Oh yes, I already know I'll be travelling super light. Just a handlebar bag with the bare essentials. I will be eating out and sleeping in bnb's so for 3 days all I think I'm going to need to pack is:
- 2 pairs of socks
- 2 pairs of bike shorts
- 2/3 tshirts
- waterproof/windproof jacket
- puncture repair kit with a couple of spare inner tubes
- I don't know.....plasters? :/
Actually, what would you add to the list?
Personally I think you'll need a rack with either a large bag or panniers. For 3-4 days I have a rack mounted bag with side pockets which roll out to form small "panniers."
You're riding in Scotland and as you've said you can have four seasons in a day. My last tour in Scotland was from Lancashire >Outer Hebrides >Ullapool >Inverness. I had beautiful weather for the entire tour except the last day when I rode 70 miles from Ullapool to Inverness in to the teeth of an easterly wind and pouring rain. I had a full set of waterproofs, extra layers and was still miserably wet and cold in July. I suggest for a Scottish tour you need to be prepared for most weather conditions.
Be sure to pack everything in plastic bags inside your bag, panniers or whatever.
Depending on where you're riding you may need to consider carrying extra food and water. I've been on several tours and had days when I found virtually nowhere to get essentials. The day described above was one of them apart from one very rural pub which offered the world's best soup - that's how it felt at the time!
My kit list for Scotland would be:
2 x cycle shirts
1 x , perhaps 2 x, pair of bib shorts.
One pair of walking trousers with zip off legs for evening
Waterproof jacket
Waterproof trousers
2 x socks
1 x T shirt
1 x micro fleece
1 x underwear
Plasters
Pain killers
Multitool
2 x tubes
Puncture kit
Zip ties
Tyre boot
Pocket knife
Whistle to attract attention when in ditch
Sudocreme
Toothbrush
Toothpaste
Spare nuts and bolts for rack
Pump
Tyre levers
2 x Waterbottle
Energy bars
Energy tablets
Food
Power pack
Phone
Maps
Survival blanket
Phone charger
GPS charger
There is probably other stuff which I've forgotten as I haven't toured for three years. Much will depend on how rural you are. If you're riding round the Borders you could ditch some of this. The places I go I need to be prepared for seeing nothing all day.