I bought a MCL fork brace last month, and installed it while I was in California. I had just finished riding from Toronto to California without the brace, so the ride back along the same route gave me a good opportunity to compare "before and after".
I think that the motorcycle handled better - in particular, it was less affected by grooves and ruts in the road that ran parallel to the direction of travel - with the fork brace installed. But, there is an important caveat here:
When I first attempted to install the fork brace, I discovered that it didn't fit perfectly. The forks were about ten to twenty thousandths of an inch too close together, which meant that instead of the brace smoothly slipping into place with no friction whatsoever, the brace would have needed a bit of tapping to get in snugly around the two lower forks. I had read a post made here in the forum by another member (I can't find that post right now) in which he reported the same problem - the brace didn't fit right - but he tapped it into place. He then experienced stiction in the forks (they would not smoothly and easily move up and down), and I didn't want to encounter that same problem.
So...
I loosened both of the pinch bolts on either side of the axle, and bounced the front end up and down a few times. I then tapped the fork brace into place, and bounced the front end up and down a few more times to confirm that the forks moved freely and there was no stiction. I then tightened up the pinch bolts and the 4 bolts on the fork brace. The next day, I visited Larry (Igofar) and asked him to carefully examine the whole front suspension on my motorcycle. Larry dis-assembled the front axle and found that some part inside the axle was not as it should be.
(Larry, if you are reading this, perhaps you could explain what you found... it was a bit too complicated for me to figure out, even though I was watching you and you were explaining it to me.) Larry fixed the part that was not correct, then very carefully inspected, loosened, and re-torqued all of the various critical fasteners in the front fork and axle assembly, including the brake calipers. All of this work was done with the fork brace installed, which means that any force being exerted on the brace due to fork misalignment was relieved.
As I said in the second paragraph, I think the fork brace improves the handling of the motorcycle when the front wheel is deflected laterally by grooves and ruts in the pavement, most especially when riding on scarified pavement. But, I think that anyone who is considering purchasing and installing a fork brace needs to recognize that the brace is only one component in a rather complex front-end assembly, and if the front end assembly is not perfectly set up to begin with (unlikely, in my opinion), it won't be possible to simply slide the fork brace into position, encounter no resistance at all, tighten the bolts and then ride away into the sunset. The whole front end needs to be loosened up and properly aligned at the time the fork brace is installed, and the fork brace itself should be fitted (perhaps not 'finally tightened', but certainly 'fitted') when all of the other fasteners that affect fork alignment and rigidity have been loosened. Then, the proper processes for tightening up all the fasteners on the front fork assembly (including the brake caliper fasteners) need to be followed. If this is done, then a satisfactory result will be achieved.
Exactly how much of the handling improvement is due to the presence of the fork brace, and how much is due to simply correctly aligning the front end, I don't know. Theoretically, the fork brace could, perhaps, just be used as an alignment tool, and then removed afterwards; but to prove or disprove this, I would have to do a few thousand miles of riding with the fork brace removed.
There are two companies that make fork braces for the ST 1300, Motorcycle Larry (MCL) and Superbrace. MCL's fork brace costs $90, Superbrace's fork brace costs $166. I'll be darned if I can figure out how the two products could be different in any way - after all, they are just flat aluminum bars with round holes in each end. They both weigh about 2 pounds.
MCL sells bug guards that screw onto their fork brace for an additional $21. It is possible to re-use the OEM Honda bug guards, but to do so requires that you attach them with glue - kind of hokey - hence I think that buying the bug guards with the fork brace is kind of obligatory. I don't know if Superbrace sells bug guards, or if the OEM bug guards can be re-used when a Superbrace is fitted. Superbrace has made a video showing how the brace is fitted to the moto and posted it here in the forum - here is the link to that video:
Superbrace installation. The process is the same with the MCL brace, although based on my experience, I recommend that the whole front end be loosened up and properly aligned when a fork brace is fitted.
Michael
The MCL Fork Brace
it's about as generic as a part could possibly be