Anatomy of a gravel race bike: my Dirty Kanza 200 rig
Originally posted on June 6, 2012 at 12:46 pmBy Josh Patterson,
One of the things I enjoy most about endurance gravel events is that they challenge participants to innovate. Gravel racing is a new and evolving niche. Companies are starting to take note, but for the most part it’s about improvisation and ingenuity.
I’ve toed the start line at Dirty Kanza five times, each year with a different bike. (Read Josh’s race recap here.) This year I think I’ve honed in on my ideal endurance gravel setup. I would not go so far as to say this is the perfect gravel race setup, but it was good enough for my mid-pack finish.
Salsa Cycles was kind enough to allow me to ride an aluminum prototype of their upcoming gravel race bike. (There was also a titanium version at this year’s race.) The yet-to-be-named bike takes design cues from Salsa’s existing cyclocross bike, the Chili Con Crosso. The new bike will be disc-specific and features many subtle changes, which are the result of “many, many miles and years of gravel racing experience,” said Mike Reimer, Salsa’s marketing manager.
The bike
Like the Chili Con Crosso, the new bike will have a Press-Fit 30 bottom bracket.
The seat and chainstays are flattened to allow for a small amount of vertical compliance.
The frame has mounts for three water bottles. I chose not to carry a bottle underneath the downtube—there are plenty of cowpies on the roads and I don’t enjoy drinking from a bottle encrusted in bovine excrement.
Wheels and tires
There is no doubt in my mind that there is exponentially more hand wringing about tire choice for gravel racing than all other disciplines of cycling combined. Tire choice will make or break your ride. Kansas gravel is generally composed of limestone and flint. Flint can be sharper than steel and will make short work of thin tires.
I opted to run Clement’s brand new X’Plor MSO 700x40mm tire. Gravel is an unpredictable and ever-changing surface; I find it hard to conceive of any tire that would allow one to “rail turns” on a gravel road. The X’Plor’s round shape, and consistently spaced, low-profile tread make for a tire that rolls fast and is extremely predictable. I ran 42psi in the front and 45psi in the rear.
I also opted to run them tubeless on a pair of Rolf Ralos 29er wheels. I’m sure Clement does not recommend this (it’s my job to try these things and occasionally make poor decisions so you don’t have to). They seated with a floor pump and held air with three scoops of NoTubes sealant. X’Plor MSO has a supple, 120tpi casing, my pair weigh approximately 430 grams, and carried me across miles of flint-strewn roads without any issues. I’m sold.
The Rolf Ralos wheelset rolls on White Industries hubs laced to what are essentially NoTubes Arch rims drilled for Rolf’s paired spokes. On my mountain bike I found this wheelset to flex more than I like, but for long gravel rides I appreciated the compliance.
Gearing
I ran a Shimano 105 group with an FSA Gossamer crankset. Nothing special, just solid, reliable stuff. For events like this I’ve found the wider range of a 50/34 t compact crankset is a better option than a traditional 48/38t, or 46/36t cyclocross gearing. Sometimes you need the little ring, other times, when you’ve got a tailwind on your side, it’s nice to be able to take full advantage of it with a 50t ring. I paired this with a 12-28 cassette and was never wanting for gears.
Frame Packs
Frame packs like this one made by Jandd and similar bags made by Revelate Designs are excellent options for carrying all the food and gear you need easy access to during your ride. I planned to carry a three-liter hydration bladder in my bag and forego a hydration pack, but when full, the pack rubbed against my knees. I ended up riding with a CamelBak Charge LR and it proved quite comfortable.
Saddle Bag
In my saddlebag I carried two tubes, a multi-tool, patch kit, tire boot, two links of chain, and two 16-gram CO2 cartridges.
Lighting
Front and rear lights are mandatory. Many riders who are confident in their ability to finish before sunset opt to run a very minimal headlight. I was not one of those riders, so I opted to run a Cygolite TridenX 750 OSP. If you think you’re going to be riding well into the night I also recommend running a helmet-mounted light to make map reading and navigation easier.
Frame Pump
Portland Design Works’ Magic Flute is my pump of choice.
Handlebar
I ran my a Salsa Bell Lap 2 handlebar about two centimeters higher than I normally would for road or ‘cross to ensure I had a position in the drops that would be comfortable for hours on end.
Questions?
Have a question about gravel tech? Feel free to ask below.