If the bicycles belong to ONE FRIEND, it's "friend's bicycles." If the bicycles belong to TWO OR MORE FRIENDS, it's "friends' bicycles."
1.8 bicycles.
There is no specific collective noun for bicycles, in which case a noun suitable for the situation is used, for example a rack of bicycles, a row of bicycles, a standof bicycles, etc.
what did the ancient bicycles look like?
Bicycles weren't invented in Canada.
More bicycles
The first bicycles were powered by humans.
KHS Bicycles was created in 1974.
Bianchi Bicycles was created in 1885.
Canyon Bicycles was created in 1985.
The population of Canyon Bicycles is 161.
Ridley - bicycles - was created in 1997.