Sorry, this is probably a really simple matter but I thought I'd ask. Today a friend and I were trying to fit a Shimano SLX Cassette 10 Speed HG62 onto an Ultegra 10speed hub and it just wouldn't fit. I lined the spines up correctly it just seemed too narrow. I'm I wrong to think those should go together or should I have just pushed harder or what? I had an MTB wheel laying around so I pulled the SRAM cassette off and the SLX cassette just slipped right on...