Is there a science to building metal bike frames?

[vespasianus]

Originally Posted by tomato coupe

It's a 14% difference, from 21.5mph to 24.5mph. That's a huge change.

Huge is a relative term but honestly, I am more than impressed with those guys in 1952. With those bikes, those gears, that nutrition and those roads. Call me mega impressed.

And imagine a modern rider doing a Jacque Anquetil:

"To prepare for a race there is nothing better than a good pheasant, some champagne and a woman."

And call me confused. Are people arguing if newer bikes are faster than older bikes?

[tomato coupe]

Originally Posted by vespasianus

Huge is a relative term but honestly, I am more than impressed with those guys in 1952. With those bikes, those gears, that nutrition and those roads. Call me mega impressed.

Yes, it's all relative. A 14% increase from 7mph to 8mph isn't that much, but a 14% increase from 21.5mph to 24.5mph, is a bigger deal.

[vespasianus]

Originally Posted by tomato coupe

Yes, it's all relative. A 14% increase from 7mph to 8mph isn't that much, but a 14% increase from 21.5mph to 24.5mph, is a bigger deal.

And I would add, the work needed to go from 7 to 8 MPH is very different than from 22-25MPH or even from 34-35 MPH.


With athletics, you can always wonder about things. For example, how would Merckx or Fausto Coppi be on a modern bike?

At the same time, if the modern racers were asked to ride a bike from 1952, how fast would they be (say in something like Liège–Bastogne–Liège).

[tomato coupe]

Originally Posted by vespasianus

And I would add, the work needed to go from 7 to 8 MPH is very different than from 22-25MPH...

That's my point.

[Butch]

To bring back frame design and like materials. Over my years I have built my own prototypes and ridden many Moots prototypes and I found some significant differences in bikes depending on geometry and to a lesser extent materials.

In the late 80's at Co-Motion I built a frame out of Reynolds 653. This was a 753 rear triangle, a 653 main frame and a 531 fork. I built it with really short chainstays, 395?, and a 75 degree seat angle and I think a 74 head. Very light steel frame, especially rear triangle and a short wheelbase. I was reasonably fit, could sprint pretty well. That bike would jump all over the place in a sprint. I believe that was a combo of geo and light materials.
After I crashed hard in a race I rode a Columbus SL frame we had built for stock that had 73 parallel angles and 410 chainstays?. The differences between the two was crazy. The 653 frame was a climbing bike and the SL frame was way better for all around. Noticeably heavier but...

At 21 years at Moots we built a lot of test mules to try different bb's, tubesets and geometries for several different models. The differences were often noticeable. Pretty much all of the time the application and the rider fit were what separated the feel. These were stock frames we worked on. Once it goes to custom, good builders know how to hit the sweet spot for a particular rider.

Biggest difference you can make with bike feel past fit IMO is wheels

I think the "science" behind all of this is "build it ride it"

[gibbo]

^^This x 1000^^


Sent from my iPhone using Tapatalk

[martl]

Originally Posted by Toddykins

Wait - Are you trying to argue that dozens of watts won’t make a difference? Dozens of watts is a huge change. Go try for yourself and see how ‘easy’ it is to raise your ftp by that much...

Yes, dozes of watts make a huge difference. I raced with a powermeter back in the days.

My point was: If a frame designed by those wizards from Giant or Specialized gave you dozens of watts advantage, it would be noticeable in race results, as that would amount to 10-20% of the average power output even in a pro race. EPO gave you around 5% and that resulted in 1-2-3 solo finishes by certain "pioneer" teams.... *Mapei* *cough*

Let me make this clear: With no amount of trickery is it possible to design a frame that gives dozens of Watts difference over a state of the art frame made 20 years ago, or even one made from lugged SLX. Not in the wind tunnel, not in the structure design, not in the material selection.*)

Everyone telling you otherwise is a bull**** merchant trying to sell you stuff, or has no idea what he's talking about.


*) if you feel otherwise, i'm open to arguments and happy to discuss how that can be achieved. Invalid answers include "i saw an ad with a guy in a labcoat and a picture of a bike in a wind tunnel" and "a guy who spent 12000$ on a Speci told me it was faster than his old ride"

[ERK55]

Need to re-name this thread- the watts thread.

[.RJ]

Originally Posted by martl

My point was: If a frame designed by those wizards from Giant or Specialized gave you dozens of watts advantage

Not when they all have similar frames

If everything is aero, nothing is aero. Again, this is a sport won or lost by millimeters at the line....

[cyan]

Is there any real difference in how a bike rides between TIG, fillet brazed, and lugged construction?

[Black Dog]

Originally Posted by cyan

Is there any real difference in how a bike rides between TIG, fillet brazed, and lugged construction?

No. As long as the tubes are all the same.

[Black Dog]

Originally Posted by martl

Yes, dozes of watts make a huge difference. I raced with a powermeter back in the days.

My point was: If a frame designed by those wizards from Giant or Specialized gave you dozens of watts advantage, it would be noticeable in race results, as that would amount to 10-20% of the average power output even in a pro race. EPO gave you around 5% and that resulted in 1-2-3 solo finishes by certain "pioneer" teams.... *Mapei* *cough*

Let me make this clear: With no amount of trickery is it possible to design a frame that gives dozens of Watts difference over a state of the art frame made 20 years ago, or even one made from lugged SLX. Not in the wind tunnel, not in the structure design, not in the material selection.*)

Everyone telling you otherwise is a bull**** merchant trying to sell you stuff, or has no idea what he's talking about.


*) if you feel otherwise, i'm open to arguments and happy to discuss how that can be achieved. Invalid answers include "i saw an ad with a guy in a labcoat and a picture of a bike in a wind tunnel" and "a guy who spent 12000$ on a Speci told me it was faster than his old ride"

Well said. There is no real empirical Data the shows that the frame provides the large scale increases in aerodynamics that are being claimed. Differences yes, but not huge when all other factors are accounted for. The idea that one bike is way faster than another (bike being the frame and fork) is simply not true. Especially when the claims are anecdotal. Humans are just about the worst testing device for these claims since our perceptions are simple poor at best and subject to so much inherent bias.

[.RJ]

Originally Posted by Black Dog

Humans are just about the worst testing device for these claims since our perceptions are simple poor at best and subject to so much inherent bias.

Yup. And even then, all the bike brands can do is stack up the possible lab test advantages in their favor, and they might still get beaten by an 'old tech' rim brake bike in the sprint after 300k.

[qnz]

Originally Posted by Butch

To bring back frame design and like materials. Over my years I have built my own prototypes and ridden many Moots prototypes and I found some significant differences in bikes depending on geometry and to a lesser extent materials.

In the late 80's at Co-Motion I built a frame out of Reynolds 653. This was a 753 rear triangle, a 653 main frame and a 531 fork. I built it with really short chainstays, 395?, and a 75 degree seat angle and I think a 74 head. Very light steel frame, especially rear triangle and a short wheelbase. I was reasonably fit, could sprint pretty well. That bike would jump all over the place in a sprint. I believe that was a combo of geo and light materials.
After I crashed hard in a race I rode a Columbus SL frame we had built for stock that had 73 parallel angles and 410 chainstays?. The differences between the two was crazy. The 653 frame was a climbing bike and the SL frame was way better for all around. Noticeably heavier but...

At 21 years at Moots we built a lot of test mules to try different bb's, tubesets and geometries for several different models. The differences were often noticeable. Pretty much all of the time the application and the rider fit were what separated the feel. These were stock frames we worked on. Once it goes to custom, good builders know how to hit the sweet spot for a particular rider.

Biggest difference you can make with bike feel past fit IMO is wheels

I think the "science" behind all of this is "build it ride it"

This is the kind of feedback I was looking for. Thanks for sharing your experience.

Its hard to tell the difference from pictures how a Moots rides vs a frame from Joe Welder. But this comment does show that there is a science to what is an optimal frame angle + frame material that an experienced builder has prototyped and tested.

[Mark McM]

Originally Posted by martl

My point was: If a frame designed by those wizards from Giant or Specialized gave you dozens of watts advantage, it would be noticeable in race results, as that would amount to 10-20% of the average power output even in a pro race. EPO gave you around 5% and that resulted in 1-2-3 solo finishes by certain "pioneer" teams.... *Mapei* *cough*

Let me make this clear: With no amount of trickery is it possible to design a frame that gives dozens of Watts difference over a state of the art frame made 20 years ago, or even one made from lugged SLX. Not in the wind tunnel, not in the structure design, not in the material selection.*)

Everyone telling you otherwise is a bull**** merchant trying to sell you stuff, or has no idea what he's talking about.


*) if you feel otherwise, i'm open to arguments and happy to discuss how that can be achieved. Invalid answers include "i saw an ad with a guy in a labcoat and a picture of a bike in a wind tunnel" and "a guy who spent 12000$ on a Speci told me it was faster than his old ride"

Just who is claiming that a frame cane save dozens of Watts of power? I think you are mis-representing the aero bike power savings that are being claimed. Generally, claims will be made for power savings of aero bicycles - which includes not just the frame, but also the wheels, the handlebar, stem, seatpost, etc. The aerodynamic drag differences between entirely different bicycles can be dozens of Watts - even if the savings of the frame alone is much less.

Your comments that the claimed power savings of aero bikes can't be true because of the relatively low average power during an entire race is also a mis-representation. Savings of dozens of Watts are only claimed under certain conditions - for example, in still air at 30 mph. Nobody is claiming that you'll have anywhere near dozens of Watts of power savings under typical riding conditions (which would drafting in pack when racing, or at lower speeds when not racing).

So when does the power savings of an aero bike make a significant difference? Under short duration but critical race situations, such as breaking away solo or with a small group, or in a final sprint. The rest of the time there are still real power savings, just much smaller.