pics basically it’s an old style seatpost that came with my duster.i did dismantle it to clean (and put it back together how it was).the saddle kept coming loose when i was riding today (even after i tightened it up murder tight as my friend might say 😉 in the end i managed to get it to stay put,but the saddle was pointing up.any ideas as to how to keep it in the position i want it at (sorry to be a numpty 😳 thanks in advance 🙂 p.s i have ordered some lovely ritchy components for my bike (which includes a new seatpost) just couldn’t resist their wet black aluminium stems/flat bar and seatpost 😀

Once that type has slipped a few times, the ridges can get worn/rounded so that it’ll then keep slipping. Suggest replacing it..

Easily fixed with a credit card.

(as Clubber said really).