125-200cc 2012 WR 125/144/165 Chain Tension

Had to change to a longer chain for a 52T sprocket. What is the correct tension, and point of reference to measure?

Thank in advance

A bit of a rule of thump here and not real scientific

when the upper side of the chain/sprocket circle is straight (no up and down free play)

the under the swing arm part has a up and down free play of about 1-1.2 inch

its a thing I check before every ride

to tight and it could break when landing hard and the suspension is used to the max
to loose and the rear tire could hook in the chain and play havoc there (strong chain would sheer off nobies though)

Robert-Jan

Manual says to lay a 35mm socket on the top of the swingarm near the front on the plastic chafe strip up against the raised portion.
Then check the bottom run of chain for a feeling of 'slightly taunt'. It does not say to raise the wheel.

Thanks for the replies. I ended up using the 3 finger method.