I broke a seat post.

On Fri, 4 Apr 2014 12:42:02 -0700 (PDT), Sir Ridesalot
wrote:

On Friday, April 4, 2014 11:12:44 AM UTC-4, sms wrote:
On 4/3/2014 6:38 PM, James wrote:

http://www.ebay.com/itm/New-ITM-Forg...-/181343516543





It's lasted several years, and wasn't especially expensive or light, but

I'm not a heavy rider and don't expect to break such things.



It is a fairly crap design, in my opinion. The post is an Al tube with

a thin layer of CFRP.



The CFRP is just a conformal coating to make the aluminum seat post

appear to be a carbon fiber seat post. But neither aluminum or carbon

fiber is a great material for seat posts. Check

http://www.rivbike.com/Saddles-Seat-Posts-s/48.htm?searching=Y&sort=2&cat=48&show=12&page=1

for some good replacements.



Another CF seatpost recall that was in my inbox today, even though it

happened last year:

http://www.bicycleretailer.com/north-america/2013/08/08/giant-recalls-200-bikes-due-seatposts

Are you serious? Aluminium is not good seat post material? What about the millions of such seatposts in use?

Cheers

One must always consider the source of the argument :-)
--
Cheers,

John B.

DATAKOLL MARINE RESEARCH wrote:
On Friday, April 4, 2014 6:16:09 PM UTC-4, Duane wrote:
DATAKOLL MARINE RESEARCH wrote:

GOOD GRIEF...the LBS works on your bike ?



why is this ?



They need to feed their kids?

Needed a new chain ring. They install it for free.

--

duane

........................

amazing....is this LBS online ?


No but I'm sure they make up for the labor in their mark up. Price for the
chain ring wasn't particularly low.

--
duane

On 05/04/14 06:57, Frank Krygowski wrote:
On 4/4/2014 3:42 PM, Sir Ridesalot wrote:
On Friday, April 4, 2014 11:12:44 AM UTC-4, sms wrote:
But neither aluminum or carbon

fiber is a great material for seat posts. Check
http://www.rivbike.com/Saddles-Seat-Posts-s/48.htm?searching=Y&sort=2&cat=48&show=12&page=1

for some good replacements.

Are you serious? Aluminium is not good seat post material? What about
the millions of such
seatposts in use?

Apparently no one of my seatposts is any good, since they're all made of
aluminum.

I'm not looking forward to spending $204 apiece to get them up to "sms"
standards. :-(

http://www.rivbike.com/product-p/sp3.htm



I was thinking about buying a Deda Zero 100.

http://www.chainreactioncycles.com/a...k/rp-prod84212

Nothing like $200.

--
JS

On Friday, April 4, 2014 11:11:27 PM UTC-4, James wrote:
On 05/04/14 06:57, Frank Krygowski wrote:

On 4/4/2014 3:42 PM, Sir Ridesalot wrote:

On Friday, April 4, 2014 11:12:44 AM UTC-4, sms wrote:

But neither aluminum or carbon



fiber is a great material for seat posts. Check

http://www.rivbike.com/Saddles-Seat-Posts-s/48.htm?searching=Y&sort=2&cat=48&show=12&page=1



for some good replacements.



Are you serious? Aluminium is not good seat post material? What about

the millions of such

seatposts in use?



Apparently no one of my seatposts is any good, since they're all made of

aluminum.



I'm not looking forward to spending $204 apiece to get them up to "sms"

standards. :-(



http://www.rivbike.com/product-p/sp3.htm







I was thinking about buying a Deda Zero 100.



http://www.chainreactioncycles.com/a...k/rp-prod84212



Nothing like $200.



--

JS

kinky ! but 2 screws ? nowhere Dude

I bought a Ritchie only to find the dang thing is held on with 4 screws. Now I have a Ritchie n a bag of spare screws.....n spare wrenches.

Andre Jute schreef op 4-4-2014 23:59:
On Friday, April 4, 2014 7:28:35 AM UTC+1, Lou Holtman wrote:
On Friday, April 4, 2014 3:38:42 AM UTC+2, James wrote:

http://www.ebay.com/itm/New-ITM-Forg...-/181343516543

The bad part is that the seat clamp is a forged and machined part, and
only inserts into the tube with a plug about an inch long, and held with
glue.

That is why I like my Thomson posts.

Even Thomson aren't immune to breakages. A few years ago a chap who posted on RBT from Chicago had a Thomson seat post break under him and cause him an injury.

Andre jute


Sure, but IIRC there was strong evidence that the bolts were
overtightened. It is a well designed seatpost. Milled from one piece of
high quality aluminum, av=curate outer diameter dimension, good quality
steel bolts which are only under tension. For a high end post reasonably
priced and reasonably light. Even Chalo approved them. To James I would
reconsider buying the Deda post. It is Italian ;-).

Lou

On Sat, 05 Apr 2014 14:11:27 +1100, James
wrote:

On 05/04/14 06:57, Frank Krygowski wrote:
On 4/4/2014 3:42 PM, Sir Ridesalot wrote:
On Friday, April 4, 2014 11:12:44 AM UTC-4, sms wrote:
But neither aluminum or carbon

fiber is a great material for seat posts. Check
http://www.rivbike.com/Saddles-Seat-Posts-s/48.htm?searching=Y&sort=2&cat=48&show=12&page=1

for some good replacements.

Are you serious? Aluminium is not good seat post material? What about
the millions of such
seatposts in use?

Apparently no one of my seatposts is any good, since they're all made of
aluminum.

I'm not looking forward to spending $204 apiece to get them up to "sms"
standards. :-(

http://www.rivbike.com/product-p/sp3.htm



I was thinking about buying a Deda Zero 100.

http://www.chainreactioncycles.com/a...k/rp-prod84212

Nothing like $200.

No, it is A$ 82.34 plus shipping. Seems like a lot of money for a seat
post. Even one that is infinitely adjustable.

But far better than US$ 200.00 :-)
--
Cheers,

John B.

ow $ carbon bears well under compression ? its the saddle holder......

just degassing....the joint is suspect.


http://www.universalcycles.com/searc...der=price_desc

On 05/04/2014 11:57, John B. wrote:
On Sat, 05 Apr 2014 14:11:27 +1100, James
wrote:

On 05/04/14 06:57, Frank Krygowski wrote:
On 4/4/2014 3:42 PM, Sir Ridesalot wrote:
On Friday, April 4, 2014 11:12:44 AM UTC-4, sms wrote:
But neither aluminum or carbon

fiber is a great material for seat posts. Check
http://www.rivbike.com/Saddles-Seat-Posts-s/48.htm?searching=Y&sort=2&cat=48&show=12&page=1

for some good replacements.

Are you serious? Aluminium is not good seat post material? What about
the millions of such
seatposts in use?

Apparently no one of my seatposts is any good, since they're all made of
aluminum.

I'm not looking forward to spending $204 apiece to get them up to "sms"
standards. :-(

http://www.rivbike.com/product-p/sp3.htm



I was thinking about buying a Deda Zero 100.

http://www.chainreactioncycles.com/a...k/rp-prod84212

Nothing like $200.

No, it is A$ 82.34 plus shipping. Seems like a lot of money for a seat
post. Even one that is infinitely adjustable.

But far better than US$ 200.00 :-)

But But But it's still Aluminium and hence dangerous!

On Sat, 05 Apr 2014 14:36:08 +0100, Clive George
wrote:

On 05/04/2014 11:57, John B. wrote:
On Sat, 05 Apr 2014 14:11:27 +1100, James
wrote:

On 05/04/14 06:57, Frank Krygowski wrote:
On 4/4/2014 3:42 PM, Sir Ridesalot wrote:
On Friday, April 4, 2014 11:12:44 AM UTC-4, sms wrote:
But neither aluminum or carbon

fiber is a great material for seat posts. Check
http://www.rivbike.com/Saddles-Seat-Posts-s/48.htm?searching=Y&sort=2&cat=48&show=12&page=1

for some good replacements.

Are you serious? Aluminium is not good seat post material? What about
the millions of such
seatposts in use?

Apparently no one of my seatposts is any good, since they're all made of
aluminum.

I'm not looking forward to spending $204 apiece to get them up to "sms"
standards. :-(

http://www.rivbike.com/product-p/sp3.htm



I was thinking about buying a Deda Zero 100.

http://www.chainreactioncycles.com/a...k/rp-prod84212

Nothing like $200.

No, it is A$ 82.34 plus shipping. Seems like a lot of money for a seat
post. Even one that is infinitely adjustable.

But far better than US$ 200.00 :-)

But But But it's still Aluminium and hence dangerous!


Well, Steel seat posts are available, and usually at a substantially
cheaper price than aluminum.. Of course they require a separate seat
clamp to clamp the seat to the post but these never seem to fail. As I
was walking back from the Sub-Way this afternoon I passed an old bike,
completely worn out, someone had thrown it in the trash..... but the
steel seat post and seat clamp were still functional and with no
cracks or other signs of failure.

--
Cheers,

John B.

On 4/4/2014 8:15 PM, John B. wrote:
On Fri, 04 Apr 2014 08:13:55 -0500, AMuzi wrote:

On 4/3/2014 8:57
PM, DATAKOLL MARINE RESEARCH wrote:
tubes are made from flat sheets then welded into tubes with a seam ...

amazing. mine break of under the saddle holder.

Once bit...there's a spare on hand at uhuhuh 24.7869 mm


Tubes and pipes may be seamless or seamed:

http://www.tubecon.co.za/en/technica...i/tube-vs-pipe

Plenty of examples both ways.

Your example seemed to be primarily a supplier of steel goods while a
company who appears to supply both steel and aluminum goods
http://www.onealsteel.com/aluminum-tube.html
seems to have this to say:

There are different kinds of aluminum tubing, with the most common and
least expensive being extruded aluminum tube. Extruded tube is
manufactured using the porthole method to produce a seamless, strong
tube. Aluminum tubes with walls too thin to be extruded are
manufactured by rolling and welding narrow aluminum strip. Welded
tube is fairly inexpensive and is used for light support products such
as lawn furniture, toys and drains.

His 6061 and 6063 aluminum tube is all extruded.

In mitigation I might add that all of the stainless steel tubing I've
seen in the past 10 years, or so, has been welded.


I replaced damaged tubes on a 1919 JIC race bike which had
thin wall (0.9)steel seamed tubes. With brazed seams no
less. Fairly light frame, probably the bees knees for 1919.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971