Saddle slide back

[Maherees]

Hi all,
I have a carbon deda seatpost and SMP well saddle which I've found the most comfortable position is a very slight nose up then I just sit in and this has mainly solved the pressure on my arms. However, it be will either slowly or suddenly slide back; no matter how much I dare tighten it.
Before I set to look at alternatives I'd appreciate any advice from the hive.
Thanks

 

[T.M.H.N.E.T]

Fibre grip or similar on the rails, maybe even thin stakeboard grip tape

 

[Maherees]

Thanks, I'll try that.