STEP 2
Insert front bottom tube into adjust tube (4)
STEP 3
Take out down tube (2)-2 ,screw off the knob on the down tube (2)-2.
STEP 4.
Attach down tube (2)-2 into adjust tube( 4), locked .
STEP 5.
Front bottom tube (3) & adjust tube (4) locked knob.
STEP 6.
Attach finished Step 5 into main frame (1) .
STEP 7.
Lock them using PIN 65mm (7) & M10 bolts +nut (8).