polyethylene plastics have always been impossible to repair without heat welding... but a new adhesive has surfaced, and seems viable.....

https://www.tapplastics.com/product/repair_products/plastic_adhesives/tap_poly_weld_adhesive/435

Cool.  Thanks for posting this.

Someone needs to try this and report on how well it does . . . .

Are the fairings on the Concours 14 made out of HDPE? I thought they were ABS but acetone doesn't seem to dissolve it.

https://www.youtube.com/watch?v=h-9yhanz5DE

Here is the manufactures video on the adhesive from the link.

Are the fairings on the Concours 14 made out of HDPE? I thought they were ABS but acetone doesn't seem to dissolve it.

Good question that. It would be nice to actually know what every part of the bike was made from. If someone does have extensive knowledge I'd love to see a sticky thread listing all the parts and materials.
I think the front fender is ABS as are the saddle bags and I suspect the rest of the fairing pieces. I'm pretty sure the rear fender is Polypropylene?  I'd also like to know what the sub frame is made of (4130 chrome moly? maybe?).

the fairings and painted parts on both bikes are ABS,and not conducive to the HDPE glue... but the "soft/black plastic" parts, like the C14 lowers, front trim, and inner fender, and also the C10 bags and rear fender, are HDPE.

the stuff I posted was mainly for bag repairs on C10's, but if the HDPE parts on either are damaged, I'm sure this should work... but watch the video, and follow the mfg's directions.

Are the fairings on the Concours 14 made out of HDPE? I thought they were ABS but acetone doesn't seem to dissolve it.

well, it does, and it doesn't.

ABS is a funny plastic, due to it's 'polar molecular structure'
for instance, trying to stick 2 pieces together, doesn't really work well...
but if you 'shave' ABS using a 'grater'type of tool" like a Sureform Rasp, and create small thin pieces with a large surface area vs low mass, it will disolve when agitated, but again, the ratio of solvent to plastic becomes critical as a factor also.

MOB, Thanks for the info.
This will come in handy for repairs.

Ride safe, Ted

I guess it should have been obvious to me that HDPE parts would not be painted parts. HDPE should also float in water.

The nose fairing is marked ABS. It readily dissolved in acetone. I cannot find a marking on the upper fairing. I will try seeing if grinding it helps it dissolve.

I did do a burn test on the upper fairing. It seemed to me that since it didn't seem to drip, that it may be ABS/Polycarbonate. I was hoping to glue it with ABS cement. It might need something different.

The mirrors appear to be marked PP. It is sort of hard to read the marking. The windshield cover is marked AES.

These two links seemed helpful.

https://www.polyvance.com/identify.php

https://www.boedeker.com/Technical-Resources/Technical-Library/Plastic-Identification