@Sev, this thread is of no use to me whatsoever, but enjoyed reading it, the level of your knowledge is very impressive
OK, so that being the case, back to basics. From your picture and everything you said, it should all fit and be working. As stupid as it sounds, have you made sure that the pads are pushed back in the caliper, or alternatively take the pads out, push the pistons back and see if it all goes together nicely, bolt holes line up and the wheel turns without clashing on anything. With stuff like this, it's always a good habit to get into to first dry fit everything and do a dry build before committing yourself fully, that way at least if stuff doesn't fit or has to come apart it can be done without too much hassle. Mechanical equivalent of measure thrice, cut once.
Thanks Andrew. Ohlins used to be very forthcoming with all that stuff, but now speaking to my go to Ohlins guys, even they struggle to get vintage bike data such as drawings and build sheets out of them. I saw it change with WP when KTM took over and decided that anything that was before their tenure got binned. I've had a pair of WP RCMA5000 forks serviced and it was literally a whole rebuild project for the guy as he had to take everything apart and measure everything given that WP no longer had any legacy data on anything pre KTM. Luckily for me he was ex Original WP Racing back in the day, so he knew the forks as he used to service them for the teams in the mid 90's and the turn of the 2000's. (a very bitter pill for them, given that it was KTM who all said and done put them out of business, and then to add insult to injury bought them out when they went under).
Excellent news. So, back to basics as I said in the post above. 1) On your calipers that don't fit, take out the pads and see if they fit. If YES: refit with pistons pushed fully back and see if they fit. 2) Fit pads of old calipers which fit to new calipers and see if the new calipers fit with old pads. 3) See if you can measure the offset from the inside face of the caliper mount to the centreline of the disc (or alternatively to the disc face and add 3mm). It should be 26.5mm, and should align with the split of the two halves of the caliper body. The disc positional tolerance is +/-0.7mm. 4) get a side by side photo of the two calipers. Maybe from the side and from the front. Just incase we've missed something. Question 2: Are you using stock yoke track width? i.e 205mm track width between fork centres? The reason I ask is because both those calipers should be the same dimensionally with respect to critical dimensions such as mounting points and offsets, so if one is fitting and the other isn't there must be a good reason. On the plus side at least you don't have to buy new discs.
Sorted, thanks for all the help @Sev amazing knowledge. I had to trim a bit of the pads, not as far as friction material though, I only realised when I took the pads out both sets of calipers and put them back to back. All together now.
Dougie, when you say trim part of the pad.... ? Are you saying the pads were thinner on one set than the other or was the profile of the pad backing that was different?
It was the pad backing, I had to grind a small radius onto the bottom of the pads to clear the bobbins, it didn’t impede on the friction material though
hmm. The correct pads for the calipers actually have an arch like and instep on them. The pad for those calipers should be the 07BB15 The framing around the friction material is quite shallow. Never mind. You've sorted it now.
@Sev, brilliant, thanks again. My pads in both sets are flat bottom, I will order replacements at some point with the correct profile.
