Fixed Rear Caliper....

[blackout]

A fixed caliper out back would yield a much better brake feel - Change my mind.

 

I use my rear brake on the street with good results, but on the track, the rear seems to be either on or off resulting in lockup.  

[r1limited]

My personal opinion.  if your rear brake is locking up while on track, two things, your suspension is not right and brake setup is not complimented by your suspension. 

 

Additionally floaters will be a better feel from fixed.  Fixed provides no flexation.  It is as I mentioned more intune with your suspenders.  This may as well include changing rear brake fluid and pad brand to offset the feel.  As example I run Motul RBF600 in the front, while standard Yamalube DOT 4 in the rear.  Standard OEM Pads as well in the rear with EBC or whatever is a better price ceramics in the front

[blackout]

35 minutes ago, r1limited said:

My personal opinion.  if your rear brake is locking up while on track, two things, your suspension is not right and brake setup is not complimented by your suspension. 

 

Additionally floaters will be a better feel from fixed.  Fixed provides no flexation.  It is as I mentioned more intune with your suspenders.  This may as well include changing rear brake fluid and pad brand to offset the feel.  As example I run Motul RBF600 in the front, while standard Yamalube DOT 4 in the rear.  Standard OEM Pads as well in the rear with EBC or whatever is a better price ceramics in the front

I hear you on the pad material, but wanting a caliper to flex, that's a new one.  

[mossrider]

1 hour ago, blackout said:

 

I use my rear brake on the street with good results, but on the track, the rear seems to be either on or off resulting in lockup.  

Using the rear brake on track takes more patience and finesse. Most people are like 70-30 or more on the street but that drops to 90+-10 on the track for the average person. If you progressively load the front brake instead of jabbing in an X or X+2 load or whatever, you can keep from upsetting the chassis and minimize the weight transfer at your brake markers. This let's the rear stay closer to or on the ground so the rear brake is at least minimally usable. When I say progressively it actually happens in split seconds but you want to load the tire, litterally mash it into the pavement. Take a dismounted front tire (no wheel), stand it up between your knees on the garage floor and lean on it. Watch the footprint. That's litterally the speed you want load the brake and what happens to the tire on track. Then you begin to lightly mess with the rear. Any less and the rear has a good chance of locking. You can also brake much harder than you realize with a properly loaded front, even at lean. Take the tire test again. This time lean the tire and try to side skid it when it's loaded. Same idea on track. 

 

I'm still on my first set of rear pads 3 years into racing but I do use them occasionally to settle the chassis or tighten a turn. Better riders use them more. Some never touch the rear.

[r1limited]

1 hour ago, blackout said:

but wanting a caliper to flex, that's a new one.

Let me explain, maybe I did not do a good job the first time

Full floaters the calipers are free to move with the disc itself, if the disc is fixed and or the calioers are not capable to move and align with the disc itself will cause uneaven preasure on the pad to disc.  Discs warp, so high low spots will be the norm, hit a high spot the brake locks.

 

Mossrider stated it well "settle the chassis or tighten a turn"

No matter what, if your suspension is right, the brakes will settle the bike evenly if applied as well mentioned by Mossrider.

 

Tire pressure, suspension, track surface conditions, ambient air all have factors on how the tires will grip the surface as well as send that feel to the front and rear break "BOOTS TOO". 

 

I have always had trouble with feel on the rears.

[blackout]

35 minutes ago, r1limited said:

Let me explain, maybe I did not do a good job the first time

Full floaters the calipers are free to move with the disc itself, if the disc is fixed and or the calioers are not capable to move and align with the disc itself will cause uneaven preasure on the pad to disc.  Discs warp, so high low spots will be the norm, hit a high spot the brake locks.

 

Not true.  The pistons on both sides of a fixed caliper will align themselves perfectly with the rotor once the pedal is pumped the first time after a bleeding or pad replacement.

[r1limited]

10 minutes ago, blackout said:

Not true.

True

10 minutes ago, blackout said:

The pistons on both sides of a fixed caliper will align themselves perfectly with the rotor once the pedal is pumped the first time after a bleeding or pad replacement.

Also True

However, the pistons as the High end calipers the 07 has will most certainly do this, to a point. 
The pressure is uneven, given the disc being fixed, calipers being fixed, discs surface is warped and heat, wrong pads, to hot a rated fluid all things being true.  That said, dinosaurs had nothing to do with it

[mossrider]

To me, mastering the rear brake is much more difficult than the front. Partly because its used much less often and less effectively than the front at track speeds, so essentially I get much less practice with it. I know some folks use thumb brakes in an attempt to get more feel or more effective use of the rear.  

 

Usually if I'm using the rear aggressively it's because I botched a corner and am rocketing thru the gravel trap toward a hard apex, lol.

[shinyribs]

I probably use too much rear brake due to growing up on dirt bikes. In the woods I'm 80% or more rear brake. I adapt without thinking about it on the street, but I suppose I'm lucky in having more experience with practicing with the rear brake other others might have. 

 

I really like using the rear brake tighten my line mid corner when needed. For me, it's much smoother and feels more natural. Of course, in real world traffic situations I'm pretty much 50/50 with front/rear brakes. 

 

Rear brakes can certainly cause issues at speed, but I think it's an important tool to use on a daily basis just to keep yourself fresh. 

[r1limited]

15 minutes ago, mossrider said:

To me, mastering the rear brake is much more difficult than the front

Go dirt tracking

[blackout]

Anyone know what a fz07 rear caliper weighs?  I'll be checking on my bike in a week or so when salt gets thrown on the roads.  

[mossrider]

Just now, r1limited said:

Go dirt tracking

I do, I love dirty bikin. The folks at the track joke that I'm faster off track than on. I like to think of that as some kind of backhanded compliment. 

[r1limited]

2 hours ago, blackout said:

Anyone know what a fz07 rear caliper weighs?  I'll be checking on my bike in a week or so when salt gets thrown on the roads.  

IMA gonna guess 3.7 - 4.7 lbs

 

This can be an intersting Pool/Poll

[blackout]

HP4 Race porn...  

[Mad]

The oem rear brake has a single piston  

so maybe a better one with two pistons facing each other will be an upgrade in feeling 

there is a bracket that allows you to put a caliper below the swing arm but I don’t remember who makes it 

[blackout]

A Wilwood caliper I might use and a Wilwood kart MC I might use to fab a thumb brake....  The piston bores on the caliper are 1.25".  The MC bore is 1/2".  

 

@mossrider, do your racing friends delete their foot pedal completely?  If I keep the foot pedal, I'll have to tap into the foot MC with a pressure fitting adapter at the fluid reservoir nipple.  I'm tempted to delete the foot pedal completely to keep the system simple and more reliable.  

[twf]

On 11/6/2018 at 5:29 PM, Mad said:

The oem rear brake has a single piston  

so maybe a better one with two pistons facing each other will be an upgrade in feeling 

there is a bracket that allows you to put a caliper below the swing arm but I don’t remember who makes it 

That would do nothing because it does not change anything. Would need to add piston on same side or change size/ratio. 

[Mad]

I’m talking about feelings just as a result of a smoother operation

[blackout]

Two pistons facing each other would be a fixed caliper.  And that is the better design.  More simple, more rigid and a better feel.

[mossrider]

23 minutes ago, blackout said:

A Wilwood caliper I might use and a Wilwood kart MC I might use to fab a thumb brake....  The piston bores on the caliper are 1.25".  The MC bore is 1/2".  

 

@mossrider, do your racing friends delete their foot pedal completely?  If I keep the foot pedal, I'll have to tap into the foot MC with a pressure fitting adapter at the fluid reservoir nipple.  I'm tempted to delete the foot pedal completely to keep the system simple and more reliable.  

Not sure if I follow the question, but, rules require a seperately functioning, independent rear brake. I have seen some remove the rear brake pedal and move to a thumb activated rear brake lever on the clipons however.  Most use the rear brakes as supplied however.

[blackout]

1 hour ago, mossrider said:

Not sure if I follow the question, but, rules require a seperately functioning, independent rear brake. I have seen some remove the rear brake pedal and move to a thumb activated rear brake lever on the clipons however.  Most use the rear brakes as supplied however.

Thanks.  You answered my question.  

 

I think I will give this a try.  Minimal cost doing it yourself.  The kits are expensive, especially from Brembo.  Wilwood is good quality at a normal price.  That's what I used on my race car that I designed and built.

 

Most likely I'm locking the rear  on track because the full boot hinders feel compared to my street riding shoes.

 

By the way, did you see Andy Palmer is coming out with a rear brake kit that uses a lighter homologated caliper?  (MotoAmerica legal)  Looks like it will drop around 2 pounds of unsprung weight.

[mossrider]

Just now, blackout said:

 

By the way, did you see Andy Palmer is coming out with a rear brake kit that uses a lighter homologated caliper?  (MotoAmerica legal)  Looks like it will drop around 2 pounds of unsprung weight.

Some people have too much free time, lol. 

 

Yeah, he's setting up shop with some friends and fellow club racers here in the frozen north. He's going after the minimum weight limit for the class in MA, among other things he's got going on.

[fzar]

14 hours ago, mossrider said:

Some people have too much free time, lol. 

 

Yeah, he's setting up shop with some friends and fellow club racers here in the frozen north. He's going after the minimum weight limit for the class in MA, among other things he's got going on.

Free time = full time job, running 5-6 bikes. As you said among other thing's. 

[wmhjr]

On 11/11/2018 at 6:36 PM, blackout said:

Thanks.  You answered my question.  

 

I think I will give this a try.  Minimal cost doing it yourself.  The kits are expensive, especially from Brembo.  Wilwood is good quality at a normal price.  That's what I used on my race car that I designed and built.

 

Most likely I'm locking the rear  on track because the full boot hinders feel compared to my street riding shoes.

 

By the way, did you see Andy Palmer is coming out with a rear brake kit that uses a lighter homologated caliper?  (MotoAmerica legal)  Looks like it will drop around 2 pounds of unsprung weight.

It has more advantages than that.  I will also be underslung.  Not a huge deal but if you're endurance racing and have to go from wet to dry or vice versa, it really does make changes go much faster.

[wmhjr]

On 11/11/2018 at 2:06 PM, blackout said:

Two pistons facing each other would be a fixed caliper.  And that is the better design.  More simple, more rigid and a better feel.

Not necessarily true.  There is nothing to prevent a two opposed piston caliper from being a floater.  My race car has 6 piston front and 4 piston rear calipers.  The rear are floaters in order to deal with the sideways thrust of the axles.  Prior to moving to that design, I struggled with knock back.  If there were some reason why the hub/rotor could flex whatsoever to/from the edge of the swingarm, a fixed two opposing piston caliper could experience the same issue.  In all honesty, not likely - cars have much greater lateral force being applied to that area.  I never really looked around to see if anybody implemented a floating two piston rear caliper on a bike to be honest.