Marcus Helman asked this question, referring to Bobet and Kubler's habit of wrapping spare "tubs" over their shoulders.
Racing jerseys in the 50s used to have five pockets - three at the back, and two on the chest. But a rider would need all these pockets to carry all the various food, tubs, spanners, cotton caps, large racing googles that they needed to carry with them, bearing in mind that there were not the same number of team cars driving closely behind, or any Mavic service cars or motorbikes.
I still have my team jersey from 1953 and can remember that the centre pocket at the back was stitched up to a width to carry a spare "tub". Remember that the road surfaces in the 50s, particulary the mountain roads, were often little better than dust tracks - hence many more punctures... and the need for more spare tubs. Tubs were also carried slung under the saddle, often wrapped up and held in place with a toe-strap.
I rode this type of jersey and slung spare tubs around my shoulders for the best part of 13 years. We had a special way of looping the tubs in a figure of eight so that they would "sit" more comfortbaly on our backs... but I bet I couldn't remember it today. Even so, we never seemed to have enough pocket space.. perhaps the "bonk bars" we used to eat were much larger than the sachets used these days.
Norris Lockley ... sandbags at the ready if it's still raining in the morning... Settle