sn said..landyacht said..A couple of our yachts on lefroy have a small 120mm x190mm x20mm wooden axle.very effective and comfy

might be a zero missing somewhere

Oh deer I did miss a zero.1200x190x20mm
something springy like ash if your in the UK.
simple test before you buy. sit it on 2 blocks and see if it bounces.
if it cracks its no good and you didnt buy it