Gravel
The Niner MCR 9 RDO is a full-suspension gravel...

The Grind: The right amount of cush for gravel riding and racing

We all agree that a bit of flex is good in a gravel bike. But how much?

Riding a hyper-stiff aero bike on gravel is silly and jarring, yet schlepping a fat-tire, full-suspension beast is overkill. So where is the middle ground? What is the ideal amount of compliance for a gravel bike? As with most things in the category, the answers are all over the place, and the jury is still out. And that’s a good thing.

From the very first legit production gravel bike — the Salsa Warbird — a bit of vibration-damping compliance was a key design goal. Now we have full-suspension gravel with the Niner MCR 9 RDO. And of course we have  a whole lot in between, with frames flexing around pivots like Trek’s IsoSpeed system on its Checkpoint to the leaf-suspension Lauf fork to suspended cockpits like on Specialized’s Diverge to aftermarket suspension parts like Redshift’s suspension stem and seastpost.

What is the ideal set-up? As with anything in cycling, the answer depends on who you are, where you live and how you like to ride.

I checked in with Joe Meiser, the guy behind the original Warbird, and also with Niner’s Zack Vestal, for their perspectives. But first, let me give you mine.

From pivots to springs to air forks to… titanium

For all-around gravel riding and racing, a little bit of comfort goes a long way. Saving a gram or two makes zero sense if the result is unnecessary pain or fatigue. I did Dirty Kanza on a Trek Checkpoint, and was so grateful for the bit of flex in the seatmast. For that race, I also used a Bontrager IsoCore bar with gel pads and a Specialized Elaston Power. I was happy with all the comfort touches.

Last year I was working for the Colorado sportive company Roll Massif. I rode a Specialized Diverge for most of the year, including at our Wild Horse Gravel and Crooked Gravel sportives, but also for the 12-hour Sunrise to Sunset mountain bike race. Yes, the giraffe-in-a-turleneck spring suspension looks a bit goofy. And yes, it does absorb a lot of the vibrations that would otherwise end up end your hands, arms and shoulders.

Specialized Diverge
My Specialized Diverge, on the Crooked Gravel course outside of Winter Park, Colorado. Note the super-pro stick-in-chain prop. Oops.

The Diverge’s seatpost has twice the flex of a normal carbon seatpost, which can feel a bit odd, like your rear tire is going soft. But it does take the edge off of bumps. Both the front spring and the seatpost work best when seated, as they suspend the rider, not the bike. My instinct when riding with a clear line of sight is to stand up over rough patches. On the Diverge, that removes the suspension from the equation (save the tires, of course). But for gravel racing, when you are often blind bombing down the road in a pack, susceptible to whatever may pop up before you can really adjust, suspension while in the saddle is helpful.

Titanium has rekindled itself for me as an excellent material for gravel. I had left it behind with Lotto-Adecco in the early 2000s, as carbon surpassed it as the wonder material, lighter and stiffer and malleable into all manner of shapes. And yet, titanium’s calm, damping qualities remain, as does the metal’s strength against kicked-up rocks and crashes. I enjoyed Litespeed’s Cherohala recently, and all but fell in love with Mosaic’s GT-1. Sure, there is no outright mechanical suspension at play here, just damping and controlled flex.

Yesterday I took the Niner MCR 9 RDO out on Panache Rowdy Ride, a Tuesday gravel rally out of the Panache Cyclewear shop. Yes, it’s heavier than a bike without full-on suspension. And no, it probably won’t be raced by folks who spend time staring at TrainingPeaks or Today’s Plan. But you know what? It’s a lot of fun to ride.

Last week VeloNews tech editor Dan Cavallari and I spent three days riding the Chamois Hagar, a wildly slack gravel bike from the Pacific Northwest mountain bike company Evil. You know what their suspension solution for gravel is? Big, fat (50mm) tires.

For the upcoming Old Man Winter Rally here in Colorado, I’m going to pin on a number with the Giant Revolt Advanced. No outright suspension there, but the bike does have engineered damping in the seatpost, fork and handlebar. Stay tuned for a review.

The thoughts behind the original gravel bike

Salsa product manager Joe Meiser can trace the Warbird, launched in 2013, back to the 2009 Trans Iowa, an ultra-distance gravel race he won on a prototype frame built with a low bottom bracket, generous tire clearance and, critically, compliance, achieved with thin, bowed-out seatstays that flex under load.

Salsa Warbird Carbon
The Salsa Warbird Carbon features bowed-out seatstays that flex to take the edge off the onslaught of high-frequency bumps.

So what’s the right amount of compliance? And how do you quantify that?

“‘Right’ is really dependent on the rider and course,” Mesier said. “We really see opportunity for damping like our Class 5 [Vibration Reduction System] for the majority of riders. We quantify it by taking measurements of vibration and events at the axle versus at the saddle or bars. We asked the question when developing Class 5 VRS: ‘To what extent can we isolate the rider from what is happening at the road to minimize fatigue without making the bicycle unnecessarily heavy or more complex?’”

Relatedly, here at VeloNews we did similar vibration measurements on various endurance bikes, also measuring at the handlebars and axles, back in 2011. While there were measurable differences between the bikes, the largest differences by far were achieved by simply putting on larger tires (at the time, 25mm was a “wide” tire) and reducing pressure. 

And, of course, Meiser and the team at Salsa built the Warbird with plenty of room for tires, now up to 45mm.

And the thoughts behind the full-suspension Niner gravel bike

Niner showed off a plastic prototype at Sea Otter in 2018 of a full-suspension gravel bike. The cycling world freaked out. Last year, Niner had an actual bike, built with a 50mm Fox fork and a 50mm shock. This is too far. This is just a lousy mountain bike. Et cetera, et cetera, went the comments.

Niner Bikes marketing manager Zack Vestal said the bike came about after staff at Niner got into doing longer gravel rides out of their Fort Collins, Colorado office, and started asking why there were no suspended gravel bikes. 

“The idea behind suspending the gravel bikes is about rider comfort for the sake of less fatigue, more fun on the bike, and a better experience riding on dirt,” Vestal said. “But it’s also really about control. A race like Crusher in the Tushar, it has some really high-speed sections but is a little sketchy on a rigid gravel bike. By adding suspension, you’re keeping the tires in contact with the ground, and giving the rider more control. That’s just a fundamental of suspension, whether we’re talking cars, motorcycles or bikes.”

Vestal disputes the idea that mountain-bike suspension and gravel suspension are the same thing, because of what the riders is doing. “In mountain biking, a significant portion of the experience is about the downhill; you’re coasting, crank arms horizontal, weight evenly distributed front to back. Gravel is about covering distance and pedaling. The suspension needs are different.”

Niner is not calling the MCR 9 RDO a race bike. “That being said, it wouldn’t surprise me if people took it racing,” Vestal said. “Look at Grinduro, or Crusher in the Tushar.”

Choices are good

One of the many fun things about gravel right now is how wide open it is: the event formats, the bike designs, the whole scene. A rider recently asked me if running a 45mm front and 40mm “would be frowned upon.” I would argue, that if you are frowning about someone else’s tires, you’re doing it wrong. Experiment and see what works best for you.

“That is what is really important here, options for the consumer,” Salsa’s Mesier said. “We’ve gone from Salsa creating the first gravel bike and being told it was ‘the answer to a question that nobody asked,’ to this being the category of excitement in road in just a few short years. Riders have so many great options in bikes and equipment with each brand looking at it through their lens. It is awesome that we have components like wheels, tires, forks, bars, stems, and posts where a rider can enter the category, upgrade, or fine-tune their experience.”

To that I would just add, don’t be afraid of trying something new, even if it is more comfortable. Roadies have long been conditioned that comfortable equals slow equals bad. For gravel racing, that is not necessarily the case.

Follow Ben on Strava.