Why Don't Gravel Riders Mix Tire Tread Patterns, Front & Back?

In gravel racing, tires are number one. Nowhere is tire choice more important than the biggest gravel race of them all: Unbound Gravel. 

Last year’s men's winner, Ivar Slik, used the Schwalbe G-One RS, a semi-slick with very minimal tread and super low rolling resistance. Keegan Swenson, last year’s men's runner-up, ran Maxxis Re-Fuse tires which are pretty much completely slick. Women's champ, Sofia Gómez Villafañe ran the Specialized Pathfinder Pro, which also has a slick center.

I always try to remind myself: it's a bad idea to copy the pros. They have fitness and handling skills that we mortals just don't have. Average riders like me are probably better off riding a knobbier tire that roll a bit slower but provide extra confidence on corners and descents. But this got me thinking, can you have the best of both worlds by mixing tread patterns? Mountain bikers have been doing this for years. So why don’t (most) gravel bikers do the same?

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Why Mix Tire Tread Patterns?

The right tires could ease your suffering. Photo: Ian Matteson

The premise is simple:

• The rear tire has the greatest effect on rolling resistance 
• The front tire has the greatest effect on cornering and braking traction

When you pedal, your weight shifts rearward. This puts more weight on the rear tire. It’s why rear tires generally wear out before front tires, and why rolling resistance matters the most in the rear. 

The opposite happens when braking. Your weight shifts forward and puts more weight on the front tire. This is why the majority of your braking power comes from the front brake. The front wheel is also where traction matters most as you lean into a corner. When riders slide out and crash, it’s usually because the front tire loses traction. 

If that’s the case, then why not maximize the performance of each end of your bike? 

Put a tire with lower rolling resistance (this usually means smoother tread) on the rear so you save precious watts and go faster. Pair that with a knobbier, grippier tire (which generally rolls slower) on the front for more cornering and braking traction. I’ve been doing this on my mountain bike for years. It’s a pretty common tactic among mountain bikers to achieve the best compromise between speed and control. 

Many don't seem to bother with mixing tire treads. The men on the Unbound podium certainly didn't. Photo: Lifetime

If you look at bike checks for pros competing in Unbound Gravel (as I’ve been doing obsessively for the last week) you’ll notice that all the pros tend to run the same tread pattern front and rear. They're pretty evenly split with some favoring fast-rolling, low-profile treads front and rear, and others choosing knobbier tires front and rear. 

In fact, mixing treads doesn’t seem like a common practice in gravel at all. Nearly every manufacturer specs their gravel bikes with the same tread pattern front and rear. Pretty much everyone I see on my regular gravel group rides uses the same tread front and rear. 

Why is that?

Perhaps it is a holdover from the days before gravel bikes. With road bikes, there was never a reason to even think about tire tread when riding exclusively on pavement. So maybe mixing treads just never crosses people’s minds.  

Maybe it actually doesn’t matter as much as I think. Maybe I need to test it for myself.

What Tires Will I Run at Unbound Gravel?

The combo I'm currently testing: Schwalbe G-One RS rear / G-One R front

I DO want the best of both worlds. I want a fast tire to make it to the finish line a bit faster, but I also want confidence-inspiring traction so I don’t bin it along the way. 

Since I work at TPC, I have access to a buttload of tires and can try several different combinations before race day. 

I’m starting off with the tire that won Unbound last year: the Schwalbe G-One RS. It also happens to be one of the fastest gravel tires tested by bicyclerollingresistance.com, and after a few rides, I believe it. Up front, I’ve paired it with a Schwalbe G-One R, which has a similar light and fast casing, but much larger knobs. This tire tested much slower than the G-One RS, but just looking at the tread, it’s clear that it will provide much more traction. So far, this setup feels REALLY good. 

Tires are the final piece of the puzzle for my Unbound setup.

Here are all the gravel tire combos I 'm considering testing in the upcoming weeks:

Hopefully, I can decide on something before the race. As you can see, I’m trying a bunch of semi-slick rear tires, paired with a slightly knobbier front. I’m not going full-slick on the rear, just because I do want that extra bit of cornering traction the semi-slick provides in the rear. When I’m 10 hours in, I’ll surely be so fatigued that my handling skills will be a joke. 

If you’ve run mixed tire tread patterns on your gravel bike, let me know! I’m interested to hear what other riders choose. And if you have tire suggestions for Unbound, I’m all ears. I like having options!

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