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.
My 15K mile service is due soon, I’ll have that checked and let you know. Did experience head shakes or any other high speed stability issues?
I stumbled across quite a number of similar complaints by other owners across social media. Some times high speed stability issues were reported.
Rumour has it that on the Stelvio they changed the spacers around the pin or otherwise simplified the arrangement but cant confirm.
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.
1 Like
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.
2 Likes
I have an update on my swinging arm issue.
The dealer basically reckoned there was nothing they could do. They all have that bit of play, and all from new. they reckon Guzzi must have built it in as a design feature. They assure me that it’ll pass an MoT, when the first ones need it in December.
I’ve finally got it tied onto a hydraulic bench. This is necessary because when I first tried to get into it, I found that you need to remove the footrest hangers to get at the s/a spindle, and the centre stand bolts onto the footrest hangers. If you put a pantograph under the engine, as stated in the Guzzi manual, it’d topple over backwards, so it needs to be tied down.
Done today. Once the wheel was out and the shock removed, so the swinging arm is free of extraneous loads, the play was very obvious, about 2 maybe 3mm at the back wheel. I would be disgusted if this passed an MoT.
On disassembly I found that the needle roller bearings were ungreased, just like my steering head bearings. There are witness marks on the top hat inner races, but they feel ok when rotating. There was end float on the thrust washers, which are plastic, run on the raw machined aluminium of the gearbox lugs and unsealed, open to all the rubbish off the back wheel that we’ve reported on elsewhere ( rubbish hugger ). I ended up adding a total of 0.80mm of shims under the thrust washers and this allowed the swing arm to move under its own weight, but still clamp up the inner races. On reassembly, zero play at the rear wheel.
I can feel the difference in the ride. As good as the handling was before, it now feels more fluid, especially when flicking it over, which I suppose is what you’d expect, as the sideways force on the wheel flips from one direction to the other.
It took about 4 hours of actual work time.
So, success. But another story of Guzzi getting it so nearly right but letting us down in the details.
I’d recommend everyone with a Mandello ( perhaps V100 Stelvio, too ? ) carefully check their swinging arm play using the technique I described earlier, leaning over the back seat and lifting the wheel hard upwards.
1 Like