XJ550 fork swap

I am contemplating a minor fork swap on the 550. I want to keep the original wheel and generally keep alterations to a minimum. All I want is dual discs - the single sure doesn't seem to be doing it.

First idea I had was getting a Euro-spec fork. Thing is, I'm here, it's there, and it seems to be a bit difficult and probably expensive.

Second idea I had was using FJ600 forks. The popular list of fork tube sizes says they are the same. The list is wrong. I measured. XJ550 is 35mm. FJ600 is 40mm. The length is the same.

The list says the bearings between XJ550 and FJ600 are the same.
Upper: 25 x 48 x 13
Lower: 30 x 48 x 13

However, the FJ upper triple is this goofy affair with proprietary single-bolt bars. Do not want.

Third idea I had was using a 650 Seca fork
XJ650 forks are 36mm according to the list. Can anyone confirm this?

Also, XJ650 bearings are close in size.
Upper: 25 x 48 x 15.2
Lower: 30 x 48 x 15

I should be able to just swap to the smaller size and install the whole fork. However, would the wheel fit?

 

I can't add any info to the fork swap but if all you're looking for is increased stopping power I highly recommend installing some stainless steel brake lines. I just added them on my xj550 and the difference is huge in comparison to the stock rubber ones. From a cost and time standpoint it would be much more advantageous over swapping the entire fork assembly. Additionally double discs won't necessarily increase stopping power, they just dissipate heat quicker which reduces break fade. I'd argue that a dual disc setup with rubber lines wont stop as hard as a single disc setup with stainless steel lines.

 

http://www.xjbikes.com/forums/threads/xj-550-with-gsxr750-front-end.85240/unread

 

I was just about to chime in with this.

One of the main reasons that I decided to go with a fork swap was for the increase in braking power. I'm not so sure about being able to keep an original wheel, but swapping a GSXR750 front end is a fairly easy swap. If you can find a cheap front end that is complete, it literally takes $40 in bearings and $20 in labor if you don't have a press or a bearing puller. You'd have to look into it, but a 96 and older (I'm pretty sure this is the year) gsxr front end has conventional forks, if you want to keep the same style of fork. Let me know if you want any information and I'd be happy to help in any way that I can!

Edit: I lied, I'm thinking of GSXR600 forks being conventional. I'm not sure how far back you need to go to get conventional 750 forks, and by that point, there is a huge possibility that the simplicity of the swap is no longer a factor.

 

Bearing removal is as easy as carefully cutting the old one off. Installation can be accomplished by freezing the stem, heating the bearing, and dropping it on (tapping it in place with a brass drift might be necessary if you don't work quickly).

 

Already have it. Brake lever is rock solid, no give.

The problem is that it takes a significant amount of force. I do it without even thinking, but my wife has much shorter fingers and has trouble squeezing hard enough.

If I could find a smaller bore adjustable lever MC, that could solve my problem, too.

Saw that. Don't want a swirly wheel. The Seca has straight spokes, and I'd like to keep it that way.

Thanks!


This was so much easier on my FJ1200... I swapped to late-model fork legs, which gave me bigger brakes, and then swapped to FJR master cylinders, which gave me adjustable levers and ability to brake with my pinkie.

I'm wondering what it would take to get the FJ600 upper triple machined flat and get some risers for conventional 7/8 bars.

 

So, after posting that I went and did a little Ebay searching.



The upper triple has these holes.

These things are apparently available for $12 a set



So, I should only really need to grind the ridges flat and I could convert FJ bars to standard.

I am going to see if the XJ wheel fits the FJ forks. This might work after all...

 

Not sure if it would make the difference your looking for but I swapped my xj550 master brake that was totaled for an xj750 and get loads of breaking power but I am new to this, If I am right and please tell me if I am wrong someone as I am just learning here, but the 750 dual break master has a larger bore that would give the single a little more strength with less pull required. the angle of the master is just a pain to make sure you are topped up right.

 

Depends on your budget I guess. German or UK ebay can be pretty good source. Also look for adverts for guys 'breaking' a bike.
Since you only really want the sliders and a caliper (not shiny stanchions) you should be able to get a deal.. Offer to organise your own pick-up courier (UPS, Fedex and TNT all operate here).. and 'Robert is your mother's brother' as we might say..

 

This guy has the parts you need.. perhaps he will make a bundle price? http://www.ebay.de/usr/tribsa123

 

A larger bore does increase the force at the piston, but it also can turn into a wooden, switchlike brake that won't be controllable if you go too large.

The master cylinder from a Maxim 750 is angled to suit the bars on that bike. The problem is that when placed on flatter bars the angle of the master cylinder is such that you can experience a loss in pressure (braking) when going through curves or during parking-lot maneuvers. The better choice is to either use a master cylinder from a Seca 650, or an aftermarket master with an appropriate bore size.

 

all you need from europe is the right lower fork to do what you want.
Just gonna say it why do you not want to rebuild your current front brake system?
or buy your wife a tennis ball to pratice squeezing to build up her hand
my brakes are not hard to activate

could try sintered/full metallic pads

 

I have the forks from an FZ600 on mine. The stem on the FZ is either too short or too long compared to the XJ,(I forget which, I made the swap over 10 years ago.) so I cut it and turned a slug and had it welded back together the same length and spacing as the XJ. Local machine shop did it for about 30 bucks. I have run an 18" Vision wheel on mine but the stock XJ wheel should work with FZ discs bolted on. The stock wheel has a plastic cover over the right side disc bolt holes.

 

this thread explains the different calipers you can use to go dual disc on a 550
http://www.xjbikes.com/forums/threads/master-cylinder-upgrade.60558/

 

This is kind of the situation now.

I suppose if I put on a master cylinder with a smaller bore, I would have the desired effect, but trying to find an MC by bore size is next to impossible. Some no-name Chinese ones are available, but if you break a lever, finding a replacement would be problematic.

What exactly am I going to rebuild there?

Everything functions properly. Caliper and master cylinder are not seized, move freely. Brake fluid is new. Hose is steel braided. Rotor is not new, but not overly grooved. Pads are in good shape.

Heh. If you find a tennis ball that can actually make fingers longer, I'd like to see it.

 

Don't buy Chinese. If you want value and low cost (compared to the big-brands) look into finding a buyer in Taiwan. That's how I used to get all of my scooter parts without paying the markup that most U.S. resellers charge. And, as always, Chacal has a variety of master cylinders and can tell you what the boe sizes are before you buy.

Here is a chart that might be of help.

http://www.vintagebrake.com/mastercylinder.htm

And Mikes XS lists he bore size for the master cylinders they sell.