Serotta titanium stem failures
12-13-05, 10:53 AM
#1
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Serotta titanium stem failures
https://www.serotta.com/pages/current.html#Dec12
Serotta News
December 12, 2005
Serotta Takes Proactive Stance on Stem Fatigue
Serotta Competition Bicycles has issued a proactive structural alert regarding its STS titanium stems. Effective immediately, Serotta Competition Bicycles urges all owners of Serotta Titanium Stems to conduct an inspection of the stem welds for any signs of hairline cracks. In addition, owners are asked to conduct a bending and twisting test to check for any unusual cracking or creaking sounds. If there is any evidence of cracks or creaking, the user is advised to discontinue the use of the stem immediately.
Serotta reports that only a few of thousands of the stems which were produced between 1995 and 1998 have been returned showing signs of fatigue failure, but as a precautionary measure, the company is issuing this warning. Any customers who would like to return their stem to Serotta for inspection are welcome to do so by contacting the company and obtaining an RA (return authorization) number.
It is not clear why these three samples have fatigued, but there are many variables that effect fatigue life including rider weight, whether or not maximum insertion depth was adhered to, handlebar selection, clamp/bar interface, bolt torque and use conditions. These in fact are conditions that affect the long term strength and durability of all stems in the market place, welded or forged.
As with all Serotta products, we conducted periodic fatigue testing on our stems which showed them to be very durable, in fact, tests showed a fatigue life cycle well beyond most aluminum stems.
Inspection procedures are as follows:
* The bending test should be performed while standing over the bike, bracing the top tube or saddle and pushing down and pulling up evenly on both sides of the bar.
* The twisting test should be conducted similarly (weight on top tube or saddle) while pulling up on one side of the handle bar while pushing down on the other and repeating.
* Visual inspection should be conducted by thoroughly cleaning all weld/joint sights and examining the entire joint area for any signs of cracking. A small reading glass is recommended to aid in this procedure.
Serotta recommends that all cyclists conduct visual inspections of their equipment (any model, any brand) on a regular basis- at least once every 500 miles, or immediately after any crash. Think of yourself as a pilot.
RA Procedure:
Send an email to Kelly Bedford, Kelly@serotta.com.
Please provide: Name, address, contact information, stem model, specifications, date of purchase, place of purchase.
Serotta News
December 12, 2005
Serotta Takes Proactive Stance on Stem Fatigue
Serotta Competition Bicycles has issued a proactive structural alert regarding its STS titanium stems. Effective immediately, Serotta Competition Bicycles urges all owners of Serotta Titanium Stems to conduct an inspection of the stem welds for any signs of hairline cracks. In addition, owners are asked to conduct a bending and twisting test to check for any unusual cracking or creaking sounds. If there is any evidence of cracks or creaking, the user is advised to discontinue the use of the stem immediately.
Serotta reports that only a few of thousands of the stems which were produced between 1995 and 1998 have been returned showing signs of fatigue failure, but as a precautionary measure, the company is issuing this warning. Any customers who would like to return their stem to Serotta for inspection are welcome to do so by contacting the company and obtaining an RA (return authorization) number.
It is not clear why these three samples have fatigued, but there are many variables that effect fatigue life including rider weight, whether or not maximum insertion depth was adhered to, handlebar selection, clamp/bar interface, bolt torque and use conditions. These in fact are conditions that affect the long term strength and durability of all stems in the market place, welded or forged.
As with all Serotta products, we conducted periodic fatigue testing on our stems which showed them to be very durable, in fact, tests showed a fatigue life cycle well beyond most aluminum stems.
Inspection procedures are as follows:
* The bending test should be performed while standing over the bike, bracing the top tube or saddle and pushing down and pulling up evenly on both sides of the bar.
* The twisting test should be conducted similarly (weight on top tube or saddle) while pulling up on one side of the handle bar while pushing down on the other and repeating.
* Visual inspection should be conducted by thoroughly cleaning all weld/joint sights and examining the entire joint area for any signs of cracking. A small reading glass is recommended to aid in this procedure.
Serotta recommends that all cyclists conduct visual inspections of their equipment (any model, any brand) on a regular basis- at least once every 500 miles, or immediately after any crash. Think of yourself as a pilot.
RA Procedure:
Send an email to Kelly Bedford, Kelly@serotta.com.
Please provide: Name, address, contact information, stem model, specifications, date of purchase, place of purchase.
12-13-05, 12:41 PM
#2
Peloton Shelter Dog
Anyone that thinks titanium bike stuff is indestrutible hasn't been around long enough. My 1991 Merlin cracked in two places in 1996 after 40K+ miles. Ti will fatigue, and it WILL break eventually.
12-13-05, 12:53 PM
#3
Senior Member
Probably not any worse than any other stem on the market. I've snapped two Modolo aluminium stems within 2 years of purchase. Interesting thing is the Cinelli I use now is lighter, more flexible, but has lasted much, much longer. I suspect in the case of the three Ti Serotta stems that's cracked, the usage loads where the primary factor. Nothing lasts forever, with enough force, everything will break.
