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Discussion Starter · #1 ·
Forget about the integrated seatposts. I'm talking about the standard aluminum or CF posts with the aluminum clamps.

There was a time, back in the 90's and 2000's when clamps were frequently designed with tightening screws positioned fore and aft of the pivot (e.g. Syncros, Thomson).

Today, seatposts almost always have the tightening screws positioned side by side.

What gives? How is this design a good one?
 

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Forever a Student
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4,963 Posts
I much prefer a single bolt system like the old Enve system to the old Thomson or standard two bolt system.

Much less finicky, much easier to adjust, torque down and be done with it.

One issue though is that, like most of their early instructional videos, Enve was handing out bad advice. They were telling people to grease the wedges and it caused them to come loose constantly. Because of this the design got a bad wrap but in reality it's very solid and used very widely by custom builders.

The old 3T difflock is a disaster though. That's the perfect example of how not to make a single bolt clamp. Absolute trash engineering right there.
 

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I dislike the single-bolt posts. It is very difficult to do fine adjustments in saddle angle, eg if you want to change it 0.5 or 1º.
The one I used, a Specialized post, after it's been torqued to spec, the cones & cups of the mechanism become very tight & wedged into place. Needs a sharp rap to loosen it, and that throws off the original angle setting.

With the 2-bolt, you can alternately loosen front bolt & tighten rear bolt (or vice versa) to change angle in tiny increments.

However, getting both bolts at the correct torque can be a little tricky, it requires several iterations to correctly get both the saddle angle and the 2 bolt torque.
 

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I agree. The Thompson system allows for precision and the seat angle remains stationary until you decide to change it.

A SLK carbon post with the single bolt system came with my cannondale hi-mod 3 years ago. It could not be tightened enough to kept the angle from changing--a total crap design.

I generally prefer carbon components but I continue to go back to Thompson seat posts after having experienced a number of carbon model failures.
I dislike the single-bolt posts. It is very difficult to do fine adjustments in saddle angle, eg if you want to change it 0.5 or 1º.
The one I used, a Specialized post, after it's been torqued to spec, the cones & cups of the mechanism become very tight & wedged into place. Needs a sharp rap to loosen it, and that throws off the original angle setting.

With the 2-bolt, you can alternately loosen front bolt & tighten rear bolt (or vice versa) to change angle in tiny increments.

However, getting both bolts at the correct torque can be a little tricky, it requires several iterations to correctly get both the saddle angle and the 2 bolt torque.
 
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