Rear shock mount points conversion | Bobber style

[midwestoutreach]

Hi all,

I just found this forum, super excited to join and read all the available threads. I especially enjoyed the full on newbie resource guide aggregated over the years.

My current motivation to get an airhead was inspired by the classic bobber conversion seen everywhere online, which I am now persuing. Yes, I get that it may be impractical, but that's not the point of this build.

I've narrowed down my search on the seat pan, indeed this is the one that looks most appealing to me and is ready for installation without major mods.


https://www.caferacerwebshop.com/en/bmw ... oeIVFBeFjw

My goal is to remove the entire rear subframe that supports the stock seat and fender. This is where I am stumped.

There seems to be a mounting point for the rear sub-frame right at the front of the seat near the tank, just at the 45 degree frame bar. (See pic below). I have seen multiple builds with custom brackets at that point. My questions is, can I mount the shock to this point or do I have to create custom brackets.

frame.jpg (53.61 KiB) Viewed 1343 times

If the brackets are adequate for shocks, what do you suggest for a comfortable ride? I haven't measured the required length yet.

I've attached a few inspirations below. Thanks for your time and this amazing forum.
https://www.bikebound.com/wp-content/up ... bber-3.jpg
https://i.pinimg.com/originals/8d/d7/66 ... 0a4a98.jpg
https://caferacerforsale.com/wp-content ... 6img_1.jpg

[Rob Frankham]

FWIW, I wouldn't be at all happy about mounting top that point without significantly strengthening it. I know that the original sub frame mounts there and that supports the original shocks but the forces are quite different. In the original setup, the forces are mainly in compression whereas in the 'bobber' version, the forces are much more in the sheer plane. I know it's been done before... many times... but that doesn't make it a good practice.

Rob

[midwestoutreach]

FWIW, I wouldn't be at all happy about mounting top that point without significantly strengthening it. I know that the original sub frame mounts there and that supports the original shocks but the forces are quite different. In the original setup, the forces are mainly in compression whereas in the 'bobber' version, the forces are much more in the sheer plane. I know it's been done before... many times... but that doesn't make it a good practice.

Rob

Agreed, hence since I've posted this my inclination is to lean with a monolever set up that is already present on 84+ r series.