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04-14-04, 09:29 AM
Over the years, one of the most difficult aspects of a bicycle to quantify has been stiffness and strength of a bicycle frame. Generally all we as consumers have to go on is road testing by consumer mags and word of mouth referrals. These are both subjective.
The only real objective criteria traditionally has been materials specifications, Ksi, Young's Modulus, etc... to guide us in selecting products we think will suit our needs. This objective criteria can often be misrepresented by manufacturers and marketing people to sway the layman towards their products.
Engineering for Bicycles, www.efbe.de/defbefrm.htm, has attempted to provide an objective set of standards that the layman can use to evaluate variables such as stiffness and potential longevity of specific products and materials.
In a nutshell, Efb has set 3 standards for bicycle frames that can be used as a point of reference to help consumers project longevity and suitability in frames on the market. These 3 standards are Top, High, and Standard. The parameters that must be met to achieve these standards are available at Efb's website, but suffice to say that the High standard appears to be more than adequate for all but the most committed cobble riders.
Testing has been done now for over 5 years, going back to at least '99, and including all types of frames from many different manufacturers. Damon Rinard uses some of their info in an oft quoted article comparing the differences in frame materials.
Unfortunately, industry spin masters continue to deconstruct info presented by Efb for their own advantage.
Take for example marketing claims by Cervelo. In their Q&A section at their website they talk about how their frames passed the rigid standards set by Efb while many titanium frames failed. Cervelo does not state that their frames did not meet the Top standard, only that their frames "passed" Efb's rigid standards. No titanium frame tested failed to meet the High standard(100,000 cycles at 1200n).
In fact, in the Efb chart, one titanium frame is listed as passing the Top standard while no Cervelo frames are shown to have passed the Top standard. Another titanium frame is shown to have passed the High standard, which is the same standard Cervelo was able to achieve with some of their frames.
Efb does not publish failure data although one can assume that if a frame passed the High standard but not the Top standard it failed somewhere between the two or was only tested to the lower standard. Damon Rinards article, posted at the Efb site, has failure data on two titanium frames, both which exceeded the minimum standard for the High rating, the same rating Cervelo achieves.
What is the point? The point is to read carefully and assume nothing. Marketing people can make statements that sound true, but are in fact incomplete.
The only real objective criteria traditionally has been materials specifications, Ksi, Young's Modulus, etc... to guide us in selecting products we think will suit our needs. This objective criteria can often be misrepresented by manufacturers and marketing people to sway the layman towards their products.
Engineering for Bicycles, www.efbe.de/defbefrm.htm, has attempted to provide an objective set of standards that the layman can use to evaluate variables such as stiffness and potential longevity of specific products and materials.
In a nutshell, Efb has set 3 standards for bicycle frames that can be used as a point of reference to help consumers project longevity and suitability in frames on the market. These 3 standards are Top, High, and Standard. The parameters that must be met to achieve these standards are available at Efb's website, but suffice to say that the High standard appears to be more than adequate for all but the most committed cobble riders.
Testing has been done now for over 5 years, going back to at least '99, and including all types of frames from many different manufacturers. Damon Rinard uses some of their info in an oft quoted article comparing the differences in frame materials.
Unfortunately, industry spin masters continue to deconstruct info presented by Efb for their own advantage.
Take for example marketing claims by Cervelo. In their Q&A section at their website they talk about how their frames passed the rigid standards set by Efb while many titanium frames failed. Cervelo does not state that their frames did not meet the Top standard, only that their frames "passed" Efb's rigid standards. No titanium frame tested failed to meet the High standard(100,000 cycles at 1200n).
In fact, in the Efb chart, one titanium frame is listed as passing the Top standard while no Cervelo frames are shown to have passed the Top standard. Another titanium frame is shown to have passed the High standard, which is the same standard Cervelo was able to achieve with some of their frames.
Efb does not publish failure data although one can assume that if a frame passed the High standard but not the Top standard it failed somewhere between the two or was only tested to the lower standard. Damon Rinards article, posted at the Efb site, has failure data on two titanium frames, both which exceeded the minimum standard for the High rating, the same rating Cervelo achieves.
What is the point? The point is to read carefully and assume nothing. Marketing people can make statements that sound true, but are in fact incomplete.