Well, this time I took pics, a test ride, and slept on it before posting, and no doubt about it - adding the .072"-thick (1.8mm) Ohlins washer to my lower shock bolt damaged the Alta dogbone. The bolt head removed about .05" / 1.25mm of aluminum at the rear & about .010" / .25mm in front. There was surely lots of side force too, so hopefully there's no dogbone deformation or future bearing issues (everything seems OK now).
It looks to me like OEM bolt-head clearance (no washer) on my '18 MXR is @ .015" / .38mm. This seems pretty damn tight to me. With this amount of clearance, I'd advise anyone installing any shock other than the OEM WP to check dogbone clearance carefully before riding. If anyone's using their Ohlins with KTM linkage, it would be great to know if there's more clearance than the Alta parts. I painted the bolt head black, and will watch for further contact.
Right now I'm running an .060" washer, only because the .072 'plowed the road' for it.
I also ran an M10 x 1.5 die down to the end of the bolt threads, which gave me about 1/8-turn more engagement before thread bottoming (this left some sharp edges to remove).
Pic below shows the .060" washer I'm using now. It worked fine on the test ride with the pre-chewed dogbone, but is way too thick for an intact one. If you're installing your Ohlins for the first time an .010" / .25mm shim washer might be OK (check to be sure), but honestly no washer is the best bet; I'd rather risk a small amount of potential thread damage than what happened here.
It looks to me like OEM bolt-head clearance (no washer) on my '18 MXR is @ .015" / .38mm. This seems pretty damn tight to me. With this amount of clearance, I'd advise anyone installing any shock other than the OEM WP to check dogbone clearance carefully before riding. If anyone's using their Ohlins with KTM linkage, it would be great to know if there's more clearance than the Alta parts. I painted the bolt head black, and will watch for further contact.
Right now I'm running an .060" washer, only because the .072 'plowed the road' for it.
I also ran an M10 x 1.5 die down to the end of the bolt threads, which gave me about 1/8-turn more engagement before thread bottoming (this left some sharp edges to remove).Pic below shows the .060" washer I'm using now. It worked fine on the test ride with the pre-chewed dogbone, but is way too thick for an intact one. If you're installing your Ohlins for the first time an .010" / .25mm shim washer might be OK (check to be sure), but honestly no washer is the best bet; I'd rather risk a small amount of potential thread damage than what happened here.
