I am inclined to think that a short bike like the Australian pursuit team used in the above link is faster, but would certainly like to hear from anyone that has tested a long bike that knows the answer. We did a few coast down tests once but they were not that conclusive. Need to have another go at it sometime. I just had the stoker slide off the back of her seat so she could fit down behind me. The few runs we did were a bit slower than our normal position. Need more runs and less wind and traffic to get a better idea though.