On 06/05/2020 08:34, AnthonyL wrote:
On Wed, 6 May 2020 03:26:32 +0100, Andy Burns
wrote:

AnthonyL wrote:

I hurriedly bought a pump some years back and have never been able to
use it.

Usually there's a locking lever, your photo doesn't appear to show one?

There isn't one, nor any apparent provision for one.

I have seen both sorts. The "nut" lets you adjust the compression on the
rubber to compensate for wear.