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A friend just purchased a ?'76 DO R90S which is in fine shape. But the front brake drags too much for his liking. He has adjusted the brake, looked in the manual for advice, followed all the "check" procedures, ?but just can't get it good enough.
The bleed back hole in his master cylinder?is not clogged, everything seems to be in order.
His front wheel will spin for 3 turns when the brake is cold, after riding and getting the brake warm, it spins for 1-1/2 turns.?
I spun my (cold) front wheel on my R90S and it spun for 2-3/4 turns, I did not ride it for a "warm" spin test.
Does anyone have any suggestions? Is the brake perhaps just fine?
Mac Kirkpatrick Glenmoore, PA
"After all, what is adventure, but inconvenience, properly regarded?"
C. Donahue
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My hunch is it’s just fine.? Mine won’t spin 3 full revolutions even when cold and I’m not the least bit worried about it. ?I suspect he’s looking for the unobtainable.? They aren’t like bicycle wheels where you can have the satisfaction of watching them spin a long, long time.? ;)? ? Thanks, Mike ? ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Mac Kirkpatrick
Sent: Tuesday, June 9, 2020 10:50 AM
To: [email protected]
Subject: [R90SWORLDNET] Front Brake Dragging Question ? A friend just purchased a ?'76 DO R90S which is in fine shape. But the front brake drags too much for his liking. He has adjusted the brake, looked in the manual for advice, followed all the "check" procedures, ?but just can't get it good enough. The bleed back hole in his master cylinder?is not clogged, everything seems to be in order. His front wheel will spin for 3 turns when the brake is cold, after riding and getting the brake warm, it spins for 1-1/2 turns.? I spun my (cold) front wheel on my R90S and it spun for 2-3/4 turns, I did not ride it for a "warm" spin test. Does anyone have any suggestions? Is the brake perhaps just fine? "After all, what is adventure, but inconvenience, properly regarded?"
C. Donahue
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I have to agree With Mike Mine didn't spin 3 turns ether remember you have 2 sets of brake pads on each side and they are in constant contact with the rotors.
On Tuesday, June 9, 2020, 10:58:38 AM CDT, Mike Vosdingh <mvoziowa@...> wrote:
My hunch is it’s just fine.? Mine won’t spin 3 full revolutions even when cold and I’m not the least bit worried about it. ?I suspect he’s looking for the unobtainable.? They aren’t like bicycle wheels where you can have the satisfaction of watching them spin a long, long time.? ;)? ? Thanks, Mike ? ?
From: [email protected] [mailto:[email protected]] On Behalf Of Mac Kirkpatrick
Sent: Tuesday, June 9, 2020 10:50 AM
To: [email protected]
Subject: [R90SWORLDNET] Front Brake Dragging Question ? A friend just purchased a ?'76 DO R90S which is in fine shape. But the front brake drags too much for his liking. He has adjusted the brake, looked in the manual for advice, followed all the "check" procedures, ?but just can't get it good enough. The bleed back hole in his master cylinder?is not clogged, everything seems to be in order. His front wheel will spin for 3 turns when the brake is cold, after riding and getting the brake warm, it spins for 1-1/2 turns.? I spun my (cold) front wheel on my R90S and it spun for 2-3/4 turns, I did not ride it for a "warm" spin test. Does anyone have any suggestions? Is the brake perhaps just fine? "After all, what is adventure, but inconvenience, properly regarded?"
C. Donahue
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Thanks to everyone for their feedback, I have passed it onto the new owner of the R90S.
Mac Kirkpatrick Glenmoore, PA
"After all, what is adventure, but inconvenience, properly regarded?"
C. Donahue
On Tue, Jun 9, 2020 at 11:50 AM Mac Kirkpatrick via <drbeemer73= [email protected]> wrote: A friend just purchased a ?'76 DO R90S which is in fine shape. But the front brake drags too much for his liking. He has adjusted the brake, looked in the manual for advice, followed all the "check" procedures, ?but just can't get it good enough.
The bleed back hole in his master cylinder?is not clogged, everything seems to be in order.
His front wheel will spin for 3 turns when the brake is cold, after riding and getting the brake warm, it spins for 1-1/2 turns.?
I spun my (cold) front wheel on my R90S and it spun for 2-3/4 turns, I did not ride it for a "warm" spin test.
Does anyone have any suggestions? Is the brake perhaps just fine?
Mac Kirkpatrick Glenmoore, PA
"After all, what is adventure, but inconvenience, properly regarded?"
C. Donahue
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With four brake pads, there will almost always be some slight drag, but being very careful to adjust the eccentric precisely on both sides will help quite a bit.? Of course he will want to clean and re-grease his front and rear wheel bearings, since this is a new bike to him and he doesn’t know when it was done last.? Also may as well lube the input shaft spline and the rear wheel drive spline while he is at it. ? Happy Motoring, Todd ? ? ? Thanks to everyone for their feedback, I have passed it onto the new owner of the R90S. "After all, what is adventure, but inconvenience, properly regarded?"
C. Donahue ? ? On Tue, Jun 9, 2020 at 11:50 AM Mac Kirkpatrick via <drbeemer73=[email protected]> wrote: A friend just purchased a ?'76 DO R90S which is in fine shape. But the front brake drags too much for his liking. He has adjusted the brake, looked in the manual for advice, followed all the "check" procedures, ?but just can't get it good enough. The bleed back hole in his master cylinder?is not clogged, everything seems to be in order. His front wheel will spin for 3 turns when the brake is cold, after riding and getting the brake warm, it spins for 1-1/2 turns.? I spun my (cold) front wheel on my R90S and it spun for 2-3/4 turns, I did not ride it for a "warm" spin test. Does anyone have any suggestions? Is the brake perhaps just fine? "After all, what is adventure, but inconvenience, properly regarded?"
C. Donahue
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As Todd mentioned there is a cool trick to align the pads parallel to the rotor. Take a black sharpie and make a series of lines like spokes on the surface of the rotor. Pull the cap off at the bottom of the pivot pin and you will see a slot. Gently squeeze the hand brake while you spin the wheel. ?The pads will wipe off the black ink. Adjust the eccentric until you can wipe off the most ink from the rotor. Now the pads will have the most contact and you can see if they are dragging.
Rchard Chawes
On Jun 9, 2020, at 10:53 AM,?
Todd Trumbore via groups.io < motorrader@...> wrote:
With four brake pads, there will almost always be some slight drag, but being very careful to adjust the eccentric precisely on both sides will help quite a bit.? Of course he will want to clean and re-grease his front and rear wheel bearings, since this is a new bike to him and he doesn’t know when it was done last.? Also may as well lube the input shaft spline and the rear wheel drive spline while he is at it. ? Happy Motoring, Todd ? ? ? Thanks to everyone for their feedback, I have passed it onto the new owner of the R90S. "After all, what is adventure, but inconvenience, properly regarded?"
C. Donahue ? ? On Tue, Jun 9, 2020 at 11:50 AM Mac Kirkpatrick via ??<drbeemer73= [email protected]> wrote: A friend just purchased a ?'76 DO R90S which is in fine shape. But the front brake drags too much for his liking. He has adjusted the brake, looked in the manual for advice, followed all the "check" procedures, ?but just can't get it good enough. The bleed back hole in his master cylinder?is not clogged, everything seems to be in order. His front wheel will spin for 3 turns when the brake is cold, after riding and getting the brake warm, it spins for 1-1/2 turns.? I spun my (cold) front wheel on my R90S and it spun for 2-3/4 turns, I did not ride it for a "warm" spin test. Does anyone have any suggestions? Is the brake perhaps just fine? "After all, what is adventure, but inconvenience, properly regarded?"
C. Donahue
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Make sure the the master cylinder is not mounted too far rearward and the arm isn’t hitting on the tank. It happened to me. Just take the tank off and recheck for brake drag.
Jerry Hale
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When mine did this, I had corroded pistons. I rebuilt the calipers with pistons from Bench Mark Works.They were half the price of OEM and have performed flawlessly. FYI. Thanks, Vech!
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Same with mine, Martin-
If folks are still on original caliper pistons after 45 years, chances are there's some corrosion, chances are the pistons are dragging while trying to retract.
Best-
George
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When mine did this, I had corroded pistons. I rebuilt the calipers with pistons from Bench Mark Works.They were half the price of OEM and have performed flawlessly. FYI. Thanks, Vech!
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Russell Vandeweerd
Martin Johnson