Easy XS fork brace

[TucmanXJ]

You can make this one, an easy, low-cost, very rugged fork brace.
It fit my XS850 perfectly.

Should fit a variety of XS bigger bore bikes.

Take 1 used XV920 front fender - very heavy (for good reason).

1. Drill & cut out 4 spot welds, pull sheet metal off aka old XV fender.

2. Remove internal brace, 1/4" heavy steel.

3. Dress, polish, plate or spray.

4. Enjoy

btw I tried to alter the brace a bit - no way without a 2 ton press and some serious heat applied.

[yamtom]

dragging on tire?

Hi,
Did you have to modify the brace to clear that tire? It appears to be dragging on it. Just Curious.

[TucmanXJ]

Brace not too close

Fork brace is sitting way down resting on the tire - still unbolted.
You can just see the bolt hole peeking out on lower left fork attachment lug.
Once fastened there's plenty of clearance.

[motoman]

Design still allows flexing, plus mount place is too low.........not even close to working like a true fork brace..............but to each his own................

[James England]

Design still allows flexing, plus mount place is too low.

Could you clarify please? It did occur to me that this is a beefier version of the standard brace which is in the front fender. Presumably it will be better than the OEM fender brace? Although, looking at the pix, I wonder how a fender is mounted?Maybe over the top of the brace?

[motoman]

Leverage plays into the mounting, so with that, if not mounted at top of fork tubes, the flexing isn't stopped between the lower triple clamp and axle mount. Fairly simple if you look at the mounting points of the forks.........lot of no support distance.....aside from the fact the flexing under corner loads creates unnecessary wear on bushing guides. Only mounting place to help eliminate both scenarios IS at top of fork tube, and preferably in a straight line mounting with least amount of joining sections.

[cywelchjr]

Leverage plays into the mounting, so with that, if not mounted at top of fork tubes, the flexing isn't stopped between the lower triple clamp and axle mount. Fairly simple if you look at the mounting points of the forks.........lot of no support distance.....aside from the fact the flexing under corner loads creates unnecessary wear on bushing guides. Only mounting place to help eliminate both scenarios IS at top of fork tube, and preferably in a straight line mounting with least amount of joining sections.

From the standpoint of physics this doesn't make sense to me. If you have the bottom of the forks locked in place, and the fender mounting points locked in place in relation to each other, the rest of the fork is NOT going to move in relation to each other. The issue as *I* see it is that that brace while better than nothing and better than just the fender (significantly better even) is still just a flat steel piece which WILL flex under pressure. That is the reason the fork braces work better, because the run flat across the top so the brace itself can't flex. If that brace couldn't flex, the forks wouldn't flex any more than with a TKat brace, but that piece doesn't have the strength needed to do that job, although far better than the stock setup I'm guessing the concept shown of modifying the forks to clamp on BOTH sides would give better stability than this brace anyways. Combine that setup with a fork brace and it would almost be like heavier forks.

[79XS11F]

That's the type of brace that is installed under the fender of my 1979 restored bike. Who ever installed it has to grind off the fenders hole shoulders to make it fit. This unit also has fitment points for the brake hoses.
Rob

[old_skool]

Although its not really working like a good fork brace, as has been said, its a lot tougher and probably helps some, which is better than no help at all, and I've seen similar braces for other bikes just like the one you made for sale on ebay, so there's probably some benefit, but basically its just like changing to a stiffer fender....which brings me to my next question, why didn't you just use the entire fender?? they're a nice looking style and you would have had a slightly stiffer setup with a fender in place?? All in all, nice job!

[motoman]

Standpoint of physics, U answered your own questioning in the second portion of your thread Cy.

[b.walker5]

Okay, I have a TKat brace (and love it) so I dont have any real world experience with a brace such as this one, other than the fact that i had what appeared to be a XV920 front guard (fender) on mine until recently. (had a heavier built-in brace than the standard XS), so what i'm thinking here might be complete drivel, and i'm not sure i can adequately explain what i'm thinking, however into the abyss i shall go.

To my mind (age addled) the two fixed points in question are the lower triple tree clamps and the axle clamps. Two rigid points in their own right. In the middle of this is the front guard, with a built in brace (of sorts). As the brace has little strength, the effect of trying to change the direction of a gyroscope (front wheel) causes the forks to flex between the top and bottom rigid points, correct?

Now, if you look at the mounting points of the front guard you will see two bolts on either side basically opposite each other. Now consider the position of those opposing bolts when the forks start to twist, when the opposing, and resisting force of the gyroscope comes into play. If you were able to see it in motion I think you would find that the bolts no longer oppose each other on the same axis. If you drew a line between the two bolts on each fork, you would find one side slightly higher than the other, depending on the turning direction of the gyroscope. If they didnt, there would be no flex to begin with.

Remember that these are completely my own musings and I am happy to be 'shot down' as it were, but if one was to introduce a sturdier brace, as the one shown above, and the bolt holes were closely matched to the bolt sizes then the ability of the bolts to 'go out of line' would be reduced, thereby reducing the abilty of the forks to twist. Not quite as good as a clamp at the top of the fork. i.e Tkat or Telefix etc, but got to be better that the original.

Not sure if I expalined this 'theory' to match my thinking but there it is, it's out there.

Have at it.

[jetmechmarty]

So, we're saying this one is "less than ideal"?

[crazy steve]

So, we're saying this one is "less than ideal"?

Yep!!

That is a 'old school' design and isn't as effective as the modern designs like TKats or the Telefix. Those are intended (IMO) as a nice 'vintage' touch if your tastes run that way, but not the equal of the newer ones...

[motoman]

The pic. of the brace Jet showed reminded me of a good friend and member(DarkHorse) here, who hasn't posted for some years, used both the TKat and the loop brace. Under most riding conditions, his observation were that both performed about the same. He and I both agreed that under extreme cornering loads, the TKat brace, being fixed in a straight line would resist those side torque loads better, especially being mounted at top of fork tube where the tube and piston are seperate only having the slider guide for some stability between the two connections.

[79XS11F]

This Daytona unit is what I found and have installed on my modified bike. It is clamped right onto the upper part of the lower fork legs. I have no idea what to expect from it for performance but it is at lighter then the other options



Rob