Disc brake adapter too close to rotor I've just bought a new (Planet X) Holdsworth Stelvio (http://www.planetx.co.uk/i/q/CBHOLSTELTIAG/holdsworth-stelvio-shimano-tiagra-4700-touring-adventure-bike) and am having a problem with the front disc brake rotor being too close to the brake mount/adapter.

The lower bolt &amp; washers holding the caliper to the adapter are less than 1mm away from the rotor and the caliper is adjusted fully outwards (away from the rotor) at this point. On spinning the wheel there is no contact, but whilst riding and putting any pressure through the frame there is nearly always contact between the rotor and the washer/adapter.




Note: next two images with bike upside down




The brakes are Avid BB5s as come standard on the Tiagra build of the Stelvio.

So far I've tried:
- tightening the bolts holding the adapter to the fork,
- adjusting the caliper position (though there is little movement since the rotor is too close),
- wheel is correctly seated in the fork,
- checking the truing of the rotor - it is true (brand new rotor).

I can only think that there might be an issue with the hub, somehow placing the rotor too far out on the left hand side? So far, the manufacturer have been helpful, but have only suggested things I have already tried.

Any ideas?
It's not the hub's fault unless somehow its axle hardware is put together wrong or it's otherwise not putting the rotor in the right spot, but that would be a weird problem, whereas forks and frames with the issue you're having are an unfortunately common one. Step one could be downloading the IS disc mount standard and confirming it's the fork's fault.

It appears the fork tabs are unfaced. It's possible that simple facing, or even just sanding off the powder/paint, could buy you the space to make it work.

If not, the main option to make this physical combination of parts work, presuming there's adequate material for it, is file off some material from the tabs and then finish by facing it again (don't try to do it all with a facer). Either that, messing around with filing the washers (might actually be a better approach if they're what's seeming to invariably hit first), or a different brake that might have marginally better clearance, or get them to send a less borderline defective fork.