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Discussion Starter · #1 ·
Hey guys,

I bought a new Easton EA90 stem that uses the new Top Lock technology bar clamp... How am I supposed to tighten it? (The Easton site doesn't have instructions up yet.)

Do I tighten the 4 bolts evenly and leave equal gaps between the faceplate and the stem at all 4 bolts? Or does the faceplate get tightened to completely close off the end with the integrating curve shapes? (That's what the stock photo shows on the un-installed stem and it seems to make more sense, otherwise why make matching faces at one end?)

This picture shows the difference in the faceplate ends: one side is curved to match the curvature on the stem's interface (red arrows); the other of the faceplate has a flat interface (blue arrow) which doesn't match the curvature of the stem.
 

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My roommate has this exact stem. Tighten the pinch bolts in a criss cross (X) order just like any other stem so you don't overstress any one area. If I remember correctly, the top two bolts match the curvature pretty closely. The bottom bolts, however, have a more significant gap... It looks weird but I guess it's supposed to reduce stress concentrations on the bar.

I hope this helped... If you tighten all bolts evenly to the torque spec you shouldn't have any problems.
 

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Discussion Starter · #6 ·
C-40 said:
Tighten the bottom bolts completely, so there is no gap, then tighten the top. All it took was a quick google search.

http://www.eastonexp.com/technology/
Yeah, I did google that same page last night, but it shows a different setup. That stem depicted in that diagram has different faceplate - stem interfaces than the one I bought. There is no "flat section" to tighten completely.

I busted out MS Paint...
 

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Discussion Starter · #7 ·
So I tightened the bolts evenly all 'round such that the mating curved surfaces at the top are in contact, but there is a gap at the bottom curved-to-flat interface. I don't see the point of making mating curved interfaces if there aren't supposed to be mated. Silly design gimmick, imho.
 

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I could be wrong, but I believe the curved section vs non-curved is so that you can flip the stem and then flip the face plate 180 and the parts that are touching are always on the top....does my explanation make sense?
 

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bismo37 said:
So I tightened the bolts evenly all 'round such that the mating curved surfaces at the top are in contact, but there is a gap at the bottom curved-to-flat interface. I don't see the point of making mating curved interfaces if there aren't supposed to be mated. Silly design gimmick, imho.
I think it should be fine. If it's good and tight, it's not going anywhere. If you have a carbon bar and are paranoid, you can always use carbon assembly paste too. From memory, your paint diagram looks like my friend's stem... I definitely remember the gap at the bottom that you mention.
 

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C-40's wrong...i have this stem, AND the instructions that came with them. Tighten the top 2 bolts first so that the points interlock completely. Then, tighten the bottom two bolts, alternating left/right. This leaves a small gap on the bottom. That's what Easton says...
 

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Discussion Starter · #13 ·
davcruz said:
I could be wrong, but I believe the curved section vs non-curved is so that you can flip the stem and then flip the face plate 180 and the parts that are touching are always on the top....does my explanation make sense?
yup. You're right.
 
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