[thaflyinfatman]

I only run hayes (for the time being and for the past 4+ years) and they usually work pretty good, but if you have felt Shimanos or Hopes then you know what GREAT feels like. I choose hayes for the ease of accessibility to spare parts but I may change to Shimano or Hope soon.

Shimanos have a better lever feel but much the same power, Hope levers annoy me (so does the noise but that seems to come and go) and they're not any more powerful either, but I have no real issues with my Hayes. They have plenty of power, I'm not complaining!

 

[zane]

Try turning the lever upwards and undoing the reservoir cap (as though you're going to bleed the brake), push the pistons back out, squeeze the lever slowly until the pistons have moved in slightly, then SLOWLY release the lever back to its original position. Top up the reservoir if need be, then close the reservoir off and repeat as necessary. This *should* decrease lever throw, obviously to increase it you do the same thing but you push the pistons out with the reservoir open, but don't squeeze the lever back in. It's fiddly and takes a while to get right, but it can be done.

HOY-O!!!! Finally, someone's addressing this problem the right way- the fluid. Think of it this way- with cable brakes, when you want to decrease the throw you pull the cable tighter in the system so the engagement point is reached sooner. With hydraulic brakes, you want to do the same- except compared to the cable the fluid is pushing, not pulling. So, you put more fluid into the system which increases the tension (pressure in the fluid) at rest. The engagement point (pressure in the fluid it takes to engage the pads) is reached sooner, and your lever throw is effictively decreased.

The problem of changing throw is also affected by the condition of your brakes- new o-rings, seals and pistons will surely help.

 

[kidwoo]

HOY-O!!!! Finally, someone's addressing this problem the right way- the fluid. Think of it this way- with cable brakes,.

Your analogy is only half the system though. Unlike a cable, the open system hayes have two components. 1)the active fluid and 2) the excess reservoir fluid not being used when braking.

If you want to think of it as a non-fluid system, it's really more like a ratchet. When you pump the lever to set the system, you're setting the pads AND setting the volume of fluid that is to be used when braking. The pad position is set further in as the pads wear by this "idle" fluid slowly being introduced into the "active" fluid over time. Same as car/motorcycle brakes. Like 1000-oaks did, you can adjust the fluid volume but it really is easier to play with the lever position screw to find your desired lever position at engagement.

 

[MikeD]

HOY-O!!!! Finally, someone's addressing this problem the right way- the fluid. Think of it this way- with cable brakes, when you want to decrease the throw you pull the cable tighter in the system so the engagement point is reached sooner.

This is very wrong. You always leave the cable at full extension. You don't use the barrel adjuster or fixing bolt to adjust the throw of the brakes. You set the cable tight with the actuating arm at full extension.(sometimes a turn or two on the barrel adjuster is needed just to take up cable slack). From there, you adjust the throw of the brakes by adjusting the position of the moving brake pad using the outside adjuster dial.

If your actuating arm isn't fully extended when the brake lever is out, you won't get the full leverage from the brakes.

MD

 

[zane]

This is very wrong. You always leave the cable at full extension. You don't use the barrel adjuster or fixing bolt to adjust the throw of the brakes. You set the cable tight with the actuating arm at full extension.(sometimes a turn or two on the barrel adjuster is needed just to take up cable slack). From there, you adjust the throw of the brakes by adjusting the position of the moving brake pad using the outside adjuster dial.

If your actuating arm isn't fully extended when the brake lever is out, you won't get the full leverage from the brakes.

MD

Um, I don't know what brakes require you to move the pads closer to the rim manually instead of just pulling more cable through, it's essintially doing the same thing. The only difference would be the angle of the arms being effected by moving the cable tighter....

And yes, I did forget about the resiorvor (sp?) fluid, but once the pads are set in place (and the resiorvor is full) doesn't everything stay the same in the system???? I'd think it would, but correct me if I'm wrong.

 

[kidwoo]

Um, I don't know what brakes require you to move the pads closer to the rim manually instead of just pulling more cable through, it's essintially doing the same thing. The only difference would be the angle of the arms being effected by moving the cable tighter....

And yes, I did forget about the resiorvor (sp?) fluid, but once the pads are set in place (and the resiorvor is full) doesn't everything stay the same in the system???? I'd think it would, but correct me if I'm wrong.

The reservoir is more like fluid in well....you know, reserve. The fluid in the line is set by pumping the lever and getting the pads to engage. Again, this is more like a ratchet. Ideally this will be the same volume every time and you could adjust from there. Problems arise when you get too much or too little in the reservoir during a bleed. This variation will (especially in older brakes that have seen some use) in turn cause some variation in the amount of fluid that is called to duty in the line and in what gets left as reserve. This is why it's important to push in your pad pistons before a bleed......so that you're always working with the same volume of fluid.

That bladder thing in the reservoir housing changes volume. It shrinks as more fluid is introduced from the reservoir into the lines. This changing volume is why you have a "breathe" hole by the way. You can also sometimes get away with a little air in the reservoir (NOT THE LINES!) since there's not really a whole lot of interaction between the two fluid stores once the system is set. You should still try to avoid it though.

If you've ever had a small leak at any of the caliper/hose, reservoir/hose junctions et and your brakes still work, this is why. You can leak a little fluid out of the active system and it will be replaced upon your next lever pump from the fluid in reserve. You can also be leaking fluid out of the reservoir and see no change.

If you get a chance take apart the lever reservoir on a set of shimano brakes and look at the bladder in those. An expandable bladder with active fluid in the lines and reserve fluid in the reservoir......just a much simpler system to look and and see what goes on. I didn't touch my xc bike for about 2 months over the winter and had it stored upside down. I had no brakes at first. After it sat upright and I got a few pumps in, the brakes were back. The fluid had run into the reservoir and either compresed the bladder or switched places with some air in the reservoir. Either way it reset itself and works fine. Kind of cool.

 

[D_D]

If you are going to use that methof I would be carefull not to pack the resivoir full of fluid leaving no room for fluid expansion.
Normally you would bleed and fill the res with the pistons pushed into the caliper. Then when you pump the lever to push the pistons out fluid moves from the resivoir to the line which creates space in the resivoir which fluid can expand into.
If you pump the pistons all the way out before filling the res you could end up with very little room for expansion.
Having never ridden a closed brake I have no idea if it would be a problem or not but if your brakes get hot you might want to make sure you leave some space for expansion.

 

[kidwoo]

If you are going to use that methof I would be carefull not to pack the resivoir full of fluid leaving no room for fluid expansion.
Normally you would bleed and fill the res with the pistons pushed into the caliper. Then when you pump the lever to push the pistons out fluid moves from the resivoir to the line which creates space in the resivoir which fluid can expand into.
QUOTE]

That's also the purpose of the bladder.

 

[thaflyinfatman]

If you are going to use that methof I would be carefull not to pack the resivoir full of fluid leaving no room for fluid expansion.
Normally you would bleed and fill the res with the pistons pushed into the caliper. Then when you pump the lever to push the pistons out fluid moves from the resivoir to the line which creates space in the resivoir which fluid can expand into.
If you pump the pistons all the way out before filling the res you could end up with very little room for expansion.
Having never ridden a closed brake I have no idea if it would be a problem or not but if your brakes get hot you might want to make sure you leave some space for expansion.

Yeah, the diaphragm takes care of that. If you *really* overfill the system though (ie try to "pressure bleed" it using a syringe and forcing fluid into the bleed nipple with the reservoir cap closed), you can blow the diaphragm off whatever it's attached to, which = not good.