Thomson Elite Road Stem Broke
 

Guys:

I was on my usual Tuesday night after work ride, about 7 miles in and my Thomson Road stem broke. It was really weird, while climbing a couple of very small rollers here in So. Jersey, pulling up on bars and out of the saddle, I felt a few pops in my front end. I thought I was getting hit by a small rock or something before I realized, my bars were coming lose.

I pulled over for a mechanical and looked at the underside of my stem and low and behold, there is a complete crack in the aluminum faceplate from where the bottom bolt is bolted to the actual stem. I gingerly road my bike back to my house to park in the garage and take out one of my other steeds to continue riding. What a bummer.

I wondered about this stem when I bought it because of the cutout faceplate and was assured there wouldn't be any issues. God, I'm only about 168 lbs., so I know I'm not the strongest rider out there. Possibly when it was installed the bike shop over torqued the bolts that eventually caused fatique and it's failure. The bike built up is just over a year old, with maybe 2000-2500 miles on it.

Here's a link to the stem in question.

http://www.pricepoint.com/detail/176...p=305%20THOX28


Anyone else ever experience this issue? I'm really bummed by this incident. Thankfully, I didn't crash and it's only a stem.

Bob

That is my stem as well. A little scary. Perhaps a call, letter , pictures to Thompson would be a good idea. Mine has 2-3 times the mileage and seems very strong. While I have pulled and push pretty hard at time, i generally keep a light touch on the bars, especially when climbing. good luck, Jon

Same stem, also cracked faceplate.
 

I had the same stem. The top of the faceplate cracked in line with the bolt hole. It was bought and installed at a reputable shop, so I assume they torqued it correctly. They sent it back to Thomson and it was replaced under warranty. I went back to a steel fork and quill stem on that bike, so I don't use one any more.

it's cnc'd what do you expect ?

My 135lb buddy had one crack on the steerer tube clamp part. As much high speed riding as he does, he was very lucky to hear the crack/pop as he was hit the little bump at the end of the driveway. It was replaced under warranty without any issues.

I much prefer the 4-bolt designs.

After two stem failures next to me (one a bolt, the other a faceplate), I buy the extra safety. Neither were this brand.

mtn stem
 

I had the same issues on my thomson mtn. stem twice. They keep replacing them for me, but it still stinks that it takes time and shipping. I'm 185, and a SSer.

Thats scary. Glad to hear you were not hurt. One of my phobias is breaking a stem or handlebar! I've been using Thomson stems on several bikes for a few years. One of the things I noticed when installing the face plate on the 4-bolt model is that you have to be very careful to torque the bolts evenly.

+1000

IMO its not enough to tourque each bolt to spec but tighten in the proper way so they are evenly tightened as you move to spec.

b21

Considering their bombproof post...
 

this is a bit of a unwanted surprise. I was close to ordering one of these for replacing my Calfee's steering wheel, but my shop suggested that my 3t fugie still had many miles left in it. Glad I stayed as I did.

It's not any different from the tightening methods of any gasketed surface. If you're torquing down a head gasket you start at the center and work your way across and outward from the center. For a 4 bolt face plate you torque upper left, lower right, upper right, lower left, repeat.

That said, from what I've seen in stem failures, it's always been other stress risers which cause the failure. You're clamping a rigid member around a round object from two paralell lines of force, there's a design flaw there. My own Thompson mountain stem failed right across the center - no bolt holes to start the crack.

From the response to this post I would say that Thompson has a real problem with face plates that few knew about. So let me ask this, anyone here have a problem with Ritchey WCS 4-axis stems? I found a crack in mine a few weeks ago, in the body of the stem just before the bolt flange for the face plate. I looked at the new ones and there are a couple of areas they have been reinforced, including where mine cracked. If you're heading out to check your own bike, there cracks are hard to see, basicly a hair thin white line which you can just about feel with a fingernail.

My Thomson is creaking(10000 miles),and though its not cracked,every time after I clean, grease and re-install it creaks a few weeks later. Deda Zero 100 anyone?

Zoinks.. I've got this stem too on my Serotta I got last year.. probably in the 4000-5000 mile range on mine.

I will give it a good inspection. I'm continually finding little creaks in my bike, but it's usually the saddle rails creaking a little.

It was definitely bought cause I thought Thomson stuff was bombproof.. I've had several of their seatposts prior to this. (I have their seatpost on my Serotta as well as my current MTB)

There has been similar thread(s) at RBR. It seems that with the Thompson stems, 2 bolt bad, 4 bolt good.

Thread resurrection!

My Thomson X2 cracked last night on the trainer.

Right down the middle on one side, nowhere near the bolt holes.

The bike is at the dealer and based on web searches it sounds like Thomson will take care of it.

Still not sure I care to continue to use it though.

I never seek to save weight on stems or handlebars. Component failure in either of these areas is potentially catastrophic.
Stems with a 4-bolt faceplate are always chosen and I carefully tighten stainless steel (not titanium) bolts to specification.
That's been my plan and I'm sticking to it!

Like pdxmech13 said, it is cnc'd. Forged materials are much stronger than cnc'd materials. I like the thomson seat posts, but there isn't much stress put on those (except compression stress). Stems on the other hand... they go through a lot.

And the two bolt design doesn't help much either.

Me too ...

My X2 recently cracked. Faceplate cracked at it's thinnest part.

Thompson replaced it with an X4. I'll keep a close watch on it.

My bolts stripped out while I was out of the saddle pounding away. The threads inside the stem came out. The stem was torqued to specification. The company was top notch about it, replaced it, but I sold it off. I tried another one recently and I could not get past my memories so I sold it too.

Love their seat posts and even the x-2 looks but...

+1

Hmm, well I sold my thompson stem a year ago when it seemed like it was the wrong length. I guess I was just lucky.

For those who think the 4 bolt designs are safer, I've had two 4 bolt face plates crack: a Deda and an Easton. Both installed correctly using a torque wrench progressively tightening each of the bolts in a rotating X pattern. I weigh 175 lbs.

I had an issue with one a few years ago. The two bolt road stem. Couldn't get the bar to where it wouldn't move, no matter how much I torqued it down. That front faceplate, with it's two screws, is worthless, IMO. I sent it back to Thompson, they sent another. I sold it. Sure looks good though, don't it?
After that, I felt like function follows form with Thompson. Additionally, I think 4 bolt stems give a bigger margin of safety in the event of a failure, no matter what the brand. Jeff N.

To everyone with issues, did you torque it to the correct spec?

And to whoever wants to get rid of your thomson stem, pm me ;)

“Safer” doesn’t mean indestructible. Not to be argumentative, but how many 2-bolt stems would you have broken during the same period? No way to know, right? I go with what makes most engineering sense to me.

By the way, IMHO a rider’s weight is not as critical as how strong he is and what he does with the bike. How a stem is loaded can vary significantly by riding style and conditions.

Dude, you are so lucky that it didn't completely fail!

Thanks
 

The newest ride I have came with the same stem and a Kestrel bar. First ride, I hopped a curb and it felt kind of odd, like the bars slipped, but they didn't. Checked the label to make sure the stem wasn't a Girvin or something and then went out and purchased a mid-range Tom Ritchey bar and stem at the LBS. Heavier, but well worth the piece of mind. I hate the dentist and don't look good with my arm in a sling. Glad to have made the change after seeing all of this. Thanks for the heads-up, that thing will go in the re-cycling bin and not get ridden again...by anyone.

Hey come on now Ed this is a family oriented forum........ :p

How about this type of threadless stem?

http://www.hubjub.co.uk/nitto/nittoct80zm.jpg

Yes, it's less convenient for changing bars, but is it stronger than the removable faceplate type? I think it is - and the fact that it's steel doesn't hurt, either.

I had a Thomson stem faceplate crack. I noticed it before it ever became a problem. I'm pretty sure that mine cracked because I over tightened the face plate bolts (probably by a lot). I would be surprised if most of the Thomson faceplate failures aren't from the same cause. Thomson recommends 5.5nm, which to a hamfister, is pretty light pressure.

A friend just sent me this photo a week ago. Installed by LBS and torqued to spec.

Thompson will replace but they claim it's a torque issue.

I had the same hairline cracks in four places on my x2 stem. Stem was replaced with no issues.

I agree but it's not like the Thomson stem is a lightweight. I got one thinking that I was making a very conservative choice. This thread has gotten me thinking...should I replace my X2 with something else or just keep an eye on it?

I'd replace that stem. You've gotten you money's worth.

That said, I'm guilty of a similar crime. I have a one-piece carbon aerobar setup with about 15,000 miles on it. I'm sure it should be replaced, but man are they expensive now. $750 for a handlebar - are you kidding?!

what else comes in silver tho?

+1, I use a Ritchey, more bolts spreads the load

REPLACE ! go with at least a X4

Check out the Deda Zero-100. It comes in a smokey silver-grey color (black too) that is way cool, IMO. Jeff N.

Touque is the big factor here, but I would also suggest contacting Thomson about it. I have several of their products and have never had a failure. It looks to me though that the sharp 90 degree corners are creating a stress point and would absolutely crack like that if overtightened.