801 320mm brake discs

If I remember correctly, you changed the discs to some stock 1290 KTM/Galfer 320mm discs?
 
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Yeah they are 1290 rotors. I am running stock dual 701 galfer discs on my 701’s mag wheel set up. They work great but do seem to be noisier than normal. They feel a lot different than the 1290s..
 
I am not skilled enough, but ... if I use for example Brembo M4.32, these calipers are same dimensions and same diameter of brake cylinders (pistons) as the original JJ. So they would brake "the same", no? Or? Where should the better braking come from??
If I will fit some M50, it will have bigger diameter of the cylinders, which means, that there will much longer lever movement on the master pump, no? But brake better, this is clear.

I was surprised, that 300=>320 discs will make just 6,7% difference of stopping power ... due to my mathematics :-D
 
animals21 said:
I am not skilled enough, but ... if I use for example Brembo M4.32, these calipers are same dimensions and same diameter of brake cylinders (pistons) as the original JJ. So they would brake "the same", no? Or? Where should the better braking come from??
If I will fit some M50, it will have bigger diameter of the cylinders, which means, that there will much longer lever movement on the master pump, no? But brake better, this is clear.

I was surprised, that 300=>320 discs will make just 6,7% difference of stopping power ... due to my mathematics :-D
Click to expand...

6.7% is the difference between breaking on time ore not, hehehe.

I am not skilled neither but I guess the Brembo M4 will be more rigid therefore loosing less power and you will probably feel it in the initial bite. I guess they will also handle better the heating when breaking hard.

For me the original JJs are good enough for street but I do not like the initial bite, it is too progressive. Perhaps changing the master cylinder will have more direct impact in braking power.
 
None of this is really about braking power, it is about having more thermal overhead. Unless you are tracking your bike going to other calipers or larger rotors is simply not necessary - the brakes are sufficient to lock up the tire so there is more stopping force available than traction. However there appears to be some issue with the metallurgy of the stock rotors and they way the are prone to warping, so that is a reason to switch. The fact that you can get larger rotors that save 1kg each is another. Looking cool like a racer is a third. If you just don't like the initial bite switch pads and save hundreds of dollars over calipers.
 
For those who might be interested, here the weights of the various Galfer and Brembo brake discs.

Galfer DF801CW; 300mm: 1175gr
Galfer DF787CW; 320mm: 1380gr
Brembo Oro 78B408B0: 320mm: 1620gr
OEM KTM-Galfer; 300mm: 1858gr.

DF801CW.jpg 1788238496579.jpg 1788238639096.jpg
 
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I didn't like the braking performance right from the start either; I replaced the stock pads with ZCOO ones, and it improved significantly. I'm happy with it as it is for now.
Besides, as long as you keep the Pirelli MT60RS tires on, the braking will always be poor.
 
thanks Tom, this is great. I was thinking about the ORO, but with this weight difference it would be (if ...) 320mm Galfer.
 
I found almost new calipers from SA1290R close to my home for 200€, so I went to buy them. They fit 1:1, Rottweiler performance used them on Duke 790 also.

Change was easy. I went just for a short ride. It went better with each braking, don ´t know, if the pads are fully settled, but it brakes better. Feeling on the lever is almost same, which is not a surprise.

Change the pads will probably be enough.

Anyway I am still thinking to get 890R or new 990R, but keep the 801, because I love, how easy the bike handles and how comfortable it is.

I also visited a dyno, but nobody is able to unlock/break in to the ECU. If that will happend, with the suspension and brakes now, I will have 801R :-D
 
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I found this a great read, describing the different stages of brake upgrades:
www.motorcycle.com

KTM 790 Duke Project: Building A 790 R

When I initiated this project with MO’s long-term 790 Duke, my goal was simple.I just wanted an excuse to keep the bike as long as possible before I would be required to give it back to KTM.However, even before I considered buying the 790 for myself, I hatched another plan.
www.motorcycle.com www.motorcycle.com

Better Brakes​

Brake upgrades were among the first changes I made to the bike, and I’m happy with the progression throughout the course of this project. The baby step of fitting EBC Double-H pads delivered the desired initial bite of the brakes, while the KTM PowerParts/Galfer Wave Discs improved the overall stopping power with the added benefit of significantly reducing the weight. For a while, I was satisfied with this arrangement. That is, until I rode the 2020 Triumph Street Triple RS, with its Brembo MCS master cylinder and M50 calipers. This started me thinking.

At this point in the project, the combination of the OEM master cylinder, the EBC pads ($80), and the PowerParts discs ($458) provided more than adequate stopping power for hauling the bike down from speed. Still, I wanted more immediate application of the front brake with less free play in the lever. While I didn’t have the budget for a full Brembo system, including M50s, I decided to try a Brembo 17 RCS Costa Corta master cylinder to see if it would get me to where I wanted to be. Long story short, the 17mm piston was too small for the piston sizes of the J.Juan calipers, and I ended up using the Brembo 19 RCS Corsa Corta($372). Now, I have the braking power, feel, free play, and adjustability I wanted all along. However, those M50s – or maybe some Stylemas – still call to me late at night, when I’m cruising the net…
 
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