Over 50mm. but the drive splines are well past worn out and it is a wonder to me that it has not yet over-ridden them.
I know from relatively recent adventures fitting a new clutch and clutch carrier that the gearbox is fine - nearly all the slop is in the original R65 final drive and I don't care about that as a R75 unit is going on very soon.
And yes, before anyone asks, I am fitting a new drive cup to whichever rear wheel I end up using - either the original R65 wheel or the LS wheel that the workshop in town still hope to salvage (they are on a "no fix no fee" arrangement as their first attempt to roll the LS wheel straight failed). The second attempt involves heating the rim to almost melt point to de-stress it and then rolling it again. Given the way aluminium behaves at near melt point, I wish them luck, OTHO, if it works I will have a serviceable LS wheel to match the K100 front wheel.
