Two-wheeler for two wheelers (6)

I believe the answer is:

tandem

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'two-wheeler for two' is the definition.
(I've seen this before)

I don't understand how the rest of the clue works.

(Other definitions for tandem that I've seen before include "Bike for two cyclists" , "Two-wheeler for two" , "Bicycle for two (plus)" , "Two-seater bike" , "Bicycle-built-for-two" .)

I've seen this clue in The Irish News.

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