Care to have a go at this question XSL WiLL?

[Jet-Mech]

G'day XSL WiLL, You were going off to work the other day and did not have time to read my long winded post, got any spare time now ?

G'day XSL_WiLL. Now the fun begins, I can start to get real technical (and long winded) !. I recall in a previous post that you received a set of Juicy 5’s with the same performance anomaly (excessive free lever movement) as mentioned in my original post. This problem was solved by properly and thoroughly bleeding the brakes.

According to my knowledge of open system hydraulic brakes, (with respect to cars) the initial lever movement does nothing until the master piston moves far enough forward to cover the fluid inlet port/s from the brake fluid reservoir.

At this point, a hydraulic lock is formed with a fixed volume of brake fluid. This fixed volume of brake fluid consists of fluid in the brake line, master cylinder and caliper cylinder cavities. Further movement of the brake lever will then start to move the caliper pistons and brake pads forward until contact with the disc is made. Further lever movement again then generates pressure on the fixed volume of brake fluid which forces the brake pads against the disc.

I am confused about your previous post as it seems that the excessive free lever movement of the Juicy 5's you worked on was somehow cured by adding additional fluid volume to the fixed volume (mentioned in the previous paragraph)?

I understand how this works in theory as the additional fluid volume means that the caliper pistons (and pads) will be already further forward in the caliper cylinder cavities, and will thus need to move less before contact is made with the disc.

If the problem is caused (as I suspect) by the pad return spring pushing the brake pads too far back upon brake lever release, any "additional" fluid volume that you managed to add by proper and thorough bleeding will be immediately forced back into the fluid reservoir once the master piston moves far enough back to uncover the fluid supply port/s from the reservoir.

In other words, I can see how bleeding may cure excessive free lever movement in closed system brakes, but not open system brakes.

Told you I was going to be technical and long winded :mad2: !

[XSL_WiLL]

Damn... Comeon now... It works. That's about all I can say. It's the same thing with my old Hayes, ram more fluid in so it doesn't pull all the way to the bar before it stops. Damn... This makes even less sense after a day full of riding and night of drinking with the chicas.

[Jerk_Chicken]

Continue to be confused by will's posts because he often asserts more information than he is qualified to give. He periodically has to be corrected due to this.

[Jet-Mech]

Damn... Comeon now... It works. That's about all I can say. It's the same thing with my old Hayes, ram more fluid in so it doesn't pull all the way to the bar before it stops. Damn... This makes even less sense after a day full of riding and night of drinking with the chicas.

No worries XSL_WiLL ! I wasn't questioning your experience with Juicy brakes or doubting that bleeding cures the problem . The engineer in me just likes to know how stuff works. I will get the LBS to bleed my brakes to fix the problem. I like to hear the sound of my own voice, but due to the limitations of the internet, the next best thing is to write a long winded and excessively technical treaste on mtbr.com . Can I still hit you up for brake advice in future if I am concise and non-technical?

[XSL_WiLL]

Continue to be confused by will's posts because he often asserts more information than he is qualified to give. He periodically has to be corrected due to this.

[XSL_WiLL]

Are you still b!tching about when I said fluids are compressible a couple months back? So I made a mistake. OKKKK... Besides, they are technically compressible, however miniscule that compression may be. And you know what I was getting at anyways.

[dogonfr]

He says what he belives to be the correct response, he like the rest of us are human & prone to mistakes on occasion. Then someone comes in & corrects you, this is a part of life. When XSL_WiLL is corrected i have never heard him whine about it, he is very good about accepting he was wrong & learning from it. I like all these new faces!

[fiddy_ryder]

. The engineer in me just likes to know how stuff works. I will get the LBS to bleed my brakes to fix the problem. I ?

engineer at heart,, likes to know how stuff works.. but cant/wont bleed your own brakes...??...

[Jet-Mech]

engineer at heart,, likes to know how stuff works.. but cant/wont bleed your own brakes...??...

Hey fiddy_ryder ! I've got no hesitiation whatsoever in rolling up my sleeves and getting dirty, hell I've done more than enough work on my own cars (including brake bleeding). My bike is only 2 weeks old so I am still in the grace period with the LBS. When I take in my bike for the 4 week checkup I will get the LBS to bleed the brakes. No point in me forking out for an Avid bleed kit if it can be done for free !

[dogonfr]

Hey fiddy_ryder ! I've got no hesitiation whatsoever in rolling up my sleeves and getting dirty, hell I've done more than enough work on my own cars (including brake bleeding). My bike is only 2 weeks old so I am still in the grace period with the LBS. When I take in my bike for the 4 week checkup I will get the LBS to bleed the brakes. No point in me forking out for an Avid bleed kit if it can be done for free !

Get XSL_WiLL a round trip ticket to maintain your bike for 4 months & im shure your brakes will be working wonderfully!!

[misctwo]

He says what he belives to be the correct response, he like the rest of us are human & prone to mistakes on occasion. Then someone comes in & corrects you, this is a part of life. When XSL_WiLL is corrected i have never heard him whine about it, he is very good about accepting he was wrong & learning from it. I like all these new faces!

i'll bet Jenna Jameson or Jenna Haze can say a thing or two about compressed fluids...i wonder if she posts here...

[dogonfr]

i'll bet Jenna Jameson or Jenna Haze can say a thing or two about compressed fluids...i wonder if she posts here...

Tease

[misctwo]

dammit i'm all horny now...

[dogonfr]

I think XSL_WiLL is at work