Originally Posted by
KCT1986
On an 11T smallest cog cassette, the 'overhang' is little bit different. Since the 11T cog doesn't have grooves that extend fully through the cog, the 'overhang' that is needed is really a gap between the cutout of the cog and the end of the splines on the freehub body.
If the gap is too small, the lockring will cause the spline to bottom-out in the cog before it can reach and push/hold the rest of the cassette in place.
The OP didn't mention the freehub model but it must have longer splines than normal Shimano MTB freehubs.
I am not sure of the freehub manufacturer (probably lower to mid range hubs to begin with) but ultimately it turned out to be a road freehub (36.75mm). what caused my confusion is the cassette that the wheels came with (this was a new bike build and complete bike not just wheels) was a mountain bike 11 speed cassette with the same 11-42 range and it fit tight with no spacer. A while back I asked if all 11-42 mtb cassettes where the same and was told they should be so you know that old saying about assuming
. everything is all good now thanks for the help much appreciated.