I am one of those people who at present don't take forward rolls!! Mainly because of a real mental block I am trying to get over, partly due to my size (fat bloke
)!! More often than not if the technique involves forward rolls and we do it in groups I will opt to sit out and watch so that I DON'T put people in that situation described above!! HOWEVER in my home dojo everyone then calls me up and says to have a go both as Nage and as Uke where they take me to the point.. Surely if your partner has a legitimate reason, be it physical or psycological, it is the in the spirit of Aikido to take them to the point just a micrometer past comfy and then bring them back? Seems fairly small minded to me to do otherwise!! I would be more than willing to be just uke for someone with bad wrists if the technique being demonstrated was say nikkajo/nikkyo!!