I need to upgrade my Brakes 75 850

I have an AP Racing Caliper on the front and stock rear. Rotors are original.

The front feels inadequate.

I suspect the front master cylinder is stock. There is a 13 mm sleeve kit available on Ebay for around $70. Has anyone used this on their bike?

I changed the rear pads because I got brake fluid on them. I put fresh pads on the back designed for the factory disc. It still feels wooden. I'm wondering if I might need to rebuild the rear master cylinder. I don't believe the rear brake could lock up the tire. It's almost useless.

I read that using a 13 mm sleeve in the rear master cylinder doesn't improve braking much and is not worth the effort.

I LOVE THIS BIKE. But the brakes must be improved. It's just not safe.

I can machine brackets for new calipers. What is the recommendation?

Here is the link to the Ebay 13 mm sleeve kit. https://www.ebay.com/itm/135749778070

Andover Norton 13mm master cylinder with stock lines / calipers & Ferodo brake pads on my mk3 and I am able to make the front tyre chirp with a decent squeeze on the lever.

I swapped my stock master cylinder for a sleeved one back when Old Britts were in business. I also drilled my rotor and had it Blanchard ground by Trudisc . Stops just fine now .

I had TWO FAILURES of sleeved MC's by a well known supplier of sleeved MCs. One failed in the garage overnight - on a ride it was fine, next day before going out, lever went to bar - no brake. The supplier apologized, sent me a "new one." This one failed between traffic lights. Stopped fine at light one; lever went to bar at light two. I ended up going through the red light with fortunately no traffic. Got another, "Oh, sorry!" from the supplier, "we'll make it right!" "Sorry" wouldn't have helped much had there been traffic... There is NO WAY I would ever consider sleeving a MC again; "fool me once..." etc. Brakes are too vital for survival...

And NO, I don't care how many people say they've never had any trouble with sleeved MCs.

I installed the CNW Brembo MC with the adapter to take the OEM switchgear. Feels/works like "current" brakes.

Oh (this added later) ...I should have mentioned that the above failures occurred several years apart. My post may read as if they happened relatively close together.

Richard Tool said:

I swapped my stock master cylinder for a sleeved one back when Old Britts were in business. I also drilled my rotor and had it Blanchard ground by Trudisc . Stops just fine now .
View attachment 124481

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I'm wondering about the effect of removing the chrome plating off the factory rotor. Does the rotor now rust? Did you have to change the type of pads?

I could put the rotors on my lathe, turn them and then use a re-surfacing abrasive to scuff the rotor. That would have been my path forward except for the chrome plating and not knowing the effect of removing it.

"I'm wondering about the effect of removing the chrome plating off the factory rotor. Does the rotor now rust? Did you have to change the type of pads?"

The effect is a greater friction coefficient. Of course it will rust. The Ferodo pads work great.
Many people have removed the chrome.

On my lathe at least you need to turn the disc around to do both sides, when you do that its likely you will be left with runout. Last one I did ended up with 8 thou and it pulses at low revs. I need a bigger lathe so I can cut both sides on one mounting in the chuck.

Fully upgrade your front brake system, best thing I did after a major stock brake failure, well after the second time, first time I rebuilt the stock system and after a few months it failed big time and spat me off, with broken bones while recovering I upgraded to a full Grimica front brake system (from RGM), for under $600 and now have good front brakes, my life is worth the $600 than having old 50 year old brakes that can fail without warning, that was over 15 years ago and the new set up is still working as they should, my Norton stops.

richlandrick said:

I have an AP Racing Caliper on the front and stock rear. Rotors are original.

The front feels inadequate.

I suspect the front master cylinder is stock. There is a 13 mm sleeve kit available on Ebay for around $70. Has anyone used this on their bike?

Click to expand...

Hi Rich,

If you're running an AP CP3696 caliper single disk setup you'll absolutely want to run a 13mm master cylinder (or 1/2" if necessary). We run Brembo square reservoir 13mm masters on our single disk race bikes with great success. Ferodo Platinum performance street compound FDB32P are readily available, or a CP1 racing compound is a more aggressive compound also available. This setup will radically transform the braking power of your bike, whether using a stock (ground) disc, or a 11.5" Production Racer setup.

Hope this helps,

-Kenny Cummings

richlandrick said:

I'm wondering about the effect of removing the chrome plating off the factory rotor. Does the rotor now rust? Did you have to change the type of pads?

I could put the rotors on my lathe, turn them and then use a re-surfacing abrasive to scuff the rotor. That would have been my path forward except for the chrome plating and not knowing the effect of removing it.

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I had my rotor Blanchard ground by Tom Tokarz at Trudisk . I highly recommend this as these rotors are not floating. I just used whatever pads Andover supplied. I live at the Jersey shore - the corrosion capital of universe and while they will get some surface rust it has never been a problem. One application of the brake wipes it away.
Here is what my rotor looks like today -

…and this is a spare that has been in a box in heated storage for many years..

Contact info- old card so if no longer accurate google Trudisk

Holmeslice said:

Hi Rich,

If you're running an AP CP3696 caliper single disk setup you'll absolutely want to run a 13mm master cylinder (or 1/2" if necessary). We run Brembo square reservoir 13mm masters on our single disk race bikes with great success. Ferodo Platinum performance street compound FDB32P are readily available, or a CP1 racing compound is a more aggressive compound also available. This setup will radically transform the braking power of your bike, whether using a stock (ground) disc, or a 11.5" Production Racer setup.

Hope this helps,

-Kenny Cummings

Click to expand...

I run the AP caliper, but run a 12mm Brembo M/C. Great feel and power. 13mm is good for the stock caliper.

I realized today that a previous owner replaced the original front rotor with a new original rotor. The braking surface was much shinier on the new rotor compared to the old one I found in a box that came with the bike. The rear rotor looked a lot like the old front rotor.

Based on feedback here I used a drill with abrasive pads on the rear disc. It certainly is not the same as having the rotors Blanchard ground, but there was a slight improvement un rear brake performance afterwards. But I'll bet the performance was better when the bike was new.

CoPilot suggested a single Brembo P4 caliper would work well with the 13mm bore MC. And 2 Bremco P4s would work well with the 5/8" MC.

I added a second rotor, caliper, and 5/8" MC to my Kawasaki H1. The results were fantastic. Better braking while retaining period correct look. I would really love to do that with my Commando. That means it's time for a new thread about fork swaps.

It really depends on how much you want to spend on upgrading the standard brakes, the 13mm master cylinder would be a good starting point with upgraded brake pads. You may be happy with the results of just doing that?

I have just bought an RGM 12" disc and making a pair of brackets, one for a Brembo caliper from a Ducati plus one for the original caliper, just to see how much improvement the Brembo will be. The 13mm master cylinder is a great upgrade but it still needs a good squeeze to pull up