Its been a while since I fitted a couple of tapered rollers to my bike.I think from the factory the 3C had a tapered bearing in the bottom and a roller in the top,is this right.My bike has the bearing set into the frame cups without any spacer tube between them,like wheel bearings have.A spacer tube would be helpful I can see,but mandatory or overkill or just added weight.Getting it the right length would be not so easy.Be interested in some comments on this.It did take multipal adjustments to get mine set when I did it 15 years ago and maybe 2 or 3 nips since then to take up knock.