Tire & Wheel Considerations

We’ve seen a lot of questions and swirl around what tires and wheel size to run for the Coast to Coast Gravel Grinder. This isn’t a unique topic of conversation for an event of this magnitude and there are many opinions out there. My goal with this blog post is to put down my opinions on what I’ve personally had success with over the years and let you, the reader, come to your own conclusion. Flash back to just 5 years ago and this conversation would be much simpler due to the fact that 700c was the primary wheel size for most drop bar bikes and the tire selection was limited. Flash back even further to 10 years ago when even cyclocross bikes weren’t really popular and folks were riding their 26 or 29” tire mountain bikes with 2” tires. My point is, people have been doing these races, and having a great time at them, before any of these current products were really available so don’t stress yourself out too much over running a 43c tire vs a 45c tire. With that being said, I’ll dive deeper into some good options based on what’s currently available.

The Wheel
A lot of folks are asking questions about tires, but I think it’s fair to start by talking about the wheels you’ll be using. Worn out bearings and sticky freehubs can rob you of all the gains you’d get from the perfect tire setup. If you’ve been slogging around in the muck for some time, take them into your local bike shop and have a mechanic get them sorted out for you. If you’re considering new wheels, might I suggest a deeper rim profile such as the Velocity Aileron which also has a wider cross section. Available in both 700c and 650 sizes they’ve got you covered. The stiffness and durability of a good wheel is critical to any long distance gravel race. You don’t want to be 100 miles into an event and have a spoke break or freehub blow apart. A good aluminum rim gives you less to worry about in the event of a mishap as well, and the saying goes “don’t race it if you can’t replace it”.

Now that we’ve got the wheels sorted lets look at what’s going on inside the rim where the tire mounts. As I recommend going tubeless you should be sure if you’re already setup tubeless that the rim strip or tape is in good condition. This is often overlooked and old tape can begin to leak air or even fail if it isn’t thick enough or the adhesive has dried up. If you’re not already tubeless I would suggest it as if you do have a puncture that doesn’t seal then the fix is to simple put a tube in it as you would have to even if you weren’t tubeless. I’ll get more into detail on the tubeless setup later though. If you really don’t want to go tubeless then I still suggest checking your rim strip and replacing it if it is worn. Also, if you’re running tubes, a good insurance policy is to use a product like the Mr Tuffy tire liner to help prevent flats from puncture.

Tubeless Setup
Ok, so your wheels are sorted and you are currently, or planning on, running tubeless tires. Tubeless setups work great and are commonplace now, but only work great if they’re properly maintained. The sealant used in tubeless setups dries out over time and thus should be checked and replaced every so often. Depending on what brand of sealant you’re using determines how often you’ll need to replace it. As an insurance policy I always “top up” my sealant a few weeks prior to a big race to be sure there’s plenty in there. If it’s been a while then I suggest removing the tire, inspecting the tape/rim strip as mentioned above and also making sure the valve isn’t clogged or mucked up. It might sound like a lot of work but with all that training you’ve done for this 210 mile gravel race it’d be a shame to have any preventable issues.

Dried-Up Stans

Manufacturers such as Stans NoTubes and Orange Seal are the leading suppliers of tubeless sealant. I’ve used both with good results. Orange seal has an endurance formula that is supposed to last longer without drying out. Stans NoTubes has a race day formula that is supposed to plug larger holes more quickly but needs to be replaced sooner. Really, the important thing is to make sure there’s fresh sealant in your tires regardless of your preference. And just because you hear liquid sloshing around in there doesn’t mean that it’s still good. Tubeless sealant particles will adhere to the tire over time leaving only liquid inside which won’t plug that pesky nail hole.

Valve Core

Last but not least, the lowly tubeless valve. These too should be inspected and replaced over time. The tubeless sealant can gum them up, the presta valve stems can get bent which can cause them to leak and the little rubber seals inside can go bad. Valves are pretty cheap and worth replacing every so often. If you, or you local bike shop, go through all these steps a few weeks before race day it will give you plenty of time to be sure everything is in working order.

There’s so many options out there it can be confusing. My rule of thumb is to err on the wide side of what I think a course will need to be sure I’m not floundering around in sand or mud, especially those of you who will be traveling in the “wake” of a few hundred bikers in front of you who have chewed up the roads. A common misconception is that wider is slower, but that’s not really the case. There’s many factors at play in what makes a tire ”fast” and width is just one of them. The construction of the tire is often overlooked, but many manufacturers offer several styles of the same tire. A 60 tpi casing can react much differently than a 120 tpi casing. A tire that’s labeled “durable” may feel much more stiff or slow than one labeled “race” or “ultralight”. I’m not going to go into depth on the specifics of tire construction or the implications. Instead, I’m going to focus on what tires should be good for the Coast to Coast Gravel Grinder. First off, there is sand on the course. You can certainly run a 700x32c tire, and it will feel fast on the east side of the state, but I guarantee you’ll have to walk some spots on the west side. I recommend choosing a tire in the 700×43 or 45c range such as the Teravail Cannonball or the classic WTB Nano. The added width will be welcome in the sand and comfortable for a long day in the saddle. If you’re running 650b wheels I would suggest a 42 to 47c tire such as the WTB Byway. Since there’s no extremely steep climbs or loose terrain where traction is an issue I don’t think an aggressive tread pattern is necessary.

If you’re rocking your mountain bike then I recommend running a tire in the 2” range such as the Schwalbe Thunder Burt. I’ve raced the Thunder Burt on gravel before and it’s faster than some of the gravel specific tires out there. Teravail Sparwood and Bontrager XR0 are other good options. The casing and construction of a mountain bike tire will be even more important than a narrower gravel tire due to the fact that there’s more tire in contact with the road. And higher air pressure isn’t always your friend with mountain bike tires. Running a firm yet supple tire is key to rolling smooth and fast.

For fatbikes I’d say stick with something close to 4” as anything wider certainly isn’t necessary. Choose a tread pattern that rolls quick like the 45NRTH Vanhelga or Schwalbe Jumbo Jim. I know what you fatbikers are thinking, the Vanhelga has some pretty serious tread on it right? Well, as it turns out, the Vanhelga is actually faster than many of its sparsely treaded couterparts because there is less tire casing in contact with the ground. Combine that with the rubber compound and tire construction and it’s a very quick tire. This goes to prove again that you can’t simply judge a tire by its looks.

Air Pressure Recommendation

One of the things I quite frequently see is folks obsessing over their tire choice down to the TPI, mm of width, rubber compound and protection. I’ll also see these same folks running way too much or too little air pressure in the same tires they obsessed over. There’s no magical air pressure number to run for all gravel tires. Each tire has its own unique character and thus requires a certain air pressure. Then there’s the rider and bike weight which further affects what pressure should be run. Tire manufacturers print a recommended range on the casing but it’s a pretty wide window. Running really firm tires can often do more harm that good as the tire begins to bounce and ride very harshly. Obviously too low of air pressure will make the tire feel “dead” and affect acceleration, cornering and climbing. Not to mention low pressure risks pinch flatting. I recommend starting a bit firmer than what you think is necessary and then backing down a few psi at a time during a long ride to see where the sweet spot is for you. You can get a good tire gauge for tens of dollars and carry it along with you on rides. This way, when you find that perfect pressure, you can record it and setup your tires to that very pressure every time you hit the road. It’s one less thing to worry about on race day as well.

At the end of the day, picking a good quality tire and having your local bike shop inspect and set them up will go a long ways. Make time to get out on the course if you can, or ride some similar terrain near your home. Experiment with different tire pressures to find out what feels best to you.

If you really want to nerd out further, here’s a short list of some useful websites and manufacturer links:

https://silca.cc/pages/sppc-form (tire pressure calculator)