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Moderatus Puisne
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Discussion Starter · #1 ·
My new fork has a carbon steerer tube, and cautions not to use "pinch type" stems.

Does this mean I need to replace my thomson stem?
 

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eminence grease
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I don't think the Thomson stem qualifies in the true sense of the term, at least in comparison to MTB stems which truly are of that design. I asked both the Easton and Reynolds techies this question and the answer was "Thomson = no problem." I think you're fine, other might not.
 

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Reynolds Ouzo pro

When I opened my new CF front fork carton from Reynolds
there was a consumer warning about NOT
using a pinch type stem such as the Thomson.
They did not mention manfacturer names, but from the pictures they had
drawn in the description you could tell the difference. I had to call them about
using a Deda stem, they said that was fine.
 

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eminence grease
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Road cyclist said:
When I opened my new CF front fork carton from Reynolds
there was a consumer warning about NOT
using a pinch type stem such as the Thomson.
They did not mention manfacturer names, but from the pictures they had
drawn in the description you could tell the difference. I had to call them about
using a Deda stem, they said that was fine.
Which is precisely why I called Reynolds and talked to them. Their answer - Thomson is not a problem. The picture in the manual is a little bit ambiguous - it is a poor depiction of a Thomson, but a great depiction of a Race Face which is truly a pinch type clamp. The Thomson is a bit different in that it spreads the stress not by pinching but by pushing the steerer against the back of the stem by bringing the two plates together. In the exact opposite direction of all two bolts stems that push the steerer against the front of the stem. The Race Face simply pinches the stem closed against a small part of the steerer.
 

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Man, I wish I knew the real motive here.
Maybe they don't want to invite lawsuits from Thomson, etc.
But I can swear that the product warning I saw in my CF box
about 1 yr. ago scared the bejesus out of me.
 

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eminence grease
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Road cyclist said:
Man, I wish I knew the real motive here.
Maybe they don't want to invite lawsuits from Thomson, etc.
But I can swear that the product warning I saw in my CF box
about 1 yr. ago scared the bejesus out of me.
I think the picture in the Ouzo manual is really not that well drawn. It's meant to look like a pinch type stem but it also looks vaguely like a Thomson. I think they'll give the straight answer if one asks.

Drawing

Motivation - they don't want consumers to crack the steerer which they will with a Race Face SysStem style clamp. The bolts in the Thomson will likely strip or break before they'll crush the tube. (At least that's what happened to one that I tried to tighten to the correct torque settings :eek: )
 

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Discussion Starter · #7 ·
well, that sort of settles it, then. Thanks, terry.

I agree, the picture in the Reynolds manual confused me, and I was thinking surely Thomson would've ... you know, thought of that, an dsaid something about "Here, the X/2 is great for carbon steerers, but the Elite isn't."

I just didn't want to break something, especially something like a steerer. Now that would suck.
 

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Hi Terry_b
Not trying to give anyone a hard time. Just trying to relay my past worries.
I received a product warning slip that was outside of the Reynolds Ouzo manual.
The ideal clamp they had drawn was similiar to the Ritchey stem that has
bolts coming from both directions to tighten the stem to steerer. Even the Deda
type stem (kind of offset type of tightening system) was in the dog house according
to their drawings of the multiple types of stems to avoid.
Glad they backed off on their warnings.:)
 

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The clamping power of the "pinch type" Thomson et al is huge. If you use a torque wrench and tighten the stem to the recomended torque (48inlbs from memory) you should have no problems.

After using the torque wrench, put a normal allen key on it, I think you'll be surprised by how "loose" the bolts are :)
 
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