I’m putting a call out to all Mandello owners for info on their swinging arms.
I, and my mate, have discovered that we have play in our swinging arms. It’s not obvious, even when up on the centre stand, because the single-sided shock unit pulls the whole thing over to one side. You can pull the wheel from side-to-side but the weight of the wheel on the end of that shock holds it very hard one way.
However, if you lean over the 'bike and pull up on the wheel, you can see and hear the whole plot clunk over. To confirm, I supported the rear wheel on a castored dolly and removed the lower shock mounting bolt. This way, the back wheel moves through about 1-2mm when pulled sideways. I can see the drive shaft housing moving relative to the gearbox casing. It appears to me that it’s not end float on the thrust washers, but radial motion of the needle rollers or more likely their races.
So far I’ve not been able to ride it into the dealer ( weather etc ) but the phone conversations indicate that “they all do it, from new” and that “it’ll pass an MoT that way”.
Personally, that’s not good enough, especially as someone whose 350LC failed on less play than this 30 years ago.
I’d be very interested if everyone would consider checking their machines and letting us know what they find.
I have an article for Gambalunga in preparation and I shall be mentioning it in there, too.
thanks for the response. The spacers around the pin is where I expect to find a problem when I dismantle it. I also believe it should be readily home reengineered, by shimming.
I’ve not experienced any high speed stability issues. I did end up with notchy steering head bearings which caused a lack of precision in the handling. From new, it’d been astonishingly precise; could stick it through the gap between white lines on a motorway. This became less so until new head bearings restored it instantly. But I’ve not noticed anything attributable to the swing-arm. But then, I think this must have been from new so there’s no change to notice.
Head bearings are a ware item. Not uncommon for head bearings to seize even after a few thousand miles… Especially on italian motorcycles where the people who assemble them are known to be allergic to grease(See issue with v85 rear shock bearing…).
Well, I have several machines with perfect head bearings after 45 years use. The only head bearings ( other than the Mandello ) I’ve replaced have been on my '78 Ducati and that was 25 years ago. Even my '77 Guzzi is still on the original head bearings.
They shouldn’t wear, if they’re not over-tightened, have water ingress or installed ungreased. Oh, they do need to be high-quality.
The Mandello turned out to have been ungreased. They’re also caged balls and torqued down to some astronomical figure, which was always seen as a sure way to destroy head bearings. Even an older Aprilia manual which uses the same parts has a warning that tightening them will lead to bearing damage.
So there’s something not quite right there.
When these ones go I’ll be replacing with taper roller sets.