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I am contemplating buying a gravel bike and wonder whether a titanium bike with titanium fork is/can be "better" than a carbon bike with a suspension component. I don't intend to ride competitively, just do fun tours and possibly multi-day bikepacking. Efficiency still matters to me, as going fast or going far outside of races is fun too.

As an example, the Bearclaw Thunderhawk, when equipped with the titanium fork, supposedly dampens road vibrations just by flex of the fork+frame construction. Meanwhile, as an example for a "mainstream" carbon gravel bike, the Specialized Diverge Comp Carbon and its siblings have the "Future Shock" suspension built into the steerer tube.

How do these two concepts compare in regards to comfort and efficiency? I would guess the advantage of the Future Shock are:

  • FS probably dampens road vibration more, as it is a full-blown spring+dampener system
  • The FS is more efficient as it only deflects in the vertical direction, whereas the titanium fork might flex in more ways and therefore possibly impact efficiency
  • Since the "blades" of the titanium fork flex, it also suspends the bike, in contrast to the FS, which only suspends the rider, which is supposedly more efficient
  • Being able to adjust the FS on-the-fly by using the knob could improve efficiency on smooth surfaces

My guesses for disadvantages:

  • Less robust, shorter lived and more maintenance needed
  • The idea of taking a stiff carbon frame and bolting on the FS suspension sounds somewhat backward

Price is difficult to compare, as you have to compare whole bikes. Am I correct with the above assumptions? What are other factors when comparing titanium bikes/forks with carbon bikes in regards to flex/suspension?

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    For gravel, I'd want a high-volume tire with a supple casing and a carbon fork, regardless of the material of the rest of the frame. I save the suspension for the roots, rocks, and drop of single track – Paul H Nov 12 '20 at 15:41
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    I prefer my carbon forks for their weight, durability, availability, and vibration damping. – Paul H Nov 12 '20 at 15:54
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    Ti forks, much like Al forks are known to b very harsh. – Carel Nov 12 '20 at 18:26
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    Not to come off as a retro grouch but uh steel works well for giving a nice ride – GageMartin Nov 12 '20 at 20:11
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    Carbon forks are strong as heck! They tend to be overbuilt for exactly the durability reasons you described. Anecdotal example: my friend’s bike got smushed lengthwise between a car and a brick wall. The carbon fork was so strong, it bent the frame to the point that it had a 95 degree head angle or something. The fork was not damaged in any way. – MaplePanda Nov 12 '20 at 22:26
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Frame and fork material

For a gravel bike without suspension, which is most current ones, a lot of the suspension and vibration damping comes from the tires. Beyond those, all frame materials can be tuned to offer more or less vibration damping. Carbon is more tunable than metals because it's not isotropic, i.e. it can be made so that its stiffness is not identical in every direction. However, that doesn't necessarily mean carbon has better damping than metal - that depends on the layup of the fibers and the fiber types selected. You could make a carbon frame ride harsher than a steel one, if you chose to do so.

Titanium and steel are considered to have a good ride quality, at least in the tubes that are commercially available. At least part of this is likely subjective, and some riders may perceive steel or titanium as riding more pleasantly than carbon. NB: I have a somewhat classically styled steel road bike, and a carbon gravel bike.

It is not really easy to compare the ride characteristics of the Bearclaw to more mainstream carbon bikes. The carbon bikes' ride characteristics will vary depending on what they were designed for. You would have to seek out reviews by competent and experienced reviewers. I generally recommend the crowd at Cyclingtips. For example, they assessed the Evil Chamois Hagar's (carbon) ride quality as poor, even "backbreaking", and the race-oriented Cervelo Aspero as similarly uncomfortable, saying that it was "brutal" on rough terrain. In contrast, they felt that the Santa Cruz Stigmata was much more comfortable.

I am not aware of reviews for the Bearclaw, but I'd caution that just because its titanium may not mean that it rides like other titanium bikes. While metals are isotropic and can't be tuned through layup like carbon fiber, a manufacturer can tune the ride by selecting different tubing diameters, thicknesses, and shaping. I suspect that the ride quality between titanium bikes is pretty heterogeneous. It's probably more homogeneous than the ride between different carbon bikes, but the ride quality alone should be able to vary substantially, as well as the bike's handling (due to geometry). That said, the sorts of people buying titanium or steel bikes tend to be seeking comfortable rides.

As to forks, as far as I know, titanium forks are relatively uncommon. As you mention, Bearclaw seems to offer a full titanium fork, and they may have done so for some time. Because of the variety of carbon forks available, and the fact that titanium forks are likely heavier than carbon for the same stiffness, I suspect titanium forks simply haven't taken off commercially. One possible rationale for a steel or titanium fork from a custom builder would be that they can select their own fork rake and length; otherwise, manufacturers will commonly spec one or two rakes across the full spectrum of frame sizes, which does mean that the way the bike handles may change with size. I'd expect a titanium fork to be good at vibration damping, but I doubt it's necessarily superior to a well-selected carbon one on an off the rack bike. Bearclaw appears to offer off the rack only.

Suspension

Suspension is still relatively rare on gravel bikes. Potentially, it can do two things.

  1. More prominently on gravel bikes, it can isolate the rider from chatter. This reduces fatigue. Some bikes have front suspension only, like the Specialized Diverge. Generally, gravel bikes with built in suspension offer a lot less travel than mountain bikes. You could also put suspension in components, like Redshift's suspension stem and seatpost, or Cane Creek's suspension post.

  2. Suspension forks and frames keep the wheel in contact with the ground over large bumps. This is important for mountain bikes. I am only aware of one current full suspension gravel bike, the Niner MCR. There are aftermarket suspension forks, e.g. the Lauf Grit, which I don't believe needs a frame with suspension-corrected geometry to mount. However, I'm not sure how much gravel cyclists need this type of suspension.

Here is a Cyclingtips review of the current Specialized Diverge, which as noted has front suspension. Testers rated it as very comfortable to ride. The review of the Niner MCR full suspension bike is also by Cyclingtips. The reviewer noted that the improvement in traction was tangible.

All else equal, I'd actually expect suspension systems to reduce efficiency, as they can bob as you pedal. One can tune the suspension (as I understand the issue, not having had much experience on mountain bikes) to minimize this. That is one minor downside: if you have suspension, you will need to tune it to your weight to achieve optimal performance. However, the more complex suspension systems do have greater maintenance needs. The BMC Urs has a softtail-like rear suspension that should require periodic cleaning and regreasing of the pins and bushings, and maybe occasional replacement of the elastomer damper. The Niner MCR's full suspension system should be much more complex to maintain. Interestingly, Specialized claims the Future Shock is fully sealed and doesn't require maintenance.

There's another complexity issue if we are talking about full suspension bikes. As a traditional suspension fork like the one mounted on the Niner compresses, your head angle steepens. The Cyclingtips team noted that the Niner's handling felt odd, "like a 29er mountain bike from yesteryear". Bike manufacturers looking to integrate more complex suspension systems will need to think about how the suspension interacts with the type of handling gravel cyclists are looking for, which tends to be different from what mountain bikers are looking for (although not exclusively; some gravel bikes like the Chamois Hagar, the Urs, and the Diverge borrow a lot of influence from MTB geometry, although they aren't identical).

Do note that not all front suspension systems cause the head angle to steepen as they compress; the Diverge's doesn't. The tradeoff is that the Future Shock is limited to 20mm travel. This would be clearly inadequate on a mountain bike, but the Diverge isn't a mountain bike.

It's worth noting that suspension is still rare on gravel bikes. I've written this assuming you were talking about a gravel bike with a suspension system more significant than just a seatpost and stem. As indicated, I'm currently aware of only one full suspension gravel bike. Current gravel bikes are trending towards as much as 700x45-50mm tire clearance, which is a lot of tire with which to cushion the ride. I'm not sure how much suspension is actually necessary.

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    Quick note on this great answer: the Future Shock won't steepen the head angle as it compresses since it's above the head tube. With full suspension bikes, once of the benefits that gets little ink in the press is that the geometry stay more consistent as both ends compress. Hardtails, OTOH, absolutely get steeper as they compress. – Paul H Nov 13 '20 at 0:59
  • @PaulH A good point, which I missed as I am not familiar with suspension design. I edited the answer to clarify that traditional suspension forks will alter the geometry as they engage, but the Future Shock isn’t a suspension fork. – Weiwen Ng Nov 13 '20 at 16:06
  • Thanks for the detailed answer. I have to admit I'm unsure as to how much suspension/road dampening I actually need. MTB-style suspension is probably way too much, I don't need the suspension to allow me to go over rough stuff (we don't have much of that here anyhow), just to make easy stuff more comfortable on the hands. I found out there is a LBS nearby that has both Ti and Carbon bikes, so it's probably best to test ride both there. – Erlkoenig Nov 15 '20 at 18:45
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A quality Carbon or steel rigid fork would work wonders for gravel riding and touring. The advantages are obvious with rigid forks being maintenance free and "plug and play" items.

However, do note that while Carbon and steel are known to dampen road vibrations, they would never rival a well tuned suspension fork (even the ones with lower travel).

As for your query, a good rigid titanium fork is hard to come upon these days and custom options are sure to break the bank. It would be more practicable to invest in a quality carbon fiber fork or steel fork depending on your preferences. Happy riding.

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    There is a specific bicycle with a specific Ti and carbon fiber fork available. And a review of the Ti one is linked. So, which one is likely to be better? – Vladimir F Nov 15 '20 at 15:55
  • I was wondering about the (ride) quality of the different materials. Only with this information it is sensible to think about prices anyways. Bearclaw only charges $100 more for a Ti fork over the Carbon fork. – Erlkoenig Nov 15 '20 at 18:38

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