rear zr bib tyre deflating help

[rossyboy99]

what is this saw it posted on freekels bem but cant actually see what it is any help please?

also my tyre is always going down takes about 3 days i have checked rim and although its ever so slightly corroded inside the rim its not arouns the edges what else could i check? or is it a new alloy jobby?

[Adam]

My tyres always used to deflate, had the alloys refurbished and they been fine since.