Factory trunk setback

[Harald]

Last month I finally took the wife out on a longish ride (500 mile round trip over a long weekend) as a trial run before some longer trips. I have the factory Yamaha trunk for my 07 FJR because I like the looks of it and I needed a backrest for the wife. What we found was that the trunk forces her into a too upright seating position and also doesn’t allow me enough room so that I can get into my preferred comfortable slouch position. It would really help if she’d lose some weight, but I ain’t holding my breath on that one.

So I decided to make a plate that would allow the trunk to be mounted further rearward. Some trial fitting showed that 2 inches back would be ideal. Rumaging through my highly valuable parts stores (junk) yielded some 1/8 inch aircraft aluminum alloy sheet, nut plates, and assorted rubber parts. The end result is a plate that allows the factory trunk mount to be relocated 2 inches back and up about 1 inch. I could have lessened the amount of upward relocation, but I didn’t want to modify the factory mount in any way.

Here’s pictures of the relocated trunk from front and side views:

Here’s a picture of the mount plate with the trunk removed. The factory mount isn’t a thing of beauty normally and now it’s slightly more ugly, but it sure works great in this position.

Here’s a picture of the factory mount removed from my relocating plate. The factory mount plate attaches to my plate using AN bolts of the appropriate length. My relocating plate is mounted using the factory trunk mount screws (with loctite of course). Note the 2 round rubber dots to the rear; they are there to remove any gaps between the factory mount and my plate to reduce flexing of the trunk mount system.

This picture shows the underside of my plate. Note the nutplates that allow me to attach the factory mount without having to hold a nut underneath with a wrench. I slightly angled the nutplates using washers because the factory mount forces the bolts to go through at an angle. I also used contact cement to glue some rubber grommets to the plate. These grommets eliminate the gap at the rear that would allow the trunk mount to flex.

The other parts that I had to make were new spacers to elevate my plate. I couldn’t find anything the correct size, so I made these spacers using ¼ inch threaded pipe couplings. To get the correct inside diameter I screwed in some hollow threaded rod (used in household lamps). Then I took the spacers to the grinder to get the correct height and angle.

The end result is a relocated trunk that works exceptionally well for my wife and I. We just did a 1400 mile run to Montana and were very comfortable. I would have preferred designing a completely new mount for the factory trunk, but I’m limited to basic hand tools and I’m very limited on time to dedicate to making fancy parts. Plus I enjoy the challenge of designing something with parts on hand. Now it’s time for someone to take my idea and build a better one.

 

[tripntx]

Thank you for sharing. Will get around to making one of these for my wife in the future, maybe a winter project, although we ride all winter down here on the Texas Gulf coast.

 

[Mizz Bustanut]

It would really help if she’d lose some weight, but I ain’t holding my breath on that one.

Hope she doesn't see this . . . . . you may find yourself in the doghouse. :haha:

 

[ionbeam]

Nice job with the trunk plate! Hope it works out for your wife. It also has the benefit of being ‘reversible’ should you want to go back to stock.

For what it’s worth, there have been several cracked rear sub frames so you may want to keep a close eye on yours now that your trunk has been moved rearward where it may put even more stress on the sub frame.

Here is a picture of Ignacio’s Oh Shucks, note his use of a metal plate, broken frame #1

Broken frame thread #2

Broken frame thread #3

If you check out garauld you will see that he offers many different rack solutions.

 

[mattster31]

Good job on the plate.........I was considering doing that with mine, but felt it might put too much stress to the rack/subframe. Sort of like a diving board effect.

Hope you don't have any troubles with it (don't overload it).

 

[RonBB]

A small word of caution. Your bike will wheelie easier now that the passenger is over or behind the rear axle. Be careful on the first few launches with the passenger on board. I can tell a difference even with small passengers. Ride safe. Ron

 

[RTSR1/FJR]

I did the same thing basically! Moved it back 2.75" with 2 - 2"X.250"X10" alum. plates and redrilled for the GIVI trunk and the GIVI mount. Wife is much happier! We're up in N.C and Va. riding this week and she says she can't believe the difference! I had already moved it 1.250" and had it like that for 2 yrs, but with the new russell seat it had to go back more. She's happy, I'm happy! lol

 

[v65]

I mentioned Iggy's cracked frame in regards to a similar mod. One other thing that he did was remove the grab bar, which apparently lends some strength to the rear subframe. I'd bet (your frame ) with the grab bar in place you'll be fine.