How to make it
- Elastic cord/ shock cord: size/diameter 4-5 mm, length 100 cm.
1. Cut the cord in 2 x 50 cm long lengths.
2. Tie the knots,
place them like shown below and
tighten hard to preserve
the loop sizes:
it's important to hold as shown below when tightening,
otherwise the loop size will change)
- A, 3 cm (measured when
- B, 10 cm (make
it longer if the frame tubes are very thick)
C, 1 cm
Cut off the cord ends
and melt them with a lighter.
3. Fasten them to the pump .