I will admit that I am not the most experienced gravel racer nor the most accomplished. But take what I have to offer in a spirit of sharing. I have found what works for me to race the Kanza in fair conditions & poor.
All three years I've raced the Dirty Kanza on my cyclocross race bike with a few modifications. The first year I used a Seven Cycles Mudhoney SLX. The past two years I rode a Trek Boone. The Seven Mudhoney was built as a cyclocross race bike, so it is steep & quick. It also has only one bottle cage. But it's titanium down tube & stays resist damage from rock throw. The Trek Boone is lighter. It also takes a frame bag easier due to internal cable routing. I put Shelter tape on the down tube & stays to help protect from rock throw damage. Both have been comfortable for me over the whole distance.
On both I used a SRAM Force drive train with 50x34 chain rings & a 11-27 cassette. I climb many steeper & longer hills where I live in New Hampshire than anything on the Kanza route. But the rollers around Kahola after 160 miles are still a grunt. Many folks choose wider range gears. I used ceramic pulleys & bottom bracket bearings to improve efficiency. How much difference those make I can not say, but any small advantage adds up over 200 miles.
Can you race the Kanza on a hard tail mountain bike? Of course you can, but it will likely be slower than a gravel or cyclocross bike. I'd encourage a rigid fork & narrow 29" tires if you do. Do you need a purpose built gravel bike? If you want a longer more stable bike, or need more compliance to be comfortable then maybe so. But I have not felt any draw backs on a good cyclocross race bike with a few adjustments.
The key to comfort on the bike comes down to position & contact. Your position on the bike will be dictated by the frame & fit. If you can not ride your bike for 6 hours without substantial neck, back or shoulder pain then you need to get a professional fit. A few tweaks to your position from stem length, saddle position, & bar height may make all the difference.
Contact points also make a substantial difference in comfort. The two primary points are hands on bars & your hiney on the seat. For handlebars I use the Salsa Bell Lap bars this year. I think that bar tape makes a bigger difference to comfort than the bar itself. For all three years I've used Bontrager Grippy Gel Tape with additional gel pads underneath the wrap. I like it because it is soft without losing grip control, and sticky without being slimy when wet.
Aero bars or not? The first year I put Cane Creek Speed Bars on my rig, I found that I used them very little. If you have a low angle stem & can get into a flat position on the bike then I think the aero bars are unneeded. Moreover bar extensions both add weight and take up valuable cockpit space. Aero position is important, but can be achieved as well by putting your hands inside the hoods & holding a flat position, like the ProTour racers do. Of course there are fast DK200 racers than me who swear by their aero bars.
Saddles are a whole other topic. I will tell what I like, the Selle Italia Flite, especially the older style with more curve in the middle. But everyone has a different shape & needs. That might be the reason there are more pages devoted to saddles in the Quality Bike Parts catalog than any other single component. My advice is to try lots of saddles until you find the shape, size, & firmness that works best for you. Then buy 4 of them so you never run out. Investing in high quality shorts & chamois cream will go a long way toward keeping your hiney happy
For the past two years I've used TRP 8.4 mini-V brakes. Again these are the same as my cyclocross race setup. I found them to be a good alternative to disc brakes. As long as your wheels are true mini-V brakes provide excellent stopping power. Rim brakes allow me to use lighter & slightly more aerodynamic wheels. The key to excellent stopping power is the pads. Every year I've used SwissStop BXP pads. On mini-V brakes those pads give me almost disc brake quality stopping power.
What about disc brakes? Certainly if you are a heavier rider disc brakes are going to work better. When you are fatigued hydraulic disc's will be easier to use. Disc brakes also allow for your rims to be out of true without causing rub. But disc brakes are heavier & typically require heavier wheels. In wet conditions disc brake pads can wear down very quickly. I have seen disc pads wear to the point of uselessness in a wet/sandy 2 hour mountain bike race. Know how to change a set of pads yourself before starting the Kanza.
Nothing is more important than staying hydrated at the Kanza. Most years the sun is bright, there is little shade, & the wind will dry you out. Getting even slightly de-hydrated will slow or stop you. Some racers rig 4 bottle cages to their set up. But bottles can shoot out of cages on lumpy roads, frequently from cages mounted behind the saddle. Others wear a Camelbak which was fine this year with cool temps. I do not like wearing a Camelbak in races, especially on warm days.
My solution is a frame bag with a 70oz. hydration bladder and 2 water bottles. Combined that gives me 125oz. of fluid at maximum. I wrap the hose around my feed bag and clip it to my stem for ready access. If you are a tall rider you may require a long hose & creative ways to keep it coiled. I drink from my set up without changing my riding position or fumbling to clip the nozzle onto the stem.
Bags & Fixings
Beyond my hydration frame bag, I have mounted a bento box on the top tube & a seat pack with my tools/ repair supplies. Each year I have used a different pack for each of these. I have varied the size & style of each until I found what is just right this year. The competing desires in the Kanza are bags large enough to carry everything you might need, but small enough that you don't weigh yourself down. It is a hard equation to solve.
Saddle bags come in a wide variety of shapes, sizes & features. Again I've used 3 different sizes, too large, too small, & just right. My just right bag is a Jandd mini mountain wedge. It is just large enough for 3 tubes rolled tight, a couple of C02 cartridges, and tools. The feature I like best about it is an external zippered pocket that holds my multi-tool.
|Too big, too small, & just right|
The more important decision is what fixings to bring in your saddle bag. Again, light is fast, but too little can mean an early end to your race. Here is what I brought: 3 inner tubes, patch kit, Park tire boot, 2-3 C02 cartridges, inflator head, Pedro's tire lever, Lezyne multi-tool, derailleur hanger, & chain link. I also carry a Lezyne Pressure Drive mini-pump mounted to my frame. I have not needed more than the tubes & air so far, but I know plenty others who have needed more.
|Yes, I did fit it all in the saddle bag|
Lights & Electronics
Never assume you will finish the Dirty Kanza 200 in the daylight, ever. The weather may be fair, you might be as fit as can be, but anyone can find misfortune on this route. A snapped chain or wrong turn can change a 12 hour podium ride into a 16+ hour slow roll. Always plan for riding the last 50 miles in the dark so bring lights up to the task. The first year I rode the Kanza I thought I would only need lights for an hour or so if at all. What I brought was far too weak for 3 hours of gravel roads & route finding while severely fatigued. This year I brought a Cygolite Expilion 680 for the bars and a Niterider Lightning Bug 120 on my helmet. I chose both because they are light weight, bright, & give 2-3 hours of run time at high power, more at medium. The NR Lightning Bug I mounted to my helmet by strapping it through the vent cross bar. At 40g it is as light as any other helmet or headband light of the same brightness.
No topic gets more attention on Dirty Kanza preparation than tires. The Kanza is notorious for shredding tires with sharp flint gravel and hard cattle guard edges. While many tires are good for the Kanza the two that I like best are the Clement MSO and the Bontrager CX0. I ran the Clement MSO 32mm my second year. It is a tough, light, & fast tire. It may be the most popular tire for the Kanza in the 40mm size. I do not like the small side knobs of the MSO. I find that cornering on loose gravel takes caution on that tire. While secure cornering is only a factor in the first 40 miles of the race, it could be a critical factor. The Bontrager CX0 has a more prominent side knob & better traction overall. It is a heavier tire & does not have the kevlar reinforcement of the MSO. I do like the more flexible casing of the Bontrager tire for both traction & comfort. I find that the soft tread of the CXO wears down in the center to provide a relative fast rolling tire after 50-100 miles. On a hard pack day I'd chose the MSO but in wet or loose conditions I'd certainly use the Bontrager CX0 again.
|bontrager CX0 after a few miles|
The other tire choice is tubes or tubeless. I always run tubeless in mountain bike races. I have always run tubes at the Kanza & will continue to do so. Why? The Kanza again is notorious for destroying tires. Most years for most people it is not a question of if you'll need to fix a flat but when & how many. Tubeless only works better until one is forced to put in a tube. Once a tire is damaged enough that sealant no longer works, a tubeless tire set up becomes more difficult to deal with. I've read reports from several DK200 racers whose tubeless systems gave them those all sorts of problems once sealant fails. The weight savings & lower tire pressure advantages of tubeless set ups can be achieved by using latex tubes. I might even put some sealant into latex tubes in the future to further the benefits. While I may experiment with tubeless tires for dirt road events, I'd still lean toward latex tubes for the Kanza.
Understand that these are my gear preferences only. Dozens of other racers have different equally successful set ups for the Dirty Kanza. I hope you find some my hard earned experience useful in setting up your own ride across the prairie & through the Flint Hills.