Originally Posted by
Rowan
Too much "science" here.
I would opt for the 24T ring. Unless you are small and lacking strength, a 24T front ring with a 32 or 34 or even now a 36 rear large cog will serve you quite well with the existing crankset you have.
The 24-34 granny set-up was what I had when touring Hokkaido (and Britain and Europe and North America) with a load that travelled around the world with us. If you take the advice in the other thread, and travel as light as possible, you will have solved one of the gearing issues -- the lighter the weight, the less need for a really low gear.
Remember also, that as you practise for the trip (and you will be practising, won't you?) and on the ride itself, you will build your strength anyway. That's what happens over 3,600km...
My first location in Japan will be Yakushima. I have been there before and it is amazing, but to get to the start of the interior mountain hike it was a 40min bus ride up up up, 40minutes of constant climbing (about 40km) of a pretty steep grade, so I might jump on the side of caution. by going as light as possible. I would rather a 22t than a 24t just to be reassured I found this
Shimano Deore FCM530 Triple Chainring | Chain Reaction Cycles, so is going from a 36t middle chainring to a 22t inner safe/ok or is that why you advised the 24t chain ring?
I'm definitely going to swap to a 11-34
Shimano Alivio HG400 9 Speed MTB Cassette | Chain Reaction Cycles since it cost next to nothing
Training for the trip is all well and good to say, but where I am, we don't have any hills to ride, so all I can really do is get time in the saddle.