• 01-14-2019
    Coolhand
    No Dentists in the ProTour. . .
  • 01-14-2019
    velodog
    Quote:

    Originally Posted by Coolhand View Post
    No Dentists in the ProTour. . .

    You must spread some Reputation around before giving it to Coolhand again.
  • 01-14-2019
    taodemon
    Quote:

    Originally Posted by tlg View Post
    Daaanngg. Do you need a sponge to soak up all that irony?

    YOU made the claim... in Post #1.
    So PLEASE follow your advice and support your claim with research.

    Pretty much this.

    YMSSRA.

    Aero has only been tested by everyone from PHDs at bike companies to independent PHDS, to independent bike mags to joe blow all unscientific on his local strava segments...

    Just because you choose to ignore something doesn't mean it doesn't exist. But don't let that stop you from enjoying your slower non aero ti bike.

    Quote:

    Originally Posted by PBL450 View Post
    Nothing to do with Ti but Spesh is trying to race their new Al at TDU. I think thatís pretty cool.

    Peter Sagan to debut alloy frame and tubeless tyres in Down Under Classic - Gallery | Cyclingnews.com

    Sagan managed second on it I guess. "New" is subjective though as the sprint frame has been around for a few years, the only new part being the disc brakes. :p
  • 01-14-2019
    exracer
    Quote:

    Originally Posted by Marc View Post
    I already told you there was, and even told you specifically when it happened and who manufactured it.


    Why do you ask questions on this forum...then argue with answers you clearly haven't read?

    Even though it happens to be the reality of things, he didn't like your answer therefore it has to wrong.
  • 01-14-2019
    Notvintage
    Quote:

    Originally Posted by Akirasho View Post
    Also, remember that professional road racing (at least) is a marketing tool and rolling billboard.

    Hence the carbon clinchers that are no better (typically worse) than aluminum rims and idiotic disc brakes (driven largely by the carbon clinchers they pushed).
  • 01-14-2019
    Notvintage
    Quote:

    Originally Posted by Waspinator View Post
    I donít think your strength/stiffness vs weight argument has been scientifically proven.

    Young's modulus of Toray T700S (common in road bikes) is 230 Gpa, and garden variety Ti-6AL-4V is around 115 Gpa. Cooked pasta noodle to uncooked respectively.
  • 01-14-2019
    Notvintage
    At this point I must ask. . Does Trek make good titanium frames? LOL
  • 01-14-2019
    Alaska Mike
    Don't get me wrong, I loved my Moots Compact so much that I bought a Vamoots RSL to build up as a race bike. At my level, the bike isn't what's making me progressively slower. The trade-offs in performance are compensated by the durability, serviceability, and aesthetics (yes, I'm shallow). And again, the trade offs are minimal at my level, which is far, far below the professional level, and nobody is paying me to ride their bikes.

    I love titanium as a bike frame material, but it has it's limits- as does every material.
  • 01-14-2019
    TimV
    Titanium bicycle frames are expensive to produce, even in mass quantities. Carbon fiber frames are much less expensive by comparison and can be built to be nearly as light, stiff, strong, etc.

    All of the big name companies build high end carbon road bikes and therefore race high end carbon road bikes. This is simple marketing (race on Sunday sell on Monday). Whether or not titanium might be marginally better than carbon is frankly irrelevant.

    My primary whip is a custom titanium Kish, btw.
  • 01-14-2019
    OldChipper
    Quote:

    Originally Posted by Peter P. View Post
    I don't know of any documentation, but I find this video interesting.

    https://www.youtube.com/watch?v=ehIEKHZOl-8

    Carbon fiber is now king because the frame can take an almost infinite number of shapes, leading to annual market changes and market driven claims of "stronger, stiffer, lighter, more compliant..." which drives demand and sales. Titanium is not amenable to such shaping (nor does it need to be, to be competitive).

    Outstanding example of flawed experiment. The tubes were not designed for having a truck driven over them, they were designed for the stresses experienced by bicycle frames.

    This is the same flawed argument that the disc brake fans make. Itís not a questions of ďbetterĒ itís a question of ďgood enough for the application.Ē


    Sent from my iPad using Tapatalk Pro
  • 01-14-2019
    OldChipper
    Quote:

    Originally Posted by Waspinator View Post
    Iíd be very curious to talk to a company that has real engineers.... ie individuals with PhDs in material sciences who have conducted well-designed research into various building materials. Boeing, for example, would have actual engineers who have carefully studied the various materials such as Al, Ti, and CF and know their properties well.

    Boeing, Airbus, etc.? You mean the companies whose latest/greatest plane design incorporate copious amounts of carbon fiber composites???


    Sent from my iPad using Tapatalk Pro
  • 01-14-2019
    tlg
    Quote:

    Originally Posted by Waspinator View Post
    I donít think your strength/stiffness vs weight argument has been scientifically proven.

    Uhhh yea... it's been scientifically proven.


    Quote:

    Iíd be very curious to talk to a company that has real engineers.... ie individuals with PhDs in material sciences who have conducted well-designed research into various building materials. Boeing, for example, would have actual engineers who have carefully studied the various materials such as Al, Ti, and CF and know their properties well.
    I'm a real engineer. Although I don't have a PhD in material science. But you could ask a Boeing engineer why they make airplanes structures from carbon fiber and not from titanium. :thumbsup:
  • 01-14-2019
    mfdemicco
    Quote:

    Originally Posted by Alaska Mike View Post

    As much as I love my high-end titanium bikes, they can't compete with my plastic bikes- all "superbikes" of their respective years. The ability to precisely tune the carbon layup just simply cannot be duplicated in production on a metal frame. They're just very, very different animals, each with its own set of advantages and disadvantages.

    That's if you buy that "tuning" really accomplishes anything but market speak. To me, a frame is supposed to be rigid and is a structure to enable the attachment of components in the proper locations. Tires and tire pressure has more effect than frame material. People say that steel rides better, Ti rides better, carbon fiber is too stiff; it's all BS.
  • 01-14-2019
    cxwrench
    Quote:

    Originally Posted by mfdemicco View Post
    That's if you buy that "tuning" really accomplishes anything but market speak. To me, a frame is supposed to be rigid and is a structure to enable the attachment of components in the proper locations. Tires and tire pressure has more effect than frame material. People say that steel rides better, Ti rides better, carbon fiber is too stiff; it's all BS.

    I pretty much agree w/ this, same thing when people talk about wheels and 'ride quality'. So many other things contribute to ride quality before wheels and to be honest frames unless you have some kind of mechanical pivot built into the frame somewhere ala iso-speed.
  • 01-14-2019
    Alaska Mike
    Quote:

    Originally Posted by mfdemicco View Post
    That's if you buy that "tuning" really accomplishes anything but market speak. To me, a frame is supposed to be rigid and is a structure to enable the attachment of components in the proper locations. Tires and tire pressure has more effect than frame material. People say that steel rides better, Ti rides better, carbon fiber is too stiff; it's all BS.

    Have you ever ridden a bike that was too soft in the tail, that flexed the wheels into the brake pads? How about too stiff, that transmitted too much road vibration to the rider or rode like a cement block? Two extremes that the tuning I speak of mitigates. When you're trying to shave weight, where you put your structural strength is very, very important, no matter what material you use. The ability to make very small tweaks to a layup give carbon fiber a very large advantage in this regard.

    I've owned all of the common bike frame materials, across a wide spectrum of performance profiles- usually with the same components attached as I tore down one frameset and built up another. Wheels, tires, and air pressure certainly do matter for ride quality, but frame design does have a very real impact. Certain combinations of parameters are much easier to meet with certain materials.

    I don't chase the latest and greatest. I've said it before- the last real advances in road bike frame design were ten years ago. I prefer simple, reliable, and easy to work on. We'll see how I deal with the PF30 bottom bracket on my RSL (adapted to a GXP crank). I'm tired of fishing cables through frames or press-fitting much of anything. I just want to ride my bike, do a quick clean-up and lube afterwards, and get on with life.
  • 01-14-2019
    mfdemicco
    Quote:

    Originally Posted by Alaska Mike View Post
    Have you ever ridden a bike that was too soft in the tail, that flexed the wheels into the brake pads?

    That's caused by low spoke count wheels with a stiff rim.
  • 01-14-2019
    PBL450
    Quote:

    Originally Posted by taodemon View Post
    Pretty much this.

    YMSSRA.

    Aero has only been tested by everyone from PHDs at bike companies to independent PHDS, to independent bike mags to joe blow all unscientific on his local strava segments...

    Just because you choose to ignore something doesn't mean it doesn't exist. But don't let that stop you from enjoying your slower non aero ti bike.



    Sagan managed second on it I guess. "New" is subjective though as the sprint frame has been around for a few years, the only new part being the disc brakes. :p

    Good correction, thanks. The frame is not new, my bad, the frame being raced at this level is new. I misplaced my new.
  • 01-14-2019
    Alaska Mike
    Quote:

    Originally Posted by mfdemicco View Post
    That's caused by low spoke count wheels with a stiff rim.

    Actually, I've had carbon fiber Cannondale and BMC frames that would flex a 32 spoke aluminum wheel into the brake pads all of the time. The seat/chain stays would flex excessively when out of the saddle. Great ride when cruising around, but when you needed to apply power they worked against you. Same wheelset in another frame would work just fine (same tire clearance). Where they chose to make the frame stiff affected how it performed.
  • 01-14-2019
    PBL450
    The takeaway is that itís expensive and itís just not that good? If there was some clear performance advantage then someone would be using it. Hell, Sky has no budget limits and lives on ďmarginal gains.Ē If there was any incremental advantage theyíd be riding it. At that level, no one is leaving an edge on the table. Iíve never ridden Ti and Iím sure it has its merits, they just obviously arenít falling into the performance category.
  • 01-14-2019
    Alaska Mike
    Aluminum makes a good crit frame because it's cheap (crash replacement) and you can get the required stiffness for the constant effort spikes in a weight that is acceptable. It's why the CAAD and Smartweld frames are so popular. It's not a big leap for this particular race. I think it's cool that he would do it.

    Given the choice, I don't think Sagan would opt for an aluminum frame by any manufacturer over the current options he has in carbon fiber for normal World Tour Races. While the geometry certainly plays into this, material does matter over a four hour race.
  • 01-14-2019
    cxwrench
    Quote:

    Originally Posted by Alaska Mike View Post
    Actually, I've had carbon fiber Cannondale and BMC frames that would flex a 32 spoke aluminum wheel into the brake pads all of the time. The seat/chain stays would flex excessively when out of the saddle. Great ride when cruising around, but when you needed to apply power they worked against you. Same wheelset in another frame would work just fine (same tire clearance). Where they chose to make the frame stiff affected how it performed.

    Explain this please. If you put energy into a frame and make it flex where does the energy go? There are only 2 things that can happen( I'm pretty sure @asgelle would know for sure)...let's see if you get them right.
  • 01-14-2019
    Alaska Mike
    Quote:

    Originally Posted by PBL450 View Post
    The takeaway is that itís expensive and itís just not that good? If there was some clear performance advantage then someone would be using it. Hell, Sky has no budget limits and lives on ďmarginal gains.Ē If there was any incremental advantage theyíd be riding it. At that level, no one is leaving an edge on the table. Iíve never ridden Ti and Iím sure it has its merits, they just obviously arenít falling into the performance category.

    From a performance standpoint, Ti can be made to perform really well. Steel can too, as can aluminum. You can build any of these materials into a very respectable race bike. That said, each has its own set of trade-offs when you're seeking performance, Maybe it's weight. Maybe it's comfort. Maybe it's cost.

    At this moment, carbon is the most infinitely tune-able material for frame design. It's also cheaper to experiment with different layups within an existing mold to achieve a desired result that can be replicated time after time. Metal bikes rely much more heavily on the skill and knowledge of the builder (machinist, welder...) to ensure a predictable outcome.
  • 01-14-2019
    cxwrench
    Quote:

    Originally Posted by Alaska Mike View Post
    From a performance standpoint, Ti can be made to perform really well. Steel can too, as can aluminum. You can build any of these materials into a very respectable race bike. That said, each has its own set of trade-offs when you're seeking performance, Maybe it's weight. Maybe it's comfort. Maybe it's cost.

    At this moment, carbon is the most infinitely tune-able material for frame design. It's also cheaper to experiment with different layups within an existing mold to achieve a desired result that can be replicated time after time. Metal bikes rely much more heavily on the skill and knowledge of the builder (machinist, welder...) to ensure a predictable outcome.

    ^This^
  • 01-14-2019
    Alaska Mike
    Quote:

    Originally Posted by cxwrench View Post
    Explain this please. If you put energy into a frame and make it flex where does the energy go? There are only 2 things that can happen( I'm pretty sure @asgelle would know for sure)...let's see if you get them right.

    In these cases, straight into the brake pads (friction), thanks to the flexible nature of the carbon layup.

    Believe me, I love that wound-up feeling of a well-made steel or titanium frame. I seriously doubt much energy is converted to heat in the case of a bicycle frame, but there are likely parasitic characteristics that differ between each material.
  • 01-14-2019
    cxwrench
    Quote:

    Originally Posted by Alaska Mike View Post
    In these cases, straight into the brake pads (friction), thanks to the flexible nature of the carbon layup.

    Believe me, I love that wound-up feeling of a well-made steel or titanium frame. I seriously doubt much energy is converted to heat in the case of a bicycle frame, but there are likely parasitic characteristics that differ between each material.

    Read my question again. When the frame flexes w/ the initial pedal input...what happens next? You're putting energy into the frame. No...the energy does not go into the brake pads. We're only talking about the frame here. Nothing else. Remember your physics class?