Rear Brake Upgrade for a Deuce

[djl]

I have never been happy with the rear braking on my '05 Deuce; brakes go from almost no brakes to lockup.  Currently running Lyndall Z+ pads, HD wannabe floating rotor and have replaced the rubber lines with SS.  Getting ready to flush old fluid and replace, replace pads and clean up the caliper.  What pads? Is one brand of fluid better than another? Should I consider changing rotors?  Suggestions please.

TIA

[Hossamania]

When you replace the pads, scrub the rotor clean with a red scotchbrite pad and brake cleaner. Napa makes one of the better brake/carb cleaners.
HH sintered pads work well. Keep greasy paws off of them when installing.
A new floating rotor wouldn't hurt, but may not be necessary. Might be a good idea to mic your rotor for thickness if you re-use it.
Brake fluid, use a quality brand. Even the HD brand is fine. I like to bleed the rear brakes old school style, no vacuum, it's pretty easily done by yourself.
Clean the caliper pistons with a shoelace and brake cleaner. I found that this helps quite a bit, as yours may be sticking a bit. They get pretty dirty back there. I can tell that mine are due to be cleaned.

[ThumperDeuce]

Many years ago I swapped the stock calipers out for Performance Machine differential bore units.  Dual 6 piston up front, 4 piston on the rear.  No regrets.  Lyndall gold up front, z on the rear.

[Armin]

Many years ago I swapped the stock calipers out for Performance Machine differential bore units.  Dual 6 piston up front, 4 piston on the rear.  No regrets.  Lyndall gold up front, z on the rear.

That's exactly what I did years ago using Lyndall or EBC HH pads with HD floating rotors. No sqealing, no fading no blocking and no regrets!

Armin.

[djl]

Thanks for the suggestions. Armin and Thumper; did you retain the OEM M/C with the Performance Machine calipers?  I assume they don't come with pads but that the OEM pads or equal will fit; special pads not required.

[Armin]

Yes, you can keep your master cylinders and I upgraded to Chromite steel braided brake lines. If I recall correctly the new PM calipers came with EBC pads and after I needed new pads I tried Lyndall gold pads which I liked very much, but I got back to using EBC HH pads due to hard availability of Lyndall pads here in Germany. Anyway I like the EBC pads performancewise but I find they wear the rotor a little faster. And you cannot use HD OEM pads with PM calipers but EBC prices are reasonable.

Armin.

[djl]

Yes, you can keep your master cylinders and I upgraded to Chromite steel braided brake lines. If I recall correctly the new PM calipers came with EBC pads and after I needed new pads I tried Lyndall gold pads which I liked very much, but I got back to using EBC HH pads due to hard availability of Lyndall pads here in Germany. Anyway I like the EBC pads performancewise but I find they wear the rotor a little faster. And you cannot use HD OEM pads with PM calipers but EBC prices are reasonable.

Armin.

So, I read from your post that the PM calipers do require special pads, IAWs, pads designed to fit the PM calipers?

[Admiral Akbar]

Put the rubber hose back on. Problem solved.. Unless you got an extended brake pedal.

[Armin]

@djl I suggest that you consult the PM website to find your desired calipers. I took the 6 piston unit for the front and the 4 piston unit for the rear wheel. The pads for the PM calipers are not specially made for PM, instead they are used in many other motorcycle brake systems.
The front 6 piston caliper uses EBC FA249HH or Lyndall Gold Plus7202 and the rear 4 piston caliper uses EBC FA244HH or Lyndall Gold Plus 7144 pads.
Check the internet for pricings.

Armin.

[djl]

@djl I suggest that you consult the PM website to find your desired calipers. I took the 6 piston unit for the front and the 4 piston unit for the rear wheel. The pads for the PM calipers are not specially made for PM, instead they are used in many other motorcycle brake systems.
The front 6 piston caliper uses EBC FA249HH or Lyndall Gold Plus7202 and the rear 4 piston caliper uses EBC FA244HH or Lyndall Gold Plus 7144 pads.
Check the internet for pricings.

Armin.

Thanks for the PNs. I have looked at the PM website and selected the calipers. Not sure if I see any advantage to upgrading the front brake. I just use the front brake to scrub off some speed going into a turn and the OEM brakes seem up to the task. What was your reason for the front brake upgrade and what is the difference in brake performance between OEM and PM?

[ThumperDeuce]

Differential bore calipers are suppose to have more even pad wear.
Keep everything matching ...  they look nicer than stock.
High speed braking the load shifts to the front so that is where I feel the braking force needs to  be.  I just use the rear for low speed braking so the front end doesn't tuck.

[djl]

Differential bore calipers are suppose to have more even pad wear. Keep everything matching ...  they look nicer than stock.
High speed braking the load shifts to the front so that is where I feel the braking force needs to  be.  I just use the rear for low speed braking so the front end doesn't tuck.

Agree on all points. Low speed braking is why I want to upgrade the rear. Pedal application is not progressive enough for me and if I am not careful, I can unintentionally lock up at the wrong time.  I appreciate all the information you and Armin have provided.

[kd]

Differential bore calipers are suppose to have more even pad wear. Keep everything matching ...  they look nicer than stock.
High speed braking the load shifts to the front so that is where I feel the braking force needs to  be.  I just use the rear for low speed braking so the front end doesn't tuck.

Agree on all points. Low speed braking is why I want to upgrade the rear. Pedal application is not progressive enough for me and if I am not careful, I can unintentionally lock up at the wrong time.  I appreciate all the information you and Armin have provided.

The brake system was produced OEM to perform properly with a flexible rubber hose.

VVV  Try this  VVV

Put the rubber hose back on. Problem solved.. Unless you got an extended brake pedal.

[ThumperDeuce]

I also use stainless braided brake lines.

[Armin]

@djl I suggest that you consult the PM website to find your desired calipers. I took the 6 piston unit for the front and the 4 piston unit for the rear wheel. The pads for the PM calipers are not specially made for PM, instead they are used in many other motorcycle brake systems.
The front 6 piston caliper uses EBC FA249HH or Lyndall Gold Plus7202 and the rear 4 piston caliper uses EBC FA244HH or Lyndall Gold Plus 7144 pads.
Check the internet for pricings.

Armin.

Thanks for the PNs. I have looked at the PM website and selected the calipers. Not sure if I see any advantage to upgrading the front brake. I just use the front brake to scrub off some speed going into a turn and the OEM brakes seem up to the task. What was your reason for the front brake upgrade and what is the difference in brake performance between OEM and PM?

The front brake is the most important brake on a motorbike since in a critical braking situation the front brake has to dissipate most of the energy due to load shift while the rear wheel has little braking effect because of lifting and it starts to skid. That's why I opted for the 6 piston caliper, it has a greater pad surface. I had the 4 piston PM caliper before and it was not bad, but the 6 piston caliper is far superior to the 4p unit. Beyond that the PM calipers are a piece of cake when it comes to the pad changing task and the pads are priced reasonably. Btw I still have a 4p PM fron caliper sitting on the shelf, if you are interested.

If your budget permits go for the 6p caliper front and 4p caliper rear, you won't regret.

Armin.

[djl]

Thanks Armin for the offer of the 4 piston front but if I am going to upgrade I will likely go with the 6 piston piece since both you and Thumper like the 6 piece but I will let you know if I change my mind.

I understand the importance of the front and rear brake in an emergency or high speed situation but I am more interested in brake application/use carving up the Three Sisters loop in the Texas hill country which is not high speed with a lot of 20-30mph very tight turns and switch backs.

Thanks again for all the information.

[ThumperDeuce]

It's not always about maximum stopping power.  All the pad area helps to dissipate the heat.  I require very light braking control pressures while setting up for my twisties.

[djl]

It's not always about maximum stopping power.  All the pad area helps to dissipate the heat.  I require very light braking control pressures while setting up for my twisties.

Nice, the look so much better.  What rotors?  HD floaters here and will try with those; may have to upgrade for the full conversion.

Agree on the light pressure which is why I have a problem with my rear brake. Low speed, say 30-40mph and light pressure doesn't generate any slow down, more pressure could lead to lockup which is the problem.

[ThumperDeuce]

Those are the Lyndall ceramic rotors, which they no longer sell.  They do make some interesting steel ones though:

https://shop.lyndallbrakes.com/collections/all/Rotors

[JW113]

Trying to understand the logic in all of the above. djl says the brake application is not progressive, locks up to easy. So the solution is to make the rear brakes even more aggressive???

Going to make a crazt hypothesis here. Why do the guys riding Japanese sport bikes not complain about this? Perhaps it's because the makers of Japanese sport bikes don't believe in HD's mantra of very low master cylinder piston to caliper piston diameter ratio? If you can lock the rear wheel, then you have plenty of braking power. No? If the complaint is hardly any range of modulation, look at the diameter of the master cylinder piston. I'm gonna make an outrageously wild claim, but I'm suggesting that if you found a master cylinder with a smaller piston, you'd gain more range between initial application of braking force, and lock up.

But what do I know?

-JW

[PoorUB]

Trying to understand the logic in all of the above. djl says the brake application is not progressive, locks up to easy. So the solution is to make the rear brakes even more aggressive???

Going to make a crazt hypothesis here. Why do the guys riding Japanese sport bikes not complain about this? Perhaps it's because the makers of Japanese sport bikes don't believe in HD's mantra of very low master cylinder piston to caliper piston diameter ratio? If you can lock the rear wheel, then you have plenty of braking power. No? If the complaint is hardly any range of modulation, look at the diameter of the master cylinder piston. I'm gonna make an outrageously wild claim, but I'm suggesting that if you found a master cylinder with a smaller piston, you'd gain more range between initial application of braking force, and lock up.

But what do I know?

-JW

My Yamaha R1 has terrible rear brakes, spongy. I don't worry about it much because a lot of the times when stopping hard the rear tire is off the ground anyway. I might use them to knock of some speed in a corner, but I don't need much feel to drag the brake slightly. Front brakes are awesome, two finger lock up with good feel.

[JW113]

And there you have it. You are right, rear brake on a sport bike is almost useless, as the wheel base is typically much shorter than a HD, the center of gravity is higher, and when front brake is applied, almost all the weight is transferred to the front tire. But your description of how the front brake works is exactly spot on, and due to the high caliper to master cyl piston ratio. The typical HD big twin does not transfer nearly as much weight to the front wheel, so the rear still has some stopping power even when the front brake is applied.

I guess the main point I was trying to make is that the reason HD brakes feel like crap is due to the brake piston ratio. djl, if  you want to make a noticeable  improvement, ride around on a mid-70s Shovelhead for a week, then get back on your bike. You'll be amazed how much better the brake feel is.


-JW

[djl]

And there you have it. You are right, rear brake on a sport bike is almost useless, as the wheel base is typically much shorter than a HD, the center of gravity is higher, and when front brake is applied, almost all the weight is transferred to the front tire. But your description of how the front brake works is exactly spot on, and due to the high caliper to master cyl piston ratio. The typical HD big twin does not transfer nearly as much weight to the front wheel, so the rear still has some stopping power even when the front brake is applied.

I guess the main point I was trying to make is that the reason HD brakes feel like crap is due to the brake piston ratio. djl, if  you want to make a noticeable  improvement, ride around on a mid-70s Shovelhead for a week, then get back on your bike. You'll be amazed how much better the brake feel is.


-JW

Well, maybe my riding skills are lacking.   However, when riding the Three Sisters in the Texas hill country, I would the rear brakes to scrub off some speed while negotiating tight turns and switch backs at 15-30mph that come in quick succession; don't like front braking in those conditions.  I just need a little braking with a tap on the pedal which I don't have now.  One of my other bikes is a BMW R9T, so I think I know what good brakes are.  The front brake on that bike is so touchy, I would never use it in the above described situation.

Don't know about brake piston ration or the technicalities involved, just want more progressive rear braking.

[ThumperDeuce]

I highly recommend the two 'A Twist of the Wrist' books by Keith Code for a technical approach to the twisties.

[04 SE Deuce]

I have never been happy with the rear braking on my '05 Deuce; brakes go from almost no brakes to lockup.  Currently running Lyndall Z+ pads, HD wannabe floating rotor and have replaced the rubber lines with SS.  Getting ready to flush old fluid and replace, replace pads and clean up the caliper.  What pads? Is one brand of fluid better than another? Should I consider changing rotors?  Suggestions please.

TIA

Don,  I have the same exact combination on the rear of my Deuce currently.  I think it's plenty of brake,  almost too easy to lock.  I had some old regular Z pads previously and they were a lot more forgiving as it took deliberate pedal pressure to lock...I kinda like that. The Z+ is nicer most of the time as they provide more braking with less pressure.  My bike came with SS lines same as Thumpers bike.  I think running a rubber line as MAX/Admiral suggested might be a good call to make the brake a little more forgiving in regards to lock-up.  It's hard to get a nice progressive feel with a foot long brake lever.  The rear brake doesn't give near the feel/feedback as the front and my foot is no where near as sensitive as my hand...hence the occasional slid or hack job on entry.

I'm an old MX'r so I run more rear brake on entry than most who have road raced.  I trail brake both ends pretty much to apex when the pace is hot. I use the front hard and feather off as I lean in. I use/drag the rear to stabilize the chassis and to scrub extra speed off if needed after I've tipped in and am off the front brake.   

If you put more rear brake on the bike I think it's just going to lock easier.  -Rick