Better braking performance for S1(2005) model

[pulsar2]

As the title says, I am looking to improve the braking performance of my 2005 Fz6. The reason I feel lacking in the braking department was my first intro to BMW S1000RR at California Superbike school (I thought I hit a brick wall on that bike) and my friend's S1000R (the naked BMW). So, I was wondering if I could improve my Fz6 to be a bit stronger when it comes to dropping speeds quickly.

As I understand, 2005 model year has two piston calipers compared to fours in later years. How does the four pot caliper perform?

I see that 2002-2003 R1 calipers are directly compatible, but not much info to go with. Anybody with 2005 (S1?) with R1 calipers?

Also for people who did R1 fork swap, I see a writeup for the conversion,: http://www.600riders.com/forum/how-to-s-/32175-how-install-r1-forks-fz6.html - But cannot make out if this was for 2007+ models or for 2004-2006 models.

If caliper replacement is not a straight forward affair by itself, I can probably combine it with a R1 fork swap (based on complexity) this winter.

I have already replaced caliper seals, and put fresh dot4 fluid to both brakes. It improved the feel of the front brake (less spongy now), but there is not much bite in them. Brake pads/discs look good and not glazed, tires are new and the bike just has approx 17k miles.

Any info in this quest is highly appreciated!!!

 

[FinalImpact]

Unless you're in position to fab up a triples or deal with a different wheel plus the geometry issue of inverted forks (R1/R6), the Early R6/R6S forks allow the S2 calipers to bolt up direct. The other method will require some machining operations.

Several folks here run the early R6 fork and I don't think anyone has a complaint about the bike not stopping as you can do a Stoppie with them if that is your intent.
03-04 R6
06-09 R6S

 

[ozgurakman]

I equipped HEL brand braided lines. Way fine than stock but not enough. Next mod is brembo SA brake pads.

Fz6 can't have good as s1000rr because of center of weight.

BUT best brakes are R6r front end (invert) and it's discs/ brake calipers / brake master cylinder.

 

[Zealot]

I equipped HEL brand braided lines. Way fine than stock but not enough. Next mod is brembo SA brake pads.

Fz6 can't have good as s1000rr because of center of weight.

BUT best brakes are R6r front end (invert) and it's discs/ brake calipers / brake master cylinder.

I think this guy is onto something.

Personally, what I'd do is make sure my brakes were operating 100% (new fluid, clean the brakes, new pads) and install braided lines.

 

[pulsar2]

I equipped HEL brand braided lines. Way fine than stock but not enough. Next mod is brembo SA brake pads.

Fz6 can't have good as s1000rr because of center of weight.

BUT best brakes are R6r front end (invert) and it's discs/ brake calipers / brake master cylinder.

You are right on the S1000R/R, I am just checking the options we have for S1 to improve the brakes. I think the brake dive is another thing that needs to be addressed along with the caliper upgrade.

I think this guy is onto something.

Personally, what I'd do is make sure my brakes were operating 100% (new fluid, clean the brakes, new pads) and install braided lines.

Thanks,I already have braided lines, caliper seals replaced and fresh brake fluids and the Brakes are 100% stock!! I saw the compatibility chart here :
https://docs.google.com/spreadsheets/d/13zl2FRRSjsGg-8gwMlGuG18TURzqnJm5-o-a0mPi-DE/pub - so thought of taking up the 2002-2003 R1 Caliper swap if it is a direct fit on my S1/2005 forks. This is since I already have a few upgrades on the stock forks - racetech springs and preload adjusters.

 

[TownsendsFJR1300]

My old 2000 Kawasaki ZRX 1100 had 6 piston calipers and would stop on a dime(even with rubber lines). It was more fun to stop than accelerate!! Definitely the fastest stopping bike I've owned..

I have no idea about adapting them to the FZ but would certainly make a hugh difference..

 

[FinalImpact]

I have to say that part of the feeling of stopping quickly comes from the suspension doing its job.
Get some damping control so it doesn't feel like you putting your fork through runny mashed potatoes!

 

[outasight20]

I have HEL SS lines and EBC HH pads on my stock calipers. Also have Racetech .90 fork springs and 10 wt fork oil. The braking is phenomenal in my opinion, although I've never ridden anything like a S1000RR or similar. I can bring lift my rear wheel at speed with only one finger with my current setup.

 

[TownsendsFJR1300]

I have HEL SS lines and EBC HH pads on my stock calipers. Also have Racetech .90 fork springs and 10 wt fork oil. The braking is phenomenal in my opinion, although I've never ridden anything like a S1000RR or similar. I can bring lift my rear wheel at speed with only one finger with my current setup.

The higher performance bikes have better brakes, better suspension, etc...

I agree, the S2 brakes with SS lines really don't have an issue. I've never lifted the rear tire (too old for that stuff) but I'm sure it would.

Now my forks do have 7.5 wt oil in them and I installed schrader valves with about 15lbs of air in each fork.
They are considerably taughter and dive is about nill.

 

[buzzbomb]

I equipped HEL brand braided lines. Way fine than stock but not enough. Next mod is brembo SA brake pads.

+1 for HEL SS brake lines! Even if you change nothing else, they'll add lots more feel and firmness to both the front and rear brakes. It's a good starting point, but of course as others have mentioned the brakes work together with suspension, and with such soft suspension a brake upgrade can only do so much. I'm looking at new pads and heavier weight fork oil with heavier springs. I haven't had any supersport background so couldn't imagine the braking and cornering of a well sorted machine, but I think this would be a good start for street use.

 

[buzzbomb]

I have HEL SS lines and EBC HH pads on my stock calipers. Also have Racetech .90 fork springs and 10 wt fork oil. The braking is phenomenal in my opinion, although I've never ridden anything like a S1000RR or similar. I can bring lift my rear wheel at speed with only one finger with my current setup.

Just a question, how much dive do you get with the Racetech .90 springs under hard braking? How does it go with rough roads and potholes compared to standard? I'm interested in this upgrade as a good street setup and think it would make a nice improvement over standard.

 

[pulsar2]

Just a question, how much dive do you get with the Racetech .90 springs under hard braking? How does it go with rough roads and potholes compared to standard? I'm interested in this upgrade as a good street setup and think it would make a nice improvement over standard.

I have the RT .90 springs as well, and found it similar to stock springs with some preload in them(got slingshot racing preload adjusters on stock forks). Even with this, I see the front shocks compress to the last two inches(probably, can measure later) to the fork seals under hard braking. The bike is certainly more stable around corners, but brake dive still exists. I do have raised the forks about 15mm and this might be contributing to the dive as well.

I think we need proper compression damping - so R6s may be the way to go as a lot have already suggested.

And once that is takne care of, the rear will need attention.:spank:

 

[pulsar2]

Oh, and I also had 15wt maxima oil in them put about a year ago. Will try replacing it and see if fresh oil makes a difference.

 

[outasight20]

Just a question, how much dive do you get with the Racetech .90 springs under hard braking? How does it go with rough roads and potholes compared to standard? I'm interested in this upgrade as a good street setup and think it would make a nice improvement over standard.

Definitely less dive than stock, but the forks will still compress almost all the way under hard braking. The difference with the higher weight oil is that it takes a bit longer for them to compress, which lends to a firmer, more compliant feeling. Bumps are a bit more harsh than stock but not bad at all. in retrospect I would've gone for .95 springs. I am 180 without gear.

This is after adjusting preload for 33mm of static sag.

 

[FinalImpact]

Definitely less dive than stock, but the forks will still compress almost all the way under hard braking. The difference with the higher weight oil is that it takes a bit longer for them to compress, which lends to a firmer, more compliant feeling. Bumps are a bit more harsh than stock but not bad at all. in retrospect I would've gone for .95 springs. I am 180 without gear.

This is after adjusting preload for 33mm of static sag.

^^ What is the Bikes sag by itself with the 0.90Kg/mm springs?

I really have no idea why they shipped the thing with a dual rate spring that starts at 0.77kg/mm - its all but useless and simply consumes too much travel holding itself upright, let alone the loads under braking.

 

[FinalImpact]

Oh, and I also had 15wt maxima oil in them put about a year ago. Will try replacing it and see if fresh oil makes a difference.

Also, not all oils are the same. That is; some may list wt X but it actually tests out to be lower or higher than what is specified. Just to keep things simple I run the OEM yamaha fork oil. IIRC Darius posted an oil chart somewhere and it compared over 50 products by tested wt vs listed wt. There was HUGE VARIATION among many brands.

 

[FinalImpact]

Last little bit; VACUUM bleeding is NOT a value add. Its great to get a new line set full of fluid but it leads to more air being trapped in the system as it takes the small air bubbles and disperses them into smaller molecules throughout the whole system. PROPER PRESSURE BLEED Condenses the AIR and forces it out.

From: BRAKE BLEEDING, CALIPER AND PAD INSPECTION

***********************************
BRAKE BLEEDING, CALIPER AND PAD INSPECTION
***********************************

First off; bleed your brakes annually! Why? The OEM DOT 4 fluid is an ether glycol product which absorbs moisture at nearly twice the rate as DOT3 fluid. These fluids are hygroscopic and absorb moisture which breaks down the hardware as it converts into acids. In addition, moisture in the system reduces the boiling point (may boil over) and can induce brake drag as the pistons do not retract as effectively when there's moisture or air in the system. Granted, new synthetic fluids withstand this better than old ether - glycol based fluids, it just makes good sense to inspect the entire system and bleed the brakes annually.


The process I use to bleed brakes:
Tip number one - buy a syringe and some soft tubing. Preferred is silicone as it can stretch to any size fitting you might encounter and it very pliable. When it comes time to do a brake flush, simply suck out the old fluid, clean out the reservoir and dump in the new DOT 4 fluid. Note: A turkey baster will work to remove old fluid too. Our goal here is to NOT MIX old and new as its more fluid to pump out.

• NOTE: Always use Fluid from a NEW UNOPENED CONTAINER!!!
  The reason being, once the seal on the container is broken, the fluid begins absorbing moisture. Also, If it possible, perform brake repairs/bleeding on low humidity days!
  PROCESS:
• Crack the caliper bleeders to insure they can be loosened and reseat them. Fit a long section of hose to the bleeder and into drain pan.
• Clean MC lid, remove it, remove old fluid (clean inside and seal if dirty). DO NOT PUMP lever when fluid is removed....
• Fill MC w/FRESH FLUID, install cap/lid.
• Pump lever/pedal and hold lever down with pressure.
• Crack the caliper bleeder and continue applying pressure to lever. When the lever bottoms, seal the bleeder.
• Repeat above steps until clean fluid is coming out. WATCH THE FLUID LEVEL! Don't allow the level to get low or it will force air into the lines!
• Do both sides if applicable.
• On the final bleed (both sides), seal the bleeder before the lever reaches bottom. This prevents air from entering the system.
• Fill MC to correct level, install lid and clean everything spotless!
• Repeat once a year using NEW DOT 4 fluid!

NEW LINE INSTALL:
If you've installed new lines and have allot of air in the system, use the syringe and open a bleeder. Connect the syringe and pull back on the plunger to pull fluid through from the reservoir.
- BEGIN AT BULLET SECTION above to obtain a firm lever!

Use a syringe to remove old fluid! It's way better than pumping it through!

If you have a long hose, run it straight into a pan or bottle. Here I was in pinch and just let it fill up the syringe.

Do not get brake fluid on anything as it eats paint and will/can dull powder coated items too.

• ** DO NOT LET THE MC reservoir go empty and suck air or your brakes will be all mushy and you'll have to start the bleeding process over!! **

***********************************
Additional tips:
IMO Vacuum bleeding never gives a solid feel. Pressure bleeding forces the trapped air under pressure to condense into larger bubbles. As the bubbles increase in size, they often move to the top where the bleeder is and can be removed.
-->>> READ THIS: To assist the trapped air bubbles in making their way out of the brake system, use a dead blow hammer or a firm block of wood and tap on the caliper striking towards the ground. DO NOT TAP INLINE WITH THE CALIPERS PISTONS ESPECIALLY on FLOATING CALIPERS! If you choose to tap that way, do so gently you can damaged the disc and induce air into the system. This small shock (hammer tap) can remove trapped air bubbles. The momentary shock helps them condense and make their way out of the caliper. Don't leave marks or damage anything. Your tapping too hard if this occurs!

Note: The rear of both S1 and S2 FZ6's are floating calipers. The front of the S2 models are fixed 4 piston calipers. S1 front calipers are floating calipers.

***********************************

 

[pulsar2]

^^ What is the Bikes sag by itself with the 0.90Kg/mm springs?

I dont remember, will check it and update. And to fix the brake dive, I am getting this - 41mm Fork Damper Valve 2001 and Up for Harley Davidson | eBay . Although the part is not a direct fit, I plan to add a bushing/o-rings to use it on our stock shocks. 30$ to add compression damping on stock forks would be worth it even though it needs a little modding Blah . Once the suspension firms up under braking, I will visit the brakes again.:thumbup:

 

[pulsar2]

Back with the sag numbers :

Full extension - 115mm
Bike only(avg) - 92mm
Static sag - 23mm
Rider sag - 32mm

I weigh approx 180pounds without gear. The forks are raised 15mm and had about 9mm preload till now. I like the way it feels with nice sharp handling around the curves as long as braking is not necessary. The fun ride just ends the moment brakes are required to slow down as the fork compresses all the way especially on downhill corners. Not at all fun. I will try to get a video of the fork travel during braking.

 

[pulsar2]

Today I expreimented with no preload and ended up finding less dive than before. The fork does not compress all the way as before and the bike is now better balanced front-to-back. I dont feel like I am doing a stoppie anymore. I initially increased preload thinking it will help ride height since I have lowered the front by moving the forks up the Tripe/T, but I think it instead reduced the springs ability to soak up braking forces effectively. Now with more available spring travel, the braking forces are absorbed well before the springs begin to top out. If this is the case, I wonder what exactly the preload adjuster would do on a linear rated spring.