Wednesday, May 07, 2025

Wide Tires On Gravel: Why and Why Not

Deeper, loose crushed rock demands a unique approach to tires. Image by Jon Duke
Welcome back to the series on why wider gravel tires may or may not be a good idea for you. In this post I will look at the "whys" of using wider tires and then I will get into why you may not want to use wider tires as well. Let's jump in....

When Wider Is Better: Let's get this out of the way right up front - Wider tires have been "a thing" for gravel riding in the past. This idea of using wider tires on looser terrain or rocky, bumpy terrain has been here for years. We discussed this a bit in our last podcast, but suffice it to say that if you hear anyone saying this is a "new trend in gravel" you can bet they haven't done their homework in terms of a historical viewpoint.

Now let's move on. It seems as though "gravel tires" were filling a niche between what was offered for road bikes and what was offered for mountain bikes in the mid - 2010's. Road tires were 'maxing out' at 28mm around this time, so anything from where cyclo cross lived up to 50mm wide was considered the territory of gravel bikes. And before you get on your keyboard to post a comment - yes, there were 50mm wide gravel tires several years ago

Otso Warakin as tested in 2017 This bike could take a 29"er tire.

There were bikes for wider gravel tires as well, so some of us have actually already been doing this wide tire thing for quite a while already. Using wider gravel tires or even XC 29"er tires in many cases, was fairly commonplace.

There a few reasons we gravitated to wider tires back then. One of the benefits to wider tires on gravel is the stability wider tires lend to the ride. This can help tremendously on roads where loose gravel, sandy gravel, or fine, deep dirt is prevalent. 

Another good reason to ride wider gravel tires is for increased vibration reduction. This is tire and tire pressure dependent though, so one has to work with the air pressure and tire chosen to arrive at a place where the tire starts to do work and absorbs vibrations without being a detriment to rolling. Too high on pressure and you are just pushing around a bigger tire. Too low and you will be wasting energy, or as the punters like to say, 'watts'.

Finally, you might be faster. Maybe.... A lot of things go into being fast, and most of those things are not tire related. However; if you are one who is going to benefit from marginal gains, you might actually be faster just because you use a wider tire. Now, maybe 1% of those reading this would benefit from this after exhausting all other avenues for getting faster, so for the rest of us, I wouldn't bank on being faster because you switched to wider tires. Maybe you will be, maybe not. I know I have a lot more to worry about than tire width when it comes to getting faster. (Putting down the snacks now....)

On the left: Teravail Ehline 29 X 2.3", Right: Teravail Sparwood 700 x 47mm Wheels: WTB Proterra i23
Gearing: This is something a lot of people are unaware of when it comes to swapping out to larger/wider tires. A wheel diameter, whatever this ends up being for any given tire/rim combination, is a part of your gearing. This concept has been lost over the past decades but it was a seriously debated point when high-wheelers, or penny farthings ruled the dirt roads.

The wheel's tread and overall wheel diameter together were responsible for your speed. Smaller wheels were easier to pedal, went up hills easier, but gave up speed to those larger diameter wheels. These bicycles were "direct-drive" - you pedaled the crank attached to the front axle with the rear trailing wheel there just to stabilize you.

When chain drive came along, a "same-sized" pair of wheels came into existence which has evolved over time to give us our 1 X 13, and 2X 12 cutting edge gravel group-sets of today. People think in terms of "low gear" and "high gear" on the cassette to comprehend if they will have enough speed or low enough gears. But they forgot the effects of a smaller or larger overall wheel diameter. It matters. Look at the image above. Those wheels are the same diameter, only the tires are different, and when you go wider on tires, you change the overall wheel diameter, and your gearing.

A lot of us mountain bikers went through this with the switch from 26"ers to 29"ers. The low gears weren't low enough anymore with larger diameter wheels. This is why gravel group sets have deeper gears than road bike group sets. The wheels are inherently going to affect your ability to climb and go fast. Now add a 29"er wheel, which is essentially what folks like Dylan Johnson in the Pro gravel ranks is doing, and suddenly you need a deeper low gear than you did with a 45mm wide rear tire.

Okay, that should be enough to chew on for today's post. Next time I will get into why you may or may not need a new bicycle to do this with, and what a bigger tire does to geometry and handling. Look for the next post in this series on Monday.

5 comments:

Tyler Loewens said...

You forgot one main point. 29er tires on an aggressive-looking drop bar bike just look so good! Granted, this is coming from the guy who had drop bars on a Mukluk for a bit, so maybe take that with a grain of salt. :)

Guitar Ted said...

@Tyler Loewens - Oh......and there is THAT! :>)

MG said...

I still have a drop bar fatbike, Tyler… Believe it or not, I used it to finish second overall (against people on actual gravel bikes) in the 50k race at the recent Winter Endurance race here in Lincoln. Yes, the conditions were rough, but I was still surprised when 3 of the top 5 finishers overall were on fatbikes.

But even on ‘normal’ gravel roads, it’s surprisingly easy to keep up with normal bikes on my fatbike.

Tyler Loewens said...

That might have a tiny bit due to your massive power though Matt. lol

MG said...

LOL indeed…