The only thing I don’t get about bikepacking (maybe I’m coming to it late and missed the explanation, or maybe I’m just missing something obvious), is this…

…why is it now better to carry your weight up high, under your seat, bars and top-tube, rather than down low, in panniers?

Ta.

It’s not, as far as balance is concerned. Having the luggage up high means you’re less likely to catch it on plants, rocks, etc when riding off road. Also, having soft bags rather than racks means they’re less likely to rattle around and break. Having said that, lots of people use panniers off road with no problems.

can think of several reasons (from small experience).

temptation to fill panniers
panniers can make steering a bit ponderous (if front) and feel light (if rear)
width & nimbleness – bike packing can go off-road, and if you head through stiles or through ruts (esp. with front low rider panniers) you know about it…

Yep – mostly covered above. Rack/panniers still have their place depending on terrain.

Soft bags also open up frame choice and might let you use a bike you already have rather than trying to find one with rack mounts.

The development of lighter/ more compact kit has really enabled the relocation of luggage. The CoG argument is therefore less important.

The major benefit is that you can use a set of soft bags on a full suss bike. They also inherently have a bit of wiggle in the mounting points, so the load can ‘give’ a bit over bumps. You’re also not carrying the weight of a rack.

If you want to head off the beaten path for a couple of days wilderness camping in a bivvi, or carry a change of clothes for a b&b trip, then bikepacking bags are great. If you want to carry a comfy tent for a bit of touring around the south of France, then panniers are probably your best bet.

my experience with bike packing v panniers is that the heavy stuff goes in your frame bag as near the bb as possible, the lighter and bulkier stuff goes under the saddle or bars.

i remember having a loaded bike with panniers and its fine for road stuff but you get the wobblies and handling is awful off road. a loaded rack also feels disconnected from the bike.

ive spend several days with my bike fully ‘bike packed’ and although the bike is naturally way heavier, the way the weight is distributed actually make the bike feel really good even in full off road settings. and as others have said, with the soft packs and compression straps, it makes the load as small aa possible.

i thought id hate my bike loaded up with modern bike bags but it think its night and day compared to racks and panniers.

I think the point is also to carry a minimal amount of ‘stuff’.

I bet some ultralight loadouts are the same weight all in as just the old school racks and panniers unloaded!