I have financed the purchases of three bicycles. The first two were mountain bikes financed as a package - 0 percent for 6 months. The second, my road bicycle, was done at 0 percent for 18 months. In both cases, I had the cash on hand to pay for them, but opted to take the free money - 0 percent financing is free money.
If you do this, be sure to figure out how much you owe each month to pay off the bicycle in the alloted time. The minimum required payment won't get you anywhere near paying off the bicycle. And the interest acrues from the minute yoiu purchase. Within 6 months, it will be close to a quarter of the cost of the bicycle and will keep growing.