Nimble operators of firms that rent recreational equipment around Lake Tahoe are doing just fine despite a nearly snow-free winter, operating as if summer never came to an end.Instead of renting winter gear such as skis, snowboards, snowshoes or snowmobiles, Lake Tahoe rental businesses say they are still renting summer equipment kayaks, mountain bikes and powerboats as residents and visitors take advantage of the unseasonably warm weather.Harry King, owner of Tahoe Eco Sports, says kayak tours and kayak rentals comprise about 90 percent of his business this winter, a radical shift from last year, when they accounted for just 10 …