Tri-Bike Aruba offers a number of bicycling options. They sell and rent bicycles. I’m also told that they will deliver them to your hotel, but I’ve never actually done that. I did purchase a mountain bike from them. The fellow who runs the shop knows his stuff. Here’s a look at their store in Santa Cruz.
Inside you’ll find a decent selection of road and mountain bikes as well as all kinds of accessories. They also do repairs if you meet with disaster. Fortunately, I haven’t had that happen just yet.
There are a number of bicycling groups on the island. I see them riding past my house, especially at the weekend. Please share the road with those of us who like to pedal our way from one end to the other. Masha danki!