Cracked Thomson faceplate !!
#1
Thread Starter
my nice bike is at home


Joined: Feb 2006
Posts: 970
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From: Brooklyn, NY USA
Bikes: 2011 BMC Race Machine / 2012 BMC Road Machine / Trek 2300 / '90's Merlin/ '70's Raleigh 20/ Ti-'swift' folder / Erickson w/S&S couplers
Cracked Thomson faceplate !!
I just noticed a HUGE crack halfway across my Thomson faceplate. The crack travels right to left just reaching the "M". Very disturbing. Noticed it about ten miles from home where I meet my friend to go riding. Needless to say I avoided fast descents and climbs, limped home in other words. My question is this: Does Thomson make a beefier face-plate to replace the cracked one?
I still think the stem looks better than most others. Perhaps this crucial item should be made of steel or titanium? CRAZY !
These things are not cheap-o either. Well maybe they are....
Also:
Here is a good idea: check your whole bike for cracks and failures every once in awhile.
I still think the stem looks better than most others. Perhaps this crucial item should be made of steel or titanium? CRAZY !
These things are not cheap-o either. Well maybe they are....
Also:
Here is a good idea: check your whole bike for cracks and failures every once in awhile.
#2
Senior Member
Joined: May 2005
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From: SFBay
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That's the first failure of a Thomson that I've heard of. Call them up and see what they say. I'd say that unless you're doing something unusual to your bike you've gotten a very rare fluke and a standard aluminum faceplate replacement will be fine. I have a Thomson x2 on my road bike and completely trust it.
#3
I eat carbide.


Joined: Jan 2006
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From: Elgin, IL
Bikes: Lots. Chapter2, Van Dessel, Giant, Trek, etc Dealers for BMC, Chapter2
Contact Thomson either directly or through a local distributor for assessment. Odds are it will be covered under warranty or they can tell you what the deal is.
Even high end zoot stems can fail. Stems are dicey - always. I haen't really met a stem I would trust blindly since threadless came out...honestly....
Also...as for checking for cracks around your whole bike. I have been recommending that everyone should do an annual teardown for just such a reason. It also helps you identify components that may not be functioning properly anymore, adjusted incorrectly, or near failure or worn.
Even high end zoot stems can fail. Stems are dicey - always. I haen't really met a stem I would trust blindly since threadless came out...honestly....
Also...as for checking for cracks around your whole bike. I have been recommending that everyone should do an annual teardown for just such a reason. It also helps you identify components that may not be functioning properly anymore, adjusted incorrectly, or near failure or worn.
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#5
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Joined: Jun 2007
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From: San Diego
Also...as for checking for cracks around your whole bike. I have been recommending that everyone should do an annual teardown for just such a reason. It also helps you identify components that may not be functioning properly anymore, adjusted incorrectly, or near failure or worn.
#7
i ride a bicycle
Joined: Nov 2006
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I would agree that you should contact Thomson and tell them about it. Chances are they will want to see the part (to try and see how it failed and if they can improve it), and will send you a replacement at no charge.
Mac
Mac
#9
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Joined: Sep 2004
Posts: 38
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It happens
A co-worker of mine had his crack, but I don't remember where. He's a big dude, but mostly just wipes his museum-piece bikes with a diaper. I would hope that as a degreed mechanical engineer, he would have properly torqued (and NOT over-torqued) anything and matched the stem to the right diameter bar and steerer. I have an X4 on my hardtail and love it...still, I would not design a stem from machined 7000 series aluminum if I did it from the ground up. Thomsom may be doing some thorough heat treating that gets around this, but there's a reason most other quality stems are forged. I try not to think about this when I'm wrenching on wide riser bars and enjoying the stiff Marzocchi/Thomson/Azonic front end on my bike. Your best friend here is a torque wrench and Phil's fine green grease on the bolts.
#10
How much does it weigh?
Joined: Jul 2005
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From: Weight Weenie on a budget.
Bikes: Lotus Fixed, Bianchi Virata 2004
This is probably the 4th or 5th time I've heard of this problem, but the 1st time coming from someone I don't ride with. Everything, all materials, and all manufacturers' products, are prone to failure. Shocking, I know.
#11
Lotion/Basket/Hose

Joined: Apr 2004
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From: Chicago
Bikes: 1992 Schwinn Paramount
It's anecdotal, but I too have seen a fair number of threads about cracking Thomson stem faceplates here, on WW, and on SerottaForums.
Edit: And a simple Google search seems to unearth a fair number of 'em.
Edit: And a simple Google search seems to unearth a fair number of 'em.
Last edited by Doctor Who; 08-26-08 at 02:11 PM. Reason: Added link
#12
I eat carbide.


Joined: Jan 2006
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From: Elgin, IL
Bikes: Lots. Chapter2, Van Dessel, Giant, Trek, etc Dealers for BMC, Chapter2
A co-worker of mine had his crack, but I don't remember where. He's a big dude, but mostly just wipes his museum-piece bikes with a diaper. I would hope that as a degreed mechanical engineer, he would have properly torqued (and NOT over-torqued) anything and matched the stem to the right diameter bar and steerer. I have an X4 on my hardtail and love it...still, I would not design a stem from machined 7000 series aluminum if I did it from the ground up. Thomsom may be doing some thorough heat treating that gets around this, but there's a reason most other quality stems are forged. I try not to think about this when I'm wrenching on wide riser bars and enjoying the stiff Marzocchi/Thomson/Azonic front end on my bike. Your best friend here is a torque wrench and Phil's fine green grease on the bolts.
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#15
There's not a bike part made that someone hasn't managed to break. Thomson is normally a set and forget type of item. I have been active on many bike forums for about 10 years, and I have never seen a thread about a broken Thomson component. That doesn't mean it doesn't happen. I would expect that they would stand behind it 100%, and would be interested to see what the outcome eventually is.
#17
Thread Starter
my nice bike is at home


Joined: Feb 2006
Posts: 970
Likes: 37
From: Brooklyn, NY USA
Bikes: 2011 BMC Race Machine / 2012 BMC Road Machine / Trek 2300 / '90's Merlin/ '70's Raleigh 20/ Ti-'swift' folder / Erickson w/S&S couplers
Will call Thompson then let you know what they say. Maybe I'll post a picture.
I haven't broken any components in years, even in my
Mt bike days, just a few frame failures, due to rust and one chain.
My weight is only 138, so I am not breaking things.
Once knew a racer, a very strong rider who broke crank arms occasionally.
I haven't broken any components in years, even in my
Mt bike days, just a few frame failures, due to rust and one chain.
My weight is only 138, so I am not breaking things.
Once knew a racer, a very strong rider who broke crank arms occasionally.
#18
been there done that with a thomson stem. it's from over torquing or uneven torquing. i know Thomson work hard to make quality gear, and i love that they're a U.S. company, but forged aluminum is just so much better than cnc for stuff like that.
#19
An oldish thread, but anyways...
I found a cracked Thomson Elite faceplate on a friend's bike once. The guy trained as a metalluragist, so I doubt he went crazy with the torque. I'm also of the opinion that using CNC for these kind of parts results in nice bling but forging is just so much smarter.
I found a cracked Thomson Elite faceplate on a friend's bike once. The guy trained as a metalluragist, so I doubt he went crazy with the torque. I'm also of the opinion that using CNC for these kind of parts results in nice bling but forging is just so much smarter.
#22
A good low-range torque wrench is expensive. My Sturtevant was $150. I am not sure I would trust the readings on a low-range torque wrench that was made to lesser standards, and certainly would not trust a big one in the lowest area of its range. 45 inch pounds is a pretty low amount and you need to get it right. I have a Thomson X2 on the cross bike and so far, no problems.
#24
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Joined: Jun 2008
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From: Kent, WA
Bikes: '07 Specialized Tarmac Pro
If you use aluminum or carbon components the question is when they will crack, not if. Both materials have a finite fatigue life. If you want something that will last longer get steel or titanium. It doesn't matter who the manufacturer is. Best suggestion was psimet2001's, inspect your bike and make sure everything is in working order and make sure there are no cracks.




