How much you spent in each country and how long you were there for?
It depended on where I was travelling. I lived very much on a shoe string. In European countries it could be 5 euros per day, but in India 5 Euros would be a very expensive day and I spent more like 2/3 Euros. Of course there were times when I was in a touristy area or decided to stay in a hostel or hotel for a night after a couple of weeks of camping. In Europe over 7.5 months I spent £3,500 pounds. I earnt about some money working in Tbilisi and by the time I had finished travelling in India / Nepal on the next leg of the journey that had also finished, so I returned to Georgia, again worked. Earnt some more cash and then the trip in Mongolia probably cost about £1,500 for 5 weeks all inclusive of travel and a few extra pieces of equipment.
Any tips on quantities and ratios? Typical meals, examples, etc.
It was possible to live on quite little food. However, cycling is hungry work so on average consumption probably went up. I ate bread, tomatoes, and cheese often and then cooked lentils on a stove in the evening and ate that with bread. During the day I had some snacks of dried fruit, nuts or chocolate biscuits. Perishable foods would be eaten more quickly. Sometimes I woudl be given food by people along the way, so I would sometimes be carrying a bag of walnuts, plums or some barbecued vegetables left over from an evening meal when I had been invited in. There were never 'daily rations' and I wish sometimes I had spent more time enjoying the local foods. However, I did experience this in people's homes and restaurants were often over-priced and not as good quality. In India, I regularly ate at roadside restaurants, because they were cheap and endlessly variable- I would eat vegetable curry with roti usually.
Riding a bike I had never ridden
The problem with going on a bike I had never ridden was that it didn't fit properly, I realised this after a month of cycling when I couldn't get used to the bike. The frame was too small which was fine for mountain biking but for long days in the saddle it was more comfortable to have a bigger frame. Because the frame was too small I spent a lot of time trying tweak things about the set up to make it more comfortable which also wasted a lot of time. For touring it is generally a good rule of thumb, if you usually fit two different frame sizes, to go for the upper size. Touring bike frames are usually quite big in comparision to usualy road bikes and particularly modern mountain bikes.
Maria travelled about 2000km from Hungary to Istanbul which was amazing on her bike. It was a 1950s recreational bike but everything worked fine after some maintenance. The brakes werent' as good, the tyres weren't as grippy, the saddle wasn't as comfortable and the fit wasn't perfect but then it 'worked', and didn't cause any lasting damage!
What to do if you lose your papers, bank cards, etc?
Always have copies of your papers. Email scanns to yourself or keep copies in a program like Evernote online. Keep photocopies with you and don't keep the photocopies in the same place as the originals so if one gets nicked / destroyed then the other will still be available.
Kit problems - where to get replacements. If by mail, where to get it delivered?
You can mail kit to people en route- you can contact people through Couchsurfing. Or you can use Post Restantes, or sometimes Embassies or NGO contacts. Postal services in different places vary in reliability and sometimes you have to go and poke around to find out where you parcel actually is. For example in Istanabul I had wheels sent there and after asking in the post office repeatedbly the whereabouts of the wheels (and them not knowing) after asking inside the actually storage depot they had been sitting there for two weeks!
What to do if you get ill?
If you get seriously ill, there are always people around to help you- usually everyone is trustworthy. In Europe you can carry a European health insurance card which gives free cover in European hospitials. It is recommended to take out an 'adventure' graded insurance policy. Companies that provide this which cover cycle touring include 'BMC' and World Nomads. Check in the policy what is covered. Take rest if you can with Couchsurfers or people along the way. Generally when you are cycle touring your immune system is improved so you recover more quickly from illnesses.
How much money should you carry on you at any one time?
Carry money in differently places on the bike, on your person and in another bag- to split them out. I was carrying quite a lot of money at times - e.g. $3000 which I earnt in Tbilisi! But I had bank cards. Different banks offer different services regarding charging for taking out money. As of this moment, I think the only one to provide this service is 'Metro' bank based in London. I took a backup debit card and credit card.
Staying connected. How to arrange updates from the British Embassy by email / how to stay connected with your embassy in general?
Don't worry about staying connected with the Embassy. You can always check fco.gov.uk for updates but they are generally very overly-conservative. The Embassy should help you out in a real emergency otherwise don't bother.
Is it better to ride alone or in a group? (Coping with boredom)
There are benefits to be had from each. Riding alone is more about observing the world more keenly, coping with fears, and learning to think in a more creative way to make your own experience. Riding in a group is more about coping with relationships and learning to be humble and not let your ego get in the way of the collective experience.