I'm afraid I can't find a "1530 Via" on the US TomTom website or on mvls model comparison chart on this sirte, so I can't decide if it is a 4.3" or 5" screen model, but I'm sure there must be something to suit in the RAM Mount range.
I don't have links for them in the US, but this is the sort of thing I was thinking of on a UK site:
RAM AQUA WATERPROOF BOX TomTom Via LIVE 125 Europe with Motorcycle, Motorbike, Bike, Bicycle Handlebar Mount RAM-B-149-AQ6U (SKU 9698)
Hi. I use an Aquabox mount from Buybits.com. It comes complete and will fit most Sat Navs. It's water proof, pretty rugged and perfect for a motorcycle. I couldn't bring myself to cough up near ?500 for a bike dedicated nav that was missing many of the features the car ones have so I have my 125 via live on my bike inside one of these Aqauboxes and it works a treat.