My rear wheel (road) shimano wh r600, is getting a bit grotchy. was gonna clean it out and thrown in some new balls.

i *think* they are 5/32.

firstly, can anyone confirm that?

secondly, where does one get such things? any decent brands or does it not matter?

(I used to couldn’t dance) tight pants

I think you think correctly:

According to this website anyway

many thanks. so do we reckon all balls are just balls?

ebay balls ok?

Ball come in different grade. Shimano normally use grade 25 stainless. Go for those. Ebay balls could be grade 100 or 1000. I know the weldite balls are grade 1000 which have no place in a precision bearing. The lower the grade the rounder the ball is and the smoother it is. Hardness also changes a little I think.

Avoid anything another than grade 25 or ceramic.
Some good lbs will stock them but less now a lot of wheels are sealed bearing

SJS have decent grades

or superstar ceramic

I stock them, I only keep grade 25 or better in all sizes. I can’t be the only shop that does.
Ceramic balss are unneccisary and are very hard. I do not know how hard they are compared to the hub shell but I would suspect the balls are harder which may accelerate wear of the hub shell and cones. Although I have no experience of fitting cermanic balls in shimano or campag hubs and running them for a few years to know what the outcome would be.

Simply bearings.