| Author | Message | ||
     Wyckedflesh |
I am very interested in getting better performance from my rear brake. For those with experience with braking systems, would switching to a larger rear mastercylinder help? Is there a caliper that could do a better job that anyone knows of? Since it is the rear, what would be a pad replacement that would give better performance? Anything that can be done to improve the rear brake would be appreciated. This is a bench racing thread so ideas are welcome. I did get a little bit of better performance when I adjusted the brake lever so I could get the full sweep the mastercylinder allows, but it is still very lacking in stopping ability. At this point you might be wondering why I care about the rear brakes. I have admitted to a really bad habit of rarely using them. Well I have been working on that aspect. I have been using the rear more and more and finding that my cornering has improved from the added more aggressive trailbraking. The lines are more stable and mid corner adjustments are much easier to make on the fly (like when an SUV crosses into my lane to cut the corner). Its been weighing on my mind alot lately and the free time to ponder the problem has me really wondering which route I should look into following. | ||
| M1combat |
Maybe something as simple as sintered pads? Is your rear brake not powerful enough to lock the rear wheel? Mine is but it does take a good bit of pressure. A larger master cyl. should do the trick. I think there's a thread in the "Old School Buell" section about calipers and how they work WRT getting more power and how the pressure is delivered. Excellent reading. | ||
| Dcmortalcoil |
Checkout the mechanics behind braking at: http://www.mecc.unipd.it/~cos/DINAMOTO/frenata/Braking%20paper/braking_new.htm It discusses the braking efficiency and the correlation between braking and the coefficient of wheel/road friction. This article also explains WHY WE ALL SHOULD BE USING BOTH THE FRONT AND REAR BRAKES. | ||
| Wyckedflesh |
M1, mine will only lock if the wheel is about to come off the ground, or if the speed is low enough. | ||
| Fullpower |
wycked: respectfully i say you should give this a lot of thought before making any change. while braking a great deal of weight is transfered to the front wheel, static weight balance near 50-50 approaches 100 % front weight bias at maximum braking. any degree of lesser braking is still pushing down on the front wheel, increasing traction at the front, and decreasing weight, and more dramatically decreasing traction available at the rear wheel. this means that while braking your rear end is lighter, and LESS TRACTION IS AVAILABLE AT THE REAR TIRE. the main reason the front brake is 10 times more powerful than the rear is to keep it from locking up when your big size ten boot comes down, whereas 2 fingers at the front lever is sufficient to do a controlled 600 foot long rolling stoppie from 130 miles per hour. "Its designed that way for good reasons" feel free to get more aggressive pads on the front if you want, but i dont recommend doing so on the rear of a bike with a 52 inch wheelbase. again, with respect,dean | ||
| Fullpower |
wycked, is it possible that your existing pads are some how contaminated, or glazed, thus reducing their efficiency? | ||
| Wyckedflesh |
That was my thought but I pulled the pads when I had the rear off getting the new tires put on. They weren't glazed at all. I think part of the problem is I got used to how much the rear brake on the Ninja worked compared to the XB's. I still scuffed them up with a wire brush before putting them back in but there wasn't any change. FP I am not looking for maximum braking performance. I am looking for a more compliant performance for trailbraking or moderate street riding. Something that gives more feel and feedback from the rear then what I have now. I can pretty much stand on the rear brake and not have any noticeable effect until the tire is about to loose traction anyways from being so hard on the front, or at slow/less then 20mph speeds. I would actually like to use less front and more rear which does help to shift the weight off the front a tad. Not tons, but enough that if I need more brake I have it at my disposal at the front. | ||
| Henrik |
I'm with Fullpower - leave it alone. I've been going through a few modifications to the rear brake on my SV to get *less* braking power. I absolutely *do not* want a rear brake that will lock up on me, especially if I'm going to learn to use it more - for say trail braking. You really just want the rear brake to help you settle the suspension as you're heading into the turn. The vast majority of the braking should be done using the front. Think of the "traction pie"; say you have 100 units in the full pie. You go into a turn hot and lean the bike over - and all of a sudden 80 - 90 units of that traction is gone. You've got to be *very* delicate on the rear brake if you're avoid pitching yourself into the next county. Making the rear brake more powerful is not going to help you being delicate. Anyway - just one man's opinion ... and you know what they say  Henrik | ||
| Dcmortalcoil |
My rear brake was really horrible, useless when I first got the bike. All I did was bleed the air out and now it's working significantly better. After bleeding, all the sponginess disappeared. | ||
| Wyckedflesh |
"You've got to be *very* delicate on the rear brake to avoid pitching yourself into the next county. That is exactly my point Henrik. The feel and performance of my rear brake is such that the only way to get it to work at all is to be hamfooted. I want to have the ability to be delicate with it. Can you honestly compare your SV's rear brake to your Bolt's rear and say they compare equally? How would you feel if you could meet the two somewhere in the middle? Not get the Bolt's rear brake up to where the SV is now but not take the SV to where the Bolt's is now, but meet the two in the middle. That is what I am after. Lets look at your pie deal. At 100% traction currently my braking performance feels 95% front 5% rear under moderate conditions. I would like to get that swapped down to say 80% front 20% rear. DC my bad, when I do anything with the brakes, I always bleed them. I may not do the full bleed that Dr. Henrik has come up with for the front, but I will do a basic bleed and carefully watch for any air coming out. | ||
| Static |
is your pedal spongy or hard feeling? I have an '03 xb9 and after I bled the air that shouldn't have been there to begin with, I can lock the rear up anytime. More importantly it has just as much response as the front and very similar in feel. ( I'm running stock pads at both ends of the bike) Is there a possibility that, though they weren't glazed, your pads became contaminated? Once that happens the friction material is no good and the pads have to be replaced. | ||
| Wyckedflesh |
It is not spongy at all. Its very linear, but it is lacking in strength. There isn't any sign of contamination on the pads, the rear has had the same feel since the day I picked up the bike. I did get better response when I repositioned the pedal but even that was minimal. | ||
| Static |
when you scuffed up your pads the last time did you also lightly scuff the disc? That too will become glazed with many heating and cooling cycles. Also, you might want to try ( in a parking lot or something) using the rear brake as hard as possible and then placing your hand near or on the disc to see whether it is hot or not. If it's cool, the larger master cyl. might be the answer, If it's really hot you have a problem with the friction surfaces. I have had numerous issues with vehicles that have pads and rotors improperly prepped or installed. Also there is some drive time needed to reseat the pads after you've replaced or resurfaced them | ||
| Henrik |
Wycked; it's difficult to put an exact measure on "how much" brake I'd want in the rear. The SV is *way* overkill. I have a GSXR rotor, which is 10 mm smaller in diameter that I'm going to try out. But I don't think it'll change much other than unsprung weight, since I've cut the brake pads back 10 mm and still have too much brake. I'll probably have the GSXR rotor drilled to get even less brake. My old S3 and my current S2 however, have very little rear brake in comparison - I'd always go flying through the rear brake drills at Pridmore's school  Somewhere in between? Maybe ... but most likely closer to the stock Buell set-up than the SV. I guess my concern with more brake power is, that I'm not sure I have the manual dexterity in my MC boot clad foot, to be delicate enough for more rear brake. The front I can modulate reasonably well, especially since I'm using the body part with the second-most motor neuron innervation - the right hand/index finger - not so sure about my foot . With that in mind I would much prefer to have a rear brake that absolutely *will not* lock up on me - as recommended in Nick Ienatch book on riding technique. But I hope you find a set-up that you feel works for you and your riding style - that's what it's all about; getting the bike set up so it works. Just be careful out there. Henrik | ||
| Starter |
The rear brake was designed for a size 12 footed ape. The only good results I've heard of is from EBC HH pads. That being said I've compared the fronts to a set of EBC HH I had in the garage and they look identical. One of my mates who rides claims it is the steel brake line that makes it fell useless coupled with the lack of moment that the lever has when being compressed. He thinks a longer brake lever would improve things. | ||
| Henrik |
...it is the steel brake line that makes it fell useless ... Sorry, but that doesn't make a whole lot of sense. Taking unpredictable hose flex/expansion out of the braking equation can only be a good thing  Henrik | ||
| Skully |
Wyckedflesh, I highly recommend AGAINST using the rear brake. There are good reasons for it being so wimpy. This Spring, Blake and I were with a friend (riding a Ducati 750SS) who got into the habit of using the rear brake much as you are describing. Worked fine until we got into gravel in a 10 mph curve on Arkansas Hwy 123. He locked up the rear tire and found out what a high side feels like. All 270 pounds of him landed on his left shoulder. Even at 27 years young, it took weeks to get full mobility of his left arm back. And yes, he was wearing a jacket with shoulder armor. YMMV, Keith | ||
| Wyckedflesh |
Keith, that is a difficult one to call, had he not used the rear, he could have folded the front under in a lowside that could have broke his knee, which is what happened to a friend of mine in the same situation. Or he could have simply done nothing, had the rear slide out on the gravel and still highside him when it caught. Not trying to paint anything into what happened, just saying the gravel itself could have caused any number of things to happen. | ||
| Buellfan |
The X1's had better pads than the XB's and they drop in. | ||
| Dcmortalcoil |
It's not locking the rear brake that causes a high side, but releasing the rear brake after the lock up. I was told (in the MSF course) to keep it locked until you straighten the bike or come to stop or near a stop. Is that a difficult thing to do in a panic situation? | ||
| Opto |
1) Compared to any other bike I've ever ridden the Buell rear brake is really weak. 2) I have not ever had any major problems adjusting to different bikes' braking systems' strengths or weaknesses. 3)Adjusting to the good feel of the Buell front brake and the weakness/almost no feel of the rear has been my most difficult adjustment which rates just as hard as jumping on a new bike with the gear shift and rear brake pedals on the wrong sides. 4) I can handle it that Buell impose this setup upon me, but I don't like it. Yes the bike stops really well, but I want a rear brake too! | ||
| Opto |
Dcmortalcoil, in a panic situation it's easy to straighten up if you've got somewhere to go that's straight ahead. If you follow that good advice, worst you can do is lowside, which is a lot better than a highside. And after you've lowsided you can also release the brake | ||
| Wyckedflesh |
A highside is when lateral traction is regained in an abrupt manner. If you are on a loose surface a highside can happen when you transition to a hard surface and regain traction from the slide whether the wheel is locked or not. | ||
| Opto |
Wicked, I've highsided on dirt just a couple times in my youth, one of them broke my right collarbone after I got catapulted hard into the ground, heard the bone snap. It was at low speed. Then I had to ride about 35 miles home with my left hand grasped to my right forearm to support my crippled right arm/shoulder so I could work the throttle and steer. Hope I learned my lesson! | ||
| Wyckedflesh |
Like I said, the sudden and abrupt regaining of lateral traction. Doesn't matter what the surface is, if the rear suddenly grabs traction from a slide it can cause a highside real easy. | ||
| M1combat |
Have you bled the rear brake? From that you describe it seems like my brake is more powerful than yours. Maybe that's all it needs? | ||
| Starter |
I highsided my GSXR in a powerslide. It too was when the rear regained traction. It was spinning then I s%^t myself cause it really stepped out and shut the throttle. Grip, buck and throw. Not my favourite riding manouver. Also stuffing around on my XB this morning I was able to lock the rear real easy. No feel through the lever though. | ||
| Wyckedflesh |
DC my bad, when I do anything with the brakes, I always bleed them. I may not do the full bleed that Dr. Henrik has come up with for the front, but I will do a basic bleed and carefully watch for any air coming out. |
