Thread: Pursuit Cycles
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Old 08-30-2021, 09:58 PM
nmrt nmrt is offline
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Join Date: Mar 2012
Posts: 1,940
Hi Carl,
Ever since the Aethos came out, I asked in multiple places about what had Specialized done to achieve this low weight. No one gave me the answer. Most people do not care about weight. But for me, at least from an academic standpoint, it was worth knowing.

Your answer is much appreciated. I think I understand how the Aethos has been optimized.

Thank you for your time. And keep building those Pursuits. One day I will be in line for a Pure Road!

Originally Posted by Carl Strong View Post
OK nmrt, this subject has a lot of layers so to keep from getting too far in the weeds I'll address your main questions in general. You have three basic questions; how do they make the frame ride so well, what do they know or do that allows them to make it so light, and can we make a bike equally as light.

I sort of covered the ride quality question. Basically everyone has a different idea of ride quality. I think the nature of the Atheos at such a light weight is to be somewhat soft. At 145 pounds, compared to a lot of frames that focus on stiffness, I can imagine that it would feel a lot better to you then something with a lot more stiffness designed into it. At the end of the day everyone has a different idea of a "good" ride and how that is accomplished will depend on the frame size, geo and rider weight. In this case my guess is that the Atheos just happens to meet your needs.

As I recall, the Atheos claimed weight was a medium size prior to paint. Our comparable weight would be about 125 grams heavier. We could easily take most of that difference out by removing the metal we use in the frame. Those items are the BB, axle inserts, cable management, etc. Our frames are built to last a lifetime and we consider these features to be very important. So Specialized and Pursuit have two different priorities. Our focus is on a long service life at a competitive weight.

The final question; what do they know or do to make the bike so light? I put this to our head of engineering Jared Nelson PhD who works in academia. He spends a lot of time in research at the pointy end of the spear in composites development. Typically advancements in this area do not come from the bicycle industry, it's too small, they come from Aerospace or DOD. He's seen nothing groundbreaking that we could point to that would allow them to easily reduce the weight. But he does have a few thoughts and I've pasted them below.

I think Specialized has done a few neat things with this frame.
  • I am seeing that they have gone back to basics and are pursuing some avenues of improvement/optimization. Here are my quick impressions related to your questions/comments:
  • I would speculate that they have pursued true optimization of the carbon fiber material(s) they are using to ensure shape and orientation yield an ideal product. Tech to support this has evolved over the last decade and it is truly becoming affordable.
  • I am confident that they have tightened up their manufacturing process and am guessing they are doing so in both manufacturing and inspection. Better consistency allows for better optimization which is ensured*by improved inspection.
  • Likely, they also have focused on ride based testing and are likely utilizing the data they gather beyond pass/fail. Again, these data support the overall optimization. The Aethos has gone in the direction of simplification with removal of many components. This significantly contributes to the low advertised weight without compromising ride.

Most of these items require significant resources and it appears Specialized has pointed a large number of them at this frame. Overall, I like that they are pushing the industry. I wish there had been some transformative material or manufacturing discovery as we are all in pursuit of that goal.
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