It also depends on the wheels/freehub - mavic for example have (and have had for some time) an extra 1.8mm spacer for 10speed - which you can remove for 11speed
http://glorycycles.blogspot.co.uk/2012/10/converting-to-shimano-11-some.html
@danb started
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It also depends on the wheels/freehub - mavic for example have (and have had for some time) an extra 1.8mm spacer for 10speed - which you can remove for 11speed
http://glorycycles.blogspot.co.uk/2012/10/converting-to-shimano-11-some.html