My Thoughts on Frame Choice

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Comments

  • Grill
    Grill Posts: 5,610
    Pross wrote:
    Open your ride, click on the performance tab above the ride profile and it will show a graph. Tick the speed box (and turn off the other 2 for clarity). You can then drag the cursor along the line and it will tell you what speed you were doing at any given point.

    Aha....I just know that. OK thanks for the info. I'll do a bit more thorough testing on the Chinese frame against the S-Works Roubaix and report back the results. I'll try to put on exactly the same wheels too to get as close performance comparison as possible.

    Thanks again for the info.

    Why? What's the point? The only person who appears to care is you...
    English Cycles V3 | Cervelo P5 | Cervelo T4 | Trek Domane Koppenberg
  • Why not? I guess there are people out there who have the same questions as me and try to prove the same thing: whether different frames give you better/less performance.
  • Grill
    Grill Posts: 5,610
    Any change you perceive will have more to do with the difference in geometry and position as opposed to the frame itself. The only way to achieve the point that you're trying to prove would be to test the actual frame against your knock-off. As others have pointed out the likelihood of your frame and components failing is proportionally much higher than proper branded equipment. Would you rather fly in an Airbus or Dengfu?

    I still can't get over how much your bike weighs...
    English Cycles V3 | Cervelo P5 | Cervelo T4 | Trek Domane Koppenberg
  • whats the point of this thread?
  • neeb
    neeb Posts: 4,467
    whats the point of this thread?
    That's the problem - the point isn't very well defined. It's not clear whether the OP is interested in whether different frame geometries and fits make a difference to speed (they clearly do), or whether frame build and materials make a difference, assuming that fit is the same (they may do, but it's more debatable and more subtle, and it depends what sort of "speed" you are talking about).

    The question in its current form can't be answered, hence some of the answers are not very helpful.. :wink:
  • neeb wrote:
    whats the point of this thread?
    That's the problem - the point isn't very well defined. It's not clear whether the OP is interested in whether different frame geometries and fits make a difference to speed (they clearly do), or whether frame build and materials make a difference, assuming that fit is the same (they may do, but it's more debatable and more subtle, and it depends what sort of "speed" you are talking about).

    The question in its current form can't be answered, hence some of the answers are not very helpful.. :wink:

    i dont think there is a question, it reads like a blog post, and trying to convince a chinese frame is just as good as a genuine one, and that expensive frames are not worth, simply as he bought a chinese frame.

    personally i value the warranty and confidence inspired by a product that i know has been produced by someone who is supposed to have strict quality controls and would be duly monitored as such, rather than some knockoff, that may well be fine, but has no guarantees
  • Pross wrote:
    Open your ride, click on the performance tab above the ride profile and it will show a graph. Tick the speed box (and turn off the other 2 for clarity). You can then drag the cursor along the line and it will tell you what speed you were doing at any given point.

    Aha....I just know that. OK thanks for the info. I'll do a bit more thorough testing on the Chinese frame against the S-Works Roubaix and report back the results. I'll try to put on exactly the same wheels too to get as close performance comparison as possible.

    Thanks again for the info.

    Where do you think your Roubaix was made?

    This thread is a waste of everyones time. You obviously haven't got a clue what you're going on about so how can you seriously even consider 'testing' a frame?
  • Pross wrote:
    Open your ride, click on the performance tab above the ride profile and it will show a graph. Tick the speed box (and turn off the other 2 for clarity). You can then drag the cursor along the line and it will tell you what speed you were doing at any given point.

    Aha....I just know that. OK thanks for the info. I'll do a bit more thorough testing on the Chinese frame against the S-Works Roubaix and report back the results. I'll try to put on exactly the same wheels too to get as close performance comparison as possible.

    Thanks again for the info.

    Where do you think your Roubaix was made?

    This thread is a waste of everyones time. You obviously haven't got a clue what you're going on about so how can you seriously even consider 'testing' a frame?

    is his strange point, not really where its made, we all know most frames are churned out in the orient, but rather that knockoff unbranded cheap chinese carbon is just as good as 'official 'branded' carbon.
  • slowbike
    slowbike Posts: 8,498
    Pross wrote:
    Open your ride, click on the performance tab above the ride profile and it will show a graph. Tick the speed box (and turn off the other 2 for clarity). You can then drag the cursor along the line and it will tell you what speed you were doing at any given point.

    Aha....I just know that. OK thanks for the info. I'll do a bit more thorough testing on the Chinese frame against the S-Works Roubaix and report back the results. I'll try to put on exactly the same wheels too to get as close performance comparison as possible.

    Thanks again for the info.

    Where do you think your Roubaix was made?

    This thread is a waste of everyones time. You obviously haven't got a clue what you're going on about so how can you seriously even consider 'testing' a frame?

    is his strange point, not really where its made, we all know most frames are churned out in the orient, but rather that knockoff unbranded cheap chinese carbon is just as good as 'official 'branded' carbon.

    .... without thinking that perhaps not all carbon is the same and the "knockoff" unbranded frames may have design flaws in them - so might the branded ones, but at least you've got a decent comeback against a known brand - ie the Carbon fork recall on Specialized recently....
  • precisely.

    personally i wouldnt risk it. i value my teeth.
  • ai_1
    ai_1 Posts: 3,060
    I'll do a bit more thorough testing on the Chinese frame against the S-Works Roubaix and report back the results. I'll try to put on exactly the same wheels too to get as close performance comparison as possible.
    I think your aspiration to generate useful data from which we can all gain is commendable. However, as others have said, it's unclear what exactly you intend to test and it seems clear that the sort of testing you have in mind will not be rigorous enough to be useful.

    It's possible to draw conclusions from almost any set of data. That doesn't mean the conclusions are justified or correct. In industry and even academia, it's common for people to find trends and evidence where there are none. In a case such as this where there are huge numbers of variables few of which can be normalised or constrained it would be crucial to clearly define exactly what you wish to learn. If your intention is to determine "Which frame is fastest?" I would suggest it will be impossible for you to demonstrate that.
    Useful and valid scientific testing (which is what you seem to be proposing) is more difficult to do properly than most people seem to think. I think you'd be surprised how often engineers, physicists and others run into trouble not with the theory of their hypothesis but in the design, execution and analysis of the testing to prove it.

    By all means assemble your average speeds by frame and plot a graph but don't attempt to draw conclusions as to frame specific performance factors.
  • earth
    earth Posts: 934
    Ai_1 wrote:
    and that light wheels make a 15% gradient feel like 5%.

    When I got my 1kg carbon tubulars I did feel that they took 3% off a
    gradient.
  • Hi all,

    Thanks for all the feedback. OK my post could have been a waste of time, but if it is a waste of time then why do you even bother reading and replying, no?

    Anyway, we will always have people in this forum asking opinions about different frame's performance. Some of the answers are always "test ride it yourself". Now that I have tried different frames for a period of time then I have every right to report it, don't I? If you think that my testing is not thorough enough or doesn't prove anything then yes of course, I wouldn't have had the proper platform like most of you wouldn't too: eg. professional wind tunnel testing, etc to collect proper data.

    Therefore, my conclusion is, other than geometry, body positioning and weight, the actual frame itself is comparable between brands, and I'm talking knock-offs vs originals and originals vs originals.
  • Grill
    Grill Posts: 5,610
    So you rode apples and then oranges and concluded that they are in fact both fruit. Congrats.
    English Cycles V3 | Cervelo P5 | Cervelo T4 | Trek Domane Koppenberg
  • Hi all,

    Thanks for all the feedback. OK my post could have been a waste of time, but if it is a waste of time then why do you even bother reading and replying, no?

    Anyway, we will always have people in this forum asking opinions about different frame's performance. Some of the answers are always "test ride it yourself". Now that I have tried different frames for a period of time then I have every right to report it, don't I? If you think that my testing is not thorough enough or doesn't prove anything then yes of course, I wouldn't have had the proper platform like most of you wouldn't too: eg. professional wind tunnel testing, etc to collect proper data.

    Therefore, my conclusion is, other than geometry, body positioning and weight, the actual frame itself is comparable between brands, and I'm talking knock-offs vs originals and originals vs originals.

    not when it breaks
  • neeb
    neeb Posts: 4,467
    And even if it doesn't break, there's no doubt in my mind that there are differences between carbon frames even when geometry, setup and weight are identical. I have had carbon frames with effectively identical geometry and identical setup with the same wheels and components fitted, which were distinctly different to ride due to differences in rigidity (probably torsional stiffness). These differences do exist and are perceptible, whether or not they make any real difference to performance. Just as with safety, it's a bit of a lottery what you are going to get with a Chinese frame from ebay - some may be good, some not. At least with the reputable brands there should be some sort of quality control in place such that all of the frames that are labelled the same should be similar in terms of performance.
  • this thread has potential. an OP refusing to believe all evidence to the contrary and trying to justify, to himself it seems, (otherwise why post about it) buying a chinese 'knockoff' rather than from a 'reputable' brand, by saying there are no differences.

    well you pays your money and takes your choice. if you buy an ebay chinarello type frame, you may get a great deal, but you will always have a nagging doubt int he back of your head about it.
  • Htron
    Htron Posts: 47
    A chinarello frame that had snapped, and that was stuffed with Chinese newspaper. Not to mention the rider's face was never the same after smashing into broken cf

    [url=Http://weightweenies.starbike.com/forum/viewtopic.php?f=14&t=90693&hilit=chinarello&start=90]Http://weightweenies.starbike.com/forum ... o&start=90[/url]
  • giant_man
    giant_man Posts: 6,878
    Htron wrote:
    A chinarello frame that had snapped, and that was stuffed with Chinese newspaper. Not to mention the rider's face was never the same after smashing into broken cf

    [url=Http://weightweenies.starbike.com/forum/viewtopic.php?f=14&t=90693&hilit=chinarello&start=90]Http://weightweenies.starbike.com/forum ... o&start=90[/url]
    coo [shudder]
  • earth
    earth Posts: 934
    A thought - these knockoff frames that look identical to the official brand may not even be copies. They may be factory seconds that did not meet the standard. I guess the proof is what quantity they are available in. My open-mould planet x started to creak after about 3 years. Longevity is a factor as well.
  • Grill
    Grill Posts: 5,610
    earth wrote:
    A thought - these knockoff frames that look identical to the official brand may not even be copies. They may be factory seconds that did not meet the standard. I guess the proof is what quantity they are available in. My open-mould planet x started to creak after about 3 years. Longevity is a factor as well.

    They're not. For the most part they're from completely different fabs in different countries. You'll never see any factory second from a big company sold in this manner.
    English Cycles V3 | Cervelo P5 | Cervelo T4 | Trek Domane Koppenberg
  • The folks saying theres no difference are wrong

    theres a huge difference between t700 and general carbon and you couldn't afford to buy the carbon in the HM and UHM ranges for the price of some of these frames

    a good brand will be using a certain quality of fibre a cheap nock off will use generic carbon possibly and i say possibly because sometimes its not even carbon, and i have seen the layupschedules and the drawings which call up black fibreglass

    what i can tell you is i had an email from a company in taiwan asking if we could re engineer a frame here in the UK that was very very popular with the cheap and cheerful frame crowd,they loved the shape etc just needed branding applied but the truth of it was it couldnt survive a fatigue test which all products should pass to be sold in europe

    Obviously buying direct from china you take the risk there are good manufacturers over there and some excellent ones but just because a cheap frame survives 10k of riding by some forum guy doesnt mean the first knock it takes hasn't pushed it past what we would call the one banger...the second knock you might find your teeth on the road
  • Barbarossa
    Barbarossa Posts: 248
    theres a huge difference between t700 and general carbon

    ? T700 is about the cheapest PAN fibre around.
  • Barbarossa wrote:
    theres a huge difference between t700 and general carbon

    ? T700 is about the cheapest PAN fibre around.


    and as I said not everyone is filling their frame molds with Pan precursor fibres
  • Barbarossa
    Barbarossa Posts: 248
    What do you think they are using then?