|   Hope Mini caliper/pad/piston question... | SS_MB-7
Jul 18, 2002 8:06 AM | | As of recently, my front Hope Mini pads have been very loud, in that, they are rattling against the rotor/piston while the brake is not applied -- very annoying. Once I lightly apply the front brake so that the pads are just touching the rotor, the noise goes away since there is no longer a gap to rattle in.
I was under the assumption that the pads are held against the pistons with magnets. However, after looking at the Mini's pistons, this does not appear to be the case. So, other than the pad retaining clip and bolt, is there anything the holds the pads to the pistons?
Ride Hard,
Mike B. |
| re: Hope Mini caliper/pad/piston question... | KMan
Jul 18, 2002 8:59 AM | | Not that I am aware of, only the little spring retention clip hold the pads back.
Mike, question for you. Should the caliper pistons be centered in the caliper? My rotors are centered in the calipers, but one piston is always further out than the other. Almost like one side is doing all the work and the opposite pistion is sitting there watching, it does move in and out a little, but not nearly as much as the other side.
KMan |
| Hey KMan! ... | SS_MB-7
Jul 18, 2002 9:05 AM | | Hmmm, I'll have to check if the spring retention clip is still in place. I believe the C2s used magnets in the pistons, so I assumed the Minis did too.
Ya, one of my pistons is further out of the caliper than the other -- not much, but visible. I have not noticed any problems due to this though. Once one pad makes contact, the other will immediately compensate.
Ride Hard,
Mike B. |
| Hey KMan! ... | Steve S
Jul 19, 2002 3:23 AM | | C2's did use magnetic pistons to retract the pads, but the Mini's use a spring clip between the pads. Although the rotors on my setup run centrally through the caliper, the pistons never seem to be central. It is only the seal on the piston that pulls the piston back and because of manufacturing tolerances etc both pistons will never move the same amount. You can take your wheel out and work the slower piston a bit holding the fast one back with a flat blade screwdriver, but I don't think that it really affects performance. I also get a bit of a zzzzziiiinnnnngggg from the discs/pads at certain speeds, but when you spin the wheel there doesn't seem to be too much drag. Certainly not enough to make a difference.
Steve |
| So, why have my pads started rattling only recently? | SS_MB-7
Jul 19, 2002 5:07 AM | | I checked my Minis last night and the pad spring retaining clip was there. So, why have my pads started rattling all of a sudden? Do you foresee any problems using the elastomer compound to hold the pads to the pistons?
Ride Hard,
Mike B. |
| You've got me there my friend....... | Steve S
Jul 19, 2002 5:59 AM | | ...can't help you an that one. Elatomer compound. Don't know what if any issues there will be. Anyway, can you really hear the rattle when you are hacking around your fave bit of singletrack??? I can't!
Steve |
| Oh ya, I can hear it.... | SS_MB-7
Jul 19, 2002 6:48 AM | | Steve,
Unfortunately, yes, I can hear it!
I hate bike noises so this is starting to drive me nuts. I'm racing/riding on a fully rigid disc-only singlespeed so there is nothing else to make noise --- except the pads! With no derailleurs, shifters, etc. and a tight chain with perfect chainline, the bike is usually dead-quiet - perfect for sneaking-up on unsuspecting gearies during a race! Now, with my pads rattling-away, my stealthy cover has been blown! ;)
I'm going to try the elastomer pad compound on the back of the pads tonight to see if that helps deaden the noise. It should help quite the pad-to-piston noise, but will not help the pad-to-rotor noise - if this is what is causing the rattling. Although, the elastomer should help keep the pads against the pistons.
Ride Hard,
Mike B. |
| So, why have my pads started rattling only recently? | drjos
Jul 23, 2002 6:52 AM | | It appears that one of your pistons is not retracting as far as it used to. This is creating a smaller gap to the rotor and is causing the rattling. My Avids make a similar noise when I feather the brakes. As the rotor spins it intermittently contacts the pads and rattles.
You might try removing the pads and cleaning everything in case it is some dirt causing the alignment change. If that isn't it you might try changing the shim washers on the caliper to re-center them on the disk.
Good luck. |
| Try expanding the clip/spring | Zuffen
Jul 23, 2002 11:22 AM | | I just cleaned my minis and found that one of the pistons was farther out than the other. I just pushed it back and it seems to retract ok now. If your pads are rattling expand or open up the clip (spring) a bit so there will not be so loose in the caliper. This way there will be more pressure on the pads to retract and perhaps no room to rattle. I think that the heat does a job on the clips (springs) and loose strength.
Ride on,
Zuffen |
| Try expanding the clip/spring | B R H
Jul 30, 2002 8:55 AM | | I bet this is it. My front brake just started rattling. The manual for the Minis recommends replacing this spring each time the pads are changed. My guess is they lose their temper (due to the heat) so opening them up a little will likely only be a temporary solution. Apparently EBC is making the pads for Hope now. It would be nice if they included new springs with the pad sets. Anybody know where to get these springs? |
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