Moving seat post



bob161069

New Member
May 16, 2007
26
0
0
Has anyone had a problem with a moving seatpost. I have an avanti sprint and no matter how tight i do up the seat post it still keeps dropping. It all most seems like a design problem. Or is this just my bike.
 

tarmacguy

New Member
Aug 5, 2007
20
0
0
42
cant say i have had this issue, perhaps could be the bolt, or the clamp..have u tightedned it too much that u have caused the seat post to become indented and now slipping down.
 

bob161069

New Member
May 16, 2007
26
0
0
I have tightened the avanti alloy seat clamp pretty tight. But theres no indentations or damage as yet. It will slip down mm by mm over a 1hr ride. Just doesnt seem right.
 

1id10t

New Member
Apr 11, 2005
343
0
0
I know this may sound like a silly question but is the seatpost the correct size/diameter? Also, do you have a seat clamp which goes around the seat tube or is the bolt integrated into the seatpost. Either way, have you check to make sure the bolt is not stripped.
 

531Aussie

Well-Known Member
Apr 11, 2004
12,652
303
83
assuming it's the right size and the bolt and thread are ok........


test it by whacking the nose of the seat kinda hard. It shouldn't twist.

You've gotta check all the bits, like, make sure the clamp ends aren't touching in the middle, or the frame gap isn't coming together, and that nothing is stopping the screw being tightened way up
 

bob161069

New Member
May 16, 2007
26
0
0
seat post is right 27.2 and clamp seems ok going to give it the wack test and see what happens
 

cruisin

New Member
May 21, 2007
93
0
0
Some quick release type seatpost clamps just won't tighten enough to hold a smooth seatpost.
If this is the case you can look at a different clamp or a less smooth post or both.
 

1id10t

New Member
Apr 11, 2005
343
0
0
cruisin said:
Some quick release type seatpost clamps just won't tighten enough to hold a smooth seatpost.
If this is the case you can look at a different clamp or a less smooth post or both.
Good call. If it is a smooth seatpost maybe give it a light rub with sandpaper/emery cloth to rough it up a little. Obviously not the whole stem but only the portion which won't be seen. It might help.
 

531Aussie

Well-Known Member
Apr 11, 2004
12,652
303
83
If the bolt in the clamp is this type, with the 2 bits, sometimes the 'nut' end, and/or the bolt has to be cut. If the bolt goes through right through to the unthread bit, it obviously won't tighten properly, even if it feels as though it is. It's often hard to see if the the bolt is 'stopping' on any parts of the nut end

473219.jpg
 

62vette

Well-Known Member
Nov 18, 2003
1,961
236
63
60
Te Ika a Maui
531Aussie said:
If the bolt in the clamp is this type, with the 2 bits, sometimes the 'nut' end, and/or the bolt has to be cut. If the bolt goes through right through to the unthread bit, it obviously won't tighten properly, even if it feels as though it is. It's often hard to see if the the bolt is 'stopping' on any parts of the nut end

473219.jpg
Aye. I've had to shorten the nut end on a seat clamp bolt before.