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Cracked Thomson Stem

51K views 153 replies 77 participants last post by  Mr Pig 
#1 ·
Hi all

I bought and installed this stem 2 years ago and the bike is rarely used. The bike is only for commuter ride for less than 30 times ever since.

Last week, I found huge crack on the stem. Mailed thomson, but no reply.

I lived overseas, the nearest distributor is in Singapore, but no email address (have someone over there to help me out with the claim, but still hoping for the result)

Today, I search 'cracked thomson stem', and surprised with the result. How can someone claims the strongest built in the world with such poor product and service?

Search for warranty information, but couldn't find it, anyone can direct me to it?

Thanks all
 

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#2 ·
That be a picture of someones stem that does not own a torque wrench (or if they own one, they sure as heck didnt use it properly......)

Thomson is awesome to deal with - I have never had a warranty issue on any of their product, but have talked w them on a few topics.

Best bet is to call them.

number can be foundon their website:

www.lhthomson.com

They will sort you out.
 
#4 ·
I'll agree with the others that it looks like the crack may be due to improper installation rather than a defect.

But call Thomson. Since it's only a faceplate, I wouldn't be surprised they'd send you a new faceplate free of charge.

And I second the idea of taking a careful look at the handlebar after removing the faceplate. It may very well be compromised, too.
 
#6 ·
I cracked two of the face plates, on the third one now. Thompson gave me a new one after emailing them and sending the cracked one back. I used a torque wrench the second time, it still cracked when using the cross pattern to tighten. Made three passes, gradually tightening the bolt in the cross pattern. It seems like it's a matter of when, not if.

Make sure you have equal gaps at the bottom and top after tightening the plate.

I'm not buying another Thompson. Sure it's a good looking CNC machined piece, but that's about all it has going for it.
 
#7 ·
rallyraid said:
I cracked two of the face plates, on the third one now. Thompson gave me a new one after emailing them and sending the cracked one back. I used a torque wrench the second time, it still cracked when using the cross pattern to tighten. Made three passes, gradually tightening the bolt in the cross pattern. It seems like it's a matter of when, not if.

Make sure you have equal gaps at the bottom and top after tightening the plate.

I'm not buying another Thompson. Sure it's a good looking CNC machined piece, but that's about all it has going for it.
i too have had issues with Thomson. they have done a great job of marketing themselves somehow as "the" stem and post, i dont buy it.

overtorqueing? are you effing kidding me? so if it is overtorqued, it sure as hell shouldnt crack...it should be, well....overtorqued, and thats it. Overrated IMHO

I also challenge any of the MTBRetards to prove that Thomson is in fact the so-called, "best". I assure you there is no data on file to support Thomson, or any stem (or post) for that matter, being the best. This whole MTBR notion of Thomson being the best is based on years of cutting and pasting of the same cliches over and over...
 
#12 ·
JayTee said:
Ummm...if overtorqueing was the culprit, then shouldn't the handlebar have cracked first??
Not necessarily. Though I have seen someone actually crush the bar at the clamp. The bar actually had a bulge in it where it had been squeezed into the cavity of the stem. (wasn't a Thomson stem - was on a bmx bike).
 
#13 ·
Never used a Thom....never could justify the price. I will not spend $80 on a stem when I can get a good-looking, rock-solid, gorilla-strong stem for half that.

Heard the stories for years...wonder why they still make 'em.
 
#17 ·
I've cracked a thomson on both my road bike and mountain bike. And I DO use a torque wrench. They sent me a new faceplate for my mtb but would not for my road bike. I love their seatposts but will NEVER buy another stem from them.

I was told that it was my fault that it cracked. Sharp edges on a machined part = cracks. I'll go for forged from now on. There is a reason that most online stores stock Thomson faceplates...
 
#18 ·
Agreed with Fo here. The usual defense is "overtorqued faceplate", but if that's really a huge problem, then cheap forged stems should be cracking left right and centre. The vast majority of riders don't use torque wrenches, yet stem failure seems to be a fairly rare occurrence across stems as a whole. The very fact that replacement faceplates are available for this stem should be warning enough.

CNC just isn't a good idea for bike parts that need to be strong. I went off the idea of CNC stems when my metalluragist buddy found a crack across his Thompson faceplace. Sure, he doesn't use a torque wrench, but he's not stupid about how he treats metals either. On the other hand, I've been riding for years with forged stems with the nuts cranked down about as hard as possible with no problems.
 
#114 ·
CNC just isn't a good idea for bike parts that need to be strong. I went off the idea of CNC stems when my metalluragist buddy found a crack across his Thompson faceplace. Sure, he doesn't use a torque wrench, but he's not stupid about how he treats metals either. On the other hand, I've been riding for years with forged stems with the nuts cranked down about as hard as possible with no problems.
This is from a different forum but this guy nailed it to a T;

"The problem is, the notion that forging will make a stronger product these days is also often wrong. The problem with forging is that is can also weaken the metal involved. If your forging process reintroduces additional impurities into the metal or the temperatures on both heating and cooling aren't as well controlled you can end up with a weaker piece of metal than what you started with. This may be more prevalent with steels but I wouldn't be surprised to see it be the case with other metals also.

It's just simply the case that the precision of making base metal stock that it's much harder to improve than it used to be. We are better at controlling the environment and fewer impurities enter the process. Outside of china and cheap grade metals, we just make too good and too consistent of metals to start with anymore.

The most important decider of strength will be the original metal selection. The manufacturing process likely matters much less(although casting will still likely have more cooling/purity issues). For all intents an purposes, with the same amount of metal and the same type of metal, a billet and a forged product will likely have similar strengths.

Billet is mostly for looks/features."
 
#19 ·
womble said:
CNC just isn't a good idea for bike parts that need to be strong.
I don't get how a part made from a single piece of metal wouldn't be stronger than something with welds. But I'm not a metallurgist.

I have seen the machines Thomson uses to test their wares against the competition, though. The failure point for one of their stems does come long after anything I have seen them test from a competitor.

As for the face plate, those pictures show that little care was used in balancing the tightness of the bolts. It really isn't hard to do and once set up is pretty bomb proof.
 
#22 ·
GrantB said:
I don't get how a part made from a single piece of metal wouldn't be stronger than something with welds. But I'm not a metallurgist.

I have seen the machines Thomson uses to test their wares against the competition, though. The failure point for one of their stems does come long after anything I have seen them test from a competitor.

As for the face plate, those pictures show that little care was used in balancing the tightness of the bolts. It really isn't hard to do and once set up is pretty bomb proof.
Forged stems don't need welds. Forging can result in a stronger part than CNC'ing, which is probably why you don't see parts such as cranks produced from CNC machines.

Though I'm not a metallurigist either- just read a bunch of stuff of stuff by Sheldon Brown ;)
 
#23 ·
I have been to the Thomson factory, and met Thomson himself (RIP) and ridden the trails behind their factory. Although Thomson is not around anymore, I believe his son is continuing where he left off. Any company run by people who ride, who supports riders and events while building top quality componentry is good in my book. Tons of people crack faceplates being hamfisted wrenchers, and I don't blame any company for not warrantying something like that. I have NEVER seen a Thomson stem that was cracked/broken anywhere but the faceplate, they are STRONG. I have a few Thomson products but to be honest they came on bikes I bought, I don't have the coin to justify the purchase, but I still think they are top notch components.
 
#24 ·
Jim311 said:
I have been to the Thomson factory, and met Thomson himself (RIP) and ridden the trails behind their factory. Although Thomson is not around anymore, I believe his son is continuing where he left off. Any company run by people who ride, who supports riders and events while building top quality componentry is good in my book. Tons of people crack faceplates being hamfisted wrenchers, and I don't blame any company for not warrantying something like that. I have NEVER seen a Thomson stem that was cracked/broken anywhere but the faceplate, they are STRONG. I have a few Thomson products but to be honest they came on bikes I bought, I don't have the coin to justify the purchase, but I still think they are top notch components.
That said, how many cracked stems have you seen, and how many were CNC vs straight forged?

I've only ever seen two cracked stems. One was a Thompson, the other was a crazy-light weight weenie stem. Still, 2 stems isn't enough of a sample size to really judge on. What's probably more relevant is that I've only managed to come across 2 cracked stems in ten years of riding.
 
#25 ·
womble said:
That said, how many cracked stems have you seen, and how many were CNC vs straight forged?

I've only ever seen two cracked stems. One was a Thompson, the other was a crazy-light weight weenie stem. Still, 2 stems isn't enough of a sample size to really judge on. What's probably more relevant is that I've only managed to come across 2 cracked stems in ten years of riding.
Agreed, breaking stems is BAD NEWS and you hear more often of broken forks and frames than you do stems. I personally cannot justify the price tag of the Thomson stuff, but I still think it is top quality high end stuff. I have one Thomson stem that is a work of art compared to most of the other stuff I've got.
 
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