I have looked everywhere, SRAM list them but in the UK its 140mm only. I wonder is it the case that the are built 150mm but with a travel reduction spacer?

I had 130mm versions come on my Boardman, and I had them extended to 150mm. Most of them have long enough stanchions and have the sag markings on hen for 130/140/150 as standard. You need a new air shaft to extend them.

I got it done at a Sram authorised dealer – he airshaft was £27 and I paid all in £60 for the part, fitting and a lower leg service. The forks were only 6 months old at the time but hey came back to me so much smoother / plusher as well as having longer travel. Well worth the £60.

Ok cheers. I am no rush so will keep looking for the 150mm but changing is an option.