Front Rotor Advice

[jacksf]

How big a deal is it to remove/replace the front rotors on a XJ? Been thinking about having Merle drill and deglaze them but don't want to start something that's a pain to finish.

Thanks

Jack

[pathfinder]

Easy on and off but to turn them is a B#$%h. Chech out mikesxs.com he has some that will fit the XS should work on an XJ, but what do I know. Before you check out Mikes I will warn you they are very pricey.

[TopCatGr58]

Hey JackSF,

Aside from recommending NOT to try to get them "turned", deglazing should be okay, there are 3 sets of special lock washers for each side, brittle metal, designed to fold up against the hex head of the mounting bolts, will fit a pair of bolts. They are also rather pricey, even from bike bandit. Top number is Yamaha OEM, bottom is BB #:

3H5-25834-00-00 WASHER, LOCK
WASHER,LOCK 34350-001 $4.12

I don't know if a standard split compression lock washer would work under the bolt since the rotors are fairly hard steel vs. cast iron for cars? But I've also seen a set of rotors mounted with allen head bolts with NO lock washers!? But they are otherwise bolton/off process!
T.C.

[John]

I have been using regular type lock washers on my front rotors for years, and they have'nt loosened up at all. In fact, my rotors and wheels are from an XJ.

[Winterhawk]

Put your rotors in a lath. Use a belt sander while the lathe is running. Finish them off Emery cloth and a piston pin. XS's have very thick rotors and in most cases you can sand them down and the look superb. Don't use a cutting tool on them.

[jacksf]

Originally posted by TopCatGr58
Hey JackSF,

Aside from recommending NOT to try to get them "turned", deglazing should be okay, there are 3 sets of special lock washers for each side, brittle metal, designed to fold up against the hex head of the mounting bolts, will fit a pair of bolts. They are also rather pricey, even from bike bandit. Top number is Yamaha OEM, bottom is BB #:


I don't know if a standard split compression lock washer would work under the bolt since the rotors are fairly hard steel vs. cast iron for cars? But I've also seen a set of rotors mounted with allen head bolts with NO lock washers!? But they are otherwise bolton/off process!
T.C.

Great, that is what I was wondering. The same guy that makes the YIC tool drills patterns on the rotors and deglazes tham also. My personal feeling is the XJ's brakes are not its strongest point. I know I need ss brake lines. Thought about using a 2 line system rather than a 3 but decided to leave that part alone. My right front, no matter what I do has always been soft, even when the bike was fairly new. But it does work, just have to really squeeze it.

[jacksf]

Here's a pic of the drilled rotors


http://plan9.dnsalias.org:88/xj/phot...s/DSC03152.JPG

[LoserShoes]

Stainless rotors can be turned on a lathe, but it takes a certain grind on the lathe bit and spray mist coolant. The chip comes off in long sharp spiral. Pretty hard to find some one that can do it in this era of CNC.

Steve

[Ken Talbot]

Hey, Jack, here's another pattern for drilling rotors:

Read all about it at this link

[jacksf]

That pic sorta tells me its not worth the time and trouble. Too fancy for my ol gir.

Thanks

Jack

[Pat Kelly]

If I can do it for "the $60 Gem" (the crappiest looking bike at Big Is Deuce) then you can too. My modification to Ken's pattern (that I used) was each hole was one size smaller from inside out. The holes nearest the hub were largest, then the next 'ring' of holes were smaller, then smaller, etc.
When I got a set of tubeless wheels the rear had a slotted rotor. I swapped the front rotors to match the direction of the rear. That's why I stand by my claim that the direction of the holes/slots is cometic (while stopped). I've noticed no difference in the front brakes after swapping the rotors side to side (last year).

[dragxs11]

Hey Jack,
If your getting pulsing brakes, first try and rough up the pads with sand paper. I've had it happen that they get too smooth and do the slip-n-grab. It happens on lots of bikes.

[jacksf]

Nope, no pulsing, no grinding, no nothing. Just slick as a baby's butt. Right now my best guess is that the hose is totally shot (original still on) and there is just not enough pressure to really clamp the pads. I want to get a complete set of ss but I want to buypass the valve in front, go directly from the rear master to the left front. I just hate to pull the whole brake system apart to measure.

I can still ride her, foot brake works fine and the front will eventually stop her just wouldn't do me any good in a panic stop, not that it was ever that good anyway. Too much mass for a single rotor IMHO, they were designed to use both brakes at the same time.

Jack

[TopCatGr58]

Hey Jack,

THere isn't any "VALVE" in the front of the bike, that's just a joint! The Proporioning valve is actually located next to the rear master cylinder, then the two lines run to the rear MC and front one. My question is WHY do you want to bypass the Prop. Valve, but keep the front linked to the rear brake lever? IIRC, it sends more pressure to the front than the rear during actuation, and bypassing it would actually lessen the front pressure, and increase the rear making it more likely to lock up the rear?

If you are wanting more braking power for the front, then link the 2 front calipers together, and separate the rear to itself!
T.C.

[jacksf]

Originally posted by TopCatGr58
Hey Jack,

THere isn't any "VALVE" in the front of the bike, that's just a joint! The Proporioning valve is actually located next to the rear master cylinder, then the two lines run to the rear MC and front one. My question is WHY do you want to bypass the Prop. Valve, but keep the front linked to the rear brake lever? IIRC, it sends more pressure to the front than the rear during actuation, and bypassing it would actually lessen the front pressure, and increase the rear making it more likely to lock up the rear?

If you are wanting more braking power for the front, then link the 2 front calipers together, and separate the rear to itself!
T.C.

Got it, and what you say makes sense. I imagine the way the brakes were designed were to provide braking to the left front proportional to the amount of braking applied to the rear to avoid locking up the rear. Additional stopping is provided by the right front which, I guess, wasn't designed to be used as a solitary braking system.

I had thought about doing the dual front but the more I thought about it the less I liked the idea. Much of it being the way I ride. I am a cruiser not a sport type, Lincoln Town Car vs. Corvette. I am still trying to get the feel of the new fork springs and bearings, really feels light compared to the old setup. Dual front braking would really dive the front making the rear less stable with all the weight being moved forward and possibly causing the rear to swing around easier.

Understand, I have no way to prove this, just things I think about when not tinkering.

Jack