Well I had some time in the last month to machine up some more spindles to try and refine the modification process a bit. The adapter plate still needs a bit of work, but it makes the mod a lot neater looking than just adding chunks of metal here and there and filling in the rest with weld as I did on the first/prototype set, which I'm still running
The back side of the spindle is machine flat and a bit of material is removed so as to align the caliper midway on the disc when the mounting plate is installed. The front 2 backing plate mounts are machine off to make room for the 250R caliper and mount. The upper ball joint mount will be reinforced once the plate is mounted.
The inner bearing hub of the 250R hub has to be enlarged to accept the pilot's stock inner bearing. 2mm larger diameter if memory serves me correct. Need to try and get a seal for there as I've been running only a sealed bearing there, no trouble so far, but might as well get a seal in there as there was one there before :wink: A new bearing spacer for inside the hub has to be machined as well as the 250R spacer will not fit over the larger bearing surface of the inner bearing on the Pilot spindle.
If you have access to a lathe, mill and a bandsaw, it's not too bad of a mod to do yourself. I will post a trace pattern of the adapter plater and dimensions of what/where the spindle was machined when I have it refined a bit more.
Parts need: 250R calipers, hubs with discs, pilot spindles, 4/144 bolt pattern rims
Parts to mod: hubs bore for larger pilot bearing, spindles to accept adapter plate.
Parts to fab: adapter plate, bearing spacer
Stock brake lines will work, that's what I still have on, even on plus 2 arms, but it puts quite a bend in them because the stock banjo bolt used has a built in bend that is not needed with the calipers.
Here's some photos:
disc brake mod photos