Modern Vespa

Hi all. I've got a 2005 Genuine Stella 2T that I am having issues with the front end. The damper finally let go, so it was time to replace the front shock, plus needed a front disc brake bleed plus new pads.

The new shock installed without issue. The issue is with the brake: upon re-installation, I see that my front caliper is not centered, but offset to the left side of the disc (inboard/driving position) by maybe 1.5-2mm. It's offset to the point that the brake pad pin contacts my tube valve at the bend. There is no play in the front hub. I am replacing pads, the pistons have been re-set into the piston pocket fully- it's the caliper that's offset, which is weird because it's a fixed position caliper and should not be this far inboard, especially when mounted directly to the caliper holder plate. It may have been like that from the onset, but it's now weird that the brake pad pin is contacting the valve...

It came stock with the red Bitubo, and I am replacing with the black coil set from Scooter Mercato: https://www.scootermercato.com/s.nl/it.A/id.11951/.f if that makes any difference.

Anyone come across this one? Next step is to remove the front hub and make sure the proper spacers are installed, but wanted to troubleshoot/investigate before I get too unnecessarily in the "take it all apart" hole.

This doesn't make much sense. The caliper position is fixed. Changing the shock shouldn't do anything. I say use it as is. The pistons will retract just enough to not touch the disc, esp. after you ride it a little bit and the new pads bed in.

The issue is not that the pads don't clear, they do. Yes, it's tight on the right side. It's that the pad PIN that holds the pad in the caliper contacts the valve now due to the position of the caliper, barely, but enough that it would eat through the valve with just a few at-speed rotations.

do you have the wheel facing the wrong direction? Or maybe the pin is pointing the wrong direction? FYI, pics would go a long way.

The shock is tied to the same hub that carries the brake caliper. When the hub moves axially on the shaft, so does the caliper. This could cause the brake disc to appear off-centre. Same could be said for the wheel hub, if it moves, so does the brake disc.

In the illustration below, indicated with blue arrow is the suspension hub. It's "free" to move, and to stop it from moving axially, there is a spacer (in green) and a seal (in red) on one side, and spacer and seeger ring on the other side (unmarked).

I would start by checking to see if there's any slop that has developed over time. Ultimately, if there's space, you can try putting 0.5mm spacers on the front axle, to force the hub to be in certain location. Perhaps you could even shim the brake caliper... 🤔

Edits: I hates autocorrect 🤦🏻‍♂️ apologies for the typos.

Photos?
Please

Something tells me the piston carrier isn't held in place properly by the snap ring

Or.you put the pin in back to front

I just replaced the pads on my Stella front end this morning. The valve should be facing the left side of the scooter (not towards the caliper). So something's off there already. Also, the pin that goes through the caliper enters the caliper from the right side and goes toward the wheel. It physically can't go more than maybe 5-7mm past the caliper and is held in place by an omega clip.