What's the 'right' tire width for gravel and road bikes?

"CW asks" is a feature series where our seasoned staff answers a range of questions. The series isn't just about delivering knowledge; it's a chance for us to share a bit of our personality and our passion with you. As we dive into some questions, please feel free to send in some questions of your own to anne.rook@futurenet.com. 

Previous Questions:

• What three things do you wish you'd known when you first started cycling?
• Does e-bike racing have a place at the most competitive end of our sport?
• If you were given $3,000 right now, which bike would you buy?
• Personality test: If you could keep just one of your bikes, which bike would it be?
• Ride of a lifetime: If you had just one ride left in you where would it be and with whom? 
• Who is the greatest cyclist of all time?
• Ride indoors or brave the elements outdoors: how will you tackle the winter season?
• The great sock debate: do socks go over or under leg warmers?
• Tubeless vs. tubed tires on the road?
• SRAM, Shimano or Campagnolo? Here's what our staff prefers and why

Question 10: What tire size are you riding (on the road and on gravel)?

Michelle Arthurs-Brennan, Digital Editor

I think I must have been one of the very last hangers-on to the 23mm road tyre. I maintained, for some time, that 25mm tyres felt 'spongy' and 'slow', preferring to teter around corners on my 23mm rubber, at one time, inflated to what now sounds like an absolutely horrendous 120psi. However, the move to 25mm eventually came, and a further increase to 28mm felt like an easier step. I've yet to make my way to the seemingly ungodly realms of 30mm, but I'm sure I'll get there, eventually. 

Despite earlier protestations, I typically prefer my road tyre tubeless, and running around 50-60psi offers a huge increase in cornering confidence, and irons out the bumps. 

On gravel, I've been less of a stalwart. Conditions vary, trails vary, to be honest more quickly than my available wardrobe of wheel rubber. Anything from 40mm-45mm seems to be the sweetspot, but I'll merrily take something wider if it's going. 

Anne-Marije Rook, North American Editor

Like Michelle, I, too, was a late convert to wider tires. Even as the trend was turning in favor of wider tires, I remember my team bike couldn't fit anything but 23s in the rear. So  I'd run a 25mm tire in the front and a 23 in the rear — and hating my life whenever there were cobbles or rough roads. 

It didn't help that the early, knobbed, gravel tires that came onto the market felt sluggish and completely dulled the riding experience. To counter this, I initially just rode Panaracer’s slick Gravelkings, even at the expense of losing traction. 

Luckily, gravel and wider road tires have come a long way these past few years, in part thanks to industry-wide adoption of tubeless technology. These days, I've fully gone over to the dirt side. I don't even own a proper road bike anymore — I just ride my gravel bike with slicks. And these slicks are usually 30s.

For gravel, I am constantly swapping out tires based on the terrain I'll be riding, the time of year and who I'm riding with. In general though, 42s are my happy place. 

Sam Gupta, Video Manager

 On the road I run a 28c, I can’t say there’s too much rhyme or reason to this choice. It’s the size I’ve been running since my rim brake days and as I’ve now transitioned over to a tubeless set up, I’ve found the width to PSI ratio has still worked really well thanks to my overall rider and bike weight being fairly low meaning I can run ~60 psi to great effect. The 28c still gives me everything I look for in terms of speed, comfort and grip, but I may experiment with a super supple 30c cotton tyre next summer to see if I’m missing out on anything. 

In terms of gravel, very little thought goes into my choices here since I’ll happily use whatever is fitted to the loan bike I’m given, that said, I will be extra happy if it’s a Pirelli Cinterato.

Stefan Abram, Tech Features Editor

For me, this depends a little on the situation. If it’s for performance, then a 28c would be my go-to on the road. For gravel racing, it would be a 700x45c. Partially that’s down to what frameset compatibility (most gravel race bikes top out at 45mm clearances), but also it’s where I’ve landed with what’s the best balance for me. 

A lot of people go a little narrower, but I prefer the cushion and slightly better puncture protection of a wider gravel tire. I don’t have hard data, but I do feel more efficient when the tires soak up a little more of the bumps, rather than getting pinged around as much. Also, with a greater contact patch there’s a greater dissipation of pressure, so stoney flints aren’t as likely to get wedged in. Stopping to fix a puncture costs a lot of time, so I prefer to be cautious anyway.

But for general, non-competitive riding my current tire width of choice on the road is a 32mm (though I’m sure it won’t be long until that’s 35mm!) For gravel, I’ve got my continuing fondness for 650b x 2.1in rubber. I really love just how plush the ride is and how much they retain the agility of a road bike. The tire circumference is almost identical to a 700x32c tire, whereas putting a 2.1 in wide tire on a 700c rim feels more like a mountain bike - because that’s essentially just what is!

Adam Becket, Senior News and Features Writer

I only ride on the road, and have one set of wheels, so this is a very simple question to answer: I ride 28s. For no particular reason, other than I find 25s too harsh and thin, and 30s just feel wide and slow, despite research on aero/rolling resistance advantages from having wider tyres.

I have one set of tires to go with my wheels, and that’s the way I like it, no fiddling about or being messy. I think my bike could fit up to 36s though, and maybe that’s what I would be tempted by if I fancied turning it into a bit more of an all-road machine than I am at the moment.

I’m comfortable and feel fast enough on my 28s, so that is where I plan to stay, all year round on the road.

Tom Thewlis, News and Features Writer

700x28c on the road. I don't own a gravel bike. 

There's nothing really to say to be honest. I just have always ridden with them and never changed. I guess it's just a case of if you're comfortable with something then there's not really any great need to do anything differently. 

Got questions -- silly or serious-- you'd like for us to tackle?  Please send your questions to anne.rook@futurenet.com.