Serotta Legend TI w/ pivoting seat stays?

[Bret Wade]

Serotta offers a pivoting carbon seat stays as an option on several of
their Ti frames which is supposed to provide some suspension travel.
My wife will be ordering a new Serotta soon and would like to hear
some opinions for or against this option. Has anyone here owned or
ridden a Serotta with this feature?

Thanks,
Bret

[Werehatrack]

On 16 Jul 2003 20:05:55 -0700, (Chalo) may
have said:

>... I have seen many such "features" come and go.
[much snippage]

Now, where did I put those waders? They were right here a minute
ago...

[Priceless bit, by the way; simply priceless.]

---
My email address is antispammed;
pull WEEDS if replying via e-mail.

Yes, I have a killfile. If I don't respond to something,
it's also possible that I'm busy.

[Bret Wade]

Chalo wrote:
> (Bret Wade) wrote:
>
>
>>Serotta offers a pivoting carbon seat stays as an option on several of
>>their Ti frames which is supposed to provide some suspension travel.
>>My wife will be ordering a new Serotta soon and would like to hear
>>some opinions for or against this option. Has anyone here owned or
>>ridden a Serotta with this feature?
>
>
> No, but I have seen many such "features" come and go.
>
> If your wife *truly believes* in the Fixed Pivot, it will reward her
> faith by granting her a miraculously cushy yet super-efficient ride.
> From her magical perch she will behold the legions of nonbelievers
> with their primitive fixed non-pivoted rear triangles and know that
> they are ignorant savages. She will effortlessly speed by them and
> scoff with derision. Other riders will weep with frustration at her
> astounding, unbeatable speed and overall superiority.
>
> OTOH, if she fails to believe in the Fixed Pivot with all her heart,
> then not only will her ride be as harsh, slow, and tiring as that of a
> normal titanium and plastic bike, but she will have added a useless
> wear item to her bike and paid a premium to do so. Cartridge bearing
> mites will mercilessly gnaw upon the races of her hubristic jointed
> dropouts, causing them to click and creak. Children will flee from
> the noise of her approach. Dogs will relieve themselves on her
> once-proud bicycle. She will be finished as a cyclist, disgraced.
>
> However, if your wife should buy a carefully made bike of
> time-honored, proven design and materials, then she will be able to
> call upon the collective faith of all those riders who came before her
> and believed in their simple, sturdy mounts, which did not fail them.
> She will retain the modest dignity of a rider who does not subscribe
> to expensive extravagances and tawdry gimmicks, but is guided by good
> taste and well-refined technology.
>
> Then, she and her bike will surely live happily ever after.
>
> Chalo Colina

Hi Chalo,

You assume much and know little about this situation. We're not
particularly interested in anyones personal bike frame philosophy. We
would simply like to know if anyone has experience with this particular
frame feature and has an opinion on it?

Thanks,
Bret

[Dave Thompson]

"RoyG" <royg at nospam> wrote in message
...
> For a different perspective Bret, you might want to go to the Serotta
> Message Board - go to www.serotta.com and click on the link at top right
of
> page. You can search or post a new message. Board has been down for last
> day but it should be back up soon.
>
This is the first sensible answer given to the OP.

[Qui si parla Campagnolo]

Bret-<< Serotta offers a pivoting carbon seat stays as an option on several of
their Ti frames which is supposed to provide some suspension travel.
My wife will be ordering a new Serotta soon and would like to hear
some opinions for or against this option. Has anyone here owned or
ridden a Serotta with this feature? >><BR><BR>

You are in CO, yes? I think Wheatridge has one of these, I would recommend she
go ride it and then a 'hard tail'...I think she will like the hardtail more.

Where is she going to get the Serotta??

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

[Bret Wade]

Qui si parla Campagnolo wrote:

> Bret-<< Serotta offers a pivoting carbon seat stays as an option on several of
> their Ti frames which is supposed to provide some suspension travel.
> My wife will be ordering a new Serotta soon and would like to hear
> some opinions for or against this option. Has anyone here owned or
> ridden a Serotta with this feature? >><BR><BR>
>
> You are in CO, yes? I think Wheatridge has one of these, I would recommend she
> go ride it and then a 'hard tail'...I think she will like the hardtail more.
>
> Where is she going to get the Serotta??

Hi Peter,

Yes, we're working with Wheatridge on this. Lisa's going down to get a
fitting next week. We are leaning towards the hardtail, but wanted to
gather some information first before we reject the other options.
Lisa's been on Serottas since '90 (Le Peep - Morgul Bismark team
bikes) and won't have anything else.

Thanks,
Bret

[Scott Goldsmith]

(Bret Wade) wrote in message >...
> Serotta offers a pivoting carbon seat stays as an option on several of
> their Ti frames which is supposed to provide some suspension travel.
> My wife will be ordering a new Serotta soon and would like to hear
> some opinions for or against this option. Has anyone here owned or
> ridden a Serotta with this feature?
>
> Thanks,
> Bret

Carbon rear ends are bolted at the drop outs on many bikes, replacing
the bolts with pivots is simple. The carbon rear lowers the cost of
production by replacing four welded joints with one. Raising the brake
bridges to accomodate a wider range of tires would be a more useful
solution, but you'd lose the marketing advantage of the carbon rear
and carbon fork.

[Chalo]

"Dave Thompson" > wrote:

> "RoyG" <royg at nospam> wrote:
>
> > For a different perspective Bret, you might want to go to the Serotta
> > Message Board - go to www.serotta.com
> >
> This is the first sensible answer given to the OP.

What, to go solicit feedback from the suckers who were taken in enough
to buy it? That doesn't sound sensible to me. It's like asking a
group of people wearing foil hats whether their hats work to keep out
the transmissions.

Chalo Colina

[Dave Thompson]

"Chalo" > wrote in message
om...
> "Dave Thompson" > wrote:
>
> > "RoyG" <royg at nospam> wrote:
> >
> > > For a different perspective Bret, you might want to go to the Serotta
> > > Message Board - go to www.serotta.com
> > >
> > This is the first sensible answer given to the OP.
>
> What, to go solicit feedback from the suckers who were taken in enough
> to buy it? That doesn't sound sensible to me. It's like asking a
> group of people wearing foil hats whether their hats work to keep out
> the transmissions.
>
> Chalo Colina

Who made you the god of replies? Who else is better to comment on the
validity of something, other than the people who have researched and
purchased a product? I could state, with equal ease, that you're the sucker
for NOT buying it if the product works like it's supposed to.

[Bret Wade]

Chalo wrote:

> Bret Wade > wrote:
>
>
>>We're not
>>particularly interested in anyones personal bike frame philosophy.
We
>>would simply like to know if anyone has experience with this
particular
>>frame feature and has an opinion on it?
>
>
> My professional opinion as a machine designer is that you don't put
> rolling element bearings in a place where there is no rotation.
> Repeated loads applied to a bearing without rotation to replenish the
> lubricant inevitably result in severe wear known as "false
> brinelling".
>
> The bearings will fail because they do not turn; play will develop in
> the affected joint. That design in principle may as well be a bolted
> joint with the bolt left slightly loose.

Thanks, this is a convincing argument against.

>
> If such a cheap and simple conceit actually made a positive
> difference, don't you think it would be in general use after more than
> 100 years of fundamentally similar bicycle frames? Smarter people
> than you and me have been thinking about this stuff all that time. I
> guarantee you that someone tried this approach generations ago, and it
> didn't work. Like then, it doesn't work now, except to separate a
> fool and his money.

This is less convincing. MTB suspension was slow to gain acceptance
too, but look at it now.

>
> If you or your wife desire a subtly better ride, use a slightly fatter
> tire. It's much cheaper than marketing-driven nonsense, and it
> actually works.

You're making assuptions again, as I never said anything about
comfort. I happen to be the happy owner of a compact aluminum frame.
But my wife wants a new Serotta and we're just evaluating the options.

I also own what I call my "Roubaix bike". It's a Ritchey Swiss Cross
with a Ruby suspension fork and slightly fatter road tires for pinch
flat avoidance, not comfort.

Regards,
Bret

>
> Chalo Colina

[Dave Thompson]

"Bret Wade" > wrote in message
om...
> Chalo wrote:
>
> >
> >
> > My professional opinion as a machine designer is that you don't put
> > rolling element bearings in a place where there is no rotation.
> > Repeated loads applied to a bearing without rotation to replenish the
> > lubricant inevitably result in severe wear known as "false
> > brinelling".
> >
> > The bearings will fail because they do not turn; play will develop in
> > the affected joint. That design in principle may as well be a bolted
> > joint with the bolt left slightly loose.
>
I don't believe there are rolling element bearings in the ST rear of the
Serottas

[Chalo]

"Dave Thompson" > wrote:

> I don't believe there are rolling element bearings in the ST rear of the
> Serottas

From http://serotta.com/pages/details.html :

"3D XL Micro Pivot dropouts are found on DKS and ST models. The sealed
bearing pivots allow for just enough movement to result in road
hugging active suspension."

It's hogwash, but I assumed that they weren't lying about the sealed
bearing part.

Chalo Colina

[Dave Thompson]

"Chalo" > wrote in message
om...
> "Dave Thompson" > wrote:
>
> > I don't believe there are rolling element bearings in the ST rear of the
> > Serottas
>
> From http://serotta.com/pages/details.html :
>
> "3D XL Micro Pivot dropouts are found on DKS and ST models. The sealed
> bearing pivots allow for just enough movement to result in road
> hugging active suspension."
>
> It's hogwash, but I assumed that they weren't lying about the sealed
> bearing part.
>
> Chalo Colina

There ain't no rolling element bearings in my Hors Categorie (DKS rear end)

[Werehatrack]

On 17 Jul 2003 18:35:29 -0700, (Chalo) may
have said:

>"Dave Thompson" > wrote:
>
>> I don't believe there are rolling element bearings in the ST rear of the
>> Serottas
>
>From http://serotta.com/pages/details.html :
>
>"3D XL Micro Pivot dropouts are found on DKS and ST models. The sealed
>bearing pivots allow for just enough movement to result in road
>hugging active suspension."
>
>It's hogwash, but I assumed that they weren't lying about the sealed
>bearing part.

I think it might be more accurate to state that they are exaggerating
the value of their feature. Whether the part about the movement is
all the way off into the realm of intentional falsehood depends upon
whether they believe their own representations.

--
My email address is antispammed;
pull WEEDS if replying via e-mail.
Yes, I have a killfile. If I don't respond to something,
it's also possible that I'm busy.

[ari]

The VW rabbit is an incredibly fun car to drive, and its the only car I
really miss driving. What a weird thing for you to write. So many people
love, restore, and collect them. They still make them in south africa, thats
a 30 year lifespan.

true, stay away from version 1.0 of any product, but the rabbit is a gem.

man..

"Werehatrack" > wrote in message
...
> On Thu, 17 Jul 2003 13:18:35 -0700, "Dave Thompson"
> > may have said:
> >Who else is better to comment on the
> >validity of something, other than the people who have researched and
> >purchased a product? I could state, with equal ease, that you're the
sucker
> >for NOT buying it if the product works like it's supposed to.
>
> Historically, this proposition is not well supported.
>
> By way of stunning example, in the mid-1970s, the VW Rabbit
> consistently got high marks from owners on *subjective* evaluations,
> but when people took a dispassionate look at the real numbers relating
> to repairs and other issues, an entirely different picture emerged.
> Frankly, the cars were crap. Eventually, they became involved in
> numerous recalls; fuse panels, rotting floorboards and brake lines,
> monstrous oil consumption due to faulty valve stem seals, and
> eventually it was found that the body's inherent flex was producing
> fractures in major structural components that could not be prevented
> by mere fixes.
>
> For its day, the VW Rabbit was on the bleeding edge of mass production
> tech...but meanwhile, across a very long continent and a little water,
> a much more patient and methodical bunch of carmakers were rapidly
> going through many designs looking for the ones that worked. As a
> result, where VW had dominated the '60s and early '70s by virtue of
> its popular, old-tech (highly repairable) vehicle, when the reality of
> its front-engine vehicles became apparent, savvy car buyers began
> staying away in droves despite the fact that the cars *continued* to
> get rave reviews from various places.
>
> So, no, the purchasers of *new* products are not the most reliable
> source of real-world information. For that, I'd talk to the people
> who traffic in *used* items, because they have to deal with what is
> left when the patina of newness is rubbed off and all that is left is
> the genuine merit to judge the item by.
>
> --
> My email address is antispammed;
> pull WEEDS if replying via e-mail.
> Yes, I have a killfile. If I don't respond to something,
> it's also possible that I'm busy.

[Dave Thompson]

"Chalo" > wrote in message
om...
> "Dave Thompson" > wrote:
>
> > I don't believe there are rolling element bearings in the ST rear of the
> > Serottas
>
> From http://serotta.com/pages/details.html :
>
> "3D XL Micro Pivot dropouts are found on DKS and ST models. The sealed
> bearing pivots allow for just enough movement to result in road
> hugging active suspension."
>
> It's hogwash, but I assumed that they weren't lying about the sealed
> bearing part.
>
> Chalo Colina

FYI, according to Dave Kirk, who invented the DKS/ST rear suspension system
while he worked at Serotta, the bearing in the pivot is an "oil-lite bronze
plain bearing", with sealing washers used as seals. Hence the "sealed
bearing". NOT a rolling element bearing as you asserted.

I would politely suggest that you offer your opinions as just that,
opinions, not as a statement of fact.

[Chalo]

"Dave Thompson" > wrote:

> FYI, according to Dave Kirk, who invented the DKS/ST rear suspension system
> while he worked at Serotta, the bearing in the pivot is an "oil-lite bronze
> plain bearing", with sealing washers used as seals. Hence the "sealed
> bearing". NOT a rolling element bearing as you asserted.

In conventional bike tech parlance that is known not as a "sealed
bearing" (which implies 'double sealed deep groove radial contact
cartridge ball bearing' unless otherwise indicated), but as a bushing.

It's probably more reliable in this application than a sealed bearing.
It wouldn't hurt to call it what it is, less marketable though it may
be.

It appears that adding an Oilite bushing was Serotta's/Kirk's way of
putting some sassy red lipstick on a bolted dropout joint. Whoopee.

Chalo Colina

[Matt Locker]

A true gem. I owned an 84 GTI through 1994. In that time I:
-lost the headlights while driving down a backroad after midnight.
The headlight dimmer switch overheated in High Beam mode, as I quickly
discovered that I could still use the low beams, thankfully.
-had my clutch/brake assembly fall out from under the dashboard.
The spot welds they used had failed
-had my headlight on/off switch burn up in a puff of smoke.
-replaced the exhaust system every 16 months
-........
Most of these fails were in the first 4 years of it's life. I once
wrote down for a friend all the failures this car suffered. It almost
filled a regular sheet of 8.5x11 paper on both sides. Compare that to
my Honda's where that same list would be zero or one line.

It was a fun car to drive - and actually made a pretty good second car -
but what a POS!

MOO,
Matt

ari wrote:

>The VW rabbit is an incredibly fun car to drive, and its the only car I
>really miss driving. What a weird thing for you to write. So many people
>love, restore, and collect them. They still make them in south africa, thats
>a 30 year lifespan.
>
>true, stay away from version 1.0 of any product, but the rabbit is a gem.
>
>man..
>
>"Werehatrack" > wrote in message
...
>
>
>>On Thu, 17 Jul 2003 13:18:35 -0700, "Dave Thompson"
> may have said:
>>
>>
>>>Who else is better to comment on the
>>>validity of something, other than the people who have researched and
>>>purchased a product? I could state, with equal ease, that you're the
>>>
>>>
>sucker
>
>
>>>for NOT buying it if the product works like it's supposed to.
>>>
>>>
>>Historically, this proposition is not well supported.
>>
>>By way of stunning example, in the mid-1970s, the VW Rabbit
>>consistently got high marks from owners on *subjective* evaluations,
>>but when people took a dispassionate look at the real numbers relating
>>to repairs and other issues, an entirely different picture emerged.
>>Frankly, the cars were crap. Eventually, they became involved in
>>numerous recalls; fuse panels, rotting floorboards and brake lines,
>>monstrous oil consumption due to faulty valve stem seals, and
>>eventually it was found that the body's inherent flex was producing
>>fractures in major structural components that could not be prevented
>>by mere fixes.
>>
>>For its day, the VW Rabbit was on the bleeding edge of mass production
>>tech...but meanwhile, across a very long continent and a little water,
>>a much more patient and methodical bunch of carmakers were rapidly
>>going through many designs looking for the ones that worked. As a
>>result, where VW had dominated the '60s and early '70s by virtue of
>>its popular, old-tech (highly repairable) vehicle, when the reality of
>>its front-engine vehicles became apparent, savvy car buyers began
>>staying away in droves despite the fact that the cars *continued* to
>>get rave reviews from various places.
>>
>>So, no, the purchasers of *new* products are not the most reliable
>>source of real-world information. For that, I'd talk to the people
>>who traffic in *used* items, because they have to deal with what is
>>left when the patina of newness is rubbed off and all that is left is
>>the genuine merit to judge the item by.
>>
>>--
>>My email address is antispammed;
>>pull WEEDS if replying via e-mail.
>>Yes, I have a killfile. If I don't respond to something,
>>it's also possible that I'm busy.
>>
>>
>
>
>
>

[Qui si parla Campagnolo]

Bret-<< Yes, we're working with Wheatridge on this. >><BR><BR>

Good choice, Ron is a good guy..

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

[Dave Thompson]

"Chalo" > wrote in message
om...
> "Dave Thompson" > wrote:
>
> > FYI, according to Dave Kirk, who invented the DKS/ST rear suspension
system
> > while he worked at Serotta, the bearing in the pivot is an "oil-lite
bronze
> > plain bearing", with sealing washers used as seals. Hence the "sealed
> > bearing". NOT a rolling element bearing as you asserted.
>
> In conventional bike tech parlance that is known not as a "sealed
> bearing" (which implies 'double sealed deep groove radial contact
> cartridge ball bearing' unless otherwise indicated), but as a bushing.
>
> It's probably more reliable in this application than a sealed bearing.
> It wouldn't hurt to call it what it is, less marketable though it may
> be.
>
> It appears that adding an Oilite bushing was Serotta's/Kirk's way of
> putting some sassy red lipstick on a bolted dropout joint. Whoopee.
>
> Chalo Colina

How little you really know.............people far better than you, or I,
really like their Serottas with the rear suspension feature.

[Peter Headland]

> Serotta offers a pivoting carbon seat stays as an option on several of
> their Ti frames which is supposed to provide some suspension travel.

Since anyone who has the least understanding of engineering can see
that this feature is bogus (a pivot at one corner of a triangle won't
do anything useful), we must assume that Serotta are either lying
deliberately or are incompetent engineers. Either of those woul be a
reason not to buy any of their products in my book...

[Dave Thompson]

"Peter Headland" > wrote in message
om...
> > Serotta offers a pivoting carbon seat stays as an option on several of
> > their Ti frames which is supposed to provide some suspension travel.
>
> Since anyone who has the least understanding of engineering can see
> that this feature is bogus (a pivot at one corner of a triangle won't
> do anything useful), we must assume that Serotta are either lying
> deliberately or are incompetent engineers. Either of those woul be a
> reason not to buy any of their products in my book...

Serotta....."lying"..."incompetent"....oh please! A dime will get you donuts
that you haven't ridden the DKS or ST equipped Serotta. Ride one, then make
your pronouncements.

[BikeRacer]

Matt Locker > wrote:

> Litespeed, & Serotta. The configuration that was the most comfortable
> was a Litespeed Classic with a Wound-Up fork. It was sooooooo smooth.
> It didn't feel like it put the power to the road quite as well as the
> Serotta but I'd gladly have that ride back for centuries.

Good lord, just what in the hell are you babbling about? "Put the power
to the road?" Geez. . .

[ant]

(Bret Wade) wrote in message >...
> Serotta offers a pivoting carbon seat stays as an option on several of
> their Ti frames which is supposed to provide some suspension travel.
> My wife will be ordering a new Serotta soon and would like to hear
> some opinions for or against this option. Has anyone here owned or
> ridden a Serotta with this feature?

im a slow newsreader, as google takes a while to pick the posts up, so
perhaps this has already been hashed over.

i am no expert, but i had assumed that the pivots were there to
greatly ease the manufacturing process. because of the pivot, frame
builders can buy these stock rear triangle assemblies (which are sold
as such, four stays, dropouts, and bonded lugs, IIRC)and just plug
them into their bike. becuase there is no welding with Cfiber, no tab
and slot brazing, and such, it is difficult for builder who is not set
up for carbon fabbing to make their own carbon rear triangles for
every size bike, for every style frame, with all their incremental
angles. with the pivot, you just cut the metal lugs to size, miter
them to the seattube and BB, and the pivot falls where it is supposed
to.

but i could, and generally am, be wrong.

anthony

[Mark Hickey]

"Dave Thompson" > wrote:

>"Peter Headland" > wrote in message
om...
>> > Serotta offers a pivoting carbon seat stays as an option on several of
>> > their Ti frames which is supposed to provide some suspension travel.
>>
>> Since anyone who has the least understanding of engineering can see
>> that this feature is bogus (a pivot at one corner of a triangle won't
>> do anything useful), we must assume that Serotta are either lying
>> deliberately or are incompetent engineers. Either of those woul be a
>> reason not to buy any of their products in my book...
>
>Serotta....."lying"..."incompetent"....oh please! A dime will get you donuts
>that you haven't ridden the DKS or ST equipped Serotta. Ride one, then make
>your pronouncements.

Better yet, why doesn't someone explain how it COULD work. I haven't
seen the frame (so won't make any pronouncements), but for those of
you who have, and do believe "it works", you have to be able to
explain how it works - and how much "suspension" is provided by the
design.

After all, if there's no reason why it CAN work, it simply can't.

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $695 ti frame

[Alexey Merz]

(Chalo) wrote in message >...
> "Dave Thompson" > wrote:
>
> > I don't believe there are rolling element bearings in the ST rear of the
> > Serottas
>
> From http://serotta.com/pages/details.html :
>
> "3D XL Micro Pivot dropouts are found on DKS and ST models. The sealed
> bearing pivots allow for just enough movement to result in road
> hugging active suspension."
>
> It's hogwash, but I assumed that they weren't lying about the sealed
> bearing part.

Heh. On the same page they gloat about the stiffness offered by their
"S" shaped chainstays, developed, they say, for the '84 olympic bikes.
Now, I had one of those very Murray-branded Serotta bikes (on loan
from a friend who'd got it as surplus from Murray in Nashville), and
it was very nice. I spent a year riding it around the Santa Cruz
mountains where I learned a lot about how it handled climbing,
descending, etc... but it was not noticably more efficient than other
bikes I've had with other chainstay designs. Serotta is a
distinguished builder and I certainly wouldn't mind having one of his
frames, but it appears that many of his "features" are marketing
hooey.

TdF riders and serious messengers alike burn up the roads on a variety
of frames made of aluminum, steel, plastic and Ti (well, no Ti in the
TdF this year). in every case it's the fit, the handling, and the
reliability of the frames that matter.

Of course, Ti, pivots, and plastic seatstays can easily be sold to
people who think that suspensions on bicycles are a recent innovation.

[Matt Locker]

Call it babble if you want. It was my impression and I'm happy to pass
it along. I felt it was appropriate to the request. And FYI, my
impression was confirmed by the owner of the Classic who also felt that
the Serotta had better acceleration - probably due to the extra
stiffness of the BB.

MOO,
Matt

BikeRacer wrote:

>Matt Locker > wrote:
>
>
>
>>Litespeed, & Serotta. The configuration that was the most comfortable
>>was a Litespeed Classic with a Wound-Up fork. It was sooooooo smooth.
>> It didn't feel like it put the power to the road quite as well as the
>>Serotta but I'd gladly have that ride back for centuries.
>>
>>
>
>Good lord, just what in the hell are you babbling about? "Put the power
>to the road?" Geez. . .
>
>

[Scott Hendricks]

Mark Hickey > wrote in message >...
> "Dave Thompson" > wrote:
>
> >"Peter Headland" > wrote in message
> om...
> >> > Serotta offers a pivoting carbon seat stays as an option on several of
> >> > their Ti frames which is supposed to provide some suspension travel.
> >>
> >> Since anyone who has the least understanding of engineering can see
> >> that this feature is bogus (a pivot at one corner of a triangle won't
> >> do anything useful), we must assume that Serotta are either lying
> >> deliberately or are incompetent engineers. Either of those woul be a
> >> reason not to buy any of their products in my book...
> >
> >Serotta....."lying"..."incompetent"....oh please! A dime will get you donuts
> >that you haven't ridden the DKS or ST equipped Serotta. Ride one, then make
> >your pronouncements.
>
> Better yet, why doesn't someone explain how it COULD work. I haven't
> seen the frame (so won't make any pronouncements), but for those of
> you who have, and do believe "it works", you have to be able to
> explain how it works - and how much "suspension" is provided by the
> design.
>
> After all, if there's no reason why it CAN work, it simply can't.
>
> Mark Hickey
> Habanero Cycles
> http://www.habcycles.com
> Home of the $695 ti frame


Having seen one (and ridden one for about 50 meters) and having
listened to a lengthy, glowing report on how well it worked from the
owner, I'll throw in my .02 worth.

The concept is that the chainstays have a certain amount of flex to
them, and the "flexibility" of the curved carbon seatstays is supposed
to allow for a tiny bit of up/down movement of the rear wheel, similar
to a Moots YBB.

It's obvious where the compression occurs in a Moots, as it's visible
and measurable. I tried to compress the rear end on the Serotta, and
will say this DEFINITIVELY: I couldn't see any movement/compression
of the carbon stays, and couldn't feel anything more than compression
of the tire.

As Mark said, if you can't prove that it can work, then it can't work.
Anybody want to take a stab at the actual compression/flexion of the
carbon seatstays when placed in a rear triangle? My guess: 0.

Now, if the carbon really works as they say and damps the vibrations,
then a sense of muted vibrations may be at play in convincing riders
that there is actual 'suspension' going on.

Scott

[Dave Thompson]

"Scott Hendricks" > wrote in message
om...
> Mark Hickey > wrote in message
>...
> > "Dave Thompson" > wrote:
> >
> > >"Peter Headland" > wrote in message
> > om...
> > >> > Serotta offers a pivoting carbon seat stays as an option on several
of
> > >> > their Ti frames which is supposed to provide some suspension
travel.
> > >>
> > >> Since anyone who has the least understanding of engineering can see
> > >> that this feature is bogus (a pivot at one corner of a triangle won't
> > >> do anything useful), we must assume that Serotta are either lying
> > >> deliberately or are incompetent engineers. Either of those woul be a
> > >> reason not to buy any of their products in my book...
> > >
> > >Serotta....."lying"..."incompetent"....oh please! A dime will get you
donuts
> > >that you haven't ridden the DKS or ST equipped Serotta. Ride one, then
make
> > >your pronouncements.
> >
> > Better yet, why doesn't someone explain how it COULD work. I haven't
> > seen the frame (so won't make any pronouncements), but for those of
> > you who have, and do believe "it works", you have to be able to
> > explain how it works - and how much "suspension" is provided by the
> > design.
> >
> > After all, if there's no reason why it CAN work, it simply can't.
> >
> > Mark Hickey
> > Habanero Cycles
> > http://www.habcycles.com
> > Home of the $695 ti frame
>
>
> Having seen one (and ridden one for about 50 meters) and having
> listened to a lengthy, glowing report on how well it worked from the
> owner, I'll throw in my .02 worth.
>
> The concept is that the chainstays have a certain amount of flex to
> them, and the "flexibility" of the curved carbon seatstays is supposed
> to allow for a tiny bit of up/down movement of the rear wheel, similar
> to a Moots YBB.
>
> It's obvious where the compression occurs in a Moots, as it's visible
> and measurable. I tried to compress the rear end on the Serotta, and
> will say this DEFINITIVELY: I couldn't see any movement/compression
> of the carbon stays, and couldn't feel anything more than compression
> of the tire.
>
> As Mark said, if you can't prove that it can work, then it can't work.
> Anybody want to take a stab at the actual compression/flexion of the
> carbon seatstays when placed in a rear triangle? My guess: 0.
>
> Now, if the carbon really works as they say and damps the vibrations,
> then a sense of muted vibrations may be at play in convincing riders
> that there is actual 'suspension' going on.
>
> Scott

According to Dave Kirk, the inventor of the DKS/ST rear end while he was at
Serotta, The DKS can deflect as much as 10mm, while the ST can deflect as
much as 3mm. And the 'pushing down on the seat' forces aren't enough to
cause any deflection. It takes a bigger force than you can apply like that.
The whole reason for the DKS/ST rear suspension to allow the rear wheel to
stay on the ground while encountering rough road surfaces. It is not a
comfort feature. If the wheel is in the air, it's not doing any driving or
steering. I've owned a DKS equipped Serotta, the Hors Categorie. It handled
extremely well, better than other Serottas that I owned at the same time,
particularly on rough surfaced descents.

[Mark Hickey]

"Dave Thompson" > wrote:

>According to Dave Kirk, the inventor of the DKS/ST rear end while he was at
>Serotta, The DKS can deflect as much as 10mm, while the ST can deflect as
>much as 3mm. And the 'pushing down on the seat' forces aren't enough to
>cause any deflection. It takes a bigger force than you can apply like that.
>The whole reason for the DKS/ST rear suspension to allow the rear wheel to
>stay on the ground while encountering rough road surfaces. It is not a
>comfort feature. If the wheel is in the air, it's not doing any driving or
>steering. I've owned a DKS equipped Serotta, the Hors Categorie. It handled
>extremely well, better than other Serottas that I owned at the same time,
>particularly on rough surfaced descents.

Does anyone have a link to photos of a bike with the DKS and ST rear
ends?

10 and 3mm is a lot of deflection - I know that there's no way to get
3mm of "suspension" out of a typical curved seat stay... at least not
more than once... ;-)

At any rate, it should be simple to measure the amount of
"smooshiness" in any seat stay by carefully measuring two fixed points
at each end while applying enough weight to the saddle (or top tube)
to simulate a bump. Perhaps it would be best to measure the
"compression" at the point the rear 23mm tire compresses 5mm for
comparison.

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $695 ti frame

[David Damerell]

Dave Thompson > wrote:
>According to Dave Kirk, the inventor of the DKS/ST rear end while he was at
>Serotta, The DKS can deflect as much as 10mm, while the ST can deflect as
>much as 3mm. And the 'pushing down on the seat' forces aren't enough to
>cause any deflection. It takes a bigger force than you can apply like that.

Well, I'm sure that whoever tried it out can push down on the saddle with
their full weight without too much trouble; let us assume they weigh 70kg.
If that doesn't cause "any" deflection - well, that can't happen, but
let's say it's 1mm, which might escape notice. Reasonably one would think
that the 10mm deflection would require ten times that force - as if 700kg
were placed on the saddle.

Now, under such a force, what happens to the tyre? (Hint; bottoms out.)
--
David Damerell > Distortion Field!

[Scott Hendricks]

"Dave Thompson" > wrote in message >...
> "Scott Hendricks" > wrote in message
> om...
> > >
> > Having seen one (and ridden one for about 50 meters) and having
> > listened to a lengthy, glowing report on how well it worked from the
> > owner, I'll throw in my .02 worth.
> >
> > The concept is that the chainstays have a certain amount of flex to
> > them, and the "flexibility" of the curved carbon seatstays is supposed
> > to allow for a tiny bit of up/down movement of the rear wheel, similar
> > to a Moots YBB.
> >
> > It's obvious where the compression occurs in a Moots, as it's visible
> > and measurable. I tried to compress the rear end on the Serotta, and
> > will say this DEFINITIVELY: I couldn't see any movement/compression
> > of the carbon stays, and couldn't feel anything more than compression
> > of the tire.
> >
> > As Mark said, if you can't prove that it can work, then it can't work.
> > Anybody want to take a stab at the actual compression/flexion of the
> > carbon seatstays when placed in a rear triangle? My guess: 0.
> >
> > Now, if the carbon really works as they say and damps the vibrations,
> > then a sense of muted vibrations may be at play in convincing riders
> > that there is actual 'suspension' going on.
> >
> > Scott
>
> According to Dave Kirk, the inventor of the DKS/ST rear end while he was at
> Serotta, The DKS can deflect as much as 10mm, while the ST can deflect as
> much as 3mm. And the 'pushing down on the seat' forces aren't enough to
> cause any deflection. It takes a bigger force than you can apply like that.
> The whole reason for the DKS/ST rear suspension to allow the rear wheel to
> stay on the ground while encountering rough road surfaces. It is not a
> comfort feature. If the wheel is in the air, it's not doing any driving or
> steering. I've owned a DKS equipped Serotta, the Hors Categorie. It handled
> extremely well, better than other Serottas that I owned at the same time,
> particularly on rough surfaced descents.

Okay, in the parlance of my upbringing (aka: good ol' boy) I'm gonna
have to call bull**** on you. I can put enough force on the frame to
compress the tire, and to generate a bit of flex in the seat rails,
but once those are bottomed out, I CAN'T generate enough force to
visible compress the rear end of a 'suspension' system??? You gotta
be kidding.

At what point does the compression of the tire end and the flexion of
the suspension system begin? I wait with abated breath for an answer.

[Bret Wade]

"Dave Thompson" > wrote:

> > Okay, in the parlance of my upbringing (aka: good ol' boy) I'm gonna
> > have to call bull**** on you. I can put enough force on the frame to
> > compress the tire, and to generate a bit of flex in the seat rails,
> > but once those are bottomed out, I CAN'T generate enough force to
> > visible compress the rear end of a 'suspension' system??? You gotta
> > be kidding.
> >
> > At what point does the compression of the tire end and the flexion of
> > the suspension system begin? I wait with abated breath for an answer.
>
> Look, I'm an owner, not an engineer, metallurgist, physics major or anything
> else. Simply an owner.
> Perhaps you would be better served to call Serotta, 518.584.1221. I'm sure
> they can explain it much better
> than I. I can tell you that I have owned three Serottas simultaneously,
> including the DKS equipped Hors Categorie, and
> there were significant differences between it and the two others in the way
> it handled bad road surfaces. So therefore it must work, for me.
>
> The OP solicited opinions from riders with experiences with the DKS/ST rear
> end. I stated my opinion, both on this board and with a PM.
> Every other poster has stated their opinion as a fact with no factual basis
> to draw on, just sheer conjecture.

Thanks to all who responded helpfully for and against the pivot. Lisa
has decided on the hardtail.

Never mind Scott, he just likes a good debate. If you think he's
annoying on usenet, you should try going on a five hour ride with him.
Bring along your GOB/English dictionary.

Bret

[Chalo]

"Dave Thompson" > wrote:

> The OP solicited opinions from riders with experiences with the DKS/ST rear
> end. I stated my opinion, both on this board and with a PM.
> Every other poster has stated their opinion as a fact with no factual basis
> to draw on, just sheer conjecture.

So how are those X-Ray Specs you mail ordered out of the back of a
comic book working?

Chalo Colina

[Dave Thompson]

"Chalo" > wrote in message
om...
> "Dave Thompson" > wrote:
>
> > The OP solicited opinions from riders with experiences with the DKS/ST
rear
> > end. I stated my opinion, both on this board and with a PM.
> > Every other poster has stated their opinion as a fact with no factual
basis
> > to draw on, just sheer conjecture.
>
> So how are those X-Ray Specs you mail ordered out of the back of a
> comic book working?
>
> Chalo Colina

Just fine. Thanks for asking.

[Scott Hendricks]

(Bret Wade) wrote in message >...
> "Dave Thompson" > wrote:
>
> > > Okay, in the parlance of my upbringing (aka: good ol' boy) I'm gonna
> > > have to call bull**** on you. I can put enough force on the frame to
> > > compress the tire, and to generate a bit of flex in the seat rails,
> > > but once those are bottomed out, I CAN'T generate enough force to
> > > visible compress the rear end of a 'suspension' system??? You gotta
> > > be kidding.
> > >
> > > At what point does the compression of the tire end and the flexion of
> > > the suspension system begin? I wait with abated breath for an answer.
> >
> > Look, I'm an owner, not an engineer, metallurgist, physics major or anything
> > else. Simply an owner.
> > Perhaps you would be better served to call Serotta, 518.584.1221. I'm sure
> > they can explain it much better
> > than I. I can tell you that I have owned three Serottas simultaneously,
> > including the DKS equipped Hors Categorie, and
> > there were significant differences between it and the two others in the way
> > it handled bad road surfaces. So therefore it must work, for me.
> >
> > The OP solicited opinions from riders with experiences with the DKS/ST rear
> > end. I stated my opinion, both on this board and with a PM.
> > Every other poster has stated their opinion as a fact with no factual basis
> > to draw on, just sheer conjecture.
>
> Thanks to all who responded helpfully for and against the pivot. Lisa
> has decided on the hardtail.
>
> Never mind Scott, he just likes a good debate. If you think he's
> annoying on usenet, you should try going on a five hour ride with him.
> Bring along your GOB/English dictionary.
>
> Bret

For what it's worth, I just bought a ti frame with a carbon rear end.
No fancy pivots, though. I'm at worst hoping for a little shock
damping qualities, nothing more.