Anybody using Mirror extensions. If so where did you get them from . reverse thread on rear brake side is the issue..
I'm not using extenders, but if you do a search on Amazon for, say,
reverse thread motorcycle mirror extenders you'll find dozens of results (
https://www.amazon.com/s?k=reverse+...ix=reverse+thread+motorcycle+mirror+extenders).
I wouldn't trust Amazon for electronic devices, memory cards, that sort of thing -- Amazon has a habit of reshipping returned items, or hosting outfits that ship counterfeits -- but in this type of product I think you'll be pretty safe. And Amazon typically has a great return policy.
You can also try the same search on Revzilla:
https://www.revzilla.com/search?query=reverse+thread+motorcycle+mirror+extenders
For just an increase in height, for instance, this inexpensive result seems to cover all the bases:
Amazon.com: Motorcycle Mirror Mount Adapter 10mm to 10mm/8mm Standarad/Reverse Motorcycle Rear Mirror Adapter Threads (Black) : Automotive
www.amazon.com
Of course, you'll see many other extenders, some that just raise height, some with a bracket that moves them outward, etc.
I believe BMW typically uses a 10mm pitch. KiWavMotors, for instance, has this page that discusses the size and direction of the threads:
https://kiwavmotors.com/en/blog/best-motorcycle-mirrors-for-bmw-motorrad
I also believe that most Yamaha, Royal Enfield, and many other makes use reverse pitch on one side -- I know that my RE Meteor 350 does -- if that helps any in your search.
Last, according to CalMoto, the stock C 400 mirrors fit:
| BMW C400GT | 2019, 2020, 2021, 2022, 2023, 2024, 2025 |
| BMW C400X | 2019, 2020 |
| BMW CE 02 | 2024 |
| BMW CE04 | 2022, 2023, 2024 |
| BMW G310GS | 2018, 2019, 2020, 2021, 2022, 2023, 2024 |
| BMW G310R | 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024 |
So if you come across an extender for the 310 models, you can know that it will also fit the C 400s
Good luck in your quest, and perhaps some members who've actually swapped out mirrors or extended the OEM ones on a C 400 will chime in here.