Although the Thomson X2 is 20-30 grams heavier than other stems in similar price categories I bought it anyways because it is one of the only silver stems out there, and I assumed that the extra material will make it stronger. The design of the stem is also outstanding and compliments just about any frame.
The X2 stem has no more that 20 rides on it, and already there are 2 cracks that go all the way through the faceplate. Currently it is being sent back to Thomson where they will examine it and send me a new one afterwards. So no riding this weekend which is a bit dissapointing. I was told that perhaps I had over or under tightened the stem, but it was tightened at 5N/M which is the recommended torque. The diagram shows where the face plate began cracking. The cracks originate from the 90 degree angle and into the faceplate. I can only assume these cracks developed from side to side torquing of the bars.
19 comments:
you're an animal.
Yash,
You're supposed to put the power (and torque) to the PEDALS, not to the stem.
Just sayin'...
now was that 5N/M on a well greased bolt (threads and flat contact area) or on a dry bolt?
and when is the last time your torque wrench was calibrated ;)
Katsumi! You can borrow the faceplate off my road machine.
Many people know that I am on the PVB Phase II plan. I have gained 10 pounds of mass and now I am breaking bike stuff left and right. Ridiculous!
The 5N/M was with some very light grease.
The face plate did not break from overtightening. What causes it to fail is that there is a sharp right angle, what we in the industry call a stress isolation point, where both of the cracks begin.
If you look at the diagram, whenever there is torque on the bars, the tip of "Male" piece(the faceplate) feels torsional stress from the female piece. After thousands of cycles of this stress, cracks begin to form at the stress concentration area at the 90 degree section.
what male doesn't feel torsional stress from a female...
(and i'll admit to not really looking at the diagram closely other than to see two scribbled lines on there)
Well said!
Also, I hope everyone noticed my amazing microsoft office skills.
Thomson is a company down this way in Macon, GA and they have always had wonderful customer service. I am sure they would replace it.
However, your biceps are pretty huge so read the fine print. I think the maximum allowed are 32 inch anacondas (tribute to the hulkster).
Wait, did I read correctly that you would not be riding/racing this weekend because of the stem breaking?
Don't you have like 2 pit bikes?
If they are all broken, I am sure that one of the many fine shops in the Boston area can loan you a stem until Thomson sends you a new one.
dude, get yer butt out for Shedd park, might be the last mild weather cross race of the year.
I plan to be at the Shredd on my pit bike!
I may be racing the weekend after but this may be my last race until the final races in RI.
As your Arch-Nemesis: I advise you to stick your current course of action. DO NOT RACE!! Rest more and you will get faster. In fact, you should stop training entirely.
The worst training bicycle racing is racing your bicycle.
You are no longer my archnemesis. I have a couple of other ones who are more realistically in my range.
You must work hard to attain your dreams.
I am getting PowerCranks so that I can develop massive power over the winter. F the weight room!!
Dude. I am retired after Lowell! no need for long hours on the trainer or riding in cold weather.
I am not racing at all next year, just gentlemen rides and hot gear.
I don't understand you Mr. Katsumi.
I suppose that if you are not enjoying racing, you should stop.
But gentleman's rides? Will you be wearing Rapha, looking PRO and riding along at a wobbling low speed on a $10,000 shiny steed, only in good weather?
No Rapha, unless they have a firesale.
My favorite clothing right now has to be Capoforma. That shit is tight.
are you forfeiting the series lead!?
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