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RidingAgain

Carbon Road Forks... Are They Good For Gravel?

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I recently bought an old '07 Scott Speedster S20 for a few bucks. The frame has two hairline cracks, one on either side of the head tube, maybe an inch in length. It seems these bikes suffered from this problem. The rest of the frame is perfect and looks like it got very little use, iincluding the carbon fork. I've been building up my stash of parts for a gravel bike or single speed build... Can this fork be used?

IMG_3979.jpg

Edited by RidingAgain

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Here's someone thoughts on the matter... Taken from an online forum thread about steel vs. carbon forks for gravel bikes...

"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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No way I would use that. Aside from the fact it's 12 years old from a bike that was ridden hard enough to crack the head tube and who knows if the previous owner used a torque wrench on the stem clamp bolts, it has caliper brake mounts which make it useless for a gravel bike. Even long-reach calipers will only clear up to maybe 30mm tires.

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 I saw that bike in the Goodwill on S. Lamar last weekend and immediately noticed the crack in the headtube. It's on the back, right above the headset cup. Looks like someone rammed it into a solid object. The wheels looked pretty borked too. All I could think was that I feel sorry for the unlucky soul who buys it.

Might be worthwhile for the drivetrain parts, but I'd scrap that frame. Remove that fork and take a good look at the crown and legs first too.

Edited by mack_turtle

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I doubt you're going to fit anything bigger than 28mm tires in that bike. Maybe even only 25. After riding several gravel routes and races around Texas, that's not going to cut it. It's going to be miserable.

Edited by mack_turtle

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12 hours ago, ebflo said:

No way I would use that. Aside from the fact it's 12 years old from a bike that was ridden hard enough to crack the head tube and who knows if the previous owner used a torque wrench on the stem clamp bolts, it has caliper brake mounts which make it useless for a gravel bike. Even long-reach calipers will only clear up to maybe 30mm tires.


Researching road bike forums, it seems that the '07 S20 frame had a design flaw that caused head tube of some frames to crack after just a few rides. Scott knew this and was replacing them with updated frames. Some riders reported that the cracks would show up in as little as a hundred miles of riding, which isn't very much. And none of the comments I read spoke of hard riding. And looking at the bike, you can see it hasn't been ridden much. The frame isn't any good, but the forks look perfect.

Good call on the caliper brakes, I hadn't thought of that.

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You have no way of knowing what that bike has been through. It might have fallen off a car rack at 80mph. The rims were all scratched up as well.

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11 hours ago, mack_turtle said:

 I saw that bike in the Goodwill on S. Lamar last weekend and immediately noticed the crack in the headtube. It's on the back, right above the headset cup. Looks like someone rammed it into a solid object. The wheels looked pretty borked too. All I could think was that I feel sorry for the unlucky soul who buys it.

Might be worthwhile for the drivetrain parts, but I'd scrap that frame. Remove that fork and take a good look at the crown and legs first too.


Actually you missed the second one... On the left side, just under the headset cup. And no, given what I found out from my research, and the fact that the rims are fine, I don't think anyone rammed into anything. It looks like what happened is exactly what happened to a lot of other similar frames... Bad design that caused stress fractures.

I'm taking it apart today and will look at the fork carefully again, but from my previous inspection it looked fine also.

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8 minutes ago, mack_turtle said:

You have no way of knowing what that bike has been through. It might have fallen off a car rack at 80mph. The rims were all scratched up as well.

Of course... But if it did fall off a car rack at 80mph, it must have done a perfect landing in someone's soft arms.

There are no dings or even major scratches on the frame. The rims are only scratched on the edges that would have been touching the ground as it was moved around. This would have been because it had no tires. The brake facing and the inside area of the rim show little wear, the spokes are perfect, as are the hubs.

Overall, it was a great buy.

I just wanted to know a little more about the fork relative to riding off road.

Edited by RidingAgain

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