I would like to try something like this.

Anybody got a link to a suitable strap or a recommended place to get one?

Just get a toe strap. Works really well!

Xcracer sell one like that.

Take the seat post out, cut a 3″ section out of the biggest inner tube you can lay your hands on. Slide it through the seatpost, squeeze the tube and CO2 through it.

In a mo I am going to try that “thisisnotaspoon”
Anymore DIY brainwaves?

There(sic) awesome.And come in about 4 days.
http://www.backcountryresearch.com/What-is-the-Awesome-Strap_ep_42.html

The XC racer one is very good. Used it for XC racing and holding batteries on long old audax’s

I’ve recently bought a barfly hopper strappy thing. Saw it on Fresh Goods Friday a few weeks ago. Works really well.

What ‘everyone’ said. The toestrap was the preferred device for doing that for many decades.

http://www.adjustable-straps.com/#solo
Scroll down for single sided in black.
Scroll up for conventional in colours

On another note, whats the Ergon saddle like ?

Sorry Lump – it’s am internet pic.
I have used two straps – velcro sellotape jobbies- but will upgrade to the better XC racer one.

How about something from Beerbabe?
http://www.beerbabe.co.uk/ourshop/prod_2911160-Saddle-Pack.html
or
http://www.beerbabe.co.uk/ourshop/prod_3559082-Noble-Seat-Pack.html

Under seat bags = not acceptable
Tools & tube strapped / tied / shoved under the seat = acceptable.

I know, sounds crazy. Oddly I have lost 2 saddle bags due to failure in the woods. I am hopping a strap will be more secure.

Not necessarily used for this , but I use it to keep pump strapped to camelbak, the elasticated, Velcro straps that are used to hold skis together.