as usual, but both dropouts are shifted over to the driveside, and the rim has to be specially dished to keep it in the centerline of the bike. Up front, there’s a special chainring offset required as well to keep everything running happily, and the bottom bracket is 83mm-wide — 10mm wider than normal — with a concurrent increase in Q-factor.
The bottom bracket is 83mm wide, and the adjoining tubes make use of every bit of that width.
Is it all worth it? That all depends.
While the wider pedal stance width is noticeable, it’s important to remember that narrower isn’t always better, and in fact, plenty of riders need to go wider for proper pedaling mechanics. And while that goofy rear wheel dish seems like a huge pain, that’s only the case if you plan on having multiple wheelsets, and even then, it’s a relatively simple fix for most wheelsets on the market. Now, if you’re hoping to swap wheelsets between the Topstone Carbon and your current disc-equipped road bike … well, that’s another story.
There are a few more annoyances I noted on the Topstone Carbon, too, but none of them are specifically related to the asymmetrical frame design.
The entire drivetrain is offset 6mm to the driveside.
Cannondales are often lambasted for exhibiting annoying bottom bracket creaking, and my Topstone Carbon test sample was no different. It wasn’t extremely regular or loud, but it was there nonetheless. Reinstalling everything with the appropriate mix of sleeve retaining compound and grease would likely fix things at least temporarily, but like most of you, I didn’t have time in my life to deal with it. Instead, I mostly just cursed the thing every time it spoke up.
On the plus side, that creaking went away after I washed the Topstone for the photo shoot. But the fact that a mere wash had that effect raised other concerns in my mind regarding sealing in general.
“It is almost impossible to keep all moisture from getting in through the seat tube,” said Mackey, “but there is a generous 6mm drain hole in the bottom bracket shell to allow any moisture to pass through. It is more likely that dirt and grit is getting in between the metal parts from the outside and causing the noise. This would explain why the noise goes away right after external washing.”
Speaking of creaks, it was only after I applied a healthy dose of grease and carbon paste to various parts of the internal wedge-type seatpost binder that that area managed to stay quiet.
And those nifty 22mm-wide carbon rims? Well, they may have seemed impressively resistant to breaking, but they also didn’t seem to want to stay true.
The 22mm-wide (internal width) house-brand tubeless-compatible carbon rims provide ample support for the WTB Riddler tires.
Even more annoying was the persistent rattle inside the down tube from the rear brake hose, despite the fact that there’s a separate, full-length carbon guide molded inside the down tube. Like the bottom bracket and seatpost, that issue can be fixed, but I shouldn’t be the one to have to do that, and neither should you. Cue the cursing, again.
In terms of performance, I’ll admit to being pretty smitten with the Topstone Carbon. It handles the way I prefer my gravel bikes to handle, offers a comfortable and composed ride without ever feeling too squishy, and it generally behaves like a proper road bike in all the ways I want it to. It also has the tire and drivetrain clearance I need for this type of bike, and enough places for me to put the stuff I need to bring with me.
But come on, Cannondale, can we please figure out a way to put some threads in the bottom bracket already? And surely a few cents worth of foam, grease, and carbon paste at the factory would go a long, long way. And how about a more rigorous build protocol for the wheels, eh?
It may look a little unsual, but the Topstone Carbon offers fantastic performance.
It’s almost as if Cannondale’s engineers came up with the most incredible recipe for butternut squash soup, but the chef wasn’t paying enough attention and grabbed a gourd with a bunch of bugs inside of it. The soup might taste the same when all is said and done, but even after you pick the little invaders out of it, the dining experience is ruined.
The formula matters, but so does the execution.
The profile of the Cannondale Topstone Carbon is quite striking with its mega-dropped seatstays. There’s a good reason for the unusual profile, though.
The chainstays are quite flat, but also very broad.
Collet-style hardware in the pivot helps keep this area from creaking.
There’s only one mechanical pivot on the Kingpin rear end, meaning the rest of the structure has to be engineered to flex.
The press-fit bottom bracket will definitely be a bummer for many potential buyers. Sure, the creaking can be fixed, but new buyers shouldn’t have to deal with it, either.
The seat tube has a deep cutout on the backside for extra tire clearance. When you tuck the rear wheel in this closely, you’ve got to carve out space somewhere.
Cannondale says the Topstone Carbon will clear a 700x40mm tire, although that accounts for 6mm of space all around.
The stiff carbon fork keeps the rotor from rubbing on the pads in hard corners.
There are two mounting positions for the down tube bottle.
The front derailleur mount can be removed if you want to run a 1x setup.
Snacks. More snacks.
The hidden seatpost binder looks neat, but it isn’t sealed very well and is prone to creaking.
Hidden fender mounts add all-weather versatility.
There’s some special hardware required if you want to run fenders out back, but it’s not a deal breaker by any means.
Want to carry more up front? There are mounts for that, too.
The WTB Riddler is one of my favorite gravel tires for the Front Range of Colorado, with a fast-rolling center tread and a squared-off shoulder that grabs well on loose-over-hardpack.
Cannondale nailed it with the 46/30T gearing here. Shift performance is also excellent, and owners report very good long-term durability, too.
Q-factor is noticeably wider with the 83mm-wide bottom bracket.
Overall, the Shimano Ultegra groupset on this test bike was without fault. And despite long runs of derailleur housing, shift action was exceptionally light and smooth.
The brake rotors are borrowed from Shimano’s 105 groupset and lack the cooling fins of the Ultegra bits.
The dramatically dropped seatstays require the rear brake caliper to be mounted up high, instead of on the chainstays. Tool access to the mounting bolts is truly horrendous, making adjustments very frustrating.
Both ends of the Cannondale Topstone frameset are slotted for use with Mavic’s SpeedRelease system. Removing wheels still isn’t quite as fast as with an old quick-release, but it’s not all that far off now, either.
The flared bars allow for a narrow, aero position up top, but more leverage and stability down below.
Cannondale includes a wireless speed sensor that was developed in conjunction with Garmin. When paired with the Cannondale app, it records your rides without needing a dedicated GPS head unit, and can also provide maintenance reminders.
Cable routing is internal through the front triangle, but everything exits at the bottom bracket.
From there, the rear brake hose and rear derailleur housing is zip-tied to the chainstays.