M
mark m
Guest
Where would be a good place to look for someone to turn a set of rotors? I installed a new set of pads this year and the pulsing has never quite gone away...
Mark
Mark
-
Required reading for all forum users!!!
Welcome!
Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.A note to new registrants...
All new forum registrations must be activated via email before you have full access to the forum.A Special Note about Email accounts!
DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.A note to old forum members...
I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.
Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...
-
Returning Visitors
If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.
If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.
frosty5011
Forum Mentor
Any little Mom&Pop brake shop, where they know you release them of any liability.
M
mike J
Guest
Most anyone who tries to turn a motorcycle rotor usually ends up trashing it. Motorcycle rotors are much thinner than a car, that along with them sometimes have holes or slots adds up to lots of chatter and big problems. You need to find someone who can grind the rotor instead of turn it. It makes a much nicer job. Mike J
Re: Turning Brake Rotors?
On my '79 1000E, (front rotors) the difference from new (.21) to service limit (.19) is only .02"
Removing an amount necessary to make them flat again will surely make them thinner than the service limit. Then they'll really warp with any use.
I don't recommend turning the rotors. Read a factory manual for your model. Compare new rotor spec with the service limit spec.mark m said:
On my '79 1000E, (front rotors) the difference from new (.21) to service limit (.19) is only .02"
Removing an amount necessary to make them flat again will surely make them thinner than the service limit. Then they'll really warp with any use.
M
mark m
Guest
On my 82 the service limit is 6mm (0.24"). I will have to check them and see where they are against that. I have to disagree about taking more than 0.020" off. It should only take a very light cut to clean them up or they would be horrible to use. Mine are not that bad at all, just a bit of a nuisance.
If they are knackered, then where do I look for replacements? E-bay? Or elsewhere? I expect new replacements are fantastically pricey and buying used brake components doesn't seem like a great plan to me. They may have the same issues I am dealing with now.
I do have a buddy who is a home machinist, maybe now is the time for a custom set of cast iron rotors...
Mark
Mark,
My '83 GS1100E had a pulsing lever years ago when it had a relatively low mileage (I don't remember the exact mileage but I think it was under 10,000). The local shop told me this was common with these bikes and that once they were turned they usually didn't warp again. They turned my rotors and I haven't had any problems since. I now have 34,000 miles on it. I'd recommend finding a good local bike shop to do the job.
Joe
My '83 GS1100E had a pulsing lever years ago when it had a relatively low mileage (I don't remember the exact mileage but I think it was under 10,000). The local shop told me this was common with these bikes and that once they were turned they usually didn't warp again. They turned my rotors and I haven't had any problems since. I now have 34,000 miles on it. I'd recommend finding a good local bike shop to do the job.
Joe
Mark, I was just trying to point out you don't want to remove too much.
In my case, I would only have .02 if they were NEW. Mine measure at .20 after all these years. So if I had your problem, according to Suzuki, I could only remove .01 and I'd be at the limit already with no material left for future wear. If yours aren't pulsing that bad, you're OK to remove some I guess, especially after what Joe said. I have to wonder why he says (he was told) they won't warp again. I'm not saying they would, but if they're cut thinner than they are now, why couldn't they?
I believe EBC makes rotors for your model. Probably others too.
In my case, I would only have .02 if they were NEW. Mine measure at .20 after all these years. So if I had your problem, according to Suzuki, I could only remove .01 and I'd be at the limit already with no material left for future wear. If yours aren't pulsing that bad, you're OK to remove some I guess, especially after what Joe said. I have to wonder why he says (he was told) they won't warp again. I'm not saying they would, but if they're cut thinner than they are now, why couldn't they?
I believe EBC makes rotors for your model. Probably others too.
C
Cajun Cycler
Guest
I was told by a dealer that turning rotors was a bad idea. I would look for a replacement set on ebay or check out Dennis Kirk. However new rotors are pretty expensive.
M
mark m
Guest
No problem, Keith. I understand your concern perfectly, to many people 0.020" is a small amount of material. But I deal with machined items everyday at work and 0.020" is actually a significant cut on many things. If the rotors are too worn, then that option is out.
And it turns out they are... :? I took a quick measurement last night and they are already a touch under the service limit, so they will be going in the scrap pile instead of being reworked.
As for warping again, I think the recut ones should be just as likely to warp as before. The only thing that will change is that the new rotors may have residual stresses in them from manufacture that will warp the rotor when it gets its first few heat cycles. After that, they should be stable.
The pulsing is not that bad at all. At speed it is not noticeable with a solid pull on the lever. The only nuisance is that I get a slip-grip-slip effect when rolling to an easy stop that makes the front pogo a bit and makes it hard to stop smoothly (don't want the cagers to think I'm a newbie with all that wobbling around...
).I am going to look at getting my buddy to work up a set of cast iron rotors with aluminum carriers this winter and I will install them for next season. I will just live with it for the rest of this season.
Mark
All this talk about about minimum service limits makes me wonder, what happens if the rotor IS past it's service limit? I'm not sure, doesn't the piston just go in a bit more and make up for it?
Are all the parts in a typical brake system only allowed to travel a certain amount? I know this is a safety issue.
Don't get me wrong, I wouldn't ride on less than service limit rotors, nor suggest someone else do, that's not what I'm saying. I'm saying what happens if you do, because I bet a lot of riders do and don't know it?
Are all the parts in a typical brake system only allowed to travel a certain amount? I know this is a safety issue.
Don't get me wrong, I wouldn't ride on less than service limit rotors, nor suggest someone else do, that's not what I'm saying. I'm saying what happens if you do, because I bet a lot of riders do and don't know it?
Riding below a service limit means the rotor will heat up excessively. The engineers designed the rotor to handle a certain amount of heat, the thickness of the rotor plays a big part in that. Hot rotors warp easier, although the cooling holes relieve stress and allow them to cool. changing to different calipers, a popular modification, may cause problems if larger pads are used since a larger pad will change the balance between cooling and heating of the rotor. It's probably best to leave things stock and not try to reengineer brakes too much.
If a groove is cut into the rotor it could fail and the result would be catastrophic to say the least.
Rotors are available used, around 15.00 a piece seems to be the going rate, and that is a better deal than turning them.
If a groove is cut into the rotor it could fail and the result would be catastrophic to say the least.
Rotors are available used, around 15.00 a piece seems to be the going rate, and that is a better deal than turning them.
A
Anonymous
Guest
I think that having the rotors turned too much would bring them below the mass deemed necessary to soak up the heat generated by a vigorous stop. I have never heard of rotors being ground but I like it. Flywheels in dry clutches are ground so that the clutch will have a perfect face to operate on so why not rotors. It could be a more sutle method.
Flywheels are far thicker than rotors and don't deal with the friction a rotor does. They operate exactly the opposite from flywheels in that they do their job sliding and flywheels work when they connect.3phase said:
If a flywheel breaks from being to thin you call a towtruck, if a rotor breaks you get to talk to St. Peter.
Yeah, heat dissipation is one of the thoughts I had too.
I never thought about the possible problem of over-heating the rotor because a more modern/multi-piston caliper was used with an older stock rotor. I bet many here have done that, but maybe they don't push their brake set up too far.
I kept mine stock, except for the SS lines and drilling the rotors out. Stock '79 was a solid rotor. I do recommend the drilling though. They run cooler and don't gall like they used to. They don't sqeal like they used to either.
I never thought about the possible problem of over-heating the rotor because a more modern/multi-piston caliper was used with an older stock rotor. I bet many here have done that, but maybe they don't push their brake set up too far.
I kept mine stock, except for the SS lines and drilling the rotors out. Stock '79 was a solid rotor. I do recommend the drilling though. They run cooler and don't gall like they used to. They don't sqeal like they used to either.
