Solution to missing expansion nuts with used givi fz351 toprack

[tejkowskit]

So 3 years back I purchased a used givi fz351 toprack on the forum. As with most of the used topracks it didn't didn't come with the expansion nuts that go in the rear tubular frame. I came up with a solution at the time that was OK, but I always wanted something better; it was snug, but not nearly as solid as I would prefer.

This seems to be a common problem with used toprack kits as once set those plugs may be very difficult to remove, and sellers just end up selling their used kit without those important pieces.

Here is the best solution I could think of, and recently installed it with great success and stability of the rack.

I used a 1" star fangled nut used for bicycle steerer tubes. I got mine here on amazon. [ame="http://www.amazon.com/AheadSet-Starnuts-Aheadset-Star-Nut/dp/B004GSQ73Q"]http://www.amazon.com/AheadSet-Starnuts-Aheadset-Star-Nut/dp/B004GSQ73Q[/ame]

Here are mine.



The I.D. of the tubular frame of the motorcycle is slightly smaller than 1", and a little grinding of the star nut is required. Take your time grinding, and compare it with the frame often so you don't grind too much away. It should still be larger than the I.D. of the tube, but only ever so slightly. The 'fangles' that are inserted first should be closer tolerance than the ones to the rear of the nut to allow for easier initial insertion.


Once the 'fangles' are ground down, they need to be hammered into the frame. Do this by threading in a bolt and tapping the bolt. I put in a hex bit with an extension up to the bolt to get a better swing of the hammer. This also gives you leverage to keep the nut going in straight. Take your time and make sure the star nut goes in as straight as possible!

Both installed

Close-up


You'll need two 6mm bolts about 2" long (unless you hammer the nuts really far into the frame you'll need longer bolts), and two washers.



Finally assemble the top rack per instructions.

 

[Motogiro]

Very cool idea!:rockon:

 

[Dannyboy676]

Great idea, was pretty stuck on this, although I don't have a grinder.
Wonder if it would work if I just hammer a 1 inch star nut in there?

 

[FinalImpact]

Good Job and great solution. I'd guess you may find those on McMastercarr in any size you desire!

These may not ever be an issue but two things come to mind.
The star works as its made of some kind of spring steel. That said, if the grinding/fitting process heats a section too much, it can loose its elasticity (spring tension). In short; if it turns blue and onto red, it may not retain its spring tension.
The other consideration is rust prevention. Perhaps spray some high melting point grease or even coat it with never seize (frame tube) before hammering it in there (thresds too).

 

[tejkowskit]

Great idea, was pretty stuck on this, although I don't have a grinder.
Wonder if it would work if I just hammer a 1 inch star nut in there?

It'll be too tight if you don't grind it down. Even a cheap bastard file will work to remove some of the metal.

Good Job and great solution. I'd guess you may find those on McMastercarr in any size you desire!

These may not ever be an issue but two things come to mind.
The star works as its made of some kind of spring steel. That said, if the grinding/fitting process heats a section too much, it can loose its elasticity (spring tension). In short; if it turns blue and onto red, it may not retain its spring tension.
The other consideration is rust prevention. Perhaps spray some high melting point grease or even coat it with never seize (frame tube) before hammering it in there (thresds too).

Although it's next to the exhaust, I don't see the nuts getting that hot. The grease is a great idea that I wish I considered before installing these. Luckily I'm don't think much water gets into this area. At least I didn't notice any signs of rust near there.