Seat constantly slipping.

[dibbers006]

The initial message was deleted from this topic on 15 December 2023 at 23:12

[TwistingMyMelon]

Is the post slipping down the frame, or the saddle off the post?

If you've done everything you've said sounds like one of the above is knackered or the wrong size

[ChrisMCoupe]

Are you sitting relatively closely over the bolts were the saddle is attached to the post, or are you putting a lot of leverage (either front or back) on the bolts? If you're not, then maybe you need to look at your saddle position and seat post lay back. Saddle really shouldn't need too much tightening.

[upsidedownmark]

Bad fit, or something is broken/cracked. Check for the latter, possibly shim for the former.

[outnumbered]

Maybe your saddle rails are too narrow for the clamp on your post.

You might also need a post with more setback ?

[The_Jackal]

Do you have a picture?
Sounds a very strange thing to happen. Something is clearly wrong.
As above the clamp is probably not contacting the rails properly.

[Kermit power]

It's certainly not your weight, or at least not your weight on its own.

I weigh 110kgs and have 4 bikes I use regularly. None of the saddles slide back on any of them. I suspect, as has been suggested above, that somehow the rails and clamp aren't connecting properly.