Hi Tupac,
Take the TPL bus that goes towards Grancia ( I don't remember but I think its the bus number 5 to fornaci - do confirm before you get on it) - do not take the post bus to grancia.
The bus drops you on the motorway about 500 meters before grancia (which by the way is the home to all the factory outlets with shops on big discounts - and offcourse ikea

!!). You'll notice a sports mall on the left midway between the TPL bus stop and Grancia (when you're walking towards grancia).
I remember seeing a whole set of dumbells (2-3 pairs of weights + rod + box) for around 49 CHF.
Good luck !
A