The first thing is to avoid packing anything "just in case". Everything needs to earn its place in your bag by being used regularly. If you feel like you "might" need something, remember that you can probably buy it locally if you discover you really need it.
Regarding clothes, I usually advise packing no more than a week's worth, however long you are travelling for, and then doing laundry. As you are cycling, you might want to pack even less. Maybe just one or two outfits in addition to what you wear. Make sure you choose lightweight, quick-drying fabrics so that you can wash things overnight. Merino wool is great because it's odour resistant, so you can wear it more often without needing to wash it. All your clothes need to go together so you can mix and match.
Keep your electronics to a minimum. A smartphone and possibly e-reader should be enough.
Take small bottles of toiletries and replace locally if you run out.