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What are the pros and cons of the lay back designed seatposts

I am about to by a Thompson Elite and would like some advice
on why I would buy the lay back instead of the in line

Rich
 

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Pros and cons

The Pros and cons are as follows:

The seat is shifted backwards, as is your weight. This is an advantage when you want weight on the back wheel for traction, or for downhills. It leaves the front end light, and easier to manual, but also tends to make it squirrley if you like to stay seated for climbs. It also technically stretches out the cockpit a bit, which again could be good or bad. Up to you as to how you portray these fatcors as being pro or con. I run a setback on one of my rigs, and I like it.

Bob
 

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If you do any pedalling use the one that brings you in a comfortable and effective riding position (patella somewhat in line with your pedal axis at the 3 o'clock position).

As soon as you stand up for downhill I don't see any difference in the two options (I have also no idea how it could influence manualing as you stay out of the saddle? Maybe you mean pulling off a wheely?)

The pro of a straight seatpost is that it will be lighter and stronger than a setback seatpost, all other things equal, plus you can usually lower your seat even a little bit further...
 

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No, not necessarily, because a seat post is nothing without a frame to stick it in.

(And please don't mistake Thomson's bent shaft design for anything different compared to straight post with an offset clamp, such as a RaceFace XY or Salsa Shaft).

RaceFace XY = 25mm setback vs. Thomson = 16mm


If the seat tube angle on the frame you're riding is too steep to put your saddle in the position you want, then a layback seatpost is for you.

In that same vein, say your saddle is exactly where you want it with a straight post, but the post is clamping the rails something forward of center, you may wish to install a setback post to clamp the saddle more evenly in the center portion of the rails.

So to recap, figure out what position you want your saddle in relative to the crank (as trialsrookie suggests), then pick a seat post to facilitate it getting there.
 

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A friend recently got rid of his lay back Thompson because he couldn't lower it enough.

I don't like lay back posts because I climb best with the seat fairly far forward.
 

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To me this pretty much says it:
In that same vein, say your saddle is exactly where you want it with a straight post, but the post is clamping the rails something forward of center, you may wish to install a setback post to clamp the saddle more evenly in the center portion of the rails.
Take a look at where your saddle is sitting in your current post. If your cockpit is nice and comfortable and your saddle is pretty much clamped in the middle of the rails then get the same as your current post (setback / straight). If your saddle is just about all the way forward (clamped right at the back on the rails) then you're probably a good candidate for a straight post. For me it was mainly saddle position that determined the post type - and with my bike the post will only go down up to the Thomson logo so it wouldn't have matter either way wether it was bent at that point or not.

Only disadvantage I can see in a straight post is that the position may not be as good with the saddle lowered all the way down (depending on the seat tube angle) - but then again if your saddle is all the way down you're probably not spending a great deal of time on it anyway.

Anyone know if a setback will aid back pain issues associated with a cramped cockpit?
I imagine it would help somewhat - but I reckon you should consider the above comments and also consider your knee over pedal spindle postition and how that may be affected. Setback posts in general shouldn't be used to adjust cockpit length but people probably do it anyway. A stem change would probably make the biggest difference providing you can go longer than current?
 

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energetix said:
I imagine it would help somewhat - but I reckon you should consider the above comments and also consider your knee over pedal spindle postition and how that may be affected. Setback posts in general shouldn't be used to adjust cockpit length but people probably do it anyway. A stem change would probably make the biggest difference providing you can go longer than current?
This is good advice.

IMO - the only real reason to change from a straight to a setback post (or vis versa) is if you can't get your seat into a proper seat/pedal position with your current setup.
 

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energetix said:
Setback posts in general shouldn't be used to adjust cockpit length but people probably do it anyway. A stem change would probably make the biggest difference providing you can go longer than current?
Here I partly disagree.

I mean, sure, obviously you don't want to buy too small a frame and then attempt to correct for it via a too-far-aft saddle adjustment.

(A) one should have the correctly sized frame, with the seat tube angle appropriate to get the riding position they need.

(B) then adjust saddle position (height & fore/aft) accordingly to get the correct position relative to the cranks, and this may necessitate a post with greater setback.

(C) then make slight tweaks to the stem length to get the total reach they desire, but ideal / preferred stem length should have been decided up front and factored into the effective top tube length of the frame.

dingleberry said:
No my cockpit is too short and I need relief!!!
Is your riding position too far forward currently (are you too far ahead of your spindle)?

In general I'd suspect "too short" a cockpit would leave the rider more upright than desirable, and less susceptible to back pain. But again, if you feel "squished" because you can't move your saddle back to where it *should* be, than you ought to increase your setback -- and some posts like the older Eastons give you as much as 40mm rearward offset to play with.

But if the problem is that your frame is a size too small, but your seated position is already optimized, moving the seat aft is probably going to hamper you, especially climbing.
 

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bainsey said:
What are the pros and cons of the lay back designed seatposts

I am about to by a Thompson Elite and would like some advice
on why I would buy the lay back instead of the in line

Rich
Offset or straight is determined simply by whichever one puts you where you want to be in relation to the pedals. Seat angle gets you part of the way there, but there is nothing wrong with a seat slid most of the way back on a setback post if that gets you where you want to be IN RELATION TO THE PEDALS. If you are already where you want to be in regards to the pedals, pushing the seat farther back (setback post) is not going to solve your problem.

Try sliding your seat all theway back on the post you have and see how it feels. If it feels better, go with the setback. If not, get the straight. However, if the only reason you are doing this is to open up the cockpit, you should also be considering if you have the right stem, espcially if you like your current position relative to the pedals.
 
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