QUESTION: Are gravel tires good for road? I’ve seen some that are on sale that would fit in my road bike frame and I really like how my gravel bike feels nice and cushy so I was thinking about getting some. Any reason why I shouldn’t? – Jack E
RBR REPLIES: Gravel tires are a poor choice if you’re going to be mostly riding on the road with them. They are generally heavier than road tires, and the additional tread and knobbies create a lot more rolling resistance on smooth pavement, which will slow you down. Maybe this doesn’t matter to you if you mostly ride alone, but if you ride with any other roadies you’ll probably find it takes a lot more effort to keep up.
But here’s the good news. It probably isn’t the tread and knobbies that is making your gravel bike feel so comfortable. It’s the extra air volume that comes with the wider tires that is providing the cushy ride. A wider tire gives a noticeable amount of suspension and comfort compared to a very narrow tire like a 23mm or 25mm pumped up to a high pressure.
This additional air volume also allows you to safely run your tires at a much lower pressure, which adds even more comfort.
So instead of buying a gravel specific tire, consider a wider road tire with a smooth tread. A bigger tire is always going to be heavier than a similar smaller one, because it has more material. But a wide tire with a smooth tread will save you some weight and also roll much, much faster on the pavement. When the pace gets very hard, you’ll probably still have trouble keeping up with road bikes with racing tires, but it won’t be as dramatic as it would be with knobby tires.
One thing to look out for is that when you go bigger than 32mm, many of the bike tires for sale are designed more as touring or commuting tires. So although they’ll be very durable and resistant to flats, they’re often slow rolling and dead feeling. Some of the lighter options wider than 32mm include tires like the Continental Gran Prix Urban, the Schwalbe G One Speed and the Pirelli Cinturato. If you’ve got a big budget, Rene Herse has a very large selection of ultralight tires that go as wide as you can fit in most frames.
I use 38mm Rene Herse ultralight Barlow Pass slicks on my gravel bike and ride that bike on the road quite a bit. I can keep up on group rides with no problem with those tires, as long as the pace doesn’t get too competitive.