I have a Giant Defy 3 and I'm not sure how tight the seat post bolts should be. I don't have a torque Allen key. Is doing the two bolts on the ring that goes around the frame as tight as I can do them with my hands ok? It's an aluminium frame. I don't I want to cause any damage to the frame.


  • 1
    Be conservative. Just enough the seat will not move.
    – paparazzo
    May 4, 2015 at 16:23
  • With aluminium frame is there a worry that IF I did tighten more than just enough for the seat post not to move, would it cause damage? May 4, 2015 at 16:27
  • 1
    Don't turn it 5 revolutions and then test. Do 1/4 turn at a time.
    – paparazzo
    May 4, 2015 at 16:36

2 Answers 2


In this manual, they state the torque for the Giant Defy seatpost should be around 50kgf-cm (5Nm). I know this is for the carbon frame, but they should be similar.

You can buy a torque wrench for around $30, which you should, because otherwise there is a high chance you will under or over tight it. I know $30 is a pain in the ass, but think this will keep your $1000 bike running smoothly for a long time.


It does not take much torque to snug up the seat post. With a long lever yes you could damage the frame. Cross one finger over the Allen key so you have a short lever and snug it up. See if you can twist the seat. If so snug each up another 1/4 turn and test.

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