Cannondale Slate Force CX1 all gravel road bike review and actual weight

The promise of gravel bikes is freedom. The ability to dive off the paved road and into the unknown. To explore those backroads, short cuts and secret paths. Or to just stave off boredom. The Cannondale Slate delivers on all those promises with one of the funnest bikes I’ve ever ridden.

When it first debuted, I (and likely you) questioned the logic of using a 650B wheel and tire for a “road” bike, but after riding it, I’m satisfied with the answer. It makes sense, and it makes for a great ride. It may not look traditional, but if you’re looking for an alternate to your standard road bike, it doesn’t get much more alternative than this…

Cannondale Slate Force CX1 all gravel road bike review and actual weight

I tested the XL, which measures in with a 590 effective top tube (576mm actual) and a 544mm seat tube. Weight for the size XL complete bike is 19.89lb (9.02kg).

Cannondale Slate Force CX1 all gravel road bike review and actual weight

We covered the frame details and tech specs when it launched, but here’s the overview: The Slate pairs 650B wheels with 42mm wide tires to create an outside rolling diameter similar to a 700×23. Add in a very short travel Lefty fork and tuned alloy frame with SAVE stays to create a little rear end flex and you have a bike designed for taming the rough stuff.

Cannondale Slate Force CX1 all gravel road bike review and actual weight

One of the things that hasn’t been discussed is the Slate’s geometry and handling. Its head angle is 71º for size Small, and 71.5º for M thru XL. That’s anywhere from one to two degrees slacker than their SuperSix road bikes, depending on frame size. The rake (aka “offset”) is 45mm, similar to most Lefty forks before they started doing the out front offset, and the same as the SuperSix. They kept it the same here because they wanted a bit more trail so that it’s more stable when things get hairy.

Diagram courtesy of Calfee Design, used with permission. Check out their article on bicycle handling here.

Rake is the distance from the steering axis in a parallel line through the hub’s axle, and trail is the distance between where the steering axis hits the ground and where a line drawn vertically from the hub’s center hits the ground. That the wheel “trails” behind the steering axis is what makes a bicycle self centering and stable. More trail equals more stability, generally speaking, meaning it’s harder to initiate a turn, but harder to knock you off your line.

“By intention, it’s biased towards stability at speed as opposed to nimbleness at low speeds,” said Cannondale’s Murray Washburn. “And if you’re running the tires at lower pressures, down near 40psi or less, you can end up getting pneumatic trail, too, which can exacerbate the effect.”

There’s a chance they could tweak it a little, similar to how they designed the new Scalpel, but Washburn says the way they were riding the prototypes dictated this first generation design.

Cannondale Slate Force CX1 all gravel road bike review and actual weight

Given the Slate’s relatively slack head angle, all of that adds up to a somewhat long trail figure of 66mm (69mm size Small). The result is ultra stable high speed and straight line handling on even the loosest, roughest surfaces. Even carving a downhill corner on loose leaves and gravel didn’t induce a death grip. Very impressive. There’s a flip side to this, and I’ll get to that later.

The Lefty Oliver has just 30mm travel, but it’s surprisingly effective. Until I double checked the numbers, I was riding around thinking it had 60mm of cush under there. Chalk that up to the combo of suspension plus big tires. The travel is ultra smooth, too, which is characteristic of the Lefty. I’ve said it before and I’ll say it again, if you haven’t ridden one, don’t judge until you do. They’re impressive. And the mountain bike versions were recently upgraded.

Cannondale Slate Force CX1 all gravel road bike review and actual weight

It has a push button lockout with external rebound control and factory set compression damping. With such little travel, you’ll want to spend some time getting the air pressure just right as it’s easy to blow through it if set up too soft.  Once dialed, it’s really well damped and (in my experience) unlikely to bottom out. Or, if it does, they’ve got a serious bottom out bumper in there because I never heard or felt any hard knocks even when dropping off curbs or bombing into root gardens on some singletrack.

Cannondale Slate Force CX1 all gravel road bike review and actual weight

The newer Lefty’s used fixed mounting points for their crowns, which the head tubes are then sized specifically for. That eliminates any play and the need for a star nut or top cap to keep things tight. Unfortunately, it also means you’re limited to whatever stems they offer.

Cannondale Slate Force CX1 all gravel road bike review and actual weight

Both the chain- and seat stays are flattened, getting thin from the side and wide from the top:

Cannondale Slate Force CX1 all gravel road bike review and actual weight

Cannondale Slate Force CX1 all gravel road bike review and actual weight

Cannondale Slate Force CX1 all gravel road bike review and actual weight

Hollowgram Si cranks with their Spidering SL chainring make for a light but stiff combo. It comes with a 44-tooth ring paired with a 10-42 wide range cassette, which worked for a wide range of riding. They’re swappable should you want to run something different.

Cannondale Slate Force CX1 all gravel road bike review and actual weight

With the first ride, I fell in love with this bike. It’s not without its quirks, but by and large, this bike is an absolute blast to ride. The Lefty Oliver does an amazing job of taking bumps out of the equation. That makes for a glass smooth ride, but with enough feedback to keep you in control. Out back, the SAVE Plus stays might do something, but it’s hard to tell with the big tires soaking up vibrations and small bumps. The Force CX1 build tested here is the top model offered ($3,999) and comes with an alloy cockpit, so there’s some room for improvement by going to a 27.2 carbon post and handlebar. Upgrading only crossed my mind because the thin round bar shape wasn’t my favorite, not from any discomforting necessity.

What are the quirks? Two things: First, the water bottle boss on the downtube is set somewhat high. That makes it easy to reach during normal riding, but means it’s unusable with a frame bag installed for bike packing. I mentioned this to Washburn and he said it was the intent, to make it easy to reach when you’re just out messing around.

I had the Slate fully loaded for a planned bikepacking trip, but weather’s foiled my attempts so far. The above pic was taken on a test run to see how it handled with a full overnight out-and-back load (also needed to see how the ENO OneLink camping system set up). Even with 25+ pounds of stuff crammed into the (seat, frame, top tube, handlebar) bags, the bike was very stable. Which leads to the second quirk…

Cannondale Slate Force CX1 all gravel road bike review and actual weight

The head angle and fork offset combination is great for holding a straight line, but can be a bit finicky when trying to cut a corner. To be fair, the Slate is designed as an all road crusher, something for taking the long way because you can and making it ever so enjoyable. But when I took it up to the grocery store or cut through the shopping center between greenways, it showed its weakness. Slower, tighter turns -like, say, wiggling between cars- required more attention than normal. The long trail meant the wheel wanted to flop hard into a sharp turn, so I had to pay careful attention to the steering in such situations.

Get it out on the open road, though, and you can almost pay no attention to it (Look, a squirrel!) and it’ll just keep pointing you in the right direction. And that direction is fun. So much fun that I started using this bike for virtually any ride that didn’t involve testing another bike. I’d ride it any day of the week.


    • They’re a pain in the ass to service, and getting tools to do so can be a hassle if you don’t already work at a Cannondale dealer.

      • All forks are a PITA to service IMHO. So I just go to a Cannondale dealer, and save money by working on everything else myself.

  1. MSRP on this bike is $4k. For what’s essentially an aluminum hardtail.

    No rack eyelets, only 1 fork leg, so no front rack of any kind, this is a lousy adventure bike. Its heavy, so performance riders won’t be interested.

    Who is this bike for? If it cost 1K I could imagine getting one to knock around on. But 4k? N, please.

    • With that build I think I would be willing to spend a bit more, perhaps ~$2600 for one–I mean, it does have a suspension fork on it and weighs under 20lbs stock for an XL. However, I do agree $4K seems steep for what it is. Certainly would not lump it in with any sort of ‘adventure bike’ based on those same reasons you gave. Sweet gravel grinder? Sure.

        • That and weight doesn’t really matter much. Drop 2-3 pounds off a bike and you’re still only looking at an overall weight reduction of well under 2%. Don’t forget that weight isn’t just the bike – it’s also the rider, clothes, water bottles, etc. All that added together is what you have to muscle across the line. Doubt this? Go look at the average speeds for the 1982 and 2012 Tour de France. Less than 1mph difference even though bikes in 2012 were much lighter, stiffer, more aero, etc. and the riders went into the race with far fewer racing days in their legs.

          The “importance” of saving a few ounces on the weight of a bike is one of the biggest BS myths ever perpetuated by the bike business.

      • Ted King could have traded bikes with any rider on an appropriately sized frame at the start line of DK and still won. He won because he’s Ted King, had nothing to do with the Slate. In fact many believe the Slate held him back.

  2. How’d you get on with the limited stack height on the XL? Quite a lot of saddle-bar drop in the photo so I’m guessing quite aggressive geo in the XL format?

    • Woody, I was very comfortable on the bike, didn’t feel like it put me in a too-aggressive riding position. The bike was a previously used demo or test bike, so steerer was already cut, but perhaps it comes with a longer one? Or, at the least, a riser stem might be available. But, honestly, it felt fine for me. I’m 6’2″ and usually run my saddle at 31.9″ from center of BB to top of saddle as measured directly along the seat tube.

      • It does not come with a long steer tube. The one on my sales floor has about 20 mm of spacers.

      • Oh how I wanted this bike, but the stack and lack of steer tube height for spacers had me too bent over to be comfortable on longer distances, even when the LBS put on a 15 degree Lefty stem. If you look at the geometry table. the Large and XL stack are identical, so clearly there is an issue with making the steer tube of the Lefty taller, or maybe Cannondale got lazy to make one to properly fit an XL frame. I’m 6’2″ like Tyler, but guessing 20+ years his senior so need a more upright position on longer gravel rides. Otherwise its a pretty awesome bike.

    • I believe Cannondale’s original intent with the stock 650B x 42 mm rubber was to get an effective outside diameter (rollout) that matched a 700C x 23 mm tire. Says so in the review.

      Basically it’s “road plus” before it became hyped as such. I remember being worried about replacement tires on the Slate when it first launched, which was why I had my doubts.

      • Still doesn’t change the fact that the actual wheel size is smaller than 26×2.5. Just seems like they would want more rolling speed for a bike like this. I love small wheels. I still own a 26″ DH bike, but when it comes to rolling speed my 29’er trail bike kills it. For a bike like this 29 is what I would want.

        • Bearcol, go to a local Cannondale dealer and try it out. Rolling speed is excellent! Use the original spec Panaracer tires pumped to max pressure (~75psi). On flats you’ll keep up with normal road bike riders easily. On downhills you might even find yourself at an advantage, because of the flywheel effect. Only during uphills you might find the heavier weight of the wheels a bit of a disadvantage. If I had only one bike for all my sports riding, this might as well be it. Being lucky enough to having several, this is one of my favorites, for sure!

          • 75 psi on this bike feels like 700×23 at 110psi – you basically loose every bit of comfort and feel every pebble and ripple in the road. I have found anything over 50psi and you begin to loose the benefit of the tires and therefor the comfort. Even with the Save seat stays and Lefty, a lot of the comfort in this bike still comes from proper tire pressure.

      • Huh?? Replacement tires for this bike were on the market years before this bike hit the market! Compass, Grand Bois and Panaracer all have offered 650b x 42 road tires. I was riding the Grand Boise Hetre years before the Slate was even unveiled. The very idea of a fat, supple 650b road tire goes back for decades.

  3. As much as I like this Slate, any Cannondale with headshock and flat bars will do what the Slate will do for much less. A modified cannondale badboy with HS comes to mind.

    But hey, whatever it takes to get folks riding!

    • If you want to be a pessimistic Debby Downer about everything, sure. I mean, this is the internet, and that’s how folks roll. Personally, I’d bet bet I could have some fun on that bike.

      You? Probably not.

  4. He’s right, it’s the worst of both worlds….but in a good way. It’s all I can do to keep up with my local C group ride. And I’m all over the place on my local trails. But my favorite thing is that I can do both with one bike! It can be down right scary on trails. It’s so damn twitchy. But I’m much better handler now on trails and roads. On the road I can lean into turns much better and descend without fear. On trails, I can climb like a goat and accelerate like a banshee. Don’t get me wrong I’m not getting rid of my mtb bike or road bike. But I can say I ride this bike 70% of the time. Any group ride over 40mi and I take this one every time. The one thing I never hear mention is the bottom bracket height. I absolutely hit everything on the trail with my cranks! Even on the road, I can no longer pedal through a turn. I put Bruce Gordons on mine so big penalty on the road. My next move will be to get a road wheelset and run 28’s. BTW, Ted King won the 200mi Dirty Kanza gravel grinder on this bike.

      • Nope. DK will be won by the fittest, strongest racer who can endure the heat, wind, terrain and distance. Winning DK has very little to do with actual bike choice.

  5. I have about 4,010 miles on my Ultegra Slate. It is perfect for what I need – a gravel bike that can do paved rides too. I currently have two wheel sets for it – one with the stock slick and another with 41 Knards. I am building up a 700 c wheel set soon (Plenty of clearance for 28C tires) and selling my Domane 5.2 (I haven’t touched it since probably June). I don’t road race, and I ride mostly gravel anymore – given all the road deaths in my area. It is heavier than my Domane, but for my riding, it is well worth it. I have a ton of great gravel roads near me and can pull 80-100 mile gravel rides and only see a few cars. I could get another gravel bike for less money that is lighter, but after 50 miles on gravel, I really appreciate the Oliver. I am compiling bike packing gear and hope to do some self-supported gravel tours – campground to campground.

    • Doubt you’ll see much gain from going to a 700c cross wheelset. I’ve been riding 650bx42 tires for 8 years now and timed myself over enough courses to have found no real difference in speed from my older 700×28 tires. When your stock tires wear out you should upgrade to Compass Babyshoe Pass (42mm) or Switchback Hill (48mm) tires in the Extralight casing. Even nicer than the Pari Moto. The Switchback might also help with the clearance issue though not by much.

      Only thing that kept me from buying a Slate is the inability to mount proper, full length metal fenders. Too wet in my neck of the woods to live without those.

      • Chris: Good to know and thanks for the tire recommendations. I will check them out. I plan on using the 700c wheel set for paved road use. I spent a week in the Smokey Mountain with my Slate and stock Panaracer slicks. Though I appreciated the added grip, the tires don’t descend nearly as fast as a standard road tire. They also don’t roll out as fast either. A local raced his Slate all summer at a closed road course motor speedway (they have weekly training races). He liked the 700c wheel better for this too. I”ll stick with the 650b for cross for sure – other than finding the limits of the Knard tire, I thought it worked as well as any cross bike I’ve used.

  6. The more gravel and back road riding I do( getting to be one of my favorite biking things) the more I’m liking the Slate.
    I currently ride a Dedacchi Supercross, which I really like, but it’s more of a cyclocross race bike than a gravel, singletrack, backwoods bike.

    I wonder if Cannondale will ever make the Slate in carbon?

    • Doubt there’d be much difference between an alloy and carbon Slate. Weight savings would be insignificant and I doubt anyone could tell the difference in ride quality. Tires are a much bigger part of ride quality than frame material. 42mm tires eliminate a ridiculous amount of road buzz. Basically you’d just end up with a frame costing substantially more money.

    • Kind of a pointless question since it sort of depends on how the aluminum frame is made. Just because two frames are made from the same material doesn’t mean they’ll be even remotely similar in terms of ride quality.

    • I have not ridden a Lauf, but I can say I really like the damping on the Oliver. It works great on gravel and is passable on a tame mountain bike trail. I also use the lockout a lot . I’d be hesitant to give both of these up.

    • Yup. I’ve been riding my 650bx42 tires for 8 years now. Took a while to get used to riding such a fat tire on pavement but I’ve timed myself enough times over enough courses to show they’re no slower than the skinnier, harsher riding tires I used to ride.

      • Chris: I may need to re-think my reply to you earlier and my plan for 700c wheels. My impression has been that they roll slightly slower. Interesting…

        • Check out the most recent copy of Bicycle Quarterly. Jan, the publisher (and multi time Paris-Brest-Paris finisher!), tested tires of various widths and brands. Jan is trained as an engineer and has worked in academia (unlike pretty much every other bike journalist out there) so his tests tend to be A) set in the real world rather than on drums/rollers/labs and B) Rigorous. Here’s the take away:
          “Nothing in our results indicates that the wide tires in our test roll slower than the narrow ones”

          Here’s what’s more interesting: the 3 fastest tires were 32, 42 and 51mm while the 3 slowest were 38, 42 and 52mm. How can that be? Simple: the suppleness of the casing – not the weight or width – is what determines the speed of your tires.

          All else being equal a wider tire will actually roll faster, counter intuitive as that may seem. I’ll be the first to admit it’s really hard to get used to rolling down the road on 42mm tires and at times they might FEEL slower but feeling slow and actually being slow are too different things. I’ve been riding for over 30 years so I still remember when 18mm tires pumped to 120PSI felt fast. 😉

          I will say there is one downside to the extralight, supple casing tires from Compass, Pacenti and Grand Bois: they seem to be more susceptible to flats from sharp objects. When I first switched over to the extralight Compass tires I experienced more flats in the first 3 weeks than I’d had in the past 2 years. All were from tiny, sharp bits of stone (on streets, not trails). Adding some Stan’s sealant to my tubes ended the problem completely and I haven’t had a flat in a over a year.

    • You’d need to build with a lefty compatible front hub, but 700c wheels should fit fine. See Chris Maltby’s comment above, he is doing exactly this.

        • I did not measure above 28’s when I fitted a 29 lefty wheel to my Slate. I emptied the air spring and bottomed out the fork. I had plenty of space to fit 28s to probably (via eye balling) 33s (and would still have ample clearance on the fork). I did not mock up a 700c wheel in the back, but there looks to be plenty of space there. If I get a chance, I’ll do this and post back in the next week or two. Watching the thread for sure!

  7. I’ve been riding one of these for a year and I love it. It’s like a hardtail that’s actually fun to ride on the road. Ride it to the trailhead, rip up the fire roads, ride it home. It can handl some pretty technical singletrack if you’re willing to try.

    The stock tires are surprisingly capable in the dirt (especially if you drop them down to 35psi). I like it better with a set of Soma Cazadero tires — still pretty good on the road, but much better in the dirt even at 45psi. Your choice in tires will depend on what you want to do more.

    All the trails around here are super hilly so I swapped out the 44t chainring for a 38.

    • That will depend on your riding style, cadence, and parcours. I have the Ultegra bike with stock gearing. I really like this for my riding and geography. Aside from the price jump to CX1 build, sticking with a 2X11 and the more narrow gear jumps was a reason I selected the Ultegra Slate.

  8. Hi Tyler, very nice article on the Slate, thanks for the good read. I couldn’t agree more on the fun factor. I felt similar about steering of the bike until I changed the 110mm stem to a 90mm one. That did the job for me; it handles more direct on the road and, obviously, helps when going down technical single tracks off road. You won’t get the super nimble feel of a road bike, but thanks to the short chain stays and all you can still “carve” around corners very nicely.

  9. So Cannondale made a 90s MTB added a leftie and drop bars and called it the slate. Wake me up when an XL has toptube of 650cm rather than the XS 570cm of this bike…

  10. There is absolutely nothing you can do on this bike that you can’t do on a cx bike except get the wobbles in a parking lot more easily… for $4K…

  11. I’ve noticed the tip in quirk as well. It tends to flop in, then want to stand up. Curiously, it seemed to be more neutral with a different tire, in this case, a 41 Knard. In talking with another owner, we guessed that perhaps the super supple nature of the stock tire, as well as the low pressure and wide round profile makes for an usual contact patch as you lean the bike. They also seem to square off a bit fast, again making for that flop and drop turn in.

  12. I’ve had my Slate Ultegra for about a month now. I absolutely love it. I believe it is just as fast as my carbon Ultegra road bike, maybe faster up to 25 MPH, and much, much more stable, particularly in rough conditions. I don’t understand all of complaints about the price. I paid a little over $3000 for this Ultegra road bike with additional capabilities for gravel etc.. You can get a 105 version for less than $3000. What’s the big deal with the price?

COMMENT HERE: (For best results, log in through Wordpress or your social media account. Anonymous/fake email comments may be unapproved or deleted. ALL first-time commenter's posts are held for moderation. Check our Comment Policy for full details.)

This site uses Akismet to reduce spam. Learn how your comment data is processed.