Does the added weight and complexity of rear suspension add or detract from the gravel experience? Ben has been finding out with Cannondale’s Topstone Carbon 2.
Cannondale have never been shy about doing things their own way, and the Topstone Carbon 2 is no exception. Ben has been clocking up the miles this summer to see if rear suspension is game changing or gimmicky on a gravel bike.
Photos by Dave Price.
Key features:
- BallisTec Full Carbon fork
- Shimano GRX 2×11 Drivetrain
- Shimano GRX brakes
- HollowGram 22 Superlight Hi-Impact Carbon Wheelset
- £4000.00 RRP
- Cannondale.com
Let’s just cut to the chase. The Topstone Carbon 2 is a ‘hard nose,’ which is a term I just made up, but is basically the opposite of a hard tail. It features a carbon rigid fork and a rear suspension system that gives up to 30mm of travel. The Kingpin suspension system does not work in the way that your normal MTB system works as it is not really active when you are stood up on the pedals. Instead it comes to life when your bum is on the saddle, improving comfort and allowing you to stay on the saddle over rougher terrain where other bikes have you hovering or getting bounced off the saddle.
With only a single, small thru-axle pivot bearing mid-way down the seat tube, the system relies on flex zones in the chain stays, seat tube and top tube to achieve up to 30mm of travel. If you stand on the pedals and bounce up and down, you will be left scratching your head as there is basically no perceptible movement. You wonder if it is working. Instead, with your weight on the saddle it offers you 30mm of subtle compliance and grip. It is basically the opposite of a lot of MTB suspension platforms that you would lock out when seated, then open up when standing for descents. It really is a strange setup, designed for a very specific task, which is seated pedalling over gravel type surfaces.
The rest of the frame looks a lot more conventional with a large downtube and head tube area mating smoothly into the straight bladed forks. There are plenty of bosses for luggage carrying duties and bike packing as well as two water bottles. The lines are kept tidy with full internal routing and the look is finished with a deep gloss paint job called, ‘Tinted Saber’ that wore very well despite plenty of miles.
The Shimano GRX groupset was a double chainset affair so I had to remember how to work a front derailleur again. With an 11-34 tooth, 11 speed cassette and 46/30 chain rings there is a wide range of gears available that should sit well with roadies and mountain bikers alike. I can see that with a full bike packing load on board and riding off road, you might want a bigger cassette, but for most riders the spec is bang on.
Brakes were also Shimano GRX with 160mm discs. These brakes really surprised me with their easy power, especially when down on the drops. In fact I don’t think there would be much point getting more powerful brakes on a gravel type bike as you would simply overwhelm the tyres and skid the whole time. It was certainly easy to lock up the rear wheel, especially on greasy roads. The only downside of the GRX brakes was after long road descents where they heat up and the piston would stick a little, not returning fully into the calliper, rubbing the disc for a while until it settled back down.
The rest of the finishing kit is pretty much all from Cannondale, including their alloy gravel bar and a very fancy HollowGram SAVE carbon seat post. Cannondale also spec their own HollowGram wheels with 22mm internal width carbon rims that are tubeless ready.
Up Hills
The Cannondale is a sprightly and tight climber thanks to its stiff frame and carbon wheel set. Despite the Kingpin suspension, there is no hint of lost power when you put down some watts, either standing or sitting and it feels every bit as direct as any other performance focused gravel bike I have ridden. Unlike some feather weight road bikes, you don’t feel the frame load up and twist under a big sprint and the whole thing feels reassuringly solid underneath you.
On the road you would never know you had any fancy flex pivots or suspension, except that you know it is a comfy bike to put in some miles on. The WTB Riddler tyres in 700c x 37mm size do a great job of rolling fast and still having a bit of bite on the gravel. I also liked the subdued graphics on the tyres, giving a stealthy look with the matte carbon rims. You can add a bit more cushioning by running up to 40mm tyres or you can swap out for a 27.5” wheel with up to 48mm rubber for serious off road comfort and capability.
When you turn off the road and hit the forest tracks of my local hills, the Kingpin suspension starts to make sense. Often on a rough fire road it can be hard to hold a decent cadence on a stiff bike as you get bounced around on the saddle, disrupting your rhythm. Not so on the Topstone Carbon. Whilst you can not really feel anything happening beneath you, something definitely is going on as you find you can stay planted on the saddle grinding a gear out. This really helps you to blast out some mileage, reducing fatigue and looking after your gooch which can easily get tenderised on long gravel rides.
The drawback of the Kingpin approach is that it is not really active when you are standing to attack a climb. This is fine on most tracks where traction is not an issue, but on steeper and more tech sections it does little to assist you in finding grip. Having said that, this is pretty rare, at least where I ride gravel.
As mentioned earlier, it has been ages since I rode a double chain ring setup and it took some time to re-learn my skills in order to keep a good chain line. I can see why brands spec it for gravel bikes, but as a simple mountain biker I would prefer a wider range cassette and single ring. This would also make the bike a lot quieter as the chain really rattles on the front mech which I found pretty annoying whenever I left tarmac.
Down Hills
I have a pretty big, fast road descent near me that I like to bomb down and it quickly gives me a good idea of how stable a gravel or road bike is as you tip into the first series of turns. I found the Topstone easy to commit to the turns, thanks in part to the 71 degree head angle that allowed me to get my weight over the front without it feeling twitchy and nervous. The tuck position on the drops was at the racy end of the spectrum for me, even with all the spacers under the stem, but to a road rider it would probably seem quite comfortable.
Off road I don’t tend to tackle much tech on the gravel bike and prefer to stick to fire roads and chilled single track where the glossy brown ‘Dale felt right at home. There was no annoying overlap of my front foot and front tyre and I felt nicely centred between the wheels which really lets you tip into the turns.
The WTB Riddler tyres do a surprisingly good job of grabbing on to the trails. I found they break away predictably giving you confidence for plenty of skids and silliness if that is your thing. The main limitation to off-roading is the fixed seat post which takes some time to adjust to, coming from my dropper equipped MTB. Having said that, I think I prefer to keep the gravel bike simple and more pure, so although I have to work on my seat up technique, I quite like the challenge.
What do we think?
The Topstone Carbon 2 is a very versatile bike that both impressed and surprised me. To me, the Kingpin suspension should be called, ‘Kingpin Compliance’ as that is more how it feels, and that is no bad thing. For winter training and mile munching this bike is well worth a look.
We Love:
- Innovative and unique Cannondale design.
- Kingpin saves your gooch
Could Do Better:
- It is brown
