Modern Vespa

Hi, i've been out on my new to me GTS300(2012)for my 1st decent ride on it, overall really impressed & surprised by the overall ride,handling/performance & i have a couple of questions about the brakes/front suspension.
This is my 1st scooter & my 1st experience with CVT & it's possible/probable that my comments/questions are a result of my riding, so here goes.
On a few (3 or4) occasions when braking reasonably hard approaching a junction or roundabout, there was a fairly severe judder from the front suspension especially when banked over & braking reasonably hard, but i have a feeling i may not have had the throttle completely backed off & perhaps the suspension was "fighting" the cvt/drive, is this a possibility ?, or should i be getting the front shock inspected ?.
Another observation is that there is far more stopping power/bite with the rear Brake than the front,i do know the rear brake(or pads) have been renewed when the bike was serviced a few weeks ago.
I'd welcome any advice/opinions on this, as i've said i've never rode a scooter before.
Cheers, Graham.

Check the steering head bearings. Over 70% of the braking force occurs on the front brake, but the suspension has to compress before the braking really starts. So it may seem to you like there is more on the back. But it would not hurt to check the front pads.

Thanks, i will need to get a service/workshop manual, so i'll start a search for one.

First of all make sure the front brake caliper has not worked lose.

A way to check your steering bearings is to stand astride the scooter with both brakes fully on and try to rock the scooter forwards and backwards, checking for any play.

Potentially it could be your wheel bearings. Raise the front wheel off the floor by pushing the under seat storage bucket beneath the body. Grab the wheel at 6 o'clock and 12 o'clock and try to push from side to side, again check for any play.

I had this same irritating problem with my GTS250. Two things eliminated the problem for me:
1. Raise the front wheel and wash the front brake disk in brake cleaner. Use an old tooth brush to scrub it and the cross holes. Spin the wheel so as to get some brake cleaner on the pads. This will remove any wax or oil that has gotten on the disk and pads. If this doesn't solve the issue 100% then:

2. Replace the front pads. A new set of OEM pads. Wipe the disk with brake clean to remove finger prints, etc.

That resolved my issue with the front brake juddering. Checking the other items above are also a good idea as is checking the tire pressure is correct.

Thanks guys, i'll go through all this, so is it doubtfull it's not operator error, by not making sure the throttles shut as i'm braking.
Thanks Graham.

Compared to a motorbike with engine braking . A scooter's throttle can be closed earlier and will coast up to a junction before brakes are used .

https://manuals.wotmeworry.org.uk/Vespa/GTS300%20Super/

The front may well shake a bit under heavy braking when riding around a corner. You learn to do most of the braking before taking a corner, as the geometry of the front is such that's it's a nadger's away from wobbling in the first place. This is what contributes to the terrific manouverability though, it's a fine line Piaggio trod. See this: FAQ: Is it normal for a GT/GTS to "wobble"?

This. I have had the top caliper bolt fall completely out. I have no idea how, but would create a clunk/judder

I've been out on the bike again Today & i've made sure the throttle is closed while braking, plus i've leaned my weight forward on the bars when braking & it hasn't done the juddering again, i think there may be a slight issue with something a bit loose, which i'll investigate, but for now i'm happy to use it as i've described.
Cheers, Graham & thanks for the help.