Seat post is sliding down - tips?

[skeeo]

Recently I replaced my suspension seat post with a non-suspension.

The post was measured at the standard 27.2mm.

I purchased a new post and put it in but it won't secure and slides down even when fully secured.

I've read about how people use coke cans and the like to make the post slightly thicker, does anyone have any other options?

Alternatively, does anyone make 27.3 or 27.4 mm seat posts?

[toolonglegs]

You may need a different or beter quality clamp.Is it lose when installed or just when you sit on it?.I had an alloy post that always slipped and as it was on a race mtb it wasn't ideal!.I took it into a automotive machine shop and asked them to knurl it lightly.Cost about $10 and it never moved again even with a pile of grease.

[LuckyPierre]

Recently I replaced my suspension seat post with a non-suspension ... was measured at the standard 27.2mm ... but it won't secure and slides down even when fully secured ...

How is your post actually secured? Does it have a quick release fitting or a seat post collar with a bolt?
If you've got the right size seat post, it really should fasten securely. If you have a quick release fitting, try tightening the nut a bit before securing it with the lever. They say that the fitting should be tight enough for the lever to leave an impression in your hand as you push it closed.
If it's a seat post bolt, make sure that the 'bolt' part is short enough that it isn't screwing into the 'nut' part as far as it can before it gets tight (if that makes sense).

[skeeo]

If you've got the right size seat post, it really should fasten securely. If you have a quick release fitting, try tightening the nut a bit before securing it with the lever.

thanks, worked wonders, i'm a cycling noob as you can see !

[MountGower]

Skeeo

This is not a piss take, but your wheels are held on by exactly the same type of thing. Perhaps worth checking.