Modern Vespa

I am the proud owner of a lovely Vespa Sprint 150 since July, and just yesterday I noticed this weekend that BOTH of my rear brake lights (the plastic red reflector piece) have broken near the screw. I don't know if this is a defect or something because nothing has happened to it and now they don't really stay in place in the hole.

I'd like to fix it myself if possible. I'm gonna go on a search for replacement parts but curious if anyone has any suggestions or has had this problem?

Mine was broke on the right side where the lip on the lense was not installed first. I decided to purchase myself after not getting any help from the dealer.I noticed this when waxing.There has been others on this forum who has had the same problem.

Thanks for the reply! Any suggestions on where to order the parts from? I haven't been able to find them yet. I may also just try some auto adhesive to hold in place if I can't find them.

I ordered mine from Scooters west and got it in 3 days

af1 racing

Scooterswest shows them in stock

Is this the correct thing?

https://www.scooterwest.com/r-h-rear-brake-and-tail-light-piaggio-bv350-642898.html

OR

https://www.scooterwest.com/tail-light-assembly-r-h-primavera-sprint-680255.html

???

All I need is the little plastic piece. A shame they broke so easily! The left one basically just fell apart when I touched it.

Any chance of a gas spill? Stuff is pretty deadly to that plastic apparently. .

#2 looks like the charm. Def not #1.

Maybe the screws were tightened too hard. My psychic powers are working today.

The most likely reason and then leading to stress fractures when riding over bumps in the road.

Unfortunately the plastic that the lenses are made of is hard , brittle and unforgiving of overtightening the screws . If you can find a small rubber washer or 'O' ring that just fits over the thread of the screw and then just nip the screw up this works for me . The rubber seems to cushion the stress . I have noticed this idea on plastic covers on electrical boxes and covers that would have the same issues .

What year is your Sprint? I may have the parts you need which came off my 2021 Sprint 150. These are indicator lights and I changed mine to white so I have the red ones. You cannot just buy the plastic lens parts. You buy the whole light fixture I believe.

I also lovingly suggest you add the model year to your listing here.

Hard plastics cannot stand long term compressive stress such as over tightened screws. Depending on the type of plastic it may it fail immediately (styrene) or it may take months (polycarbonate) The secret is to tighten the screws until just snug.

Before retirement I spent many happy hours calculating torque figures for the assembly of plastic components for the automotive industry and its like trying to pluck a budgie while wearing boxing gloves.

I really wish designers would spec in compression limiters more often...

But those cost money, and its all about profit isn't it.

680255 and 680256 is what you need.The small plastic lip that you install first is what will break.When I took mine apart the lip was on the outside.I did put a small rubber washer on mine to cushion on both lamps.

I guess it's impossible to buy a torque wrench for such fine tolerances?

Nope, they're out there... but expect to pay.

The power screwdrivers we used at work were 1800 bucks each, and the torque meter to set them up was 4300.

I've got a $100 mechanical wrench in the garage that goes down to 20 inch pounds, but for some products we assembled we were often going as low as 4.5 inch pounds, thats less than 0.4 foot pounds.

Two of these are 680255 (left) and two are 680256 (right).

I bought it this July so I think it's 2021 probably? Here's a picture that shows the item number. I think it says: piaggio 50R-00 13820 tri.o.m. 1,366-d

Appreciate all the help! I use my vespa as my main vehicle so it's definitely been over a fair amount of bumps in the road.

That's the way to go. I just talked to the service manager at our local dealer and he told me they have seen a lot of lamps broken on the right side only.He also said to push the wiring harness up out of the way.

If you bought it in July 2021 it should be still under warranty.

Mine is still under warranty but dealer is almost 90 miles one way plus I would have to ship it there because I do not have a trailer anymore

Yes Heather mine have exactly those numbers on the lens which you can see below. Notice on the silver housing it says Red Lens 680256.

That's the same as your second link in your earlier post. That's the one you want.

I see.
Then it will be cheaper to buy online the parts and change them.
Think of that tip from Johntee on the rubber washer.
Real good tip. The rubber spreads the force of the screw and the friction holds the screw in place.

Billrush shows he has the one you need.Be careful when installing or the will break the lip off. I wish they had 2 screws holding them in.The rubber oring works great.I put a dab of silicone on the end of the screw.Remember to push the wire harness out of the way

Bill's helping me out with the replacement parts (Thanks Bill -- I PMed you my info!)

I'll definitely keep all these tips in mind when I go to replace. It'll be great to have them fixed up!

Thanks for your help everyone!