Inverted forks on my xj 550

This was a fun project to conquer.

 

these are a set of 2012 zx6 inverted forks on my 82 xj frame. Also ask questions if you have any.

 

I would imagine the triple tree is from the zx6 as well? What did you have to do to get the frame and triple tree to play nice together?

 

I'm running a 2005 GSXR750 front end on my bike. I can't speak for this setup, but you'll need to make sure that the stems are similar in length from the bottom triple to the top triple and that the diameters are the same.

 

I took out both the top and bottom bearing races an had them bored out to the same size as the goose on the zx6 forks.

 

I also put new smaller bearings in the races, there was about an 8" gap at the top witch I had a couple spare old races I used as a shim and guide, since I wasn't able to use the inner races.

 

I will take a few more pictures when I get home this evening.

 

Here is a side view

 

It Looks So Mean. I like it!

 

Doesn't it tho!! im digging how both tires are the same size.

 

Slower steering .. YAY!!!

 

The 550s aren't meant for speed. I like the way it looks and from the feel of it doesn't feel much different than the stock front end.

 

Have you had the engine in with the new forks on? Or are you making that call from "Fred Flintstoning" it up and down the street? Heh...

 

The motor will be back in either later today or at the latest tomorrow evening. I just sat on it with a friend sitting on the bars for weight.

 

Is this done for looks or to lower unsprung weight?

 

Looks, better traction, more stopping power updated suspension, cruise control.

 

Many dozens of club racers from the era will heartily disagree with you.


FWIW a slightly wider tire does not increase the contact patch enough to increase traction.

If you like the look, well there's that, but don't fool yourself into thinking the extra tire width is doing anything other than slowing the turn-in response.

To be clear, the only criticism I have is in running the same width tire front and rear.


Where is the crusie control coming from? Add-on vacuum system?

 

Reducing unsprung weight can increase traction by allowing the tire to remain in contact with the road more often instead of hovering above the road after absorbing a small bump.
I assume (in this case) that any weight saved by inverting the forks may be gained back with a heavier wheel/tire?

 

Did you weigh and compare the fronts before making the switch?

My guess is that you already have close to the same unsprung weight with the second caliper, disc, larger wheel, and larger diameter fork tubes.

But again, that's not really the problem. The forks you put on are far better than what was there, but you have now thrown off the relationship between front and rear tire width, affecting turn-in rate. So my question is, what are you going to do to remedy that?

Granted, you might not need to, but it's still a factor worth considering.

 

Just from reading about your installation, I would be weary to ride that. If something doesn't fit right and fails because of it, it will be catastrophic. I would pull it out and run a custom stem. Otherwise any gains from the superior setup will be negated due to improper setup. Not to mention that it can be incredibly dangerous.

 

This doesn't sound very safe.... Did you machine the bearings?! And stack a bunch of them on top of each other?
You might have to redo this if you want to ride it more than once.....

 

^ Agreed. The proper (and safe) way would be to use roller bearings that match the head tube and the stem diameters, or to have the stem machined if needed.

 

how are you getting cruise control from a front end swap?

 

I removed my stock bearing races brought them to work and opened the I/D of the race to match the O/D of the stem then replaced the old bearings with new ones. the new fork setup has a throttle lock on the end.

 

The races is part of the bearings....you should never machine a bearing they're garbage now, just throw them away an by new ones of the right dimensions or modified your stem to suit originals....

 

These races are flat with a channel in the middle for the bearings to ride in. I didn't machine any bearings I replaced my old bearings with new ones.

 

I just opened the middle hole for the new stem to fit through it.

 

Exactly that's part of the bearings.... But suit yourself you'll see what i mean. These bearings is one of the most important things on a motorcycle....

 

The forks have throttle lock on the end?!?!

 

Yes. have you never seen one?

 

I'm getting the sense of concern of the safety of this retrofit and maybe some more detailed photos would be instructive?

 

Let's hope you never get an engine in that one....

 

Not on a fork end.......

 

What are we supposed to be looking at? All I see is a broken bearing cup

 

sorry the end of the grip in the second picture there is splines that's the lock

 

Why do you say that swede?

 

there's a big difference between "fork end" and and "handlebar end"

Sort of like there's a big difference between "dead" and "alive".......

 

+1

 

If that's not broken out, explain it.......cuz it sure looks broke. If it is, those bearings won't be in there long.......

 

You are going to die. Seriously. I'm not joking around at all here.
That is not even remotely a safe bearing setup, even if the bearing cup is intact.
You have too much of a gap (in several places), the bearings have no shielding (and no grease).

 

Ehh I think it'll be ok.

 

It won't. Not for long.
Considering all the help we've given you so far, I have to wonder why you are not taking our advice now.

 

+1

 

I'm not finished with it yet this is just a mock fit up to see what all I will need to change and how I can make it safer.

 

That is the sketchiest thing that I have ever seen. Please do yourself a favor and do not ride that until it is fixed. You have ball bearing showing and that is never a good thing. It may "feel solid" now, but one bump, or even vibration from moving might shift the whole thing out of wack and you will eat concrete and it will do damage to both you and your bike.

 

Not good.
There is not suppose to be a gap between the upper tree and the bearing lock nuts. They are suppose to be tightned together. You need to loosen the forks to allow them to come together or make a spacer. The upper tree will keep the steering head bearing locknuts from working loose when installed correctly.

 

Oh, thougth you said it was ok....?!