jim beam said:Ozark Bicycle wrote:
- on Octalink, etc., v. square taper BBs -
Quoted message said:Quoted message said:Quoted message said:>>>> i'm a ~205# and i love octalink - it's definitely stiffer. i noticed it
>>>> immediately i climbed my first hill on my first octalink crank set,
>>> I am surprised that someone with a technical/engineering background
>>> would make a statement like this when, it seems, no attempt was made
>>> to eliminate all the variables, including expectation effects. :-0
>> no one was more surprised than me. on my first experience, all other
>> componentry on the bike was identical. going octalink was merely $20
>> more expensive than buying new chain rings, so i thought i'd give it a
>> go. i had no expectations other than not having chains slip on worn
>> teeth. especially as i thought frame flex was much more of a factor.
> Hmmm....I wonder if "having chains slip on worn teeth" caused you to
> hold back a bit on your old setup? Perhaps the freedom from slip led
> to an increased effort which led to an impression of greater stiffness
> in the spindle. I think coming off worn, slip prone chinrings to a
> totally new crankset muddies the comparison quite a bit.
>>>> and
>>>> i noticed it again recently when i built a cross frame with a square
>>>> taper. the cranks were awful.
>>> Was it the cranks (i.e., the crankarms) or the spindle that was
>>> "awful"?
>> probably both.
> Or perhaps it was just the crankarms. That's the point: lacking any
> kind of control of the variables, you'll never know.
>>>> went back to octalink again - much stiffer
>>> Unless the crankarms were identical , this observation is useless.
>> not useless, but since you have to have octalink arms to run an octalink
>> spindle, the two events are inextricably tied.
> Sure, but if this impression of additional stiffness is verifiable
> under controlled conditions, it would be good to know if the benefit
> came wholly (or, at least, mostly) from the crankarms or if Octalink
> really has something to offer (other than marketing) that makes it
> worthwhile to scrap the well established square taper standard.
there was a report published in one of the euro mags that was posted
here on r.b.t and debated some while back. the big hollow stuff was
measurably stiffer.
Quoted message said:Sure, but does that translate into anything that can reliably be
discerned by actual human beings riding bicycles? It's just possible
that all the measurements do is to fuel expectation effects and help
sell the "new technology".
maybe, maybe not. does it matter? rec riders want the bling.
Do they "want" it, or are they sold it? IMO, it's the latter; the
mags, etc., are filled with the various stuff about "new!",
"stiffer!", "better!" and other BS that implies that one's extant
square taper BB is woefully inadequate. Now, without question, Shimano
is in the process of walking away from the Octalink "standard". I
wonder how those with perfectly usable Octalink cranks will feel when
they can no longer buy one of those wonderfully stiff Octalink BBs
(?).
Quoted message said:for a
pro, what's the percentage difference between the times of 1st & second
places in the tdf? at the pro level, differences often scoffed at on
r.b.t are very important. rolling resistance differences between tires
are minimal, yet my "wet" tires are consistently 5 minutes per hour
slower than my "dry" tires, regardless of bike. average over thousands
of miles. they "feel" different too. is it significant?
5min/hr is a gross difference; do you really think there is that kind
of diff due to BB spindle "stiffness"??
Quoted message said:Quoted message said:On a related note, I find it fascinating that some people are ga-ga
about the supposed "stiffness" of external bearing BBs while at the
same time they bury their heads in the sand regarding the very real
added drag of those designs. Go figure.
i don't think a stiffer crank makes me faster, but it definitely feels
better to use. just like a fast car is nicer to drive, even though it's
no quicker on a speed restricted freeway. as i said before, i
originally had no expectations so i doubt i was "feeling" what i wanted
to. and having recently re-tested, again, i'd forgotten what a
difference it made and so had no expectations. whatever it was feeling
so different, i really doubt it was placebo.
regarding "drag", there's definitely negative expectation there. people
complain because, at low speeds, i.e. by hand, cartridge bearings have
direct rubber on steel contact which feels stiff. but does that drag
exist at higher speeds? i "expect" that there's some hydrodynamic stuff
going on but can't say for sure. what i have done however is coasting
tests on "draggy" mavic cosmos wheel bearings vs "non-draggy" shimano,
and i see no difference in real world.
Added drag in hubs is a bit different than the added drag in those
external bearing BBs, IMO. YMMV.
Quoted message said:for bb's, it's not a function of
the spindle - a square taper cartridge bb is no less "draggy" than a
shimano octalink cartridge bb - i've just opened a couple of new-in-box
bb's and checked them out.
The subject was added drag in *external bearing* BBs, not drag in
Shimano square taper BBs v. Shimano Octalink BBs.
Quoted message said:Quoted message said:Quoted message said:>> out of curiosity, do you weigh as much as me? could this affect your
>> own experience with octalink?-
> I'm within a few pounds; in a good year, mid-season, I'm down to the
> mid-high 190s. Right now, more like 210+.- Hide quoted text -
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