One for the Lightweight or Mk IX experts

[PeterCrespin]

After spending a pretty penny getting a set of MkIX front brakes adapted to mimic long-nose D parts, I was dismayed to find not all five-stud discs are the same. The MkIX holes are on a slightly large pitch circle diameter and the central hole over the hub is 3.5" instead of 3.25". At first I thought the parts had been wrongly made because they didn't match every other Jag disc I've come across. Bear in mind the disc bolts are not the same as the lug nut stud and I assume Mk IX wheels do still fit other bolt-on Jag hubs.

Just in case I DO have a badly-made set of MkIX discs does anyone have a bare disc or a MkIX hub they could measure the centre hole please, please?

Thanks
Pete

[Harold Lang]

Have a couple of sets of Mk. IX calipers & discs, will get measurements off to you in the morning.

regards Harold Lang

[Harold Lang]

Hi Pete,

Disc hub bore diameter is 3.484", Sorry; no hub to measure.

Harold Lang

[PeterCrespin]

Thanks Harold. Same as mine (I rounded up a bit).

I've ordered a slice of 3.5" pipe with 1/4" wall thickness, so there won't be much machining needed to make up a couple of adapter rings to position the disc. Then I'll rotate it on the flange and drill five fresh fixing holes midway between the existing ones to preserve balance.