Rotor turning/resurfacing in Colorado?

[rgoot01]

Do any Colorado members know where I can send my rotors to be turned/resurfaced. I live in a small town in the mountains and no one does this here and I can't get a good lead on who does. Any help is greatly appreciated. Thanks.

[hightec_redneck]

Hello, I do not know how bad your rotors are, but the stock rotor material is not very hard. I also live in a fairly remote area and just finished resurfacing mine. I used a 6 inch random orbital sander and started with 80 grit paper. Then using light even pressure went around the rotor taking a little off with each revolution. I know this is not the easy soultion, but if you are careful and take your time, it can be done. I stepped to 120, then finished up with 220. If you are interested in doing it yourself, let me know and I can explain in more deail.

[rgoot01]

I entertained the idea of doing it myself as well. I worked for a good number of years as a wrench for a rock quarry and found myself on many occasions having to improvise either tooling or machining processes in order to get a piece of equipment up and running. I personally am confident in my abilities to where I would have no problem doing my own resurfacing of the rotors. Now given that you have resurfaced your own rotors with success, using nothing more than basic tools, it looks I like have some rotors to remove. Thank you for your reply it is greatly appreciated.

[crazy steve]

These were never intended to be resurfaced; the only option is replacement which is why you can't find anybody to do this. Minor grooving won't hurt a thing, only if you have grooves deeper than about .010" should you worry.

As to 'resurfacing' these by hand (!!??), rots of ruck. These are precision parts and the importance of uniform thickness, how parallel the two sides are, and maximum runout can't be stressed enough. Factory limits are minimum thickness: 6.5mm or .260" and runout > .15mm or .006".

I'm not saying you can't get lucky and manage to do this by hand, but miss on any of the above and you can have brakes that will be unpredictable under hard braking and may injure/kill you. Not worth it to save a few bucks, not when good used rotors are readily available from multiple sources. Look in the 'parts for sale' forum here, or EBay among other places.

How touchy are these to 'hand work'? Some vendors sell 'show polished' rotors that are fully polished (including the braking surface) and I can tell you from experience that the much less aggressive polishing process will remove enough material unevenly to make these unusable on a normally-ridden bike.

'78E original owner

[jmnjrpa]

Look out

The surest route to the grave that I know of is HAND WORKING the rotors!!! DO you know how much .006 is?
that is the width of 2 hairs. Don't gamble with your life that way.

[jmnjrpa]

Btw

Any decent machine shop can redo the rotors for you if they are not too bad.

[fredintoon]

Do any Colorado members know where I can send my rotors to be turned/resurfaced. I live in a small town in the mountains and no one does this here and I can't get a good lead on who does. Any help is greatly appreciated. Thanks.

Hi Robert,
you have a 1980 Standard which I understand does not have slotted rotors?
Like hightec sez, Yamaha rotors are not particularly hard.
What they are is made from an alloy that's as tough as old boots.
They cannot be resurfaced on a brake shop's specialized disk & drum lathe.
Those machines work great on cast iron but the Yamaha disk surfaces just get all torn up.
I salvaged a rear disk that the PO had run the pads down to metal on with a sanding disc
on an angle grinder one time so hightec's surface sander trick should work for you.
Think about getting later model slotted disks or drilling the ones you have
(drill press, cobalt steel drill bits, slow speed, high bit pressure and lots of cutting fluid)
Slots or a hole pattern tend to keep a disk in better shape,
some claim that the grooves
in a marked disk will partially clean up in use after it's been drilled.

[rgoot01]

Thanks for the info Fred. I think I am going to give it a whirl. I do plan on drilling the rotor, in fact I downloaded the templates from Ken Talbots post on drilling the rotors. The wear on the rotors are normal, infact I really don't need to do anything to them, but I want to clean them up since they will be off when I drill them. I appreciate everyones concern towards doing it myself,but I know how to use abrasive power tools, am confident in my abilities, and know that the results will still be better than running my chopped KZ1000 with nothing more than a rear 650 wheel and only braking be that of rear drum. Also would like to say that even though tolerances are in thousandths;calipers, micrometers and precision ground straight edges, will keep me from any questionable outcome.

[crazy steve]

....The wear on the rotors are normal, infact I really don't need to do anything to them, but I want to clean them up since they will be off when I drill them...

If it's only appearance you're looking to improve, stay away from sandpaper and use a maroon scotchbrite roloc pad on them. This will remove all the 'grunge' without removing good metal. That's what I did to mine, and it made them look near-new. To see how well it works, look here:

http://www.xs11.com/forum/showthread...t=shiney+stuff

A couple of these were brown when I started....

'78E original owner

[bikerphil]

I do plan on drilling the rotor, in fact I downloaded the templates from Ken Talbots post on drilling the rotors

I drilled these rotors with Ken's template, but I opted for the 3/8" holes....

[Ivan]

So, you're running a liter bike with only a rear brake, and now you're going to try resurfacing a rotor by hand that was never meant to be surfaced by a machine?

Seriously, get your life insurance paid up and pick out a couple songs for your funeral service. Not that you can't gamble with your own life, but at least try to leave those who do care about your life with some financial security and save them the ****ty job of having to think what to play or say at your service. You might want to make sure your life insurance doesn't have a suicide exclusion either.

[Jerry]

There have been threads on this before. The margin for wear on the rotors is very small, to the point where it is better to replace rather than re-surface. However, I did have a set done several years ago at a machine shop. The shop used a large surface grinder rather than a cutter to do the work. Rotors looked very nice and were just at minimum spec when done. Cost was about $30.00 per rotor. I would not do that again, but it proves it can be done if you have access to the right equipment and the rotors are not in to bad a condition to begin with.

There is a cross-list in a past thread of what Yamaha rotors fit the XS and XJ; IIRC they are mostly Seca units from the early '80s.

Re drilling, 1 comment. TKat, a well-known machinist who makes a great fork brace for the XS - XJ 11s, once commented that the beginning hole in each "set" should be off set a few degrees to help eliminate harmonic vibration within the rotors. This means that one set should start a little closer to the hub, then the next set a little farther away, the next set closer again, and so on until the rotor is completely drilled. He also recommends champhering (sp?) the holes.

[rgoot01]

So, you're running a liter bike with only a rear brake, and now you're going to try resurfacing a rotor by hand that was never meant to be surfaced by a machine?

Seriously, get your life insurance paid up and pick out a couple songs for your funeral service. Not that you can't gamble with your own life, but at least try to leave those who do care about your life with some financial security and save them the ****ty job of having to think what to play or say at your service. You might want to make sure your life insurance doesn't have a suicide exclusion either.

Ever look at a custom bike and see a lot of the with only a rear brake? These bikes are heavier than my chopped XS. The rear brake only works fine. Rather than be negative why don't you look at it this way, I obviously have a greater confidence in my abilities than you have in yourself. How do I know this, because I am willing to do it.

[rgoot01]

If it's only appearance you're looking to improve, stay away from sandpaper and use a maroon scotchbrite roloc pad on them. This will remove all the 'grunge' without removing good metal. That's what I did to mine, and it made them look near-new. To see how well it works, look here:

http://www.xs11.com/forum/showthread...t=shiney+stuff

A couple of these were brown when I started....

'78E original owner

Yes. I thought of the scotchbrite. In fact thats probably wht I will do because it is just the very surface I want to clean. There aren't any gouges or anything like that.

[psycoreefer]

Ever look at a custom bike and see a lot of the with only a rear brake? These bikes are heavier than my chopped XS. The rear brake only works fine. Rather than be negative why don't you look at it this way, I obviously have a greater confidence in my abilities than you have in yourself. How do I know this, because I am willing to do it.

Just because you see it done on a custom bike doesn't mean its a good idea, will it "work" sure it probably will, is it a good idea? well that's open to interpretation. Its a well known fact that 70% or more of your bikes braking power is from the front, this mean with no front brake it will take you 70% longer/further to stop then a bike with both brakes, you have to decide if that is a risk your willing to take, I wouldn't and It doesn't sound like Ivan would either, but it is your risk to take. Ivan was just trying to point out (in his own not so subtle way) that what your doing is a "high risk" modification.

To say that you have more confidence in your abilities is an assumption, all you can really say is your willing to take a bigger risk.

I'd say that if you want to ride a rear brake only setup thats your choice, just be aware of the risk your taking and please leave lots of room in front of yourself should you need to stop in a hurry. We all hate to see stories of other riders injured in accidents, regardless of if we agree with their approach to modifications. Plus I think some of the custom bikes look real cool too, I just wouldn't personally ride many of them, but cool to look at.