As mentioned elsewhere on the forum, I had cause to load up my bike with more luggage than usual this morning, all in I ended up with a 46kg bike.
What I found interesting was that my overall average speed was only 1mph down on that which I would expect unladen, and (on a touring bike with *very* low gears avaiable) I didn't find the hill from Edinburgh Park through Wester Hailes and up to Lanark Road felt particularly harder than the usual lightly laden bike.
Now obviously when racing, or attempting to cover a large distance in a limited time for other reasons, that is a significant difference, (iirc 2 minutes over six miles) but for "normal" cycling for transport I wonder if we cycle snobs ( I must confess swmbo has informed me I am one!) pay too much attention to weight over other factors in cycle choice....? Maybe "tanks" are ok even in hilly Edinburgh?
(subject to a good range of gears and a relaxed attitude to the speed showing on the computer)