I cycle loch lomond once a week . usually sunday morning
both sides at the moment are very busy and looking like a shit hole to be honest,
balloch would be a no go,
best to get futher away , there is a motor home stop over at tarbet across from hotel, in betwen tarbet and arrochar is another one at the slanj. two places in the car park at the far end of helensburgh beside the park , all of these are better options than balloch . tyndrum has a pop up site if you go further on . my best advice would be the slanj , get up early and get passed the road to crainlarich , or take the alternative route past inveraray. its a better drive ,