Can we transport our bycicles from chengdu by train to kunming? What trainnumbers?

yes, you can transport, but you need to check in it and do not take it with you. If you want to use this way, you need to pack you bycicle on your own, so that it will not be damge during the transporting.
There are six trains operating between the two places and they are K673, K113, K145, K1139, K853 and K165.

thanks for your answer,

we prefer K853.

how can we check that this train can transport our bicycles?

It is suggested to go to the local railway station to ask directly.
if you have any Chinese friend in China, it is suggested to ask him to accompany you.