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earlethomas

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Reply with quote  #1 
I see a fair amount of steel frame 'adventure/gravel' bikes with carbon forks...advantages/disadvantages, other than cost?
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BluesDawg

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Reply with quote  #2 
Carbon is much lighter. Good steel forks are generally more compliant (in a good way) than most carbon forks. 
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Skldmark

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Reply with quote  #3 
Steel forks are more suitable for mounting racks and accessory gear in most cases. May even have custom braze-ons added as needed.
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bobknh

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Reply with quote  #4 
Usually you don't have much choice -- a bike is designed for a particular fork. The geometry, and flex characteristics of the fork should match the bikes intended use. The material used for the fork is selected to optimize those characteristics. Here is an example of an all steel bike designed for a very short rider at the DK200 http://www.gravelcyclist.com/bicycle-tech/featured-bike-venny-wilmeths-custom-hans-schneider/  . While the generalization that carbon is lighter, and steel more compliant is generally true; carbon composites are very strong for their intended purposes, and don't suffer from metal fatigue, while steel components can be made very light owing to steels inherently high tensile strength. Here is an example of a all purpose bike built by J P Weigle that runs 40mm+ tires, fenders, etc and weighs around 20 pounds - steel fork included https://janheine.wordpress.com/2017/08/03/cyclodonia-on-the-j-p-weigle-from-the-concours-de-machines/  .
I'm not trying to suggest that steel is superior material to carbon -- but only that when all is said and done, the bike's design and purpose will dictate the optimal fork material. In fact, in my own case, I'm currently having a custom steel gravel bike built by 44 Bikes. I discussed the possibility of a steel fork with the builder, who recommended the Enve CX carbon fork for my bike. While he could build me a custom steel fork he felt that the Enve would be optimal for the kind of riding I do- maintained dirt and gravel roads, and high speed group rides on pavement. Sorry, no fenders on my bike!
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Brennus

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Reply with quote  #5 
appreciate  your thoughts on this one bobknh!

I've got a bike with a steel fork and a bike with a carbon fork.  The steel fork has kind of a classic look.  For me, the most obvious difference between the steel bike and the carbon bike is the feel of the fork.  When riding through a washout or bouncing over a rock the compliance/flex of the steel fork is obvious.

Now, is that a good thing or a bad thing?  Maybe it's ok since a little bit of flex in the front end isn't going to cost anything or much of anything in terms of lost power.  In fact, when reading about some of the new gizmos that offer a few centimeters of travel on the front end of the bike it's worth asking just how much flex a classic steel fork actually provides?  And what is the real weight difference between a gizmo front end with 3cm of travel & a traditional steel fork?
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bobknh

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Reply with quote  #6 
Quote:
Originally Posted by Brennus
appreciate  your thoughts on this one bobknh!

I've got a bike with a steel fork and a bike with a carbon fork.  The steel fork has kind of a classic look.  For me, the most obvious difference between the steel bike and the carbon bike is the feel of the fork.  When riding through a washout or bouncing over a rock the compliance/flex of the steel fork is obvious.

Now, is that a good thing or a bad thing?  Maybe it's ok since a little bit of flex in the front end isn't going to cost anything or much of anything in terms of lost power.  In fact, when reading about some of the new gizmos that offer a few centimeters of travel on the front end of the bike it's worth asking just how much flex a classic steel fork actually provides?  And what is the real weight difference between a gizmo front end with 3cm of travel & a traditional steel fork?

Hi Brennus - I'm flattered. I'm about as opinionated about bike tech. as anyone else; and frequently wrong. I'm not sure about any claims of improved comfort or compliance of bike gizmos. I owned a Trek Domane with an elastomer shock absorber between the seat tube and frame. Although I liked the bike very much because of it's geometry and handling, I never noticed much effect of the elastomer damper. In fact I got the most improvement in shock absorption and comfort, by replacing the stock Bontrager TLR tires with more supple tires, which I could run at lower pressure with latex tubes. The 25mm Bontrager TLR's ran like bricks - even at lower pressure. My Conti 4000 IIs's with Vittoria latex a 70PSI were noticeably smoother and faster - especially on rough chip seal. If you want a smoother ride, then my advice is wider tires, supple sidewalls, and lower pressure will give you the most improvement.
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earlethomas

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Reply with quote  #7 
Thanks for all your replies. It's interesting that while there seems to be a near consensus that steel forks absorb better, I still see many bikes, especially higher end bikes, with carbon forks as standard. One thing on a road racer trying to shave weight, but it seems that carbon on rougher ground makes little sense, other than they look kind of badass.

bobknh, I'd be curious as to why your builder is recommending carbon. It's a bit confusing...I read one manufacturer's blurb that said the carbon forks would 'smooth out the ride'.
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bobknh

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Reply with quote  #8 
Quote:
Originally Posted by earlethomas
Thanks for all your replies. It's interesting that while there seems to be a near consensus that steel forks absorb better, I still see many bikes, especially higher end bikes, with carbon forks as standard. One thing on a road racer trying to shave weight, but it seems that carbon on rougher ground makes little sense, other than they look kind of badass.

bobknh, I'd be curious as to why your builder is recommending carbon. It's a bit confusing...I read one manufacturer's blurb that said the carbon forks would 'smooth out the ride'.

There were several reasons, both the excellent performance of the Enve CX fork on his builds, and difficulty obtaining the fork materials from his steel suppliers. I also made it very clear from the start, that I wanted the lightest bike possible. I would guess however, most of his customers also request carbon forks, and to meet his market demand, he has decided to build most of his bikes with carbon forks. BTW, I also have an Enve carbon fork on my steel American made Lemond Washoe road bike, which is one of the most comfortable and best handling bikes I've owned. There just aren't that many builders around like J. P. Weigle, who will take the time, effort, and expense, to custom build steel forks. Custom steel forks are harder to find and likely to cost as much as, or more than comparable quality carbon forks. 
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AlanEsh

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Reply with quote  #9 
Quote:
Originally Posted by earlethomas
Thanks for all your replies. It's interesting that while there seems to be a near consensus that steel forks absorb better, I still see many bikes, especially higher end bikes, with carbon forks as standard. One thing on a road racer trying to shave weight, but it seems that carbon on rougher ground makes little sense, other than they look kind of badass.

bobknh, I'd be curious as to why your builder is recommending carbon. It's a bit confusing...I read one manufacturer's blurb that said the carbon forks would 'smooth out the ride'.

There's nothing weird about running a carbon fork on rough roads, it's pretty standard for many gravel bike setups. Big chunks of gravel, heavy washboard, highly variable surfaces: in those situations you're running fluffy tires and the flex of a steel fork isn't necessarily desired, nor does it do much to soften the ride (tires trump fork). If you can save some weight with a carbon fork out there on a 100 mile hilly gravel ride, that's a good thing.

As far as "smoothing the ride" that's very dependent on the fork. A carbon fork built for cross or gravel is going to be stiffer than a road fork, and unlikely to smooth the ride more than a steel fork. On the other hand, I had a steel fork on a KHS cross bike that was terribly stiff, so maybe that's just the nature of the cross/gravel beast.
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sgtrobo

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Reply with quote  #10 
just my opinion here.  Thousands of miles on a Cutthroat (carbon fork), SuperX (carbon fork), Sequoia (steel first, then carbon fork), and an older Fargo (steel fork)

For me, if I want to hook up a rack, I go with the steel fork.  Otherwise, I go with the carbon fork, without question. >38c tires running tubeless at slightly lower pressures make way more of a difference in absorbing the chatter up front than the fork material.  If you're running on gravel with 28c tires, then perhaps a steel fork will make a difference, but with bigger tires, I'd go with the lighter weight and stiffer construction of the carbon fork
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Smithhammer

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Reply with quote  #11 
Quote:
Originally Posted by earlethomas
Thanks for all your replies. It's interesting that while there seems to be a near consensus that steel forks absorb better, I still see many bikes, especially higher end bikes, with carbon forks as standard. One thing on a road racer trying to shave weight, but it seems that carbon on rougher ground makes little sense, other than they look kind of badass.


Agreed. 

Racers will tolerate a fair bit of discomfort to shed weight, and for exactly this reason, I don't think that racing equipment choices are what the other 95% of riders should always base their own choices on. But the industry loves convincing people that we should all take our cues from racing, and we should all be obsessed with shaving every last gram. 

If you're not seriously racing, I see no real advantage to a super stiff carbon fork for dirt/gravel riding. I'd take a well made, raked steel fork any day. Even with a 40c tubeless setup, cuz why not? On a long day on rough, uneven surfaces, I can't say I've found the combo to be "too plush."

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drwelby

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Reply with quote  #12 
One point to add to the discussion: There's no way to get the flex of something like a classic steel fork and run disc brakes. Once you add the disc brakes you're looking at stiff and really stiff.

Fat tires certainly help, but as you go lower in pressure you hit a point where the tire starts to misbehave.
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bobknh

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Reply with quote  #13 
Quote:
Originally Posted by drwelby
One point to add to the discussion: There's no way to get the flex of something like a classic steel fork and run disc brakes. Once you add the disc brakes you're looking at stiff and really stiff.

Fat tires certainly help, but as you go lower in pressure you hit a point where the tire starts to misbehave.

Good point. The steel fork options I was considering all had canti pegs for canti, linear pull, or center pull rim brakes.  I don't recall seeing any steel forks with disc post mounts.
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Smithhammer

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Reply with quote  #14 
Quote:
Originally Posted by drwelby
One point to add to the discussion: There's no way to get the flex of something like a classic steel fork and run disc brakes. Once you add the disc brakes you're looking at stiff and really stiff.


There may be some truth to that, but my steel disc fork still flexes a lot more than any straight carbon fork I've used.

Quote:
Originally Posted by drwelby
Fat tires certainly help, but as you go lower in pressure you hit a point where the tire starts to misbehave.


When the tire starts to 'misbehave' in that way, it's a clear indication you've gone too low with pressure, not necessarily a shortcoming of the larger tire itself.

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drwelby

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Reply with quote  #15 
Quote:
Originally Posted by Smithhammer


There may be some truth to that, but my steel disc fork still flexes a lot more than any straight carbon fork I've used.


I don't doubt it, but that's why I said classic steel fork. I have a fork I built with the Kaisei imperial oval blades and a 1" Pacenti superlight steerer and that's in a whole different class of flex.

Quote:
Originally Posted by Smithhammer

When the tire starts to 'misbehave' in that way, it's a clear indication you've gone too low with pressure, not necessarily a shortcoming of the larger tire itself.


What I was getting at is that with overly stiff forks people will say "just drop your tire pressure" but you can only go so far with that, especially if your fork has limited clearances.

It gets weirder to figure things out when you have the fat tires and fork working in series - on a recent frame I built I thought the fork was really stiff because I couldn't see the blades move. The pressure gauge on my pump was broken so I was going by feel - turns out I was running the tires 10psi lower than I thought I was. When I pumped them up to the right pressure then the fork blades were suddenly working again!
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Smithhammer

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Reply with quote  #16 
Quote:
Originally Posted by drwelby


I don't doubt it, but that's why I said classic steel fork. I have a fork I built with the Kaisei imperial oval blades and a 1" Pacenti superlight steerer and that's in a whole different class of flex.


That sounds like a sweet fork - love to see a pic of it. 


Quote:
What I was getting at is that with overly stiff forks people will say "just drop your tire pressure" but you can only go so far with that, especially if your fork has limited clearances.

It gets weirder to figure things out when you have the fat tires and fork working in series - on a recent frame I built I thought the fork was really stiff because I couldn't see the blades move. The pressure gauge on my pump was broken so I was going by feel - turns out I was running the tires 10psi lower than I thought I was. When I pumped them up to the right pressure then the fork blades were suddenly working again!


Yeah....buying a super stiff carbon fork, then realizing it rattles your teeth out of your head and leaves your hands numb at the end of the day, and then attempting to address it by running low pressures in your tires is a bizarre approach to me....but hey, if the "pros" are running carbon forks, then that's what I should want! [biggrin]

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AlanEsh

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Reply with quote  #17 
Quote:
Originally Posted by Smithhammer

Yeah....buying a super stiff carbon fork, then realizing it rattles your teeth out of your head and leaves your hands numb at the end of the day, and then attempting to address it by running low pressures in your tires is a bizarre approach to me....but hey, if the "pros" are running carbon forks, then that's what I should want! [biggrin]

What's bizarre about running 40mm gravel tires at 35-40psi? That's how they were designed; they roll well, grip well, track well, and absorb shock very well. Add a lighter weight carbon fork and where does this solution become inferior to a steel fork with higher pressure tires?
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ljsmith

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Reply with quote  #18 
Quote:
Originally Posted by AlanEsh

What's bizarre about running 40mm gravel tires at 35-40psi? That's how they were designed; they roll well, grip well, track well, and absorb shock very well. Add a lighter weight carbon fork and where does this solution become inferior to a steel fork with higher pressure tires?


I think the point is that tire pressures should be set for the best compromise of rolling resistance and comfort.  If you have to drop your tire pressures lower because you use a carbon fork then you are no longer using ideal tire pressure. Basically your tire pressure should be the same whether you run a carbon or a steel fork.

As far as carbon forks, they can be stiff, flexy or anywhere in between depending on how they are designed.  I have a Whisky No 9 fork that is super stiff, but I also have a 3T Luteus which is very compliant.  You can't just say all carbon forks are super stiff so steel is better.  
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Smithhammer

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Reply with quote  #19 
Quote:
Originally Posted by ljsmith

I think the point is that tire pressures should be set for the best compromise of rolling resistance and comfort.  If you have to drop your tire pressures lower because you use a carbon fork then you are no longer using ideal tire pressure. Basically your tire pressure should be the same whether you run a carbon or a steel fork.


This. 

And personally, I don't run my tires at a higher pressure than 35psi or so, even with a nice compliant fork. To me, it's a double bonus. But then I spend a fair bit of time on rough Rockies gravel, torn up FS roads and singletrack, so I have no problems with the combo of a compliant fork and reasonably low pressures - in fact, I love it. I think the prior point is more about trying to use tires to address the shortcomings of a fork (unnecessarily stiff), which in my opinion, is addressing the wrong thing.

Quote:
As far as carbon forks, they can be stiff, flexy or anywhere in between depending on how they are designed.  I have a Whisky No 9 fork that is super stiff, but I also have a 3T Luteus which is very compliant.  You can't just say all carbon forks are super stiff so steel is better.  


True. 

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