Saturday, May 03, 2008

4 Brano's 'C-Thru' Frame


Brano Meres' C-Thru frame and bicycle, one which he displayed at the NAHBS 2008 earlier this year, is not to be mistakenly confused with an isotruss frame as some of you may. The geometries are quite different. While one has a well defined open lattice structure, this one just has "holes". For more pictures, visit Brano's website link here.

Brano is a mechanical engineer and when I caught up with him last week to ask him what his plans are with this bike, he did mention that "I just wanted to use and test this framed structure for the bicycle. I built just this one frame and I don't want to build another one."

For a fun show bike project, I have to say that it looks really marvelous.

By now ofcourse, you should have known that the isotruss bike (famously the Arantix Delta 7) although very creative and original, has come under overwhelming criticism from critics and riders all over. Personally, when I look at this frame, I first ask the question : "What great need is it satisfying?" Like many people with whom I have exchanged comments, I feel that it is a misapplication of engineering, the costs are over the edge and the aerodynamics and aesthetics are way down there. Even if they do plan on covering this frame up with a sheath, it may, as one engineer told me, lead to the development of inefficient 'eddies' that will probably just double the problems.

Everything that can be done on bicycles in terms of raising stiffness and strength by appreciable quantities has already been done. The other marginal differences are just a way to make you pay more out of your pocket. Out-of-limits stiffness, like I say, is actually counter effective and contributes nothing to performance.

To be a believer, watch videos of Johan Museeuw destroying his competition on relatively "flexible" Colnago steel bikes, including some at the cobbled Paris-Roubaix. Apparently, even steel was stiff enough for him.

As far as the C-Thru and aerodynamics are concerned, Brano said : "I plan to compare it with the standard tubed frame in the wind tunnel, just for the interest."

4 comments:

  1. "Everything that can be done on bicycles in terms of raising stiffness and strength by appreciable quantities has already been done." = Caveman statement!!!!

    How can you say something so middle ages. I really enjoy your blog but this is the first time that I've seen something so out there from you. I don't believe we've done everything and the isotruss may not be the aerodynamic miracle you've been waiting for but surely it may open other doors as most technologies do. A few years ago people thought Gary Fisher and friends were crazy trying to ride in the mountains, now its as big as road riding.

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  2. le blaireau,

    You do have a point and that is as technology advances, we will push further the boundaries. So going strictly with that, my statement was wrong.

    In the months and years ahead, we're going to make further advancements in CNT tubes, we'll probably incorporate self healing tires and tubes and even self repairing paint for bicycles. The cabled bicycle may become history and new manufacturing practices could make acquiring composite structures and metal tubing more cheaper (they already came up with one recently for Titanium).

    But I'm opionated. We've seen that for the past 100 years little has really changed dramatically in frame design. Starley's diamond truss design is relatively unchanged even today. Large diameter tubing brought some appreciable changes to stiffness since it increases as the fourth power of the tube cross-sectional diameter.

    Okay, if the UCI lifts its current limitations of permitted bicycle design, we can factor in all those odd designs that people have come up with over the past few years.

    But again, the big question is, how much of an improvement can they deliver? Neither is there a good peer reviewed scientific paper out there that shows generous amounts of stiffness has anything objective to contribute to cycling performance.

    I remain on the conservative side, and I will say this again, that these new "marginal" technologies that show up every 5-10 years are just a way to make people pay more.

    I appreciate new technology but its also important to get back to the real world. For bicycle companies, its okay to be imaginative/creative. Otherwise, they'd never remain in business. Consumers need not be so naive, in pouring thousands for little or no improvements.

    Thanks for reading! Sorry for the confusions.

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  3. To the first comment,you're quick to quote but you missed out the key point. He mentioned "appreciable". If your brain is so developed as to differentiate between .5mm and .3mm of lateral deflection at the bottom bracket, thats extraordinary. Most people can't and that difference hardly means anything serious to the racing cyclist.I think he was trying to put things into perspective here, not shut down any further ideas on bicycle development.

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  4. Anonymous1:22 PM

    Gary Fisher trying to ride in the mountains has nothing to do with the topic at hand, which is stiffness in bicycle frames.

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Thank you. I read every single comment.