Got a 7 spd cassette today, I put a 4.5mm spacer on the hub, took the bolts out of the cassette and fitted it on to the hub (all the spacers went on correctly) and tightened it up, unfortunately the cassette was a little bit loose (is this normal when the bolts are taken out?)

Any how after a lot of head scratching I decided to install the spacer between the small cog of the cassette and the lockring and this tightened up nicely.

As anyone else done this and is it safe?

Thanks