Alloy vs Carbon for gravel
 

I'm about to buy my first gravel bike and I'm looking for recommendations on material. I've an alloy and a carbon road bike. I do feel the difference between the framesets, but I've never find the alloy frameset bad or harsh. It's responsive and lively. I prefer my carbon bike because it's lighter and feels stiffer, but I don't have issues with comfort on the alloy bike either.

On gravel, I think that the comfort must come mainly from the tires. I find it hard to believe that there is a huge difference between frames when you run your tires <40psi. Also I see a lot of riders running alloy or steel bikes on gravel... at least more than on road...

Any first hand experiences are welcome :)

If I were racing on gravel, I'd take a serious look at carbon. However, all my first-hand experience is on aluminum and steel.

As I think about it, my first cut might be to decide whether I wanted racing versus endurance geometry.

If I were building a gravel bike today, it would be built around either a Rodeo Labs Flaanimal 4.1, or a Ritchey Outback (as I have 11k miles on a Swiss Cross, and no complaints.)

So I'mma say steel.

In general, a carbon bike will be lighter.

If you want a light build then carbon frame, bars, seatpost, etc are the way to go.

Light is relative though. My Niner is 20 lb and that's considered light for a gravel bike.


-Tim-

My Ritchey is under 24lbs, and I made no effort to make it light-- it's got a Surly steel fork (2.2lbs on it's own,) a Selle Anatomica saddle, 180/160 brakes, and a honkin' 10-42 cassette. It could be 4-5lbs lighter quite easily, if I cared at all.

I did say, "In general."

I have a 15.6 lb steel fixed gear bike. Custom frame, True Temper S3 tubes. So there is no doubt in my mind that a light steel gravel bike could be done.

Generally speaking however, it is going to be easier to do light build with a carbon frame than with steel.

in my experience(limited compared to some and way more than some), comfort will come from tire size, tire pressure, frame geometry, and fork design.

frame material is obviously important, but I didn't list it because I think those other 4 components play a bigger part in comfort when you are comparing quality frames in carbon, aluminum, and steel.

- a larger tire will provide more comfort due to reducing vibration.
- tire pressure will provide more comfort when aired properly for rider weight and surface(s) being ridden.
- frame geometry that matches what the rider wants for riding purpose will provide comfort. Thongs like chainstay length, head tube and seat tube angles, stack height, fork rake, etc all combine to make a bike comfortable or terrible, depending on the rider and how the bike is to be used.
- fork design is, to me, hugely important when it comes to comfort. A quality QR steel fork will absolutely flex more than a 15mm TA carbon adventure fork. That flex, to me, equals comfort. The steel fork is still plenty stiff enough for my riding ability and I am not negatively affected in terms of steering accuracy or anything like that.
its my view that most of these carbon thru axle forks are wildly overbuilt and stiff. I dont think any of that translates to any sort of benefit. I dont think a super stiff 15mm TA overbuilt fork will make me steer more accurately, make me faster, or improve comfort.
its a trend to have a massive head tube thats comically stuff and a fork to match. And heck, that trend could continue and become standard design, but it certsinly wont be with respect to comfort. Full carbon forks benefit from a tapered steerer because the gradual curve of the taper is better for carbon layup(so I have read). Makes sense in that regard to design around the tapered steerer, so head tubes are a huge 44mm as a result.

its all just makes for such a stiff front end. The performance gain of that stiff front end is, to me, nin-existant. The comfort decline of that stiff front end is noticable.

I own a quality steel gravel bike, used to own a different steel gravel bike, and have ridden aluminum as well as carbon gravel bikes. The aluminum and carbon bikes I've tested were friends bikes and also from a local shop. In total I spent probably an hour on 4 of those bikes. I think it was plenty of time to feel what I liked and disliked, but understand some may disagree.


I would figure out my budget then look at options within that price range that have the components and geometry I like, then narrow it down by frame material and bike look(paint).
a quality carbon frameset, a quality aluminum frame with carbon fork, or a quality steel frame with carbon fork will all make for a great bike if the geometey, components, and paint work for you.

If i had to choose between a carbon frameset with Tiagra or a quality aluminum frame with carbon fork and 105 hydraulic brakes for the same price, like the Cannondale topstone, I would probably go for the Cdale due to components and the fact that i bet its a comfortable bike based on the geometry.

but again, a fork that isnt stiff overbuilt TA carbon will flex and provide comfort. It'll be heavier though.

But salsa says their newer aluminum warbird is more compliant than their older titanium warbird... :-O

For me, it is a huge difference. I've ridden several brands in a aluminum vs carbon comparison - and the carbon is always light years smoother and more compliant - with out any drawbacks. My current bike is carbon, and its the only bike I'm comfortable gravel griding on without a thudbuster seat post.

And yes, with a thudbuster and big cushy tires I can get a pretty good ride. Stiff frame with cush in the seat post and tires gives a responsive ride and a comfortable ride.

Or, you could just read this article and decide for yourself: https://cyclingtips.com/2018/04/jra-...-still-matter/

I'm not sure that means much. I had one of their older titanium Warbirds. While the BB was flexy, overall, compliance wasn't that great. I replaced it with a (stiff) aluminum Niner RLT9 that was pretty comparable.

Woah man! Thank you so much for this link. I found the article very-very interesting.

hmm curious to brand/model. I have found Cannondale CAAD to rival 'Many' carbon frames. Not only rival but surpass many carbon frames in performance and ride quality.


the real answers comes from more questions. What is your gravel? How far are you riding on gravel? fast pace vs slow pace?

while tires do make a difference. When It comes to actual real world comfort. I's rather ride an alloy synapse on 25c at 80 psi on gravel rather than my alloy Trek Crossrip on a 40c tire at 40 psi. Because the Trek just sucks that bad.

Hah. My alloy road bike is a caad10 with dura ace c24 wheels, high end contact points and mechanical ultegra. The carbon bike is a high end hi-mod supersix. :)
Interesting that you said that your trek crossrip sucks. It seems like a solid entry/mid level alloy bike.

it is absolutely solid, which is what makes it suck so bad. lol it's like riding on a solid rock.

My alloy bike forever was an alloy synapse 105. great but a bit on the porky side. I replaced it with a himod disc di2 supersix.

I guess if I was to look at aluminum gravel bikes now it would have to be a Topstone, Niner RLT or maybe a Salsa journeyman with 650 road plus. yet on Niner.... the RLT RDO is so much more, even the steel 853 is light enough that I wouldn't even consider the alloy RLT. If it fell into a budget thing for me, then the Journeyman with $ invested into wheels. the Only negative about the RLT RDO is the lack of tire clearance. It really all depends on how much tire you need. If you love your supersix then you would absolutely love the Niner RLT RDO on a tubeless 38 Especially if you never needed more tire or needed mud clearance. Test riding ithe RLT RDO gave me the impression that I was on (almost) on my supersix yet with huge tires.

Gravel for me multi functions as commute/utility , and occasional multi day rides. So I want a bit more than entry level, and I also want utility. 40c + fenders, which leaves me looking at Giant revolt and Salsa Warbird version 4. (both being carbon) I was seriously Impressed with the Alloy Topstone though. Had they gave me a fork with attachments I'd be all over it.

Mason Bokeh alu, or a Zanc like the following sweet puppy:-
https://forums.thepaceline.net/showthread.php?t=222335

This is a very interesting discussion and the topic of my personal interest. I look for the best comfort I can get that is why I have bought steel Jamis Renegade Exploit bike and now I am experimenting with bigger tires (I have Panaracer Gravel King SK 43c but I am going to change the wheels for wider Tubeless ready and put WTB Riddler 45c on them).

From what I have learned and from my own experience comfort is a combination of many things. This is very nicely explained on the Cervelo website: https://www.cervelo.com/ride-quality
Tires are the most important thing but even the biggest and most supple tire will not provide great results if everything else will be very harsh and stiff.

The starting point is the frame material. It is easier to make stiff and harsh aluminum frame than steel one that is why in general steel bikes are more comfortable. But there are great examples of aluminum frame bikes (Cannondale road bikes or Mason Bokeh) that manages to create a very comfy ride despite aluminum frame. Steel bikes are generally more comfy not only because steel absorbs road chatter better than aluminum but also because of its weight the frame tubes are rather narrow so naturally they will flex more and flex is the key to the comfort. This nicely brings us to the carbon frame that can be engineered to have the biggest flex of them all (aluminum, steel or even titanium) and that is why you can have a suspension like rear triangle of GT Carbon or flexing good 2 cm seattube on Storck carbon bikes. And by adding additional compounds to the carbon (like Spec or Look is doing) you can also get the best dumping of high frequency of road chatter. So very well engineered carbon frame can be the most comfortable but also a very expensive one.

Then there is seatpost and handlebars. Canyon VCLS 2.0 seatpost (which I have) makes the ride a great deal more comfortable. Handlebars are important factor but only recently we see a crop of solutions that allows a downward flex that increases ride comfort (Storck carbon handlebars or Giant D-Fuse aluminum). When you add to that flexing Handlebar a good bar tape and you will use good gloves you will add a lot of comfort to your bike. Cervelo on its site is saying that stem is general irrelevant to the comfort but when you use something like Shockstop suspension stem you will definitely feel the difference (that is why I will also add this stem to my bike).

So to sum up: a great comfort it is all about combining a very well engineered frame with a big tubeless tire and additional parts like gloves and comfy saddle. If you start with a very stiff frame it will be very difficult to make it comfy and even the comfiest frame with very narrow and high pressure tire will make the ride unbearable on gravel.

steel

That's about what mine weighs also. An RLT9 RDO is carbon fiber and about 1/2 lb lighter, same geometery. I was thinking about upgrading to the carbon version, but with the minimal weight difference I couldn't justify the cost, couldn't even rationalize it! :)

Hmmm...seems a bit on the porky side.

My 59cm RLT RDO is 18.2 lbs with XTR pedals and two cages.

Fwiw, I ride a ton of shale trails. Every time I ride, sometimes several times per ride, I kick up a big chunk of rock that hits my bike.

I ride steel and a powder coated frame so I'm not super concerned. If I was kicking up rocks like that into a carbon or aluminum frame, I'd cringe.

I'm at 22lbs. I could drop to 20 if I needed to.

People who endlessly mention how much their bike weighs go to the same ring of hell as people who talk about how much their shoes cost.

I think the ones who swear that a 22lb bike will slow them down to a crawl vs a 16lb one are worse. Lately I'm wondering if I'm reading the 41 vs the cx/gravel subforum.

Here's a review that had a demo bike weighing in at 18.5lbs without pedals or bottle cages in a 59cm, so I added a pound for pedals to get 19.5 lbs. You probably have lighter wheels or something. Here's the article https://pelotonmagazine.com/gear/nin...l-goes-carbon/

haha, It happens to my carbon pivot LES all the time around here in the NE when mountain biking. And yes....I cringe every time it happens lol. But nothing in comparison to when my Hakka got hit last summer. Cracked the downtube almost in half. It was still completely rideable and I chose to ride it home 30 more miles that way. So I learned the hard way that rocks alone probably won't do enough damage to carbon to ruin the bike :) and since bike weight came up. My Hakka comes in at 18.5lbs w/ i9 alum wheels, sram force1 group, carbon bars, 2x h2o cages, alum post/stem, xtr spd pedals. Could easily get it into the 17s if I wanted to throw money at it. but no need. It's been such an amazing bike. Comfortable on long gravel rides, commuting around, racing cx. Absolutely love it's versatility. Lacks rear mud clearance for CX though.

My answer to the original question would simply come down to funds. If you can spring for carbon, go for it. Otherwise, alum or steel will be just fine, too :)