Rotor/Caliper Issue

[racerrad8]

Hopefully you have not taken it all apart yet.

Can you make sure the fork are the same installed height in the triple trees? If one fork is higher than the other then you will have an offset and the rotor will be rubbing the calipers.

When you say everything is symmetrical are the rotors both off set to the same side, the outside? Or is one to the outside and the other to the inside?

Randy - RPM

[scott_1200]

I don't have the triple clamps off yet.  I'll try adjusting the height of only one of the forks, like you suggest.  I would have never thought of that.  Thank You!  I'll make the adjustments in 0.5mm increments. I have been using the top lip of the handlebars to set the height of the forks.  I have been setting the bottom of the fork cap (the screw-on one) even with top of the handlebar clamp.

Scott

[scott_1200]

Both calipers are twisted inward towards the tire.  Its the outside edge of each rotor that is rubbing against the caliper.

Scott

[racerrad8]

I have been setting the bottom of the fork cap (the screw-on one) even with top of the handlebar clamp.

Scott

The handle bar clamps are cast and are close as far as being the same height, but I would remove the clamps and measure from the machined surface of the upper triple tree.

Both calipers are twisted inward towards the tire.  Its the outside edge of each rotor that is rubbing against the caliper.

Scott

That tells me the offset & thickness of the new rotors has exaggerated the issue since the are both canted inward at the top.

If they were in on the left and out on the right then that would be the fork height. Then next step before you tear everything down is to confirm everything is square and the same height, then compare the mounting tabs compared to the rotor and see if they are parallel.

Randy - RPM

[Mark Olson]

I'm running the stock wheel size and forks.  Are those calipers bolt on replacements?  Will they work for the 300mm rotor?  Sorry for all the questions and getting a bit off track from the topic.

Scott

Scott ,
the link I gave you is a direct replacement bolt on and go part. even the pads interchange. since your forks are 89 or later.

that is a good price on the calipers , pull the trigger. you are just gonna buy them later anyway.

sounds like you are just rubbing cause of the bigger rotors.

The calipers are a mod most of us have already done . If you look in the gallery check out the front wheels and calipers.

If you don't like the blue ones you can find gold ones to match what you have.

Adding a 14mm master cylinder helps with the feel.  fjr1300 or R-1 .

[scott_1200]

When I get home today, I'll put it all back together again and do checks suggested and post back.  I'll also order those calipers!

For the brake master cylinder, I am using an aftermarket Nissin setup with the urine cup setup.  I'll post some pics of the setup.

Scott

[craigo]

I'm running the stock wheel size and forks.  Are those calipers bolt on replacements?  Will they work for the 300mm rotor?  Sorry for all the questions and getting a bit off track from the topic.

Scott

Yes, they are bolt on replacements. And I do not know if they will work w/ the 300mm rotors. It really sounds like you have more going on there than just the 10mm difference in size. That offset is a strange problem you have there.

CraigO

[scott_1200]

Got home and made some progress.  I put everything back together and was very careful to get the forks at exactly the same height above the triple clamp (see http://www.flickr.com/photos/scottmorton/6751842085/#) and then put the wheel back on and tightened the axle.  I took several measurements from the caliper mounting holes on the fork tubes on each side (see http://www.flickr.com/photos/scottmorton/6751842549/#).  I also checked for any warps in the rotor by giving it a spin (see http://www.flickr.com/photos/scottmorton/6751842311/#). No warps found. 

I then mounted the right caliper (same side as the slightly bent fork) and no more rubbing! The rotor was also pretty well centered, not perfect, but really close.    I then mounted the left caliper (same side as the straight fork) and it's still rubbing.    I am going to try to raise the left fork a little to see if the left caliper will rotate back to center.  I'm just going to loosen the axle, place some wood under the wheel to support it and then loosen the left side of the triple clamp and gently slide the fork up just a little (0.5mm or less) and then tighten everything back up.  I'll report back in a few.

Here's a pic of the brake master cylinder:
http://www.flickr.com/photos/scottmorton/6751941307/#

And a pic of me working on the bike:
http://www.flickr.com/photos/scottmorton/6751941275/#

Scott

[scott_1200]

OK.  I raised and lowered the left fork by a millimeter or two in both directions and then tightened everything up.  No luck.  The left rotor still rubs against the caliper.  The right caliper did move just a hair, but it isn't rubbing against the rotor.

So I'm thinking of taking everything apart tomorrow, including the triple tree and then on Wednesday, take everything to that shop to have the bent fork fixed and to also check the triple tree alignment and have it straightened, if needed.  When that is all done, I'll start all over and hopefully the calipers will center perfectly over the rotors.

Is there a thread that shows how to take out the sanction tube?

Scott

[Arnie]

Scott,

Any of the fork rebuild threads are good.  There is a picture file of the same thing available too.
You may want to replace the bushes, fork seals, and definately the fork oil as long as you have them apart.

Cheers,
Arnie

[scott_1200]

So the next step is to get the bent fork straightened.  I don't know of any shops in the Phoenix, AZ area that have the tools and have torn apart these forks before.  So it looks like I'll need to tear them apart myself.

I found the word document with the step by step low down to tear apart and rebuild the forks in the "Files" section. A Big THANK YOU to all who contributed to that. It doesn't look too hard, just time consuming.  I'll also have to make the tools necessary to do the job.  I don't have much free time so this might take me a week or two, just to build the tools and tear apart the fork.  The seals and bushings are less than a month old.  Should I order new ones or are the seals replaced only when you see them leak? Or do the seals have to be replaced because they have to be damaged to get the fork apart?

Scott

[craigo]

Hi there,

This may help you out.

http://www.devil-riders.com/vb/showthread.php?t=11938

Fast Track Motorcycle Frame Straightening

1734 E Main St
Mesa, AZ 85203
(480) 649-1093

Worth a shot, but the link has a rave review on these guys

CraigO

[Arnie]

I found the word document with the step by step low down to tear apart and rebuild the forks in the "Files" section. A Big THANK YOU to all who contributed to that. It doesn't look too hard, just time consuming.  I'll also have to make the tools necessary to do the job.  I don't have much free time so this might take me a week or two, just to build the tools and tear apart the fork.  The seals and bushings are less than a month old.  Should I order new ones or are the seals replaced only when you see them leak? Or do the seals have to be replaced because they have to be damaged to get the fork apart?

Scott

Scott,

The only special tool you need is the 27mm hex on the end of a long shaft to hold the damper rod while you remove the allen bolt from the bottom of the fork.

Inspect the seals carefully after you have the forks apart.  You may be able to get them apart without damaging the seal lips, but for the minor cost of new seals its probably not worth tearing them down AGAIN.  JMO

Arnie

[scott_1200]

Hi!

I've called the Fast Track shop and they sound like they can do the job and the prices are reasonable.  They need only the sanction tube, so I thought I would remove it myself to save a few bucks.  I'll go ahead and use those saved bucks to get some new seals.  This will be the very first time at tearing apart the forks so I might take a few days to go slow and careful.  Once I get the sanction tube out, I'll take it to the Fast Track shop to get straighted and then put everything back together.

For the tools, I think I can find something to use for the larger hex bolt to remove the cap from the sanction tube.  It's the smaller hex bolt thing and also building the PVC pipe thing to press in the new oil and dust seals. Easy stuff to make, I just have to get the time to get everyting and put it together.  Other priorities have limited my FJ project time, but I'll eventually Get'r Done. 

I am also fighting against Mod-ous Improvement-ous Syndrom (MIS).  That is, the urge to modifiy the forks with cartridge emulators and new springs for improved feel and performance. Must resist....must resist......not enough time...

Scott

[Flyover Country Joe]

Scott,
Just wanted to warn you to remove the small Phillips head screws on the rear side of each slider before you try to break loose the hex bolt at the bottom of the leg. If the damper rod spins while you are taking it apart, you will probably be buying new locator screws. Good thing they are still available from Yamaha, DAMHIK.