Having never competed in a gravel race, I’m curious if the percentage of people riding carbon is as high as road racing, particularly for the people who want to race and not just ride the event.
I’ve read all the forums about alloy versus carbon. Obviously, lots of competing opinions. I’m not trying to rehash all the old information. I’m just a schmuck looking for a new bike and potentially looking to save a few bucks.
(I am very familiar with carbon road bikes)
Thank you for your time!
The closer to the pointy end of the race, the more carbon you will see. I think aluminum is the least common material on gravel. Carbon-Steel-Aluminum.
What about Ti? 
Maybe it’s regional, but I don’t see many steel bikes in gravel races. I’d say it’s an even mix of carbon and aluminum, then steel. And even fewer ti.
Agreed. There just aren’t many steel bikes available when compared to other materials. I teased above, but I suspect Ti and Steel have relatively similar counts.
Aluminum is the everyman’s material and available on many, many brands and models. Nothing wrong with it either. Modern build technology makes it very functional. Couple that with some smart stem and seatpost choices and you can have a very fast and comfortable aluminum gravel bike.
The more climbing, the lighter you want the bike to be. The faster and longer the course, the more aero you want it to be. Carbon typically wins out in both of these.
Also I’d guess at the pointy end of races, most riders are sponsored in some way and ride whatever their sponsor wants, so that might be a bad place too look for advice.
In almost every racing discipline you will see more of the pointy end riding carbon than aluminum. The two big factors that I see pushing it that way are:
Those racers may be sponsored or on a sponsored team that pushes the higher end bikes to the riders (which are almost always carbon
Most aluminum bikes top out at the 105/rival component spec and with eh wheelsets for their stock builds. So to get the higher end bling like Di2, nice wheels, etc you have to go for the carbon frames
Thanks for the replies. Great info.
A more pointed question for my case.
I’m looking at the 2021 Trek Checkpoint ALR 5. I like the spec (grx600/800) but not the wheels.
At $2100 it’s close to a carbon price with 105 type components. I’d rather have the GRX.
The dilemma is getting the ALR 5, upgrading the wheels and seat post OR just going all in on a nicely spec’d carbon bike (4K price range)? Thoughts?
Carbon … almost always. And as an FYI, the most common bike I see is the Open U.P. … most common tire is some variation of the Schwalbe G-One
Think of the guys who you know that win races - the guys who are always at the front. As a subset of those, let’s think of just the ones who are riding carbon bikes. As a thought experiment, do you think that all other things being equal - if you swapped their carbon frame out for an aluminum frame, that this person would no longer be at the front?
Let’s try an additional thought experiment. What percentage of benefit do you think that carbon vs. aluminum provides, and what are you willing to pay for that premium? If it provides a 1% increase in performance by some measure, what is that worth? Would you notice it, over the length of a race? People will say things like ‘stiffness’ and ‘chatter’ and ‘feel’ and the like but to be honest, frame material isn’t as important as the interface between your bike and the ground. Wheel/tire combination and tire pressure.
In my humble opinion (I apologize if I stepped on toes) I would opt for the aluminum frame and then perhaps save money make sure you’ve got a good set of wheels and tires on the bike. A good set of bibs to sit on. Good components. Frame material comes after those other things - all else being considered. If money weren’t an object, sure go for all carbon everything.
This is especially true as the tire size grows. The lower your tire pressure the less of an impact your frame has on the ‘compliance’ of the bike-rider system. So the impact the frame has on a road bike with 25c tires at 80 psi will be greater than that same frame with 38c tires at 40 psi.
Though the thing that may actually make a difference are the suspension features that come on many higher end carbon frames that are not present in the aluminum variant like the kingpin from Cannondale, the future shock from Specialized, Isospeed from Trek, etc.
the impact the frame has on a road bike with 25c tires at 80 psi will be greater than that same frame with 38c tires at 40 psi
The impact of the tire will be greater as well, perhaps more so than the frame. A plush, high quality, high tpi tire at an appropriate pressure can have an (arguably) bigger difference on ride quality than the frame material - even at more narrow widths. As an example, I’ve had 24c S-Works Turbos that felt worlds better than 25c Vittoria Rubinos, even with the Rubinos at lower pressure and on the exact same Roval CL-50 rim. Good discussion.
Yup, tires are key. Tubeless of course, and select model and size as appropriate for your area and use.
Suspension is fixable via Redshift ShockStop Stem and Seatpost. Or you can pick from a range of carbon seatposts too, that give more compliance. Those combined with tire setup will all but nullify the difference in frame materials for all but the most discerning among us (myself included).
Yup! From a physics perspective, as the spring rate of your tires gets lower it will have a greater affect on the system than the other components because it is the first spring in the system and any force has to pass through it first.