Front End Upgrade?

I stopped by the bike yard today to see if they had any new arrivals.

I was checking out what I believe is an '89 Yamaha Radian. It caught my attention cause it has dual front brakes. Unfortunately, it runs a 16" tire and that would drop my bike a little to low.

That lead me on to looking at an XS model. Is it possible to put an XS, dual disc, front end on the old 650 maxim?

 

To run an XS650 front end you would have to change the tubes and triple tree. The XS650 uses 35mm tubes while the XJ650 uses 36mm tubes. If the neck is the same length as on the XJ650, you should be able to swap the triple tree over with a possible bearing change. Maybe someone on here has done the swap and will chime in. Of course doing this kind of swap you will also be looking at a wheel swap as well. Master cylinder will also need to be swapped. Gauges and ignition may also not mount up properly to the new triple tree.

 

Thats what I thinking. The fork tubes on the XS are junked anyhow. I think I may be able to find another donor bike to pull tubes from for the XS front end.

The master cylinder and gauges are all there too. What I don't understand is why Yamaha put rear disc brakes on the XS and not the XJ. Also the speedo runs to like 140 or something. I'm gonna ride my bike out there today and really compare the two a little better.

Another thought hit me this morning. I believe the dual disc front end should be a little wider. That leaves me questioning if the top tree will have any clearance issues with the 750 tank I am putting on my bike....

Anyone have any more thoughts or experience?

 

Might want to check out if the steering head bearings (size) are the same.

 

Prince_albert
You can save yourself a lot of hassle, and headache by just using the '83 750 Maxim front end for a dual disc brake swap. It is a tried, and proven mod.

Note: I suggest the '83 750 maxim only because of the low fluid sensor in the '82 master cylinder.

The front wheel is the same on both 650's, and 750's. Remove the cover from the right side of the 650 wheel, and bolt up the brake disc.

Parts needed:
Forks (will slide into the 650 steering head with no issues, same lower tree on the '83 750)
Brake calipers
Brake rotors
Master Cylinder
Lines (750's double up on the bottom of the brake union to add the right side brake line.)

Areas of concern:
Master cylinder mounting: The 750's use a straight mounting on the master cylinder as apposed to the angled mounting on the 650's.

Front forks: 750's use air assist on the front forks. Seperate on the '83. Crossover hose on the '82. The '82 air assist crossover may not work with the 650 lower tree.

Ghost

 

Same fork tube diameter can be found on:

Code:

FZ-600 S/SC/T/TC/U/UC 86-88 36mm Fork Tube
FJ-600 L/LC/N/NC      84-85 36mm Fork Tube

Compatible Steering Stems (XJ650 Frame, bearing swap on triple tree):

Code:

Bike    Year  Bearing Sizes     New Fork Tube Size
YZF600R 95-00 25x47x15   Upper -- 41mm Fork Tube --
              30x55x17   Lower
Note: Must grind down bottom of headstock ~1.0mm
FZR600  89-99 25x47x15   Upper -- 38mm Fork Tube --
              30x55x17   Lower
XJ650   80-83 25x48x15.2 Upper -- 36mm Fork Tube --
              30x48x15   Lower
FZ600   86-88 25x48x15.2 Upper -- 36mm Fork Tube --
              30x48x15   Lower

Of course, double check everything especially triple tree lengths before you commit to a purchase!

 

I Know this post is really old, but this is exactly the topic I have a question on.

I got rid of the original speedometer/tachometer and I have a clip-on steering.

Now the upper triple tree looks bad with the brackets for the original steering... will an upper triple tree off an 1986-1988 FZ600 will fit my 1982 XJ650 ?

Or i need to get both the top and bottom triple trees..

Thank you guys!

 

you may be able to have the brackets milled down to remove the riser

 

When I was changing front ends on this bike I used All-Balls. They seem to have a solution for any situation. The 02 gsxr front end needed a bearing cup made, like on a bicycle ,to make up the difference in length . My XJ,XS and my DS80 have tapered rollers in the steering neck.