whoof wrote:I tour in Europe and if I needed anything else I would go to a shop.
People say that, but IME it isn't that straightforward.
Even in Western European countries with lots of cyclists, you can often be at least a couple of days cycling from a decent bike shop - for example there are only two proper bike shops on Corsica, so if you have a problem somewhere between them then you need to limp to one or the other. And in many places they shut Sundays, and maybe Mondays as well. Shops are usually pretty good about helping out touring cyclists, but there's a limit to how much you can expect to jump the queue if they have a lot of regular customers waiting. Outside of the main towns bike shops often are one-person businesses operating on a shoestring, and have very limited stocks - so even if you just want a proper chain lube then you may be struggling. It may actually be quicker to get something shipped to you by Chain Reaction than wait for the shop to order it in from a local distributor.
These examples are very much from experience (although I should say that I have had plenty of positive experiences to put on the other side of the balance sheet). You can't take spares to counter every eventuality, but I tend to take the attitude that if a part is easy to replace, and light, then it's worth carrying. If you know you're likely to need something (eg chain lube) then it makes most sense to pack it rather than hope to be able to buy it on the road.