I am still trying to imagine how balsa-filled rims were made. Is there a natural process (such as freezing or drying) that can make balsa shrink by an appreciable amount so that you can 'stuff' it into the rim before the rim is bent together and pinned?
Or do you think they had a straight version of the rim and used little poker-things to push the balsa into the rim, and then with a heavy press did they squeeze the tire bed and inner side together to 'anchor' the balsa blocks?
I can even imagine them sewing together a string of 36 balsa blocks and dragging it through the rim all at once, under tension, before compressing the rim to anchor the blocks, and then drilling the rim for spoke holes. That would probably be the most cost-effective way to insert the blocks into the rim.
Does anyone have an idea of how this was really done? Has anyone ever seen one of the blocks when removed from a destroyed rim?
- Don Gillies
San Diego, CA, USA