After inspecting my 09 sub frame and finding a stress crack on the left side, I went with the right side brace and a bolt on left side gusset. I fabricated the right side after seeing the Japanese made part and used aluminum for both. The sub frame on the 09 and up is straight with a slight bend near the seat. The rubber plugs can be removed and a 13" piece of 1/2" steel electrical conduit taped in on both sides. The OD is a slip fit and the tubing will bend enough to follow the sub frame bend. The left side brace works as a coolant tank guard against any rocks that might fly up from the tire. I used self taping screws to attach it through the sub frame and the conduit. This should hold the light loads that I carry, medium size tool bag and an occasional Kolpin 1.5 gal fuel pack.


Right side brace.

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Left side brace and guard.

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1/2" electrical conduit inserted in the rear frame tubes.

 

What thickness aluminum is everybody using for the muffler-side braces?

 

I used .080 aluminum plate. It is real easy to work with and very light weight.

 

Light for sure but very thin. ...just over 1/16. Is that strong enough? I mean, how much strength would that add to a steel tube? Especially since it's just flat stock and not angle stock. What would prevent it from just kinking over in between bolt locations? Off of the top of my head i was thinking to go with at least 3/16 if it's aluminum. I was actually thinking steel would be less prone to fatigue induced stress fractures. What do you think about 1/8 steel? A little heavier definitely, but on such a small piece we're only talking a few ounces difference.

 

How much weight are you planning on carrying? The brace is only adding to the loss of the third bolt point of the stock muffler. With the inserted tubing and the additional light bracing the sub frame is strong enough for the loads that I carry, no problems so far. If you are planning on using the bike as an adventure/camping bike you might need more support. I carry 1.5 gal fuel and tools and it works great for me.

 

I'm not bashing, but i just measured my stock muffler tab thickness at 5/32 (0.15625). That's a steel tab welded to a very substantial member (the entire muffler). If the idea is to substitute a plate for that, i think it needs to be stronger. 1.5 gallons of gasoline (10 lbs + container + mounting brackets) and tools (my tool load is heavy. Yours?) I'm guessing you're in the 20 lb range. I'm hoping to be strong enough for a little more (hopefully 40 lbs). For sure the tubing inserts do a lot, but I would rather think of those as added insurance and not the load bearing structure. I'm thinking about fabricating a brace similar to those I've seen before, except with 5 mounting bolts (extending farther back) and possibly with an inverted T shape by welding a rib to the bottom edge in order to prevent a kink.

 

That conduit looks like it is rigid type, that is pretty heavy stuff. EMT conduit is a lot thinner than that, unless you flattened the end beating on it!
1/16" AL is not going to be very strong without bracing, unless it is hardened/treated AL. You better weigh your kit and tank, mine is way over 20# for tools alone. But I ride in the middle of nowhere.

 

I used 1/4" aluminum plate.

 

It was hard to measure installed, but the one out of Japan is about 5.5 millimeters. That's less than 1mm thinner than 1/4 inch.

 

I have over seven years and 10K plus miles on my bike carrying the same load on long desert and mountain trail rides with only a small stress crack showing up at the left side subframe. The bike has a Nomadic rack that distributes the load over three points. If someone is worried about not reinforcing the subframe enough, keep in mind that the additional bracing is not carrying the full load but backing up the current structure. Like I said earlier, look at what you plan on carrying and use your judgment on what you feel comfortable with when building the bracing. For me, light materials worked without adding more weight to the already heavy bike and has held together for about a year now.