Rigid rear fender frame support issue

[Micromark]

Well, the learning process is alive and well. Rode the bike to a buddies place and on the way noticed an unusual noise.
Turns out a rear fender support (which also supports the oil bag at the bottom) single bolt/stud had broken off in the frame at the crossmember. The through bolt inside the rear fender had started to cut the rear tire when it came loose from the fender spacer. Thankfully, it did not lock up the rear tire... Looking at how the rear fender was originally supported with only ONE bolt/stud was “no bueno”. Going to install a 1/4” double bolt/weld on crossmember fender support.

[Tattooo]

If that's all you have holding the fender on your going to have a problem from now on..............

[TriNortchopz]

it looks like there are a few holes drilled through the rear section; are they just drilled through? maybe look at these:

https://www.lowbrowcustoms.com/fab-parts/bungs.html

[7and7is]

Just curious why not mount some fender struts, perfect opportunity to be creative.



this is my swingarm sporty with TS fender was not happy with the one bolt mounting so made up a couple of cheap aluminum struts and its way more rigid you can stand on it.

[farmall]

Struts, a doubler plate or "fender washers" to spread load on the fender where the new bolts go through the fender to the frame, and all-metal locknuts anywhere you use nuts would be the wise way to go. Rigids lead hard bouncy lives. Any blind threads into bungs should get Loctite. (Loctite doesn't seize fasteners, corrosion and galling do so I avoid dry threads. Split lockwashers are shit which is why they're not used on modern aircraft.)

Consider overkill the minimum to shoot for and your ride won't self- disassemble on the road.

[Micromark]

If that's all you have holding the fender on your going to have a problem from now on..............

Yeah, I’m pretty sure it has happened to someone else as well.
Not a well thought out setup... but hey, there’s room for improvement.

[Micromark]

it looks like there are a few holes drilled through the rear section; are they just drilled through? maybe look at these:

https://www.lowbrowcustoms.com/fab-parts/bungs.html

Thanks for the link. I took the sissy bar and seat springs off to extract the broken stud from the frame crossmember. Those may be the holes you’re seeing. The fender mounted to the bar as well.

[Micromark]

Struts, a doubler plate or "fender washers" to spread load on the fender where the new bolts go through the fender to the frame, and all-metal locknuts anywhere you use nuts would be the wise way to go. Rigids lead hard bouncy lives. Any blind threads into bungs should get Loctite. (Loctite doesn't seize fasteners, corrosion and galling do so I avoid dry threads. Split lockwashers are shit which is why they're not used on modern aircraft.)

Consider overkill the minimum to shoot for and your ride won't self- disassemble on the road.

I agree. TC Bros has a weld on 1/4” bracket with two holes a couple inches apart to mount the fender with leather washers. I’m kinda leaning in that direction.

[Micromark]

Just curious why not mount some fender struts, perfect opportunity to be creative.



this is my swingarm sporty with TS fender was not happy with the one bolt mounting so made up a couple of cheap aluminum struts and its way more rigid you can stand on it.

That looks great! The sissy bar (which I removed) has attachments for the rear of the fender.
I’m really trying to preserve this bike the way she is. The guy that striped it passed away too soon in life so also trying to preserve the paint as well... kinda sentimental.

[Tattooo]

The sissy bar (which I removed) has attachments for the rear of the fender.
I’m really trying to preserve this bike the way she is. The guy that striped it passed away too soon in life so also trying to preserve the paint as well... kinda sentimental.

I guess I missed something....... You say you want to preserve the bike the way it was because the old owner passed away but your taking parts off, then your having problems??? I don't understand???????

[Micromark]

I guess I missed something....... You say you want to preserve the bike the way it was because the old owner passed away but your taking parts off, then your having problems??? I don't understand???????

The bike was built in CA in ‘05 by a now defunct builder. It was pinstriped by a well known artist in CA. The painter is the one that passed away young and I’d like to preserve his work on the bike (which includes the sissy bar and rear fender).
The support broke when I was riding. I had to take it apart to try and extract the broken stud in the frame (and as you mentioned) beef up that fender support or it will happen again and again.

[Tattooo]

The support broke when I was riding. I had to take it apart to try and extract the broken stud in the frame (and as you mentioned) beef up that fender support or it will happen again and again.

Ok now I understand.............

Can you post several pics so we might be able to give you some guidance?

[Micromark]

I’ll try to get some up tomorrow.
Here’s an example of how not to mount a fender on a rigid I guess....



There were also 2 bolts at the rear on either side where the sissy bar is. The one you see in the middle that broke and the bracket bolted to the bottom of the oil bag with a spacer.

[Micromark]

I’m thinking that the oil bag is shaking on it’s rubber mounts and putting too much stress on the bolt in the middle going into the frame.

[Micromark]

Side view of rear fender showing rear sissy bar attachment and front bracket for the bottom of oil bag...