wrong fork tube xj750

my bike is a 5n1 1982 built xj 750 ,I know this bike has been in an accident before mine because of the various scrapes and the fact it has two different fork tubes ,one with a black plastic cap covering a push in plug with a wire retaining clip (the correct one?) and the other a screw in plug with a hex key drive for removal, was this style from an earlier model? the mechanic who replaced fork seals told me that the anti dive was missing ,forgot to ask which side, I can only presume it was some lower workings inside the fork, and is it acceptable to only have one side working?

 

Anti-dive changes the way the dampening works when you whack the front brakes on... so... having only one working may be problematic.
But... in saying that, being a human I'm sure you'll get used to it

 

Photos would help us identify what you have.

 

This is a horrible idea/situation, it's DEATH waiting to happen.

See above.

 

You really should have matching forks , it's easy to identify the anti dive is on the lower fork with a 6 inch hose going to the caliper ,unless it has been bypassed . If it were me I would replace both forks , I would really check the head stock and frame with the tank removed . Make sure there are no bent tube . You can find forks on eBay easy enough usually not real expensive , you can use the Maxim 750 fork which does not have the anti dive, but I believe you have to use the Maxim triple tree , sure chacal or hogfiddles, XJ550H might have input on this , cheers

 

Okay allthough its common to only have suspension in one fork on a mountain bike, on a motorcycle, which is much heavier and faster... This is a recipe for disaster.
Different forks will cause the wheel to try to twist on its vertical axis, as one fork will be stiffer that the other.
This can cause the forks to bind and will also act very strange when leaning into a corner.
No matter what get a matching set... Serious injury or death may result!

 

sounds like a xj700 or virago fork tube with the threaded cap

anti dive bolt to bottom of fork tubes


sounds like the whole tube assembly was swapped into the forks

 

All external anti dive components there, I think my mechanic said there was something missing, I presumed he meant internally? So I need one fork tube and whatever I need for the anti dive. I am trying to get one local (Australia), postage and exchange rate is a killer, although looking USA for rh engine cover

 

Yo

You're just missing the brake-side of the anti dive. That makes the anti-dive inactive, but poses no danger.
The lowers are the same, so my guess is that the upper tube was replaced (likely due to being pitted since the other tube is the correct one, and appears to be straight).
The internals are unique to those forks, so I doubt that they are from the bike that the replacement tube came from).

Go ride.

 

Twin disc , looking at externals all the anti dive is seems to be there , (sorry about the picture quality). I will ask my mechanic when he gets back exactly what was missing when he did the fork seals, I need to either straighten or replace the fork tube with the hex cap as it is bent after a spill.
thanks for all the replies. Graham

 

very difficult to straighten fork tubes with out proper equipment.

 

see this thread about anti dive good photos
https://www.xjbikes.com/forums/threads/doing-the-750-secas-forks-rebuild-now-a-how-to.18730/

 

The brake actuator side of the anti dive is missing from both of your lower tubes. Without those parts the anti-dive does nothing.

 

True, but that equipment is far more commonplace in Australia and the U.K. than in the U.S.
They fix things, we throw broken stuff away and buy new (which is pretty dang wasteful).

 

Sorry K_moe misunderstood, actuators are still connected to brake line, so I don't need to bleed brakes when resembling. When I find out what my mechanic said what was missing ,which I thought was inside the fork tube I will decide whether to purchase the bits I need and get the tube straightened or get a new fork.

 

NO....and it's not acceptable to have mixed forks!! And personally, I wouldn't try to straighten them. I'd get replacements

 

IF the internals are the same, the spring rates identical, and the tubes of the same diameter and length there will be no functional difference.
All of those things should be checked (the upper tube is clearly the correct diameter), and based on what the mechanic noticed about the "missing" anti-dive parts (I'll assume he meant the parts that are still on the bike) he seems to know his stuff.

There are (mostly were anymore) bikes that have the spring in one fork, and the damper rod in the other. Those were lighter (and less expensive) machines for the most part, but the suspensions worked well enough, and were safe for normal road use.

 

That's a lot of "IF"'s

 

No more than usual. Refurbishing forks (refurbishing anything really) should always include inspecting the parts, even when fitting NOS replacements.

 

i'd be looking for the adjustable Maxim forks, myself