I have a small gap between the twisty plastic pre-loader and my BB shell, I’m sure it’s supposed be tight against it? There is no play or anything, seems to be working fine, just bugging me…
Can’t see your pic but sounds like what I had using a hope bb with a raceface crank. Couple of spacers from wheelsmith did the job. Available in 24mm and 30mm in 0.5mm or 1mm thicknesses.
Ok i have tried taking off the crankset and reinstalling, but its goes back together the same way. the gap i thought i had is actually filled with the RF dustcap, but this does not seem to make good contact with the bearing…
Again there is no play and everything works fine, chainline etc all good.
when the non-drive side crank is in my hand i can turn the pre-loader fine, but once ive installed and torqued up it goes nowhere. the videos and instructions ive seen all show the crankset being manually pulled through the bb a couple of mm, i cant do this either.
the crankset was originally fitted on a PF BB92 – its now in a threaded 73mm bb shell with hope external cups, the drive-side cup has a 2.5mm spacer behind it.
The preload nut has a beveled step in it, it is physically impossible to get the gap illustrated in your second picture to 0. There seems to be no gap between the inner bearing race and the inner part of the preload nut, and that is what is important.
What worries me is
but once ive installed and torqued up it goes nowhere
This would suggest you are either fitting the crank with the preload adjuster already wound in, or there is an extraneous spacer/washer somewhere – in your first picture I think there is a plastic washer between the BB and the preloader. There is such thing as too much preload, just as there is too little.