rpm's fork brace

[Dads_FJ]

If you have removed the stock brake hose brackets, you *must* put some washers under your fender tabs to compensate or you will crack your tabs.

Yes, the FJ's spindly (by today's standards) 41mm fork tubes flex, the brace helps.

So the brackets go between the front and rear sections of the fender?  This doesn't show that.  http://www.boats.net/parts/search/Yamaha/Motorcycle/1987/FJ1200T/FENDER/parts.html

What am I missing?

[FJ_Hooligan]

The brake line brackets go next to the fork, behind the fender tabs.  If you don't re-use them (or an equivalent washer stack as Pat mentions) your fender will crack, fork brace or not.

[Dads_FJ]

The brake line brackets go next to the fork, behind the fender tabs.  If you don't re-use them (or an equivalent washer stack as Pat mentions) your fender will crack, fork brace or not.

Thanks!  I hate creating my own problems.   

[Mike Ramos]

"...the brace helps..."

Hell has frozen over!  The midget & preacher agree on something...!  Hallelujah...!

Actually, there is a video from the Colorado Rally that shows the forks working overtime - spindly or not, the Fork Brace ties the front all together allowing for better & SAFER handling.  A good investment from my point of view.

Gotta go - keep smiling & ride safe.

Midget Mike.

[ELIMINATOR]

Brace fitted. Felt subtly better, but that might just be my imagination

[Pat Conlon]

Trev, load up your bike with your touring gear and find a twisty road.
I noticed the difference in the side to side transitions.

And yes, my diminutive friend, we agree on much more than we disagree, for sure. 

[rktmanfj]

I felt like adding the Superbrace to my fork made a big difference, as well.

Someone wanted to debate the point with me awhile back, but I think that the Renntecs make a similar improvement to the frame.

Between the two, IMO, the bike feels a great deal more solid.

[movenon]

I don't have an aftermarket brace yet but in my FJ reconstruction I have to repair my front fender and the stock brace is loose at present. If you hold the front wheel with your knees and wiggle the handlebars the amount of flex is extreme. My stock brace is in good condition and the holes are not elongated but its not that much material to counter the forces involved. A brace is on my list along with the Rentec's before spring. For normal riding the stock brace is probably OK at best, if in good condition but there is room for improvement not to mention the damage it can do to your front fender tabs from flexing or twisting. Flexing can't be good for the fork bushings either over a period of time.

On the subject of flex. The rear subframes are also weak and flimsy. Mine was out of alignment and I thought I was going to just replace the sub frame but my son came over with a 6 foot pull bar that rested against the rear tire with a notch for a chain up about 4 feet on the bar. Hooked the chain to the sub frame and I swear a 10 year kid could over pull it... 2 minutes and it was good as new. Not much you can do about it. It was just an observation. I have heard some say "they felt the frame flexing". Now I wonder if what they really felt was the sub frame moving.  

Back to the fork brace, I use to wonder myself if they really were that much better than the stock fork brace but from what little have seen from a garage engineering stand point I believe they are. They are on the infamous "list".....
George

[andyoutandabout]

I like my RPM brace and I'm not going to give it back.
I was an early adopter and it's done exactly what it should for years.
Andy

[FJ1100mjk]

Regardless of the brace's loading schemes, an aftermarket fork brace would offer enhanced rigidity due to its higher section modulus, which is greatly influenced by its thickness. Without owning one, I'm guessing that the aftermarket brace's thickness is 13mm, whereas the fender bracket I'm guessing, is around 3mm.

Not sure if the design intent of the, as it is called in the fender's parts list a bracket, is being misinterpreted as fork brace though. I've seen it listed as a "brace" on Ebay, so that's gospel. It surely offers enhanced rigidity, due to it being in its position, and tied, albeit loosely, to each slider. Certainly more rigidity to the fork assembly than if it was omitted. However, seeing how it is assembled:  itself having clearance holes (as opposed to the aftermarket's brace that is securely clamped), secured with lightly torqued fasteners, and that the bracket's bearing surfaces are interfacing with painted plastic, which is a piss poor interface if there ever was one for the loads that the bracket sees, I can't see it offering much for rigidity in comparison to an aftermarket brace.

I don't have one if front of me at the moment, but from what I can recall from the design of the fender's mounting tabs, is that they have a sharp corner where they rest on the bosses of the slider. I'm guessing that that the inside radius for them is the minimum for an injection molded piece, and it would have been better from a stress concentration perspective to have given a larger radius to the tab's design. The current sharp corner does little to prevent cracking with flexing. Be it from front end flexure, or the omission of brake hose brackets and washers.

For me, for the time being, I'll keep running without an aftermarket brace. For fender cracks as and if they develop, I will use my plastic repair kit http://www.plastex.net/ to keep them in check. And if I miss my exit line in a corner by three inches because my forks flexed a sixteenth of an inch, well then I'll just have to deal with it. Something I've dealt with for a while now.

Probably missing something, so have at it.

Rubber side down!

[ELIMINATOR]

After having encountered a set of bends in daylight for the first time since fitting the fork brace, that for the previous four nights were taken in the pitch black of night. There seems to be a better improvement than I at first thought, I felt more comfortable and went a bit faster than I normally would, I still however would be left behind by myself if I were riding my BMW 1150GS.

[fintip]

Added a link to this discussion on the FJowners.wikidot.com/forks page.