Hi ya, it's rare I pop on this area, Rob's just told me about this thread.
The clear tubes we don't use any more, some got broken and we just use the alloy one's now.
I originally made them to save money on paying out for the alloy one's.
They're off ebay as '50mm acrylic tubes' in lengths of 1m each. I then joined each section together with 50mm black drain pipe as sleeves in about 8'' lengths and cut down the centre so you can wrap them around, couple of jubilee clips each end and a bit of tape over the tiny gap to prevent any suction loss.
They were light but could have been even better had I sourced tubing that was thinner walled as these we about 3-4mm if I remember and a bit of extra weight was gained from the silicone bend too which I don't recommend as the inside of that meeting a section of tube isn't flush and often became blocked.