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Seatpost lenght question

Old 06-08-07, 12:37 AM
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UmneyDurak
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Seatpost lenght question

So I am thinking of replacing my stock seatpost with Thompson Elite with zero offset. Right now I have about 165 mm exposed, it has offset and is clamping the seat almost at the end of railing.. How much of a seatpost needs to be in the frame for it to be secure? I think, total length, 200mm would be too short. What do you guys and gals think?
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Old 06-08-07, 12:40 AM
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FlatFender
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You want about 4" at LEAST in the frame.
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Old 06-08-07, 12:51 AM
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bikejack
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Most posts have a minimum insertion mark so just make sure you have your length at least on top of that
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Old 06-08-07, 01:19 AM
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Originally Posted by UmneyDurak
So I am thinking of replacing my stock seatpost with Thompson Elite with zero offset. Right now I have about 165 mm exposed, it has offset and is clamping the seat almost at the end of railing.. How much of a seatpost needs to be in the frame for it to be secure? I think, total length, 200mm would be too short. What do you guys and gals think?
Is your seatpost not marked with a minimum insertion? If your current seat post works, why wouldn't the new one? Also, I believe seat posts come in lengths of (guessing here) 250 and 350 mm so if you're worried you could buy a long one. You could probably check the company websites to find out.
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Old 06-08-07, 07:34 AM
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Thompson road seat posts have the "minimum insertion mark" between 65 mm and 100 mm from the end depending on length and diameter so you want to be sure to have at least that much in the frame. If it's a concern, just buy the 330 mm post intended for MTB or compact frame use. That should guarantee you plenty of length at a very small weight penalty.
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Old 06-08-07, 07:40 AM
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Originally Posted by Camilo
Is your seatpost not marked with a minimum insertion? If your current seat post works, why wouldn't the new one? Also, I believe seat posts come in lengths of (guessing here) 250 and 350 mm so if you're worried you could buy a long one. You could probably check the company websites to find out.
The logical steps to take
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Old 06-08-07, 10:57 AM
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Shouldn't be a problem. Thompson 250mm seatposts (the shortest offering) claim a max height adjustment of 185mm. You only need 165mm.
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