Worn rotors

[alke46]

So I have my GS down for maintenance over the winter and taking measurements on the brake rotors showed that all 3 are under the spec limit. The fronts are way undersized, almost like they were put on by a PO from another bike.
The spec limit for the front and rear is shown in the FSM as .24 in. and mine measured .239 rear and .195---.197 front. The rear is just barely under the limit but it needs to be turned and can not be turned without being way under limit. I don't even know what happened to the fronts unless they are not specific to the bike.

So what are my options? Should I just get an after market rotor or should I do the salty_monk upgrade? In my opinion, the stock setup handles the stopping just fine considering it is 1979 standards. Of course the brakes don't stop the bike like today's bikes but then it also does not come with all the extra technology of today's bikes.

All input will be appreciated. Thanks for reading.

[80GS850GBob]

What you want to for stopping power is up to you...it's your bike, not ours. We can all suggest anything but it's your call ultimately.
Now, as far as new or new to you rotors go, since your happy with the way they worked, all you need to do is outsource new{er} rotors and pads. Always swap them as a set. Ebay, here and any other cycle forums can supply you with leads to rotors that are in spec. Have the seller tell you the thickness to determine that it's in spec.
Options- well, you have all sorts of options but it comes down to what you want. Some folks prefer the purists aspect being that everything is dead stock while some are fine with a restomod and newer braking....some even go with a whole new front end. It's your canvas and you can paint it {build it} how you want. The Salty Monk restomod set up works better than stock and if you either keep your air pressure up or go with new fork springs the whole front end feels better - did that to my 850G.

So, aside from new {thicker} rotors....what do you want to do?...dead stock, mild revamp or wild?

[alke46]

What you want to for stopping power is up to you...it's your bike, not ours. We can all suggest anything but it's your call ultimately.
Now, as far as new or new to you rotors go, since your happy with the way they worked, all you need to do is outsource new{er} rotors and pads. Always swap them as a set. Ebay, here and any other cycle forums can supply you with leads to rotors that are in spec. Have the seller tell you the thickness to determine that it's in spec.
Options- well, you have all sorts of options but it comes down to what you want. Some folks prefer the purists aspect being that everything is dead stock while some are fine with a restomod and newer braking....some even go with a whole new front end. It's your canvas and you can paint it {build it} how you want. The Salty Monk restomod set up works better than stock and if you either keep your air pressure up or go with new fork springs the whole front end feels better - did that to my 850G.

So, aside from new {thicker} rotors....what do you want to do?...dead stock, mild revamp or wild?

My interest is probably staying closer to stock. Thanks for your input.

[srsupertrap]

I had my 79 GS1000e & 81 GPz550 (rear only) rotors resurfaced by Chris Schumann (EBay smw70ss). He uses a rotary surface grinding machine and the results were excellent. Not cheap but less than EBC aftermarket rotors etc. I don't see the EBay ad presently but I can send you his email.

I thought the front rotors for the GS1000E were thinner? Looked at FSM Pg 12-7 states Front Disc thickness is .20" The service limit is .18"

[alke46]

I had my 79 GS1000e & 81 GPz550 (rear only) rotors resurfaced by Chris Schumann (EBay smw70ss). He uses a rotary surface grinding machine and the results were excellent. Not cheap but less than EBC aftermarket rotors etc. I don't see the EBay ad presently but I can send you his email.

I thought the front rotors for the GS1000E were thinner? Looked at FSM Pg 12-7 states Front Disc thickness is .20" The service limit is .18"

This is where I get confused, the FSM I am looking at shows chapter 10 page 19 "front and rear disk thickness" standard: (0.26 ~ 0.27 in.) Service limit: under (0.24 in.)

I would also like to know how I can find cross reference numbers so I could expand my search for good used ones.

[alke46]

Upon further review, yes Steve, you are correct. The FSM section covering the 1000E does show the thinner disks for the front. My mistake. I was looking at the specs in the chassis section and did not do my deeper searching. Forgiveness is hearby asked.

[80GS850GBob]

... Forgiveness is hearby asked.

Non sense...you asked a valid question...with the different models Suzi offered it's easy to get lost in the "mine has this but yours has that".
Simply consider this as your future info for when you do need to replace them and never be afraid to ask questions.

[limeex2]

Unless you want the exact stock look, GS1100E are bolt on, easier to find and lighter.

[alke46]

Unless you want the exact stock look, GS1100E are bolt on, easier to find and lighter.

Thanks, information appreciated.

[srsupertrap]

Larry,
No worries, looking back EBay seller: smw70ss was charging like $40/rotor in 2007 so the price has probably creeped up from there. If I came across as a aloof expert that was never my intent . . . my apologies.

[alke46]

Larry,
No worries, looking back EBay seller: smw70ss was charging like $40/rotor in 2007 so the price has probably creeped up from there. If I came across as a aloof expert that was never my intent . . . my apologies.

Oh no, not at all. Clearly it was my fault for not looking in the 1000E supplement. I am currently scouring the ebay pages trying to find some rotors from the 1100E models. If I can find some that are in good shape, I realize I will probably want to send them out for re-surfacing. The appearance of slotted rotors would also improve the look of the bike IMHO.

Chuck Hahn has provided a link to a place for re-surfacing so that's what I probably will do.

Thanks again.

[workonwood]

Just did the 82 1100E slotted swap on my 79 1000E. You will have to change the front calipers if you do this. I bought mine on ebay, all were over min. sent them to Tom at Truedisc. $45 each he did a great job. EBC pads and you set. https://www.truedisk.net/


IMG_3609 by David Shupe, on Flickr

[workonwood]

IMG_3607 by David Shupe, on Flickr