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-   -   Cracked Thomson faceplate !! (https://www.bikeforums.net/road-cycling/458531-cracked-thomson-faceplate.html)

kraftwerk 08-26-08 10:55 AM

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.

jccaclimber 08-26-08 11:05 AM

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.

Psimet2001 08-26-08 11:07 AM

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.

RoadToad 08-26-08 11:46 AM

yikes...

paul_858 08-26-08 12:52 PM


Originally Posted by Psimet2001 (Post 7346290)
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.

And ensures that you will have a reliable well tuned bike.

tkblazer 08-26-08 12:55 PM

this is actually a common problem with thomson stems, just make sure you torque down the face plate to spec and that should help prevent this from happening

sac02 08-26-08 01:01 PM

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

CastIron 08-26-08 01:21 PM


Originally Posted by tkblazer (Post 7346997)
this is actually a common problem with thomson stems, just make sure you torque down the face plate to spec and that should help prevent this from happening

Source?

doppiodan 08-26-08 01:50 PM

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.

prendrefeu 08-26-08 01:58 PM

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. :)

Doctor Who 08-26-08 02:09 PM


Originally Posted by CastIron (Post 7347166)
Source?

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.

Psimet2001 08-26-08 02:26 PM


Originally Posted by doppiodan (Post 7347368)
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.

Good point.

tkblazer 08-26-08 03:12 PM


Originally Posted by CastIron (Post 7347166)
Source?

i have a few friends that it happened to and my LBS The Path Bike Shop has seen it enough that they actually stock replacement face plates

CharlieWoo 08-26-08 03:16 PM


Originally Posted by tkblazer (Post 7347886)
i have a few friends that it happened to and my LBS The Path Bike Shop has seen it enough that they actually stock replacement face plates

== ANECDOTE

krusty 08-26-08 03:21 PM

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.

Doctor Who 08-26-08 03:25 PM


Originally Posted by CharlieWoo (Post 7347907)
== ANECDOTE

Well, without an official recall and/or a scientific analysis, all we have are anecdotes, unfortunately.

kraftwerk 08-26-08 08:38 PM

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.

Surferbruce 08-26-08 09:08 PM

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.

womble 10-28-08 04:18 AM

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.

bikevoyeur 10-28-08 04:46 AM

The faceplate on my (overpriced) Easton EC90 Stem developed a crack as well. I switched to DEDA ZERO 100 swearing off carbon stems. Now this? Will this maddness ever end!?

dave99ag 10-28-08 08:25 AM

Talked to a Thomson rep at Interbike about this issue on an X2 stem. They said it's usually an issue of over torquing like others have said.

Grumpy McTrumpy 10-28-08 08:32 AM

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.

botto 10-28-08 08:35 AM

Next time get a Deda stem.

bwunger 10-28-08 10:56 AM

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.

Phantoj 10-28-08 12:18 PM

Steel and titanium, in most high-performance applications, have a finite life too.


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