American Classic Seatpost Failure
sols...@tampabay.rr.com
specifically, the single clamp bolt broke, causing my saddle to
disconnect from the seatpost. While I was riding. I crashed, my
bicycle was destroyed, and I was very seriously injured.
American Classic denies any design or manufacturing defect. I plan to
report the failure to the Consumer Product Safety Commission (CPSC) in
an effort to alert other bicyclists to the potential danger and/or
force a recall. To bolster my claim that an investigation is needed,
I'm searching for others who have experienced a failure with the same
clamp bolt. I've heard second-hand stories of other American Classic
seatpost failures. A few concrete examples, with names, dates, etc.,
might be enough to get the CPSC's attention.
BTW, my problem was with the prior generation seatpost, not the new
curved top design (although I note that the curved top design also
relies on a single clamp bolt).
Thanks in advance.
Carl Sundquist
How was your bike destroyed?
Jay Beattie
How old was your post? The first generation with the silver bolts
were recalled. Check the CPSC web-site for dates and models. -- Jay
Beattie.
Chalo
>
> The American Classic seatpost hardware failed on my road bike. More
> specifically, the single clamp bolt broke, causing my saddle to
> disconnect from the seatpost. While I was riding. I crashed, my
> bicycle was destroyed, and I was very seriously injured.
>
>
> BTW, my problem was with the prior generation seatpost, not the new
> curved top design (although I note that the curved top design also
> relies on a single clamp bolt).
I'm sorry to hear you were hurt. I have been badly busted up as a
result of equipment failures, and I can attest that it made me angry,
apprehensive, and hesitant to enjoy cycling. If there was any
consolation, it was that such experiences made me understand my
equipment better and make substantial improvements to my bikes.
I can't speak to the design of the American Classic post, except that
it, like all American Classic products, is designed for light weight
above all other significant virtues. If you want ruggedness and
structural redundancy, AC is clearly not a brand of first resort.
Also, lots of proven seatposts use single clamp bolts, for instance
the SR Laprade. It would be difficult to find a much more reliable
and broadly tested seatpost than that. The Nitto/Ritchey forged one-
bolt post is another design that must be regarded as totally proven.
http://www.bikepro.com/arch_products/seatposts/asr.html
http://www.bikepro.com/products/seatposts/ritch.html
In the future, you should consider the Thomson Elite seatpost to be
utterly dependable. It is weirdly strong, quite lightweight, and easy
to install and adjust. It uses two small but very strong clamp
bolts. For what it's worth, I doubt that any seatpost will behave in
a safe and predictable manner in the case of a clamp bolt breakage.
Chalo
jim beam
what was the tightening torque on the bolt?
John Forrest Tomlinson
wrote:
>The American Classic seatpost hardware failed on my road bike. More
>specifically, the single clamp bolt broke, causing my saddle to
>disconnect from the seatpost. While I was riding. I crashed, my
>bicycle was destroyed, and I was very seriously injured.
>
>American Classic denies any design or manufacturing defect. I plan to
>report the failure to the Consumer Product Safety Commission (CPSC) in
>an effort to alert other bicyclists to the potential danger and/or
>force a recall. To bolster my claim that an investigation is needed,
>I'm searching for others who have experienced a failure with the same
>clamp bolt. I've heard second-hand stories of other American Classic
>seatpost failures. A few concrete examples, with names, dates, etc.,
>might be enough to get the CPSC's attention.
I broke the bolt on one of those while riding, but wasn't injured. The
post was old with a lot of use.
Just about everything eventually breaks - especially lightweight
stuff, so I wasn't especially concerned beyond checking my parts a
little more carefully from time to time and replacing some stuff
before I notice problems.
sols...@tampabay.rr.com
>
> How was your bike destroyed?
Carl,
I'm not sure how it happened, but when the bike & I went down,
something dented the top tube. A small dent in steel might not be a
big deal. But in thin-walled aluminum (Cannondale), it may not be
safe to ride.
Steve
sols...@tampabay.rr.com
Jay,
My clamp bolt was not silver. I've searched the CPSC site, and can't
find recall data for prior generation American Classic seatposts.
Steve
sols...@tampabay.rr.com
> In the future, you should consider the Thomson Elite seatpost to be
> utterly dependable. It is weirdly strong, quite lightweight, and easy
> to install and adjust. It uses two small but very strong clamp
> bolts. For what it's worth, I doubt that any seatpost will behave in
> a safe and predictable manner in the case of a clamp bolt breakage.
>
> Chalo
Thanks, but I may not be able to ride a road bike again. It's easier
to reconstruct bikes than people.
Steve
Chalo
>
> Chalo wrote:
> >
> > In the future, you should consider the Thomson Elite seatpost to be
> > utterly dependable. It is weirdly strong, quite lightweight, and easy
> > to install and adjust.
>
> to reconstruct bikes than people.
That's unfortunate to hear. I hope that over time you prove yourself
incorrect on that point.
I can say that my body likes to return itself to a reasonable likeness
of its previous condition. (Though my teeth did not grow back; I had
to seek professional help with that.) Your body most likely can heal
too. Make the demand of it and see how it goes.
Chalo
sols...@tampabay.rr.com
> That's unfortunate to hear. I hope that over time you prove yourself
> incorrect on that point.
>
> I can say that my body likes to return itself to a reasonable likeness
> of its previous condition. (Though my teeth did not grow back; I had
> to seek professional help with that.) Your body most likely can heal
> too. Make the demand of it and see how it goes.
>
> Chalo
OK, I'll be more explicit. I shattered a portion of my spine. I now
have a titanium cage where one of my vertebra used to be. The
surgeons also fused several of my vertebrae together, limiting my
flexibility, and making a road bike position very uncomfortable. This
former USCF racer now rides a recumbent trike (Catrike Speed).
Ron Ruff
> Just about everything eventually breaks - especially lightweight
> stuff, so I wasn't especially concerned beyond checking my parts a
> little more carefully from time to time and replacing some stuff
> before I notice problems.
Very true. You can't expect bike parts to last forever, and you must
accept some responsibility in checking your equipment. If I sued the
manufacturer every time a part broke... well, I'd have a few lawsuits.
Most recently I had a Ritchey crank snap in two while sprinting... I
landed on the ground but wasn't hurt badly enough to worry about.
BTW, I used an AC seatpost for several years when I was racing a
lot... probably 40k miles and a lot of crashes, but it held up fine.
I now use a Thomson Elite post, which has a good rep for durability.
landotter
Was the saddle clamped in using a torque wrench? When bits get lighter
and racier, the more sensitive they are to improper torque. It's also
why proving any case against American Classic is probably doomed. At
least you're alive enough to complain!
Chalo
>
> Chalo wrote:
> >
> > I can say that my body likes to return itself to a reasonable likeness
> > of its previous condition. (Though my teeth did not grow back; I had
> > to seek professional help with that.) Your body most likely can heal
> > too. Make the demand of it and see how it goes.
>
> have a titanium cage where one of my vertebra used to be. The
> surgeons also fused several of my vertebrae together, limiting my
> flexibility, and making a road bike position very uncomfortable. This
> former USCF racer now rides a recumbent trike (Catrike Speed).
That sucks. I broke vertebrae T6 and T7 in a car crash over twenty
years ago, but since my convalescence they have given me no further
trouble. I count myself very lucky for that.
I'm glad to hear that you don't suffer debilitating paralysis, and
that you have other options available to you for continuing your
cycling habit.
I don't know whether sitting upright on a bike is feasible for you,
but not all normal bikes require a stooped posture or a flexible
spine. It's hard to beat a 'bent tadpole trike for back-friendliness,
though.
Chalo
jim beam
> John Forrest Tomlinson wrote:
>> Just about everything eventually breaks - especially lightweight stuff,
>> so I wasn't especially concerned beyond checking my parts a little more
>> carefully from time to time and replacing some stuff before I notice
>> problems.
>
> Very true. You can't expect bike parts to last forever, and you must
> accept some responsibility in checking your equipment. If I sued the
> manufacturer every time a part broke... well, I'd have a few lawsuits.
> Most recently I had a Ritchey crank snap in two while sprinting... I
> landed on the ground but wasn't hurt badly enough to worry about.
the ritchey design is fundamentally flawed - the "i-beam" thing. it's
known to be a fatigue risk since that profile means the skin is much more
highly stressed and slightest riser therefore initiates fatigue. modern
designs use an ovalized crank arm which is much less sensitive.
this is not new technology. if competent, ritchey should know this and
minimize hazard to the consumer accordingly. on this basis, and in the
light of a number of these failures, i'd pursue ritchey as they clearly
haven't done their homework and are jeopardizing consumers.
thef...@gmail.com
I'm sorry to hear of your injuries, keep your recovery goals high.
Bodies are remarkable things but sometimes they're just looking for a
fight. I knew a guy who lost a good bit of one calf when a shotgun
slid down a log and discharged into his leg. Doc said he would loose
the use of that calf, but by (in part) riding himself into the
ground , that calf eventually worked pretty well although it was the
weaker of the two, being somewhat smaller.
I looked at my bike last night as I have an AC seatpost, probably from
the late 90s. Never a problem but now I'm so spooked I'm going to
replace it. The Thomsons mentioned in the thread look pretty sweet.
Early Christmas.
sols...@tampabay.rr.com
In my opinion, that is a very prudent decision. I take some comfort
in the knowledge that I might have helped you avoid a terrible crash.
Of course, most cyclists will not see this thread, which is why I'm
alerting the CPSC. My hope is that the CPSC will issue a recall. I
believe that most bike shops keep appraised of such recalls, which
could benefit those who have their bike professionally serviced.
John Forrest Tomlinson
>I looked at my bike last night as I have an AC seatpost, probably from
>the late 90s. Never a problem but now I'm so spooked I'm going to
>replace it.
Good move. I wouldn't ride a post like that more than a couple
thousand hours.
Andrew Lee
> force a recall. To bolster my claim that an investigation is needed,
> I'm searching for others who have experienced a failure with the same
> clamp bolt. I've heard second-hand stories of other American Classic
> seatpost failures. A few concrete examples, with names, dates, etc.,
> might be enough to get the CPSC's attention.
I recall that back in the early(?) '90s when I subscribed to Velonews, there
was a photo of Jonathan Vaughters riding his bike without a saddle in a race
coverage photo. He was riding out of the saddle, obviously, and the
seatpost tube was just sticking out of his frame. My recollection was that
it was an American Classic post with a broken bolt.
Found this with an internet search:
http://search.bikelist.org/beta/ViewMessage.aspx?id=76728
I probably still have that issue of Velonews, but it's sitting in the closet
of my childhood home (thousands of miles away), so I can't be any more
specific when/where.
sols...@tampabay.rr.com
> solse...@tampabay.rr.com wrote:
Thanks, that's an excellent tip. I'll see where it leads.
Duncan
news:293df733-1a02-4872...@o2g2000yqd.googlegroups.com...
> The American Classic seatpost hardware failed on my road bike. More
> specifically, the single clamp bolt broke, causing my saddle to
> disconnect from the seatpost. While I was riding. I crashed, my
> bicycle was destroyed, and I was very seriously injured.
>
> American Classic denies any design or manufacturing defect. I plan to
> report the failure to the Consumer Product Safety Commission (CPSC) in
> an effort to alert other bicyclists to the potential danger and/or
> force a recall. To bolster my claim that an investigation is needed,
> I'm searching for others who have experienced a failure with the same
> clamp bolt. I've heard second-hand stories of other American Classic
> seatpost failures. A few concrete examples, with names, dates, etc.,
> might be enough to get the CPSC's attention.
Just as an extra data point, I've had three bolts snap on an Easton EA50
seatpost. I was lucky that my worst injury was the nose of the seat
flipping up into a fairly sensitive area. This was MTB racing however so I
was a little more prepared for the unexpected.
I put it down to my over tightening to stop the seat slipping and creaking.
Since getting a two bolt seatpost nearly two years ago I haven't had a
single problem.
I've also known of two Thomson seatposts shattering from bad landings which
is a lot scarier than a bolt snapping.
sergio
> Since getting a two bolt seatpost nearly two years ago I haven't had a
> single problem.
I am glad to vouch for two-bolts seat posts.
I have been using the two bolt Campagnolo ones for exactly 36 years,
now, and never suffered a broken one.
Happy I have stuck to them ever since.
Sergio
Pisa
jobst....@stanfordalumni.org
>> Since getting a two bolt seatpost nearly two years ago I haven't
>> had a single problem.
> I am glad to vouch for two-bolts seat posts. I have been using the
> two bolt Campagnolo ones for exactly 36 years, now, and never
> suffered a broken one. Happy I have stuck to them ever since.
Ah yes, we ancients remember when Campagnolo first introduced this seat
post it was steel with its head welded onto a polished chromed thin
walled tube. Unfortunately they were not protected from the inside
and the transition to the solid head was a stress concentration. The
heads broke off.
Since those days, I have ridden the one piece cast aluminum version
that is probably the most reliable two bolt post made, the one Sergio
rides, no doubt. If one of the bolts fails, the seat becomes loose
but cannot fall off, but I have not heard of a failed bolt. Their
problem is that they are difficult to adjust, their two cap screws
being head-up under the saddle and not readily accessible.
I don't care because I don't need to adjust the saddle once installed
and secured. It's a one time chore, but worth the reliability and
assurance it gives. The one bolt, screw from below seat posts, came
along to make installation and adjustment easier, rather than to save
weight. The weight weenies came along later with drillium in the
1960's and 1970's, when all aluminum components were drilled and
countersunk to "appear" to be lighter, since then it became a fetish
with lighter "space age" materials at great cost per gram weight lost.
To hell with riding, it's all about equipment now.
Jobst Brandt
russell...@yahoo.com
I have an American Classic seatpost from 1998. Ridden it many
thousands of miles. Likely I'll keep on riding it for many more
thousands of miles. One of the problems is its a 27.4 diameter and my
frame requires that unusual size. Only AC and Kalloy make that
bizarre size.
russell...@yahoo.com
>
> - Show quoted text -
I forgot I have an American Classic post on another bike too. Not as
many miles on that one. But I'll keep riding it too. Good past.
Allows lots and lots of setback. Easy to adjust the tilt with the
little bolt nub.
sergio
Their
> problem is that they are difficult to adjust, their two cap screws
> being head-up under the saddle and not readily accessible.
So true. A tricky endeavour indeed, but well worth.
A few years ago I was able to convince a chap from Geneve that he
should equip his (three, I think) bikes with that type of seat post.
I got three of them and mailed over to him, with a long and wordy
instruction sheet.
He soon after paid for the posts and sent me also a complimentary box
of Swiss chocolate bars,
After a few weeks he gave up the excercise and I got also the posts
back.
Sergio
PIsa
ycle...@verizon.net
> The American Classic seatpost hardware failed on my road bike. More
> specifically, the single clamp bolt broke, causing my saddle to
> disconnect from the seatpost.
Sorry to hear about your accident and injuries.
I had a similar failure on a Campy Chorus seatpost some years ago.
Ended up in the blackberry bushes. On another occasion, I snapped
another Chorus seatpost off about 2 inches above the seat tube
following an offroad adventure prompted by severe shimmy on a descent.
Remained upright on that one. Maybe I should call Campagnolo, but I
tossed the parts. Things do fail, and do so under normal circumstances
as well as severe.
DirtRoadie
> On Nov 25, 11:42 pm, "Andrew Lee" <whatsupand...@hotmail.com> wrote:
>
>
>
> > solse...@tampabay.rr.com wrote:
> > > force a recall. To bolster my claim that an investigation is needed,
> > > I'm searching for others who have experienced a failure with the same
> > > clamp bolt. I've heard second-hand stories of other American Classic
> > > seatpost failures. A few concrete examples, with names, dates, etc.,
> > > might be enough to get the CPSC's attention.
>
> > I recall that back in the early(?) '90s when I subscribed to Velonews, there
> > was a photo of Jonathan Vaughters riding his bike without a saddle in a race
> > coverage photo. He was riding out of the saddle, obviously, and the
> > seatpost tube was just sticking out of his frame. My recollection was that
> > it was an American Classic post with a broken bolt.
> Thanks, that's an excellent tip. I'll see where it leads.
That sounds familiar but what I remember is the same situation
involving Mike Engelman in the Mt. Evans Hill climb one year.
It stuck in my mind because I had also suffered the broken bolt
syndrome and resulting crash (with minor injuries).
To help put a date on my incident it was some time shortly after the
AC factory was destroyed or heavily damaged by a fire.
AC later changed to use a beefier bolt, but it can still be subject to
some pretty heavy stress especially, for example, if the saddle is
mounted far back.
DR
Gennaro
[...]
> Just as an extra data point, I've had three bolts snap on an Easton EA50
> seatpost.
[...]
> Since getting a two bolt seatpost nearly two years ago I haven't had a
> single problem.
Isn't Easton EA50 already a two bolt seatpost?
sols...@tampabay.rr.com
<russellseat...@yahoo.com> wrote:
>
> I forgot I have an American Classic post on another bike too. Not as
> many miles on that one. But I'll keep riding it too. Good past.
> Allows lots and lots of setback. Easy to adjust the tilt with the
> little bolt nub.
Hey, are you the Russell Seaton who rode PBP 2007?
I rode on my AC seatpost for thousands of miles too, until it broke.
I urge you to do some research; the failure of my AC seatpost is not
an isolated incident. Of course, if you insist on using the AC
seatpost even knowing the risk, then that's your business.
Steve
A Muzi
>> The American Classic seatpost hardware failed on my road bike. More
>> specifically, the single clamp bolt broke, causing my saddle to
>> disconnect from the seatpost. While I was riding. I crashed, my
>> bicycle was destroyed, and I was very seriously injured.
>> American Classic denies any design or manufacturing defect. I plan to
>> report the failure to the Consumer Product Safety Commission (CPSC) in
>> an effort to alert other bicyclists to the potential danger and/or
>> force a recall. To bolster my claim that an investigation is needed,
>> I'm searching for others who have experienced a failure with the same
>> clamp bolt. I've heard second-hand stories of other American Classic
>> seatpost failures. A few concrete examples, with names, dates, etc.,
>> might be enough to get the CPSC's attention.
>> BTW, my problem was with the prior generation seatpost, not the new
>> curved top design (although I note that the curved top design also
>> relies on a single clamp bolt).
russell...@yahoo.com wrote:
> I have an American Classic seatpost from 1998. Ridden it many
> thousands of miles. Likely I'll keep on riding it for many more
> thousands of miles. One of the problems is its a 27.4 diameter and my
> frame requires that unusual size. Only AC and Kalloy make that
> bizarre size.
The Thomson USA 27.4 is a superior product
--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971
** Posted from http://www.teranews.com **
russell...@yahoo.com
> > solse...@tampabay.rr.com wrote:
> >> The American Classic seatpost hardware failed on my road bike. More
> >> specifically, the single clamp bolt broke, causing my saddle to
> >> disconnect from the seatpost. While I was riding. I crashed, my
> >> bicycle was destroyed, and I was very seriously injured.
> >> American Classic denies any design or manufacturing defect. I plan to
> >> report the failure to the Consumer Product Safety Commission (CPSC) in
> >> an effort to alert other bicyclists to the potential danger and/or
> >> force a recall. To bolster my claim that an investigation is needed,
> >> I'm searching for others who have experienced a failure with the same
> >> clamp bolt. I've heard second-hand stories of other American Classic
> >> seatpost failures. A few concrete examples, with names, dates, etc.,
> >> might be enough to get the CPSC's attention.
> >> BTW, my problem was with the prior generation seatpost, not the new
> >> curved top design (although I note that the curved top design also
> >> relies on a single clamp bolt).
> > I have an American Classic seatpost from 1998. Ridden it many
> > thousands of miles. Likely I'll keep on riding it for many more
> > thousands of miles. One of the problems is its a 27.4 diameter and my
> > frame requires that unusual size. Only AC and Kalloy make that
> > bizarre size.
>
> The Thomson USA 27.4 is a superior product
> --
> Andrew Muzi
> <www.yellowjersey.org/>
> Open every day since 1 April, 1971
>
> - Show quoted text -
No setback on the Thomson.
russell...@yahoo.com
> >> The American Classic seatpost hardware failed on my road bike. More
> >> specifically, the single clamp bolt broke, causing my saddle to
> >> disconnect from the seatpost. While I was riding. I crashed, my
> >> bicycle was destroyed, and I was very seriously injured.
> >> American Classic denies any design or manufacturing defect. I plan to
> >> report the failure to the Consumer Product Safety Commission (CPSC) in
> >> an effort to alert other bicyclists to the potential danger and/or
> >> force a recall. To bolster my claim that an investigation is needed,
> >> I'm searching for others who have experienced a failure with the same
> >> clamp bolt. I've heard second-hand stories of other American Classic
> >> seatpost failures. A few concrete examples, with names, dates, etc.,
> >> might be enough to get the CPSC's attention.
> >> BTW, my problem was with the prior generation seatpost, not the new
> >> curved top design (although I note that the curved top design also
> >> relies on a single clamp bolt).
> > I have an American Classic seatpost from 1998. Ridden it many
> > thousands of miles. Likely I'll keep on riding it for many more
> > thousands of miles. One of the problems is its a 27.4 diameter and my
> > frame requires that unusual size. Only AC and Kalloy make that
> > bizarre size.
>
> The Thomson USA 27.4 is a superior product
> --
> Andrew Muzi
> <www.yellowjersey.org/>
> Open every day since 1 April, 1971
I just looked on the Thomson website and they don't even list a 27.4
post.
A Muzi
>>>> The American Classic seatpost hardware failed on my road bike. More
>>>> specifically, the single clamp bolt broke, causing my saddle to
>>>> disconnect from the seatpost. While I was riding. I crashed, my
>>>> bicycle was destroyed, and I was very seriously injured.
>>>> American Classic denies any design or manufacturing defect. I plan to
>>>> report the failure to the Consumer Product Safety Commission (CPSC) in
>>>> an effort to alert other bicyclists to the potential danger and/or
>>>> force a recall. To bolster my claim that an investigation is needed,
>>>> I'm searching for others who have experienced a failure with the same
>>>> clamp bolt. I've heard second-hand stories of other American Classic
>>>> seatpost failures. A few concrete examples, with names, dates, etc.,
>>>> might be enough to get the CPSC's attention.
>>>> BTW, my problem was with the prior generation seatpost, not the new
>>>> curved top design (although I note that the curved top design also
>>>> relies on a single clamp bolt).
>> russellseat...@yahoo.com wrote:
>>> I have an American Classic seatpost from 1998. Ridden it many
>>> thousands of miles. Likely I'll keep on riding it for many more
>>> thousands of miles. One of the problems is its a 27.4 diameter and my
>>> frame requires that unusual size. Only AC and Kalloy make that
>>> bizarre size.
> A Muzi <a...@yellowjersey.org> wrote:
>> The Thomson USA 27.4 is a superior product
russell...@yahoo.com wrote:
> No setback on the Thomson.
True. Offset version not offered in 27.4.
Still, the AC is known for snapping its skinny bolts. IMHO that may be
related to clamp deformation as much as the bolt itself.
A Muzi
>>>> The American Classic seatpost hardware failed on my road bike. More
>>>> specifically, the single clamp bolt broke, causing my saddle to
>>>> disconnect from the seatpost. While I was riding. I crashed, my
>>>> bicycle was destroyed, and I was very seriously injured.
>>>> American Classic denies any design or manufacturing defect. I plan to
>>>> report the failure to the Consumer Product Safety Commission (CPSC) in
>>>> an effort to alert other bicyclists to the potential danger and/or
>>>> force a recall. To bolster my claim that an investigation is needed,
>>>> I'm searching for others who have experienced a failure with the same
>>>> clamp bolt. I've heard second-hand stories of other American Classic
>>>> seatpost failures. A few concrete examples, with names, dates, etc.,
>>>> might be enough to get the CPSC's attention.
>>>> BTW, my problem was with the prior generation seatpost, not the new
>>>> curved top design (although I note that the curved top design also
>>>> relies on a single clamp bolt).
>> russellseat...@yahoo.com wrote:
>>> I have an American Classic seatpost from 1998. Ridden it many
>>> thousands of miles. Likely I'll keep on riding it for many more
>>> thousands of miles. One of the problems is its a 27.4 diameter and my
>>> frame requires that unusual size. Only AC and Kalloy make that
>>> bizarre size.
> A Muzi <a...@yellowjersey.org> wrote:
>> The Thomson USA 27.4 is a superior product
russell...@yahoo.com wrote:
> I just looked on the Thomson website and they don't even list a 27.4
> post.
> http://www.lhthomson.com/elite_sizes.asp
> http://www.lhthomson.com/masterpiece_sizes.asp
They are still readily available however.
jim beam
and what was /your/ bolt torque???
andre...@aol.com
> On Mon, 24 Nov 2008 19:35:21 -0800, solsen23 wrote:
> > The American Classic seatpost hardware failed on my road bike. More
> > specifically, the single clamp bolt broke, causing my saddle to
> > bicycle was destroyed, and I was very seriously injured.
>
> > American Classic denies any design or manufacturing defect. I plan to
> > report the failure to the Consumer Product Safety Commission (CPSC) in
> > an effort to alert other bicyclists to the potential danger and/or force
> > a recall. To bolster my claim that an investigation is needed, I'm
> > searching for others who have experienced a failure with the same clamp
> > bolt. I've heard second-hand stories of other American Classic seatpost
> > failures. A few concrete examples, with names, dates, etc., might be
> > enough to get the CPSC's attention.
>
> > BTW, my problem was with the prior generation seatpost, not the new
> > curved top design (although I note that the curved top design also
> > relies on a single clamp bolt).
>
>
> what was the tightening torque on the bolt?
I had an AC seatposts in one of my bikes. When I bought it, it didn't
come with any instructions about torque. In fact, most of the
components that I have purchased over the years with exception of very
few ones have any mention about torque.
John Forrest Tomlinson
>
>I have an American Classic seatpost from 1998. Ridden it many
>thousands of miles. Likely I'll keep on riding it for many more
>thousands of miles. One of the problems is its a 27.4 diameter and my
>frame requires that unusual size. Only AC and Kalloy make that
>bizarre size.
Change the fastening bolt. Or at least inspect it carefully from time
to time.
John Forrest Tomlinson
<russell...@yahoo.com> wrote:
<about American Classic posts>
>Easy to adjust the tilt with the little bolt nub.
Yeah.
John Forrest Tomlinson
wrote:
> the AC is known for snapping its skinny bolts. IMHO that may be
>related to clamp deformation as much as the bolt itself.
Interesting about clamp deformation. I've had a few of the posts and
they've changed the design over time, perhaps trying to deal with
that.
jim beam
change, yes. inspect - unlikely you'll spot problems with the naked eye
if it's fatigue in the shaft. better to simply replace.
John Thompson
> I have an American Classic seatpost from 1998. Ridden it many
> thousands of miles. Likely I'll keep on riding it for many more
> thousands of miles. One of the problems is its a 27.4 diameter and my
> frame requires that unusual size. Only AC and Kalloy make that
> bizarre size.
Maybe we're just lucky. I have two AC posts, one from the early 80s and
the other from the early 90s -- neither has given me any problems over
the years.
FWIW, Campy 27.4mm posts show up on eBay fairly often. I got a Super
Record one pretty cheap (~US$20) presumably because of the odd size. It
fits a Reynolds 753 seat tube, though. :-)
--
John (jo...@os2.dhs.org)
Chalo
>
> Russell Seaton wrote:
> >
> > I have an American Classic seatpost from 1998. Ridden it many
> > thousands of miles. Likely I'll keep on riding it for many more
> > thousands of miles. One of the problems is its a 27.4 diameter and my
> > frame requires that unusual size. Only AC and Kalloy make that
> > bizarre size.
>
> Maybe we're just lucky. I have two AC posts, one from the early 80s and
> the other from the early 90s -- neither has given me any problems over
> the years.
It sounds like maybe it would be a good idea to replace the old screws
with new high-quality items from a reputable manufacturer like Holo-
Krome or Unbrako.
Chalo
Dennis Ferguson
> In the future, you should consider the Thomson Elite seatpost to be
> utterly dependable. It is weirdly strong, quite lightweight, and easy
> to install and adjust. It uses two small but very strong clamp
> bolts. For what it's worth, I doubt that any seatpost will behave in
> a safe and predictable manner in the case of a clamp bolt breakage.
Also for what it's worth, I have broken a Thomson Elite seatpost so
they are not necessarily immune to stupidity (if you need a setback
seatpost you should get one even if you can get the saddle in the right
place on the straight post you already own by pushing it all the way
back in the clamp...). Neither bolt broke, instead the thick aluminum
tab on the lower part of the clamp through which the front bolt is
inserted sheared off after about 5000 miles of use. If I can find the
seatpost in the garage I'll take pictures.
I will say, though, that when this happened the rear bolt by itself
managed to keep the saddle between me and the naked top of the
seatpost. The saddle didn't come off, it just kind of tipped over
backwards but left me something to sit on until I could get up off
it. While my first choice would be to never have another seatpost
fail, failing that my second choice would be to have it fail like
that one did so I'm even more of a fan of these seatposts.
Dennis Ferguson
Duncan
news:ggjsfn$4kb$1...@newsreader1.mclink.it...
Just looked it up and it seems it is these days. My seatpost would be four
years old.
Hopefully most manufacturers have seen the light and have given up on the
one bolt design. Having only one bolt can mean far more than double the
load on the bolt depending on the design.
Philip Holman
"jim beam" <spamv...@bad.example.net> wrote in message
news:WTZWk.3935$3v2...@fe02.news.easynews.com...
> On Tue, 25 Nov 2008 12:22:58 -0800, Ron Ruff wrote:
>
>> John Forrest Tomlinson wrote:
>>> Just about everything eventually breaks - especially lightweight
>>> stuff,
>>> so I wasn't especially concerned beyond checking my parts a little
>>> more
>>> carefully from time to time and replacing some stuff before I notice
>>> problems.
>>
>> Very true. You can't expect bike parts to last forever, and you must
>> accept some responsibility in checking your equipment. If I sued the
>> manufacturer every time a part broke... well, I'd have a few
>> lawsuits.
>> Most recently I had a Ritchey crank snap in two while sprinting... I
>> landed on the ground but wasn't hurt badly enough to worry about.
>
> the ritchey design is fundamentally flawed - the "i-beam" thing. it's
> known to be a fatigue risk since that profile means the skin is much
> more
> highly stressed and slightest riser therefore initiates fatigue.
> modern
> designs use an ovalized crank arm which is much less sensitive.
>
Jim, by "the skin" do you mean "extreme fiber" ....I'm not quite
understanding what you are saying here.
Phil H
jim beam
the exterior surface.
Jay Beattie
> John Forrest Tomlinson wrote:
> > Just about everything eventually breaks - especially lightweight
> > stuff, so I wasn't especially concerned beyond checking my parts a
> > little more carefully from time to time and replacing some stuff
> > before I notice problems.
>
> Very true. You can't expect bike parts to last forever, and you must
> accept some responsibility in checking your equipment. If I sued the
> manufacturer every time a part broke... well, I'd have a few lawsuits.
> Most recently I had a Ritchey crank snap in two while sprinting... I
> landed on the ground but wasn't hurt badly enough to worry about.
I do expect certain parts to last forever, but that is because I am
from a generation where certain parts did last forever, e.g., stems,
bars, seatposts, pedals. I have broken a half dozen cranks, and I
don't expect those to last forever. (I don't replace them
prophylactically, although I should replace my right crank arm (a
relatively new Ultegra) because it got scarred by my ortho boot when I
was riding after my leg FX.) I have broken seatposts (bolts), but
they were crappy fare from Weyless and Avocet, and all that happend
was that I slipped backwards (but didn't hit the wheel and rip up my
ass like Jobst's friend). I broke olde tyme pedals, but they had Ti
spindles back when Ti was a crap shoot. Otherwise, my bars,stems,
posts and steel pedals were bomb proof -- and bomb weight.
Nowadays, nothing is break-proof. I've broken pedals and bars from
good manufacturers. But, with that said, only those people who read
industry news or take the sport seriously understand that light weight
parts can break -- and most people (including most jurors) do not
expect products like seat posts, saddles, stems, bars to break, and
most do not understand that parts these days require more care and
feeding that parts of yore. -- Jay Beattie.
John Forrest Tomlinson
<jbea...@lindsayhart.com> wrote:
>I do expect certain parts to last forever, but that is because I am
>from a generation where certain parts did last forever, e.g., stems,
>bars, seatposts, pedals. I have broken a half dozen cranks, and I
>don't expect those to last forever. (I don't replace them
>prophylactically, although I should replace my right crank arm (a
>relatively new Ultegra) because it got scarred by my ortho boot when I
>was riding after my leg FX.) I have broken seatposts (bolts), but
>they were crappy fare from Weyless and Avocet, and all that happend
>was that I slipped backwards (but didn't hit the wheel and rip up my
>ass like Jobst's friend). I broke olde tyme pedals, but they had Ti
>spindles back when Ti was a crap shoot. Otherwise, my bars,stems,
>posts and steel pedals were bomb proof -- and bomb weight.
>
>Nowadays, nothing is break-proof. I've broken pedals and bars from
>good manufacturers. But, with that said, only those people who read
>industry news or take the sport seriously understand that light weight
>parts can break -- and most people (including most jurors) do not
>expect products like seat posts, saddles, stems, bars to break, and
>most do not understand that parts these days require more care and
>feeding that parts of yore. -- Jay Beattie.
Even the good old stuff from back in the day -- like Cinelli 64 etc
bars shouldn't last forever. The stems maybe, but I wouldn't trust
those bars for more than ten years of hard use.
Also, it's still possible to get bars as strong as that, new --
current Nitto stuff is like that.
Jay Beattie
wrote:
>
> - Show quoted text -
I still have a pair of Cinellli 64s from the mid '70s with lots of
hard miles that are on my infrequently ridden touring bike. I am
still waiting for the center collar to loosen or for the bar to crack
somewhere. I broke a pair of new Cinelli bars after less than a year
of mostly commuting on my cross bike. I've never used Nitto bars, but
I'll keep them in mind the next time around.
Sort of OT, but I wonder what the incidence of bar failure is on cross
bikes. I now have shallow bars and stay on the drops when riding
trails, and take some good rock impacts that cause loading on the bar
ends, much more than riding on the road. If my bars broke when I hit
a rock or a rut, that could cause a serious injury. When I broke the
Cinelllis, I was commuting on the road and had time to shift my grip
and bring the bike to a stop. I finished riding to work slowly with
one bar. -- Jay Beattie.
bjwe...@gmail.com
wrote:
If anyone is still interested in this:
http://www.astro.umd.edu/~bjw/misc/rbt/amclassic/DSCN2067_25.JPG
http://www.astro.umd.edu/~bjw/misc/rbt/amclassic/DSCN2068_25.JPG
http://www.astro.umd.edu/~bjw/misc/rbt/amclassic/DSCN2069_25.JPG
Both are American Classic posts, the black one on
the left is pretty old, the silver one on the right is
newer (appears to have a date code "99").
These show the different types of lower clamps. The
older lower clamp, which may be made from an
extrusion (it has the same cross-section for nearly
all its length), is fairly thin under the seat rails. The newer
one, which may be a forging, is thicker and has more
vertical structure, which should make it significantly more
resistant to bending under the load from the seat rails.
The older post has a single 6mm clamp bolt. The newer
post has a significantly beefier 8mm clamp bolt, still
taking a 5mm hex wrench.
However, I have at least one AC post with the new
clamp and a 6mm bolt; the 8mm bolt came after the
clamp redesign. Both designs have a 6mm setscrew
for tilt adjustment.
Both old and new clamp bolts have a domed
shoulder on the bolt head, where it bears against
the seatpost surface. This is because as you change
the tilt of the clamp, the angle of the bolt to the post
changes. If the dome were not there, the bolt
would not contact the seatpost surface squarely.
This would put a bending moment on the bolt, and
that's really bad for a highly stressed bolt.
For this reason I strongly believe that you should
not replace an AC seatpost bolt with a standard
square-shouldered hex cap bolt, even if the
standard bolt is very high grade. Get the real thing
from AC or add a domed washer somehow.
(By the way, most or all one-bolt posts have to come
up with some way of addressing this problem of angle
between clamp and bolt, by using a curved surface
somewhere - Kalloy-type posts have a nut with a
curved bottom, there are Shimano posts with a
cylindrically curved washer, and so on.)
Ben
jim beam
while the latter post is a minor improvement, it's still putting lipstick
on a pig. the tilt mechanism is ridiculous.
imo, the only modern seat posts worth anything for general use are campy,
easton and some of the ritcheys - ac clearly don't know what they're about
with their convoluted load paths and mis-applied materials.
ycle...@verizon.net
In the mid-80's as far as I know there was no "bolt torque" for a
Campy Chorus seatpost. I snugged it with a metric hex key.
As for the Chorus post that snapped, no torque was involved other than
that applied by my behind to the back of the saddle as I crossed a
shallow ditch and skidded to a halt just shy of a cable across the
drive to a wooded lot at the bottom of the mountain.
Cheers,
MD