I broke a seat post.

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

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


--
- Frank Krygowski

On Friday, April 4, 2014 3:57:57 PM UTC-4, 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





--

- Frank Krygowski

That

Nitto Lugged seat post 27.2 x 250 - 11048

looks like it would have an awful lot of stress on it. I'd not be one to trust it.

Cheers

On 4/4/2014 3:42 PM, 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


What about the millions of CF ones in use? lol


As an aisde, I was surprised the last time I went to the LBS. He was
working on my bike. It was on his stand and he had it clamped to the
seat post. I said I'd never seen him do that. He said he cracked an
aluminum frame in his clamp and since then he's been using the seat
post. I said but this one is CF? He said yes but it's made to be
clamped. lol.

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

why is this ?

two kalloy posts snapped here both under the mounting plate.

tubes are AAA and in stock. I'll ship for $10.

plus handling.

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

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

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 ?

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.
--
Cheers,

John B.