R&D

"Ryan Cousineau" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

In article <[email hidden]>,

Francesco Devittori frenkatfrenkdtcm said:

peter.kidwell said:

"Francesco Devittori" <frenkatfrenkdtcm> wrote in message
news:[email hidden]...

>peter.kidwell wrote:
>
>>...
>>What does The v as in 8v and 6v mean -- sprockets ?
>>
>>PK
>
>velocità? (=speed)

Quoted message said:

Quoted message said:

If you followed the thread the question is refering to Tim Mc Namara
email
and he isn't meaning velocity.
Pk

Quoted message said:

I read
----------------------------------------------------------------

Quoted message said:

...and a 6v Hyperglide freewheel (for my-other-wheel-is-in-the
-shop reasons, it's using my race wheel, which has an 8v
cassette freehub at the moment).
--

What does The v as in 8v and 6v mean -- sprockets ?
-----------------------------------------------------------------

I understand that 8v cassette freehub is an 8 sprocket (= 8 speed = 8
velocità) cassette.
I could be completely wrong but I don't see why

Francesco has it. I can't cite, but it's a common, pretentious way of
indicating the number of gears at the rear, even in English.

--
Ryan Cousineau, [email hidden] http://www.wiredcola.com
Verus de parvis; verus de magnis.

It's a first for me No of sprockets is common
PK

Ryan Cousineau said:

In article <[email hidden]>,

jim beam said:

Ryan Cousineau said:

In article <[email hidden]>,
[email hidden] wrote:

>Ryan Cousineau <[email hidden]> writes:
>
>
>
>>Jobst says the next major [bicycle] interface that needs redesigning
>>(possibly the last? He's already happy with threadless stems and
>>cautiously optimistic about Hollowtech II-type crank/BBs) is the
>>pedal-crank joint. He has engineered (and implemented on his own
>>bike) a redesign using a conical interface between the pedal and the
>>crank, using a split washer to take up the space. It prevents
>>fretting, which wears the crank and is a major cause of crank
>>failures at the pedal eye. But the change Jobst has created has not
>>yet been implemented. Unless he's gone and patented the design,
>>there might be a boutique market for some machinist to advertise and
>>sell this modification. In production, I don't imagine it would be
>>very expensive at all, and while it would require a modified crank,
>>it would be compatible with virtually all current pedals.
>
>That won't be possible because my modification was adapted to a
>specific pedal shaft whose thread relief happened to be cylindrical
>and could accept a custom made conical (split) ring. This will not be
>possible as a product because thread reliefs are not sufficiently
>uniform in length or diameter. The conical collet must fit fairly
>accurately to work. It requires a design change to pedal shafts.

Quoted message said:

there's nothing grossly wrong with the current system. sure, some
cranks have failed at the pedal eye, but others fail at the spider or
elsewhere on the arm. if every single crank always failed at the eye,
/then/ it would be a design issue.

similarly, there's not a hard & fast rule about fretting being the cause
of eye fatigue. the orientation of the shoulder caused by any fretting
is not a stress riser in the orientation of maximum stress. sure, pedal
eyes may have fatigue appear to come from an area that's been fretted,
but that's not a definitive analysis of cause & effect.

The issue is, as I understand it, that the fret-marks act as fuses
(starting points) for fatigue cracks.

well yes, but "classic" stress risers that initiate fatigue are usually
oriented perpendicular to the prinipal stress. in that instance, you
would expect the crack to grow from the shoulder nearest the bb, not
half way down the eye where the shoulder is axial with principal stress.

Quoted message said:

Quoted message said:

as for "alternative" design options, why not consider a tapered thread?
these are used in fatigue applications because [if executed right] all
the threads get loaded, not just the first 3, and where a close seal is
important, which addresses some of the fretting issues, such as they may be.

A conical tapered interface addresses the issue just as well, and is a
lot simpler to manufacture.

not really. tapered threads are very common & not exactly high tech -
steel plumbing fixtures for example. in that application, tapered
threads ensure a good seal.

Quoted message said:

All parts of a bicycle are engineered well enough that they work for
most riders most of the time. But in some places, they are only a minor
redesign away from being much better. Hard, long-distance riders
currently consider square-taper cranks a consumable item. There is no
reason they should be so.

you could say the same of rims wearing out under braking, but there has
to be a practical cut-off point. technically, you can make car engines
last indefinitely if you want to sacrifice the output, weight & expense,
so where do you draw the line? we are dealing with aluminum after all -
a material without an endurance limit. the number of riders that really
do put huge mileage on cranks is statistically very small. pro's
regularly replace, as do most other high mileage riders. designing
every omponent for the few that want significantly higher mileage
without ever upgrading - just like manufacturing every crank to cope
with chalo for example - is not going to satisfy 99.99% of users.

Zog who? said:

I'd quite like tubeless tyres for the road if this meant they could
safely be fitted with tools. I've had enough of trying to squeeze
too-tight new tyres over the rim by hand.

I don't see why you subject yourself to such exercises. I have always
used plastic tire levers to dismount and mount tires on my rims with
no problems. I think rather than try to develop iron fists, a bit of
skill in mounting tires would go a long way.

I see no good reasons other than snake bite protection for tubeless
tires, however, this is not really what anyone wanted because once
that hazard goes away, it'll be surprising how many rims will be
trashed by those no longer occurring snake bite flats. It's bad
enough now. A river-bottom (smoothly rounded) stone can significantly
ding a rim without causing a flat as it is.

Some day when Christmas arrives and the wish comes true, we'll realize
that it wasn't our wish after all.

Jobst Brandt
[email hidden]

Ryan Cousineau said:

Quoted message said:

Quoted message said:

Jobst says the next major [bicycle] interface that needs
redesigning (possibly the last? He's already happy with
threadless stems and cautiously optimistic about Hollowtech
II-type crank/BBs) is the pedal-crank joint. He has engineered
(and implemented on his own bike) a redesign using a conical
interface between the pedal and the crank, using a split washer to
take up the space. It prevents fretting, which wears the crank
and is a major cause of crank failures at the pedal eye. But the
change Jobst has created has not yet been implemented. Unless
he's gone and patented the design, there might be a boutique
market for some machinist to advertise and sell this modification.
In production, I don't imagine it would be very expensive at all,
and while it would require a modified crank, it would be
compatible with virtually all current pedals.

Quoted message said:

Quoted message said:

That won't be possible because my modification was adapted to a
specific pedal shaft whose thread relief happened to be cylindrical
and could accept a custom made conical (split) ring. This will not
be possible as a product because thread reliefs are not
sufficiently uniform in length or diameter. The conical collet
must fit fairly accurately to work. It requires a design change to
pedal shafts.

Quoted message said:

Well, that sucks. But I sense an opportunity! Since there is no
sizing in bicycle cleats, why not design an integrated
crank/BB/pedal spindle? You could use press-fit or some other
appropriate semi-permanent attachment. I am only sort of joking.

Quoted message said:

More seriously, offering crank/BB/pedal kits for a few of the most
popular pedal styles (say, a Look kit, an SPD kit, a Crank Bros kit,
and an SPD-SL kit) would probably cover the majority of the market,
and might still be commercially viable (you would only have to tool
up three or so designs to start marketing the idea, and you could
expand into as many pedal designs as made sense if the system proved
popular.

Quoted message said:

Furthermore, and correct me if I'm wrong, it would be possible for
pedal makers to start offering pedals that were compatible with a
standard machined conical crank recess, but that came with a washer
to retrofit them to conventional cranks. This would require buy-in
by the pedal makers, but not at the expense of abandoning their
current market..

Not so. Machining a conical countersink into the crank is difficult
to align concentric to the thread and can only be done in a machine
shop that understands the problem. I don't see people taking new
cranks as I did and getting them modified at the standard machine shop
rate... or at all.

As I said, even within the same manufacturer, the thread relief is
essentially undefined other than roughly, which is all that is
required at present. Therefore you cannot make adapters to fit an
unknown dimension. I did this because I needed to and because I have
someone with the shop capability.

Quoted message said:

I may be missing something, but the details of this problem seem to be
more marketing-oriented (mostly around the plan to produce an initially
backward-compatible system so that consumers do not feel in danger of
being orphaned, but without inducing fatal design compromises) than
design-oriented, and probably solvable.

That's part of the problem but the other is that manufacturers are as
resistant to recognizing the cause of pedal eye failures as they were
to the notion of fatigue failures in spokes when "the Bicycle Wheel"
described the concept and why it occurred so often. As you see, there
are still pockets of resistance to that and fretting damage in head
bearings.

Quoted message said:

Quoted message said:

Quoted message said:

There are lots of experiments involving tubeless road tires right
now. Shimano has already shown a set of road wheels for tubeless
tires, even though I know of no tire-maker actually selling them
yet (they are being tested in racing teams).

Quoted message said:

Quoted message said:

This is not a step forward because patching such tires is more
difficult than tube tires. The impetus comes from MTB's and snake
bite flats. It ignores flats from intrusions (thorns, nails,
glass).

Quoted message said:

What is the added difficulty of patching these tires? From my
motorcycling days, I remember patching tubeless tires from the
outside with a tool like a crochet hook and a plug of rubber, but
won't a conventional patch (or something similar) applied to the
inside of the tire carcass work as well?

Tire casing, the carcass is what you see stacked in junk yards, dead
tires.

There isn't enough depth in a bicycle tire casing for that sort of
hole repair that works mainly for nail or thorn type punctures. Glass
cuts require more than a rubber band plug with glue. Besides, why do
it other than to save the cost of a tube?

Quoted message said:

In practice, MTBers running tubeless may use tire slime to give a
measure of puncture proofing, and most carry a conventional tube as
a field fix for a flat.

I'm sure few riders have had my experience with slime in which a
ruptured casing cased a minor blowout on a straight section of road at
over 20mph. With lubricant in the rear tire, the bicycle was all over
the road in broadslides before I could bring it to a safe stop. This
is caused by tire walking, not by the tread sliding on the road. Just
visualize a flat tire with slime on the inside and how easily it would
slide left and right while the tread is firmly on the ground.

I am not in favor of such tire fillers and if a front tire were to go
flat it would be an immediate crash. I hope tire manufacturers
perform this test on a test track and skilled rider.

Jobst Brandt
[email hidden]

Quoted message said:

Ryan Cousineau said:

Quoted message said:

>Jobst says the next major [bicycle] interface that needs
>redesigning (possibly the last? He's already happy with
>threadless stems and cautiously optimistic about Hollowtech
>II-type crank/BBs) is the pedal-crank joint. He has engineered
>(and implemented on his own bike) a redesign using a conical
>interface between the pedal and the crank, using a split washer to
>take up the space. It prevents fretting, which wears the crank
>and is a major cause of crank failures at the pedal eye. But the
>change Jobst has created has not yet been implemented. Unless
>he's gone and patented the design, there might be a boutique
>market for some machinist to advertise and sell this modification.
>In production, I don't imagine it would be very expensive at all,
>and while it would require a modified crank, it would be
>compatible with virtually all current pedals.

Quoted message said:

Quoted message said:

That won't be possible because my modification was adapted to a
specific pedal shaft whose thread relief happened to be cylindrical
and could accept a custom made conical (split) ring. This will not
be possible as a product because thread reliefs are not
sufficiently uniform in length or diameter. The conical collet
must fit fairly accurately to work. It requires a design change to
pedal shafts.

Quoted message said:

Well, that sucks. But I sense an opportunity! Since there is no
sizing in bicycle cleats, why not design an integrated
crank/BB/pedal spindle? You could use press-fit or some other
appropriate semi-permanent attachment. I am only sort of joking.

Quoted message said:

More seriously, offering crank/BB/pedal kits for a few of the most
popular pedal styles (say, a Look kit, an SPD kit, a Crank Bros kit,
and an SPD-SL kit) would probably cover the majority of the market,
and might still be commercially viable (you would only have to tool
up three or so designs to start marketing the idea, and you could
expand into as many pedal designs as made sense if the system proved
popular.

Quoted message said:

Furthermore, and correct me if I'm wrong, it would be possible for
pedal makers to start offering pedals that were compatible with a
standard machined conical crank recess, but that came with a washer
to retrofit them to conventional cranks. This would require buy-in
by the pedal makers, but not at the expense of abandoning their
current market..

Not so. Machining a conical countersink into the crank is difficult
to align concentric to the thread and can only be done in a machine
shop that understands the problem. I don't see people taking new
cranks as I did and getting them modified at the standard machine shop
rate... or at all.

As I said, even within the same manufacturer, the thread relief is
essentially undefined other than roughly, which is all that is
required at present. Therefore you cannot make adapters to fit an
unknown dimension. I did this because I needed to and because I have
someone with the shop capability.

Quoted message said:

I may be missing something, but the details of this problem seem to be
more marketing-oriented (mostly around the plan to produce an initially
backward-compatible system so that consumers do not feel in danger of
being orphaned, but without inducing fatal design compromises) than
design-oriented, and probably solvable.

That's part of the problem but the other is that manufacturers are as
resistant to recognizing the cause of pedal eye failures as they were
to the notion of fatigue failures in spokes when "the Bicycle Wheel"
described the concept and why it occurred so often. As you see, there
are still pockets of resistance to that and fretting damage in head
bearings.

just like there's resistance to learning the difference between a
journal bearing & a roller bearing? until the "fretting" model can
account for indentation of a clean, new, well lubed, well adjusted
headset in a single impact, then there's little more mud in the water
than you would have us believe.

Quoted message said:

Quoted message said:

Quoted message said:

>There are lots of experiments involving tubeless road tires right
>now. Shimano has already shown a set of road wheels for tubeless
>tires, even though I know of no tire-maker actually selling them
>yet (they are being tested in racing teams).

Quoted message said:

Quoted message said:

This is not a step forward because patching such tires is more
difficult than tube tires. The impetus comes from MTB's and snake
bite flats. It ignores flats from intrusions (thorns, nails,
glass).

Quoted message said:

What is the added difficulty of patching these tires? From my
motorcycling days, I remember patching tubeless tires from the
outside with a tool like a crochet hook and a plug of rubber, but
won't a conventional patch (or something similar) applied to the
inside of the tire carcass work as well?

Tire casing, the carcass is what you see stacked in junk yards, dead
tires.

There isn't enough depth in a bicycle tire casing for that sort of
hole repair that works mainly for nail or thorn type punctures. Glass
cuts require more than a rubber band plug with glue. Besides, why do
it other than to save the cost of a tube?

Quoted message said:

In practice, MTBers running tubeless may use tire slime to give a
measure of puncture proofing, and most carry a conventional tube as
a field fix for a flat.

I'm sure few riders have had my experience with slime in which a
ruptured casing cased a minor blowout on a straight section of road at
over 20mph. With lubricant in the rear tire, the bicycle was all over
the road in broadslides before I could bring it to a safe stop. This
is caused by tire walking, not by the tread sliding on the road. Just
visualize a flat tire with slime on the inside and how easily it would
slide left and right while the tread is firmly on the ground.

I am not in favor of such tire fillers and if a front tire were to go
flat it would be an immediate crash. I hope tire manufacturers
perform this test on a test track and skilled rider.

Jobst Brandt
[email hidden]

In article <[email hidden]>,

jim beam said:

Ryan Cousineau said:

In article <[email hidden]>,
jim beam <[email hidden]> wrote:

Quoted message said:

Quoted message said:

All parts of a bicycle are engineered well enough that they work for
most riders most of the time. But in some places, they are only a minor
redesign away from being much better. Hard, long-distance riders
currently consider square-taper cranks a consumable item. There is no
reason they should be so.

you could say the same of rims wearing out under braking, but there has
to be a practical cut-off point. technically, you can make car engines
last indefinitely if you want to sacrifice the output, weight & expense,
so where do you draw the line? we are dealing with aluminum after all -
a material without an endurance limit. the number of riders that really
do put huge mileage on cranks is statistically very small. pro's
regularly replace, as do most other high mileage riders. designing
every omponent for the few that want significantly higher mileage
without ever upgrading - just like manufacturing every crank to cope
with chalo for example - is not going to satisfy 99.99% of users.

Rims are clearly a wear item: they are a friction surface under normal
use. The point about cranks is that they don't do anything: they are
fastened securely to other parts at each end, and that's it. We already
know how to design such interfaces for a fit that doesn't move or wear,
and there is no need to add metal or change materials to get to an
improved design that will have a magnitude more durability.

--
Ryan Cousineau, [email hidden] http://www.wiredcola.com
Verus de parvis; verus de magnis.

Ryan Cousineau said:

In article <[email hidden]>,

jim beam said:

Ryan Cousineau said:

In article <[email hidden]>,
jim beam <[email hidden]> wrote:

Quoted message said:

Quoted message said:

All parts of a bicycle are engineered well enough that they work for
most riders most of the time. But in some places, they are only a minor
redesign away from being much better. Hard, long-distance riders
currently consider square-taper cranks a consumable item. There is no
reason they should be so.

you could say the same of rims wearing out under braking, but there has
to be a practical cut-off point. technically, you can make car engines
last indefinitely if you want to sacrifice the output, weight & expense,
so where do you draw the line? we are dealing with aluminum after all -
a material without an endurance limit. the number of riders that really
do put huge mileage on cranks is statistically very small. pro's
regularly replace, as do most other high mileage riders. designing
every omponent for the few that want significantly higher mileage
without ever upgrading - just like manufacturing every crank to cope
with chalo for example - is not going to satisfy 99.99% of users.

Rims are clearly a wear item: they are a friction surface under normal
use. The point about cranks is that they don't do anything: they are
fastened securely to other parts at each end, and that's it. We already
know how to design such interfaces for a fit that doesn't move or wear,
and there is no need to add metal or change materials to get to an
improved design that will have a magnitude more durability.

with respect, i doubt you'd get a magnitude more of durability. this
component that "doesn't do anything" is seriously stressed and as such,
for a component with no fatigue endurance limit, it /does/ have a finite
life. air frames "don't do anything" but they are life limited. even
steel submarine hulls are life limited, and several inches of solid
steel are about as durable as it gets. the main reason bikes aren't
subject to a regime of constant checking is because failure rarely leads
to fatalities unlike the other two examples. and of course, who wants
to pay $3k for a crank that's been _proven_ to be defect free? or only
be able to take it on the road after it's had it's annual
"airworthiness" certificate and log book inspection? not me.

In article <[email hidden]>,

Quoted message said:

Zog who? said:

I'd quite like tubeless tyres for the road if this meant they could
safely be fitted with tools. I've had enough of trying to squeeze
too-tight new tyres over the rim by hand.

Quoted message said:

I see no good reasons other than snake bite protection for tubeless
tires, however, this is not really what anyone wanted because once
that hazard goes away, it'll be surprising how many rims will be
trashed by those no longer occurring snake bite flats. It's bad
enough now. A river-bottom (smoothly rounded) stone can significantly
ding a rim without causing a flat as it is.

But the rim damage won't be any worse, will it? I've had a fair number
of snakebites lately, and none of them seem to have resulted in fatal
rim damage. Unlike MTBs, there isn't much incentive to run lower tire
pressures on the road than is currently done. You have pointed out that
rim heating during descents provides a key upper limit to preferred tire
pressures, but the only incentive to pressures lower than that limit is
comfort, something provided best by fatter tires.

Quoted message said:

Some day when Christmas arrives and the wish comes true, we'll realize
that it wasn't our wish after all.

Just because you didn't get everything on your list doesn't mean it's a
bad Christmas.

I would rank eliminating tubes as low on my list (I won't buy new rims
once this gets to market). But won't their deletion provide similar
benefits to those that have driven cars and motorcycles to tubeless
tires?

--
Ryan Cousineau, [email hidden] http://www.wiredcola.com
Verus de parvis; verus de magnis.

Tim McNamara said:

Ryan Cousineau <[email hidden]> writes:
Something I'd really like to see is the development of actual taste in
cycling clothing.....
I want less Lycra, especially Lycra gloves- yuck.

Have you looked at sailing gloves? particularly good for training
and in the rain 😄

they are a hell of a lot tougher, I would be happy to put my hand
down at 30mph - come in all finger tips open or
only index and thumb open - and, importantly - no lycra!

...Matthew