‘82 650J Maxim front end conversion

I have a full stock 1982 650 J Maxim and I’m looking to swap the front end to an ‘85-‘88 FZ 700 or FZ750. Has anybody done this? Will it be an easy swap with minimal fabrication?

 

All Balls does list upper and lower bearings for that conversion (87 FZ700) so it is doable from that perspective. They do not list the stem length though or lock to lock dimensions/clearance from tank etc. Do you have the donor front end already? Unless someone else here has done this, you'll probably want to grab a triple tree from both bikes and compare. Should be fairly inexpensive to source them.

 

I don’t have the donor yet, didn’t want to purchase and find out later it’s going to be a long road of fabrication. But buying the triple tree and comparing is a good idea. I will do that. Thank you.

 

You can convert just about any front end, that being said there is some major factors to consider.

1. the new steering stem diameter and length.
2. are bearing and race sets already made for that speciffic conversion, and if not the special made cost for them.
3. can the frame neck handle the potentially altered rake angle, and bearing race install method
(may require added strength gussets welded in)
4. bearing type..ie.. sealed vs taper.. etc. and does the neck need to be modified to fit the type of bearing the donor front end requires.

it's a fairly techy.. process that needs some research for anyone, but if your not used to this kind if work, I recomend you stick to the already approved fitment front ends and bearings. similar to the "all balls" site that @jayrodoh has mentioned for you.

start here:

https://www.allballsracing.com/forkconversion/

 

Generally I like to go to modern type forks, I.E. cartridge style forks. There are conventional cartridge forks and upside-down cartridge forks so if you want the traditional look
use the conventional and still get modern performance. Second choice is larger diameter tube conventional, with improved brake calipers and rotors that still may have small diameter
axle size. There are a number of 41mm dia. tubes out there. That way your original wheel may have a chance of bolting up? If using older damper rod forks I suggest also using
Race Tech Emulators to upgrade to near cartridge fork performance level. Emulators work very well.
Cheers, 50gary

 

Another thing to consider is the rear wheel.
I believe the FZ750 front is 16" x 2.75 and this would complement your 16" x 3.0 rear.
Nothing looks dorkier than the wider rim up front, not to mention what it might do to the handling.
The shaft drive limits your option for rear wheels without custom fabrication.
One bike you may consider for the front wheel and forks is the 86-88 FZ600 or YX600 Radian.
These forks will slip right into your stock fork crowns, keeping your instruments/headlight the same and ensuring nothing fowls your tank.
This wheel is 16" x 2.5 which combined with your OEM rear gives you the same wheel/tire combination as the Radian.