i would like to use my brooks flyer on a build i'm doing, but when i pick it up and heft it in my hand.. wow, it's so heavy. i used the flyer on an ebike and it was very nice, but weight wasn't an issue with that bike.
the risten spring weighs in at 337grams plus the weight of whatever saddle you use. i think the brooks flyer was around 860. so 6 of one, half a dozen of the other....