R
Ryan Cousineau
Guest
In article <[email protected]>,
jim beam <[email protected]> wrote:
> Ryan Cousineau wrote:
> > In article <[email protected]>,
> > jim beam <[email protected]> wrote:
> >
> >
> >>Ryan Cousineau wrote:
> >>
> >>>In article <[email protected]>,
> >>> "Zix" <[email protected]> wrote:
> >
> >
> > [REI Novara]
> >
> >
> >>>>I was looking at their Strada racing bike which has an
> >>>>aluminum frame and Shimano 105 components in 5 places,
> >>>>and I was curious if anyone had any experience with this
> >>>>bike. Here is a link:
> >>>>http://www.rei.com/online/store/ProductDisplay?storeId=8000&catalogId=4000
> >>>>0008000&productId=47968697&parent_category_rn=4500865
> >
> >
> >>>>Personally I am not sure that an Alu frame is for me,
> >>>>having experienced for a year the Alu stiffness factor in
> >>>>my previous bike, but I'm responding to the components
> >>>>and sale price and trying to be practical.
> >>>
> >>>
> >>>Behold the Approved Standard rbt answer:
> >
> >
> >>>-the feel of "stiffness" is best tuned by adjusting your bike's tire
> >>>pressure in 5 psi increments. There are only a few exceptions, most
> >>>notoriously the infamously whippy Vitus 979 frames. The second most
> >>>important factor in the ride of a bike is probably frame geometry,
> >>>followed by the type of bar tape you use.
> >>
> >>that's parody, right? tire pressure has absolutely ZERO effect on a
> >>frame's mechanical properties or a wheel's mechanical properties, both
> >>of which are significant factors in ride quality. it may be ok to joke
> >>about this stuff once in a while, but it's dangerous here on r.b.t.
> >>because repetition means people start to believe the most outrageous
> >>b.s. as "fact".
> >
> >
> > Jim, I hope I'm not misrepresenting others here, but my impression is
> > that one regular in this newsgroup who makes his living designing and
> > selling titanium frames (Mark Hickey) and one regular in this newsgroup
> > who literally wrote the book on bicycle wheels (Jobst Brandt) have both
> > basically said that given the relative amounts of flex in an inflated
> > tire (significant by design) and virtually any bike frame or wheel
> > (magnitudes smaller), the chance of the frame or wheel's "ride quality"
> > being discernible to any sensible degree is virtually nil.
>
> well, i wouldn't call hickey a "designer". he merely parrots anything
> brandt says, has no interest in data acquisition and doesn't know what
> modulus is. brandt otoh uses deliberately misleading examples to try to
> convince either himself or others that he knows what he's talking about.
> if a bike had /no/ tires, it would still react to loading based on its
> structure. the fact that loading still ends up being transmitted to the
> bike via the tires cannot be avoided - a 200lb person sitting on a bike
> still exerts a 200lb load regardless of tire pressure.
Jim, broadly tarring a guy who has a pretty good reputation for building
Ti frames that work properly and another guy who has spent considerable
years in engineering and the bike industry is not gaining you debating
points.
The tires flex. Heat is generated. those loads are damped. Sic transit
gloria mundi. How do you think pneumatic tires work?
> > I would treat geometry considerations separately: angles and dimensions
> > affect how a bike feels in interesting ways, but most bikes exist within
> > fairly small variations on these parameters.
> >
> > I know you disagree, but I judge the "tire-supremacist" arguments as the
> > most reasonable explanation. My own experience has been that frame
> > materials are not very important to bike feel, but I would not put
> > myself forward as an expert.
> >
> i don't know much about tires either, but i know a bit about materials
> and their application, and i can say with certainty that the structural
> attributes of a bike are /not/ affected by tire pressure. and it's the
> structural attributes that affect the way a bike reacts to you riding it.
Frames flex. But not that much unless you've built a Rinard beam bike.
The diamond frame design has pretty much evolved because it's the
stiffest, lightest structure that will fit a human body and two wheels
(and because the UCI has deemed further evolutions improper...).
I would really like to see a blind test of a steel vs. al or Ti frame,
where they had the same geometry, but if there are any differences a
rider can feel between the steel and aluminum frames, we can fix that
with tire pressure, different bar tape, and a new seat.
To get an idea of how much frame materials matter to feel, or damping,
or whatever, note that both the most notoriously flexy frame (I nominate
the Vitus 979) and the most notoriously stiff frames (choose your
favourite year of Cannondale) are made of aluminum.
Frame material is a specification of a bicycle that I think most buyers
should not stress about: it may be determined by other factors, most
notably a desire for, oh, extreme light weight or the ability to carry a
frame repair kit with you on the road or the ability to stick magnets to
your frame. But attributing special damping properties to frame
materials without regard for frame design, especially given the much
more important contributions to "ride" and "feel" made by things like
wheelbase and tire size and pressure, is not reasonable.
--
Ryan Cousineau [email protected] http://www.wiredcola.com/
"I don't want kids who are thinking about going into mathematics
to think that they have to take drugs to succeed." -Paul Erdos
jim beam <[email protected]> wrote:
> Ryan Cousineau wrote:
> > In article <[email protected]>,
> > jim beam <[email protected]> wrote:
> >
> >
> >>Ryan Cousineau wrote:
> >>
> >>>In article <[email protected]>,
> >>> "Zix" <[email protected]> wrote:
> >
> >
> > [REI Novara]
> >
> >
> >>>>I was looking at their Strada racing bike which has an
> >>>>aluminum frame and Shimano 105 components in 5 places,
> >>>>and I was curious if anyone had any experience with this
> >>>>bike. Here is a link:
> >>>>http://www.rei.com/online/store/ProductDisplay?storeId=8000&catalogId=4000
> >>>>0008000&productId=47968697&parent_category_rn=4500865
> >
> >
> >>>>Personally I am not sure that an Alu frame is for me,
> >>>>having experienced for a year the Alu stiffness factor in
> >>>>my previous bike, but I'm responding to the components
> >>>>and sale price and trying to be practical.
> >>>
> >>>
> >>>Behold the Approved Standard rbt answer:
> >
> >
> >>>-the feel of "stiffness" is best tuned by adjusting your bike's tire
> >>>pressure in 5 psi increments. There are only a few exceptions, most
> >>>notoriously the infamously whippy Vitus 979 frames. The second most
> >>>important factor in the ride of a bike is probably frame geometry,
> >>>followed by the type of bar tape you use.
> >>
> >>that's parody, right? tire pressure has absolutely ZERO effect on a
> >>frame's mechanical properties or a wheel's mechanical properties, both
> >>of which are significant factors in ride quality. it may be ok to joke
> >>about this stuff once in a while, but it's dangerous here on r.b.t.
> >>because repetition means people start to believe the most outrageous
> >>b.s. as "fact".
> >
> >
> > Jim, I hope I'm not misrepresenting others here, but my impression is
> > that one regular in this newsgroup who makes his living designing and
> > selling titanium frames (Mark Hickey) and one regular in this newsgroup
> > who literally wrote the book on bicycle wheels (Jobst Brandt) have both
> > basically said that given the relative amounts of flex in an inflated
> > tire (significant by design) and virtually any bike frame or wheel
> > (magnitudes smaller), the chance of the frame or wheel's "ride quality"
> > being discernible to any sensible degree is virtually nil.
>
> well, i wouldn't call hickey a "designer". he merely parrots anything
> brandt says, has no interest in data acquisition and doesn't know what
> modulus is. brandt otoh uses deliberately misleading examples to try to
> convince either himself or others that he knows what he's talking about.
> if a bike had /no/ tires, it would still react to loading based on its
> structure. the fact that loading still ends up being transmitted to the
> bike via the tires cannot be avoided - a 200lb person sitting on a bike
> still exerts a 200lb load regardless of tire pressure.
Jim, broadly tarring a guy who has a pretty good reputation for building
Ti frames that work properly and another guy who has spent considerable
years in engineering and the bike industry is not gaining you debating
points.
The tires flex. Heat is generated. those loads are damped. Sic transit
gloria mundi. How do you think pneumatic tires work?
> > I would treat geometry considerations separately: angles and dimensions
> > affect how a bike feels in interesting ways, but most bikes exist within
> > fairly small variations on these parameters.
> >
> > I know you disagree, but I judge the "tire-supremacist" arguments as the
> > most reasonable explanation. My own experience has been that frame
> > materials are not very important to bike feel, but I would not put
> > myself forward as an expert.
> >
> i don't know much about tires either, but i know a bit about materials
> and their application, and i can say with certainty that the structural
> attributes of a bike are /not/ affected by tire pressure. and it's the
> structural attributes that affect the way a bike reacts to you riding it.
Frames flex. But not that much unless you've built a Rinard beam bike.
The diamond frame design has pretty much evolved because it's the
stiffest, lightest structure that will fit a human body and two wheels
(and because the UCI has deemed further evolutions improper...).
I would really like to see a blind test of a steel vs. al or Ti frame,
where they had the same geometry, but if there are any differences a
rider can feel between the steel and aluminum frames, we can fix that
with tire pressure, different bar tape, and a new seat.
To get an idea of how much frame materials matter to feel, or damping,
or whatever, note that both the most notoriously flexy frame (I nominate
the Vitus 979) and the most notoriously stiff frames (choose your
favourite year of Cannondale) are made of aluminum.
Frame material is a specification of a bicycle that I think most buyers
should not stress about: it may be determined by other factors, most
notably a desire for, oh, extreme light weight or the ability to carry a
frame repair kit with you on the road or the ability to stick magnets to
your frame. But attributing special damping properties to frame
materials without regard for frame design, especially given the much
more important contributions to "ride" and "feel" made by things like
wheelbase and tire size and pressure, is not reasonable.
--
Ryan Cousineau [email protected] http://www.wiredcola.com/
"I don't want kids who are thinking about going into mathematics
to think that they have to take drugs to succeed." -Paul Erdos