tag:blogger.com,1999:blog-13887692.post1972973586908665836..comments2024-03-13T02:16:08.135-04:00Comments on Cozy Beehive: Thomson Elite Setback Post FailureRon Georgehttp://www.blogger.com/profile/18394865788996482667noreply@blogger.comBlogger11125tag:blogger.com,1999:blog-13887692.post-7016296230112223222012-03-29T09:16:22.430-04:002012-03-29T09:16:22.430-04:00Hi all,
I'm thinking to buy one Thomson Elite...Hi all,<br /><br />I'm thinking to buy one Thomson Elite setback.<br />Does it mean that I shouldn't buy it????<br /><br />Thanks<br /><br />JMAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-13887692.post-273932315998742632009-04-19T17:18:00.000-04:002009-04-19T17:18:00.000-04:00Anon : A lot of companies these days are wary abou...Anon : A lot of companies these days are wary about products coming from not only, say Brazil, but also India and China. While they may be able to reduce costs sourcing from here, its mostly their customers who tell them they don't want any products sourced from those countries. Its a perception of quality.Ron Georgehttps://www.blogger.com/profile/18394865788996482667noreply@blogger.comtag:blogger.com,1999:blog-13887692.post-88354214029993300752009-04-19T16:40:00.000-04:002009-04-19T16:40:00.000-04:00...and I don't know the reason why we can't use th......and I don't know the reason why we can't use those bars from BrazilAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-13887692.post-36765877664214899572009-04-19T16:37:00.000-04:002009-04-19T16:37:00.000-04:00I work for a company where 6061-T6 from Brazil is ...I work for a company where 6061-T6 from Brazil is forbidden, that is the first thing I have to check in the certificate of compliance before accepting any raw materials.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-13887692.post-68846215326440929272009-04-19T12:50:00.000-04:002009-04-19T12:50:00.000-04:00Bluenoser : Good point. Not sure where Thomson sou...Bluenoser : Good point. Not sure where Thomson sources their material from but I'll ask.Ron Georgehttps://www.blogger.com/profile/18394865788996482667noreply@blogger.comtag:blogger.com,1999:blog-13887692.post-856912882375059352009-04-19T06:30:00.000-04:002009-04-19T06:30:00.000-04:00Ron,
We had a strike at a steel mill hear years b...Ron,<br /><br />We had a strike at a steel mill hear years back which led to a shortage of steel pipe.<br /><br />I was having problems with tearout while threading pipe and replaced numerous dies.<br /><br />I used a scrap piece of Canadian pipe for a nipple and no tearout. Closer look showed the pipe from another country with lesser QC being used was full crap causing the tearout.<br /><br />I'd be looking at the supply of material. Do they re-test if suppliers change?<br /><br />-BBluenoserhttps://www.blogger.com/profile/03448920726947078281noreply@blogger.comtag:blogger.com,1999:blog-13887692.post-59787024691710203342009-04-18T17:49:00.000-04:002009-04-18T17:49:00.000-04:00Ryan , one more thing : I totally believe in the f...Ryan , one more thing : I totally believe in the fact that fatigue cracking always initiates from a structural or material defect.Ron Georgehttps://www.blogger.com/profile/18394865788996482667noreply@blogger.comtag:blogger.com,1999:blog-13887692.post-42953571729812558192009-04-18T17:47:00.000-04:002009-04-18T17:47:00.000-04:00Ryan, & Ghostrider :
I've wanted to quest...Ryan, & Ghostrider :<br /><br />I've wanted to question the make of the post, but AL 7075-T6 is of aerospace grade and widely used in those industries. Some of the attractive features of the alloy is that it is machinable., has a high strength to weight ratio, and are resistant to corrosion because of the Zinc additive. However, that doesn't protect it from degradation over time, mostly from fatigue which occurs at cyclic stress levels considerably lower than the tensile or yield strength of the material. (Even worse is corrsion fatugue, where the material is destroyed much faster)<br /><br />As one of the givens, I did mention the make of the post, but what gets me is if anodization had anything to do with lessening the fatigue characteristics. Despite their many advantages such as corrosion resistance, they are known in the materials industry to reduce the fatigue properties of the substrate metal. I've read some engineering research papers that talk about how the anodized coating thickness can strongly influence fatigue characteristics. Too much of coating actually has more detrimental effects than thinner ones.<br /><br />A fatigue crack such as that in high cycle fatigue (low stress) mainly originates on the surface of the material where microscale stress risers are likely to exist. This is why I question the ridges on the surface of the seatpost and wonder if they behave like stress risers. But hold on there...as I'm not saying this is what happened with this seatpost. It could very well be that the substrate Al metal had imperfections in it (voids and inclusions) that started a crack and a chain reaction of fatigue events. <br /><br />Absolutely...a materials/fracture analysis is very necessary to determine what exactly caused this. Until then, its speculation...but nevertheless, good speculation.Ron Georgehttps://www.blogger.com/profile/18394865788996482667noreply@blogger.comtag:blogger.com,1999:blog-13887692.post-15650708776996539362009-04-18T09:15:00.000-04:002009-04-18T09:15:00.000-04:00If I recall correctly, EN, DIN, DIN+, JIS, Cen, ec...If I recall correctly, EN, DIN, DIN+, JIS, Cen, ect all require fatigue testing of the finished product in order for the product to be deemed within the standards they require. <br /><br />Why, for a second time is there still no speculation as to the quality of the material which this product was created with? <br /><br />If this post came back to me, a materials test would be one of the first things I would do. <br /><br />Why do you not even have that on the list? <br /><br /> - RyanAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-13887692.post-59878208095930529132009-04-16T23:34:00.000-04:002009-04-16T23:34:00.000-04:00I didn't know that about anodization...so why do s...I didn't know that about anodization...so why do so many companies choose to black-anodize their parts? Should we all rally for a return to natural silver aluminum components? ;)<br /><br />The fine ridges have been on aluminum seatposts for decades...I suspect it's a leftover from the machining process and may have some effect in reducing slippage into the frame. Nearly every example of alloy post I've got in my fleet exhibits these fine ridges, from Campagnolo 2-bolt posts all the way to cheapie Kalloy jobs.GhostRiderhttps://www.blogger.com/profile/09987949431503645433noreply@blogger.comtag:blogger.com,1999:blog-13887692.post-19169476606277833912009-04-16T07:51:00.000-04:002009-04-16T07:51:00.000-04:00Yikes. Cheers Ron. I'm going to check mine - I don...Yikes. Cheers Ron. I'm going to check mine - I don't fancy a surprise Thomson Elite 'buttock breach'!Thoshttps://www.blogger.com/profile/03745847702335928410noreply@blogger.com