XM Carbon Speed Race Frame - The wish list

[PeterXu]

This should be final version and we do steepen the STA.

[Sander2177]

This should be final version and we do steepen the STA.

Yep looks great peter!
Quick get it into production ASAP 54cm first   

[Sakizashi]

Is there any similarity in the tri-bike adjacent geometry to this concept from around 1991?

https://www.bikeforums.net/classic-vintage/1293665-road-test-bike-review-1991-clark-kent-ax-1-alexi-grewal.html

Very cool article. It's not a bike I am familiar with.

The relative intent is the same. Obviously, there is a vast difference between the quintessential race bike geo and fits of this decade vs. 3 decades ago. Some elements, like the steep STA and the long front center relative to the CS lengths, are similar, but we also need to keep in mind that bar geometries are different, as are the ways that saddles fit / the lengths of their rails. Given that this bike faded into obscurity, I hope its different this time around.

[patliean1]

This should be final version and we do steepen the STA.

Wouldn't the overall effective top tube length (figure O) shorten with a steeper seat tube angle?

For a size Large, the top tube length (figure O) is the same on both the old and newly updated geometry chart 564mm

[voidptr]

This should be final version and we do steepen the STA.

Please also consider increasing the BB drop to at least 75mm. Everyone is on 30mm+ tires and short cranks. 70mm is outdated.

[jfcb]

So while yes I would appreciate seeing a more progressive approach to frame design, I also know first-hand how finicky athletes can be. At least here in Chicago-land. They mostly just want budget alternative to brands they are already well familiar with.

This pretty much captures the winning recipe behind the strong sales of Chinese frames.
"Progressive" design, geometry and looks can be a hit or a miss, which is a risk you might not want to take as a company knowing you want your investment to pay off. In particular with new technology and designs like a special steerer tube/ fork require a lot of testing, iterations and hence time, because in the field failures and recalls can cost you a lot of money as a company. So I beleive XMCS made a good choice with their aero frame.

[Leclerc]

I am perhaps a little more modest, and I was satisfied with the original frame geometry. However, I am more interested in the approximate price and availability of larger frames.

[glepore]

First, because there is still a lot of learning about this concept left to do, and a lot of potential UCI regulations that could reduce your investment to rubble overnight. I look at VB, and I do not see that kind of bike unless you are looking at the larger two sizes. If anything, it's more of a toe dipped into the water to create some differentiation. I DO see it with Ridley, and there is a lot to learn by looking at how people are actually riding the Noah Fast 3.0 in real life, but those bikes are pretty rare outside of situations where you see riders sponsored by Ridley.

But the bigger issue is that even with the Ridley existing, it's still mostly a novel and niche concept. On the average 30-person group ride, 0-1 persons are thinking about this. In my experience, that one person is either a serious crit racer or a high-level triathlete.

I agree that the sort of geo you're talking about works, but its mostly a niche concept for a reason. If you're not always in "speed mode" that sort of geometry is either wasted or not comfortable. I've not been on a Noah Fast, so grain of salt, but practically every review says the same thing, "great bike, single focus". The sl8 and their ilk are popular not because they're progressive, but because the are "progressive enough" while still being absolutely wonderful all around bikes to ride daily.
I doubt the market of "serious crit racers and high level triathletes" would support Peter's ambitions.

[toxin]

I categorically disagree that progressive geometry is uncomfortable. Reviewers tried to set the noah up like their 73 sta climbing bike and they found it uncomfortable. I find my "progressively" set up bike way more comfortable than it was with a traditional set up, and I find myself wanting an even steeper sta (75ish rn) and more reach. Whenever I've heard of somebody who did try a properly set up progressive fit bike, the feedback has always been positive

[kubackje]

I categorically disagree that progressive geometry is uncomfortable. Reviewers tried to set the noah up like their 73 sta climbing bike and they found it uncomfortable. I find my "progressively" set up bike way more comfortable than it was with a traditional set up, and I find myself wanting an even steeper sta (75ish rn) and more reach. Whenever I've heard of somebody who did try a properly set up progressive fit bike, the feedback has always been positive

Isn't having too much weight in the front a problem for many people? Which can cause pain in the hands, wrists, shoulders etc. Maybe I need to understand this fit more.

[voidptr]

Isn't having too much weight in the front a problem for many people? Which can cause pain in the hands, wrists, shoulders etc. Maybe I need to understand this fit more.

[toxin]

If weight on the hands is a problem for someone, they shouldn't be looking at race oriented bikes in the first place and buy an endurance bike.

[Sakizashi]

I agree that the sort of geo you're talking about works, but its mostly a niche concept for a reason. If you're not always in "speed mode" that sort of geometry is either wasted or not comfortable. I've not been on a Noah Fast, so grain of salt, but practically every review says the same thing, "great bike, single focus". The sl8 and their ilk are popular not because they're progressive, but because the are "progressive enough" while still being absolutely wonderful all around bikes to ride daily.
I doubt the market of "serious crit racers and high level triathletes" would support Peter's ambitions.

Agree that the market that has a strong desire for that product today is too niche and its probably too much of a lift to try and grow it for a company like XMCS. It could be like MTB tires for gravel race bikes, where it started with a 27.5 niche for ultra endurance gravel racers and is turning into a requirement for new frames, but at the 29er size. Where is is right now is probably not where it will be if it takes off. That uncertainty is an opportunity but also a risk.

Disagree on why it's a niche concept. It's easiest to think of the modern iteration as moving the BB back rather than changing multiple numbers, but the problem is that most people believe in the church of stack and reach; we are literally changing the location of the reference point for the geometry, so most people think it's this huge change they can't adjust to. The perception of it being a huge change + being "new" is just where we are with the concept.

Isn't having too much weight in the front a problem for many people? Which can cause pain in the hands, wrists, shoulders etc. Maybe I need to understand this fit more.

In my experience, no, not really if you can move your arms under your body. That does stress your core more, though.

That said, nearly everyone I know who regularly rides a bike fit like this is above 3.5w/kg in terms of FTP (just as a fitness benchmark), with a lot of us over 4 or 4.5 even in our detrained winter state. Those higher sustained outputs mean that when riding, we naturally have much less weight through our hands. The counter to that is that even those fit folks do a lot of social riding and lower-intensity riding, and don't seem to complain about it.

[srf0638]

I categorically disagree that progressive geometry is uncomfortable. Reviewers tried to set the noah up like their 73 sta climbing bike and they found it uncomfortable. I find my "progressively" set up bike way more comfortable than it was with a traditional set up, and I find myself wanting an even steeper sta (75ish rn) and more reach. Whenever I've heard of somebody who did try a properly set up progressive fit bike, the feedback has always been positive

If weight on the hands is a problem for someone, they shouldn't be looking at race oriented bikes in the first place and buy an endurance bike.

"Except for all the people who can't ride them, these fits are great!"

(Shitposting aside, you reckon "properly set up" includes short cranks?)

[pylepilot]

Request the handlebars have some extra long reach so I can rest my forearms on the tops (with my hands on the hoods) in an aero 90 degree elbow position, and stay there for hours. Do this to the maximum extent while staying within the UCI rules.  Or provide two options, one within the UCI rules and then one that does not comply with the UCI rules that allows extra long reach.  Thanks.