bad disk brake performance

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Flo said:
I have led a closeted life. When did Norton start chroming their discs?
Only seen cast iron ones.

There's some form of dull chrome plating on the Norton discs, obviously not as shiny as the thin plating used on Triumph discs, but they certainly aren't bare cast iron.
 
steveyacht said:
I used some pretty aggressive sand paper on my rotor, cleaned it with Brake Cleaner and put on a set of AP Racing brake pads.... Made a HUGE difference. I am very happy with the performance of the brakes now, as compared to before.

http://www.apracing.com/info/index.asp? ... e+Pads_977

Steve

In looking at the AP Racing site I didn't see pads for the stock Norton disk brake.
Can you be more specific as to what I should be looking for.

Thanks
Bob
 
There is a Ferodo pad set available that works well,( check Vintage Brake webste or Old Britts), actually even better with the rotor Blanchard ground so that the hard chrome surface is skimmed and the cast iron is exposed. Old Britts does a fine job of that. With that , the resleeved M/C or a Grimeca/Magura/ Brembo 11to 13 mm M/C , a steel braided brake line , the front can be locked up with 2 finger pressure. Not modern 4 pot type performance, but very respectable and progressive indeed. Cheers, Augie
 
My brake was 100% absolute crap.

then:
-Norton Andover Master Cylinder
-Ferodo Pads
-Braided hose

Now it brakes like a modern bike. I can block the front wheel with 2 fingers.
It's safe and feels good.

Orso
 
There are el-cheapo ~US$99.99- India rotors on ebay. They look to be cast and some paint, no chrome. Maybe they are better than the slick chrome, don't know , don't have one.
The racing pads mentioned earlier may be unpredictable until the heat gets up, that's what racing pads used to be like when I used them on another motorbike anyways.
The ferodo platinum pads are very adequate, those I have and I have removed the chrome from my rotor via resurfacing.
Before you do anything about replacing components be absolutely sure your stock system is working as designed. Be sure the pistons in the caliper are both free to do the job. The stock chrome plated steel pistons can corrode and swell outboard of the seals and be real stiff to move. Also be sure the M/C is up to par and all the air is purged from the system. The inboard caliper piston is a bugger to get air out of if there has been some introduced. Look at the position of the bleeder drilling, it enters the inner bore at the bottom, how on earth can this expected to be bled while bolted to the slider, I don't know? As far as the rubber hoses, yes they may be old and should be replaced if so. If the hoses are suspect then get the steel pipes also, they will be corroded inside too.
The babble about M/C piston to caliper ratio has merit. Keeping the stock M/C appearance and having a smaller bore is a challenge I have not yet pursued. But there is no free lunch, a smaller bore means more lever travel for the same displacement. The stock lever may need replaced with one offering a different pivot to piston contact ratio. All in all I don't outdrive my brakes with speed in confined areas. I am a slow poke so my stock setup works for me.
All the best.
 
Summarizing for my own self wanting a decent break that is essentially still Norton.

1. 12-13 mm master cylinder, I like 13 mm as less lever travel for about same effect.

2. Resurface rotor surface by the sand blast listed already or by cross hatching grinding or serious grit sanding. DO NOT remove the chrome by normal turning method that leaves spiral finish live old records or as done in ordinary auto shops.
Tests have shown deep wear grooves have no bad effect p until removed by the spiral routine method then brake distance triples!!!

3. Fit metallic impregnated pads sanded down flat with new surface. Do not use solvent on friction pads as can carry lube down into pores to out gas or grime with use. Physical removal and or detergents.

4. SS braid hose protected from hack sawing parts it touches.

5, RGM race lever which has closer pivot and slightly longer lever.

6. Lighten disc by big holes in center and lots and lots of little holes in friction area to lessen the flywheel mass it must slow before bike pilot can tell.

7. On factory master cylinder there is a big rubber end boot with a tiny fluid restrictor hole, whose only function I can glean was to 'protect' those used to drum brakes from flying over the bars. I saw no restrictors in the resleeved items so poked a cheery red hot 16 penny nail through my current ride '72 Trixie
and got decent feel and braking w/o doing any thing else but cleaning up friction surfaces. Trixie still needs a mans grip to make tire noise but she now can when I'm scared enough.

Peel had em all done and I liked it better than the moderns I've squealed or stoppied on in horror and surprise, so much so I can fly into brake zone faster
and slow quicker than the moderns I now distdain as so over braked they are dangerous in panics and on loose or slick stuff. When I pull into shop or at gas pumps I tend to try out max brake last few feet, Peel would lock and slide while my SV650 would about tip over in surprise, so had to release which adds a foot of more to final whoa not planned for. i know for sure Peel can out stop my fat non DOT race tire dual 320 mm front rotor Suzuki. Ya got to pay extra for ABS on new bikes but comes standard on '72 Norton
 
AntrimMan said:
There are el-cheapo ~US$99.99- India rotors on ebay. They look to be cast and some paint, no chrome. Maybe they are better than the slick chrome, don't know , don't have one.
The racing pads mentioned earlier may be unpredictable until the heat gets up, that's what racing pads used to be like when I used them on another motorbike anyways.
The ferodo platinum pads are very adequate, those I have and I have removed the chrome from my rotor via resurfacing.
Before you do anything about replacing components be absolutely sure your stock system is working as designed. Be sure the pistons in the caliper are both free to do the job. The stock chrome plated steel pistons can corrode and swell outboard of the seals and be real stiff to move. Also be sure the M/C is up to par and all the air is purged from the system. The inboard caliper piston is a bugger to get air out of if there has been some introduced. Look at the position of the bleeder drilling, it enters the inner bore at the bottom, how on earth can this expected to be bled while bolted to the slider, I don't know? As far as the rubber hoses, yes they may be old and should be replaced if so. If the hoses are suspect then get the steel pipes also, they will be corroded inside too.
The babble about M/C piston to caliper ratio has merit. Keeping the stock M/C appearance and having a smaller bore is a challenge I have not yet pursued. But there is no free lunch, a smaller bore means more lever travel for the same displacement. The stock lever may need replaced with one offering a different pivot to piston contact ratio. All in all I don't outdrive my brakes with speed in confined areas. I am a slow poke so my stock setup works for me.
All the best.

I'm going to be using the $100 Indian rotor on my bike (ordered from Domi after we found out my stock rotor was junk). It came with some funky-ass coating on it so we sandblasted as much as we could off of it and then we painted the center black. I'm planning on sending my master cylinder off for resleeving in the next few days because it needs a rebuild anyway, so..what the hell. Hopefully that makes the brakes feel at least somewhat functional. We'll see.

-Jordan
 
Jumping from a Honda Blackbird to my Stock chromed disc braked MK111, for a short while feels like the brakes are wood! But with both brakes pulled hard and a down change they are exceptable...just, give your self a extra couple of seconds. BUT if a car pulls up sudden, swerve :!: and not into a on-comming truck :lol:
Options are standard looks or stopping power, sensible riders who go on big trips like Gino, prefer the latter. Me ,i know the limitations and ride very,very carefully.
I was doing 80 yesterday over the moors, kept thinking i hope the sheep know its a Norton! one thing is ,they could hear me comming!
 
Any and every motorcycle will have worse braking effect than about any 4 wheel cage and in the cycle vs car contests the bikes mostly lose in the turns because bikes can't brake as hard nor take corners as fast around. I've learned the hard way the value to develop reflex to steer around a hazard first instead of trying to just brake in time. But most safety is just not riding to need to brake much if at all. Braking while leaned is the absolute worse state to be in on a cycle, especially if brake power is really good.
To know if I'm fit enough for a thrilling joy ride I attempt brake lock up on way to highway and if I'm not up to ride a bit of locked front tire then I know I'd best behave slower that day. I do not access my skill level by how hard I can lean and turn and drift or slide or leap hi side saves, child's play compared to max brake control and not fall down or hit stuff. I start going at fairly high speed then harsh pull downs in a cascade of down shifts to speed up some for next hard pull down practice till stopped or going at a crawl.

BTW to best break in new friction pads you attempt to brake as hard as possible w/o letting the tire lock up, in a dozen of more max heating cycles that should exceed any real life use of repeated braking.
 
The disc brake on my 1973 850 was awful, so bad it was dangerous. I've heard some horror stories about the re-sleeve option so I fitted a Grimeca master cylinder from Andover Norton and it's brilliant. I've since done a couple of track days at Brands Hatch with no problems at all. I think if your happy with your front brake on a track like Brands Hatch you've probably got it right. Cheers, Steve
 
Ugh braking gives me the willies no matter how good the brake and the traction, especially when leaned, so I just plain flat never EVER do that unless going rather safe and slowly thank you. Seems every time I break that rule I get real upset or crashed.
bad disk brake performance


I've got a foot on both sides of Commando scope, my factory Trixie to test me to keep her true as I can to Norton yet decent as possible performance and function. She is what she is and I know better than try to track day play on her, just enjoy sane to timid thrills. If there was a rubber hose covered steel braid hose I'd put that on her as last step to have quite good brake and lock up reserve in legal speed range.

On Ms Peel I'm constantly having to let go of factory items. 'Princess Lea at Empire rally wowed me on her Honda F4 hydraulics and switch gear, so will mimic her's but still will retain the Lockheed sculptured caliper, but on 1" larger OD light wt. Wave rotor. Will find out how it handles repeated hard use on tight track about 4 hr from here. But this is Tri-linked Peel with hobot THE Gravel'r so I know better than to ever enter a turn so fast I need any brakes rather than tire spin throttling up all the way through. I do need crisis brake though in sudden road hazards that trap me w/o an escape route, and by gosh I'd just better be going slow enough just then to pull down in time or SPLAAT.

bad disk brake performance


bad disk brake performance


http://cgi.ebay.com/ebaymotors/FRONT-BR ... ccessories
 
Has anyone done the RGM sleeve kit themselves and can they recommend that a non-shop do it (i.e. the likelihood of f'ing the whole thing up)? When one fits another type of master cylinder, is there a standard screw pattern to hold it to the switch assembly or is it a custom job to fasten it down to the switch?
 
Spreads the heat dissipation ?

Area does matter, but rather indirectly - its a balance of area, heat dissipation, rust removal, water shedding and the factor X.

BTW, Commando iron rotors were all thinly chromed with bright chrome - the gleam of shiny metal is still around the edge of the now bare iron on disks, if you examine closely.
And right around the outer edge of the disk. (Original disk to pic, if anyone wants to see.)
Front brake is awful until the original chrome layer is worn off....
 
If holes not bigger OD than thickness of the disc lost surface area is a wash for the extra bite of pad encountering more edges. Wave rotors take that to an extreme.

Old Norton disc platters have rather wide swept area, which means that inside of pad ain't dragging up as much heat friction as the other pad, which tends to wrap both rotor and pad. Moderns get around this by narrower swept area of larger OD to minimize the velocity difference and make up for lost area by a few smaller pads in an arc.
 
On the subject of drilling/slotting rotors, I found this web reference

http://www.surrealmirage.com/subaru/brakes.html

I just had my rusty stock rotors "turned" with an abrasive to smooth the surface and the tech asked if I wanted them drilled and I declined (it was cheaper any way).

Has anyone done the RGM cylinder mod themselves? Can I do it with a drill press and index table to hold the part?
 
Be aware though that that article is referring to car disk rotors, and these can be ventilated internally in various forms. Unlike bike discs, which are a single solid (thin) item in comparison.

I drilled a front disc back in the 70s, and in the rain and dust and rust it bit harder quicker, which is good enough for me. Gives all the dust and stuff somewhere to go ?

BTW, Norton discs will warp with no drilling - the uneven wearing off of the chrome gave the game away, back when they were near new .
Perhaps thats why most modern discs are the floating variety ?
 
Floaters rotors allow some give and take of rotor warp to get more equal better pad pinch. Peel and my SV are floaters - takex a bit getting used to the slight rattle when turning and handling.
 
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