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Stem Handlebar Clamp Not Flush

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Stem Handlebar Clamp Not Flush

Old 10-28-13, 11:50 AM
  #1  
1989Pre
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Stem Handlebar Clamp Not Flush

My stem and handlebar (at the clamp) are both 25.4. However, even after tightening the stem's handlebar clamp securely, The clamp plates are not flush (space at top bolt is about 3/16" and the other, at bottom of clamp, is about 1/32". I admit that I did not use a torque wrench to secure the two bolts, but they are good and tight.
It seems to me that the clamp plates should be flush. Is this correct?

Paul
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Old 10-28-13, 11:57 AM
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Normally you have a gap at the top and bottom of the faceplace (this is on the basis you are using a stem with a face plate, make / morel or photo would help here) this gap would normally be equal all round, if using a 2 or 4 bolt face plate.

An exception would be the Easton Top Lock design, where the upper clamp faceplate is always flush with the stem, and there is a gap between the faceplate and stem at the lower bolts.
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Old 10-28-13, 12:37 PM
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Aha. thank you very much. So, the gap should be equal, but it is normal to have them. Okay. The bars I am using are Scott LF Liteflite Aero Drop and the stem is the ITM The Big One. I haven't seen either of these products in anything but 25.4.

Paul




Originally Posted by jimc101 View Post
Normally you have a gap at the top and bottom of the faceplace (this is on the basis you are using a stem with a face plate, make / morel or photo would help here) this gap would normally be equal all round, if using a 2 or 4 bolt face plate.

An exception would be the Easton Top Lock design, where the upper clamp faceplate is always flush with the stem, and there is a gap between the faceplate and stem at the lower bolts.
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Old 10-28-13, 01:35 PM
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You need the gaps so that the faceplate bolts will be exerting clamping force on the bar via the plate, not just clamping the plate to the stem. Ideally you would draw the bolts tight evenly so that the gap was equal top and bottom.
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Old 10-29-13, 08:43 AM
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Okay, that makes sense to me. Upon further investigation, it appears my bars (at the clamp) are 26.0., not 25.4 as I had believed. Also, I have found 5 (five) different specs for the handlebar clamp of the ITM Big One stem; 25.4, 25.6, 25.8, 26.0 and 26.4. (not sure which one I have).
I made sure the gaps on both my upper and lower face-plate bolts were even. Both gaps are 1/16" with the bars tightened down securely. If that sounds reasonable to you guys, I'll go with it.

Paul
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Old 10-29-13, 09:02 AM
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Unless you are using shims, the bar and stem need to match, i.e. you can't run a 25.4mm bar in a 26mm stem, photos would be useful
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