Arrived with clumsy fools about the start of June to see BMX track obstacles (5,5)

'june to see bmx track obstacles' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.

'arrived with clumsy fools about the start' is the wordplay.
'arrived' becomes 'came' (come can mean to appear or arrive).
'with clumsy fools' becomes 'ls' (I can't justify this - if you can you should give a lot more credence to this answer).
'about' is an insertion indicator.
'the start' becomes 'jump' ('jump' can be a synonym of 'start').
'ls' placed around 'jump' is 'ljumps'.
'came'+'ljumps'='CAMEL JUMPS'

'of' acts as a link.

Can you help me to learn more?