Depends on how many, TBH. This time of year, the leaves will soon be falling anyway, so by removing them now you at least have control over where they go.

More importantly, the black spot spores go with them and not on the ground to re infect next year's crop.

I think I'd spray with a good fungicide like Rose clear now, but pick up all the fallen leaves and do not put in your own compost bins. When you prune again dispose of these stems in the council bins.

After you have pruned the affected roses thoroughly clean your tools to reduce spreading it to other healthy roses.

https://www.rhs.org.uk/disease/rose-black-spot

As said, spray now with Roseclear. Next year, spray before bud burst and then several times during the year. Don't forget to spray any woodwork supporting the rose as it will harbour blackspot spores also.

Thankyou Jimmy, Seaburngirl and Grandad all your advice taken on board and will be reporting back to you all, many thanks. Ian.