every september, me and my pal's have a week offroad tour in scotland.
we ride all week in the same clothes (pongy) and carry 1 set of clothes for the evenings (shorts,t/shirt/light shoes).
so in my rucksack for the week i have, 1 3ltr bladder, 1 waterproof, 2 tubes, multitool, shorts, t/shirt and sandals, maps, phone and charger and food for the following day.

thing is it still seems very bulky.
any idea's to lighten the load.

One set of tools between you.

One working phone and a back up, or non if you want to make it more of an adventure.

Small packet of soap powder to wash kit.

Where are you staying each night?

Whiskey.

Agreed about sharing phones and tools. Otherwise, the big weight saving would be had by cutting down the clothes. If you just rode in the light-weight gear you're spending the evening in you'd cut weight and bulk, but you'd be even mankier and it'd make the evenings uncomfortable.

MTFU 8)

I use a 2.7ltr Ortlieb saddle bag to carry my clothes on multi-day road rides. Its waterproof, sturdy and quite light. If you're just looking to de-bulk the rucsac then this would be a neat solution, doesn't save any weight obviously.

You could risk carrying less water. I've done a few multi-day trips with one 750ml water bottle. I just fill up from big streams/rivers or rely on passing shops. It sounds a bit risky/stupid but I've not yet made myself ill, or ever ended up badly dehydrated. I've spoken to plenty other folk who are happy to rely on streams and rivers for top ups, assuming they're out in the wilds a little and use some common sense.

i was thinking of using 2 bottles on the bike rather than the bladder.
that would take the main bulk out of the bag.

i would also just take one bottle and refill where i could, you could always get a water filter or steripen.

although i'd still take a bladder to fill in the evening.