Can I treat my shimano goretex mw80 boot with nubuk leather wax?

Hi,

Short answer is no... If you use a wax on the fabric of any goretex product you will effectively kill the breathability.

Is the boot leaking? If so then there is a tear in the gore lining which is not fixable. It would cost more than a new pair of boots..

If it's to make the outer fabric repel water better then the best I know of is from the NikWax range. They do a lot of spray on repellants that are designed for gore products.
I take it these boots are soft and flexible for the bike, yeah? In that case you probably want to look at the repellants designed for clothing rather than those for footware...

Either way, here's NikWax's site for info, not all shops will stock the whole range but if they are good they can advise you.. If you're not sure then walk away because using the wrong product on these boots could adversly affect their performance and ruin the look of them.. Sometimes store staff will try to get you to buy what they have in stock rather than getting you what you need..

www.nikwax.com

Hope this helps..