I often get asked what the right bike setup is for these events, and truthfully - I discuss these types of things with others as well as spend too much time thinking about them on a semi-daily basis. I offer some of my thoughts here, but that's all they are - not correct or incorrect. With that in mind, the type of bicycle (cyclocross vs. MTB) is not a critical decision ATMO. Cyclocross bikes have the potential to be lighter for going uphill and, depending on the surface, faster on the road. MTB's can be faster on the downhill sections with the ability to run larger volume tires for more control.
The list goes on and on: MTB's with disc brakes, cyclocross bikes with disc brakes, suspension, aerodynamics, body position, etc. Let's just assume that the strongest, fittest, and most skilled rider with the least amount of punctures/mechanicals sustained to their chosen race rig on the day is probably going to win, regardless of the bike everyone else is using. Notice I didn't say anything about road bikes in the previous paragraph. They aren't going to get you there faster, but that doesn't mean they won't get you to the finish.
|Lots of cyclocross bikes (Fred Jordan Photo)|
That said - there are few critical parts of any bicycle that warrant special attention if it is going to be raced in an ultracross event with the goal of finishing as quickly as possible: Tires, Brakes, and Gear Ratios. This assumes that your bike is maintained - clean, lubricated, properly adjusted, and shifting flawlessly and running quietly for race day. No reason to tempt a DNF.
There are really only 3 choices for tire systems - standard clincher/tube, tubeless clincher, and tubular. All will get you to the finish. All will take sealant. All will let you run a range of tire pressures.
- Consider a light talc on the tube/tire interface, latex tubes, and more pressure with standard clincher tires to help avoid pinch flats.
- Tubeless systems can allow for lower tire pressures, but make sure to try a range of pressures. Always make sure there is enough sealant in the tire and it is seated/sealed properly. An extra wrap of tape or two on the inner rim surface can sometimes create a more secure bead. Barring a large puncture, this system works very well at keeping air in the tires and you on your bike.
- Tubular tires have the same advantages as tubeless systems, but they also won't "burp", allowing for lower pressures. They can also be lighter in weight. The disadvantage with a tubular is if you flat, you may have to install a spare tubular tire if sealant doesn't work. You'll have to run more pressure and/or ride less aggressively with the spare as well.
- 34c is about the lower size limit for utlracross events, ranging up to 1.8/1.9" tires with appropriate tread for bikes that can fit them.
Tire choice is probably the most important decision I make leading up to an ultracross race. It depends on the terrain and road/trail surface. I rode clinchers my first time at Iron Cross, and 700x34 tubeless tires this past year. At Southern Cross I ran 700x34 tubulars because in February I still had them mounted up from cyclocross season. I probably would have used them for the HillyBilly, but my tubular wheels are in road mode so I went with the same tubeless setup from Iron Cross with 5 more psi. I'm a bit of a tire pressure geek, and I'll run anything from 40 to 65 psi for ultracross.
|A road bike on this? (Fred Jordan Photo)|
Brakes are also limited to 3 choices - cantilever, V, and disc. Again, all will get you to the finish. There isn't much to talk about here, but in terms of stopping-power:lever-pressure ratio disc brakes trump all, and V-brakes are better than cantilevers. In my opinion, for ultracross racing discs will generally make you faster because you can shred more on the downhills, they are not affected by a rim out of true, and they work well in all conditions. Disc brakes also allow for more tire clearance in the frame design. Rim brakes can be lighter and do stay a bit more true to the spirit of the event (or at least they used to). I use cantilever brakes, but they work better for cyclocross than they do ultracross. A more aggressive pad compound can make them more efficient. Mini V-brakes designed to work with road levers make a good choice to increase performance for non-disc compatible bikes. I plan to try them in the future.
Gear ratios or gearing can really make or break an ultracross race. I'll avoid the singlespeed discussion here for the most part. Anything in the 60-70 gear inches range would probably work well, depending on the terrain. The most critical ratio for the geared bikes is of course the low side. A 34x32 will probably be sufficient for most of the climbs encountered in the hillier ultracross races, although I haven't done Three Peaks USA with its 10,000' of climbing in 50 miles! I've run as high as a 39x25, but have used a 38x26 in the past three races. Every time I wish for a 38x28 and after HillyBilly this year I vowed to finally get a 28t.
So there you have it - thoughts from a hack racer who likes ultracross and cyclocross in general. They can be great fun, and of course they can be miserable at times. But every one is an experience you'll be sure not to forget, with lots of friendly like-minded folks. So come on out to Three Peaks or Iron Cross X and see what it's all about!