I did a little debugging - the problem seems to be that
jr:choice-name(${Gear_ID}, '${Gear_ID}')
appears to return nothing when inside a repeat group, but does return the expected result when not inside a repeat group. I'm not sure whether this is by design, or a bug....
@ggalmazor, @martijnr, do you happen to know? Note, when inside a repeat the resulting XML looks like:
jr:choice-name( ../MeshSize_ID ,' ../MeshSize_ID ')
note the leading/trailing space on the second arg. Could this be throwing things off?