minimum insertion seat post

[thelawnet]

My wife has an XS ladies bike. She is 5'1", so in reality this is too small for her. I think the seat post was 30cm.

You can see where it was inserted, far below the minimum...

Snapped when my son was riding it. No injury, fortunately.

It was some sort of suspension seatpost I think. Have now replaced with a new 40cm non-suspension seat post.

[NATURAL ANKLING]

Hi,
Make him pay

[thelawnet]

Hi,
Make him pay

As far as I can establish the post has been like that for a while and was at my wife's height. So I'm blaming her. I'm pretty sure he didn't adjust the height.

[Nigel]

It was some sort of suspension seatpost I think. Have now replaced with a new 40cm non-suspension seat post.

Assuming the suspension was working, then it was there to reduce the impact on the backside from road bumps/irregularities/potholes/rough surface. If the rider was sitting fairly upright on the bike, the impacts can be much more than those who adopt a more racing position. I hope your wife doesn't mind being whacked from the road with the new rigid post.


- Nigel

[Brucey]

the bottom of such suspension seat posts is usually internally threaded to accept a preload adjuster. If it isn't set far enough into the frame, the bending loads are seen by the screw threads, as well as the vertical loads. The screw threads make a very good stress concentration feature, so it isn't surprising to see the bottom cracked off like that.

cheers