Hi,
There's some great information in the above posts.
Myself, I cycled the
Camino Frances in 2015, departing from my home in Holland and cycling back. Two years previously I couldn't cycle 20 km. I cycled because an operation on my right knee meant that walking was out of the question. I carried all my gear, including camping gear.
If I may be so bold as to summarise the important information....
1. Practise as much as possible beforehand in as real a situation as possible. Take loaded trips at weekends to hotels/B&Bs, or even try camping if you fancy it! This will help you get used to riding a loaded bike, will help you decided what clothing/gear is comfortable or not, will help you decide and use any gizmos you may want to bring & how to work them on the road!. Finally, it teaches the 2 of you how far you can go, how much you carry and how you react to each other and the world on a bike.
(If you don't have "touring bikes" don't worry. A cheap, simple MTB will be enough if you stick a couple of cheap racks on for bags.
2. Don't let anyone dictate your pace/distance other than yourselves.... unless you view this as a race. You're a team - your pace is your pace. If you find yourself running out of time, you can always catch a bus (even with a bike!) Also, there are many interesting people to meet along the Camino - sometimes on the path itself. A built in countdown clock does not facilitate this!
I found many mornings I did zero mileage simply because there were so many walkers. I stopped at the first place I could have coffee and waited, relaxed, watched until the way was clearer. My occasional cycling companions could not do this because they had to be someplace by a certain time.
3, Resist, at all costs!, the temptation to carry anything on your back! This is not comfortable!
4. Practise as much as possible before you go! Yes! Again! Together!
5. Listen to your body. Adjust your pace and plans accordingly.
6. Be aware that travelling by bike is typically faster than walking, so you lose the opportunity to develop a "Camino family" as walkers do. However, you have pretty much the freedom to stop and see anything you want because you're under far less time pressure (or you should be!)
And some of my own.....
Practise as much as you can before you go!
The last 100 km to Sarria becomes very busy, and therefore more difficult on a bike. I stopped and waited for late afternoon/early evening and cycled almost deserted paths.
Early mornings in the big cities are a great time to explore as the city wakes up. Great coffee and pastries from bakeries just opening for the day. Great views of buildings as the sun rises.... (it never rains in my recollections!
)
If you can, leave some time in your planning to head to the coast after Santiago, or to just absorb Santiago, itself.
Personally, I was disappointed in Santiago itself - I found it to be incredibly commercial - but the coast was wild and beautiful.
Don't be afraid! If a hill is too steep, if a bike breaks, if you have a fall, there is always someone around to help. There is an infrastructure developed for pilgrims of all types. It's there if you need it.
It rains. Bring some rain gear.
And.... Enjoy!
Frank