Cali EV Rear Suspension Mount

I am refurbishing a 97 EV and have found the upper suspension mount thread to be worn. Parts List says that it should be M6 * 35, but these do not hold. Either corrosion or previous-owner brute force has opened the holes up. The earlier Cali1100i/EV 8mm screw will not fit and I suspect that the suspension mount is smaller diameter than the earlier frames. (Can anyone confirm?).

Oddly enough, a good-old British Association (OBA) will screw in and hold. I know that OBA is nominally the same as M6, being 1mm thread pitch, but with slightly different thread form and outside diameter. (6mm OD instead of M6’s 5.794mm-5.974mm OD).

I know that the screw does not, in fact, do much other than retain the suspension unit on the mount, but I don’t want to unnecessarily weaken the mount post.

I could (I know) simply tap out to M7 * 1.0, or alternatively I could drill deeper and then re-tap M6 * 1.0 with longer screws.

I would appreciate any suggestions or prior experience.

If that’s true that’s a bit mad reducing it from M8.

I did not explain myself well.

The earlier ‘KD’ frames had 14mm Suspension Mount Posts with M8 screws. The later ones had 12mm posts with 6mm screws.

Don’t ask me why; one of those strange, but true Guzzi Cosmic Mysteries?

Might be to do with Guzzi/Piaggio moving away from Bitubo Air Shox to those nasty Sachs-Boge things. I now have some decent adjustable Hagon Shox as the original Bitubo Units died.

Yes must be because the mounting eye size changed.


Decision made i.e. drill deeper than the current 21mm and re-tap M6 * 1.0. This will not weaken the mount post and only requires longer screws.

Will update when the frame is back from the paint shop and re-assembled.