Riles

I have Hope Mono mini's.

The problem I have is I cannot seem to avoid the rotor rubbing against the pad..

It is frustrating bcause I set them up and the they work fine, but then when I use them they start to rub.

Shud the piston retract fully back into the Calliper because mine do not go all the way back in, I push them in, but then when I use the brake they do not retract fully back.

Also, if I take them out for cleaning the bike - is it important to make sure the same pads go back in the same calliper the same way around ? I take front and back out and put them back without checking.

I assume all you with Disc brakes avoid this problem ? i.e the wheel rotates without any resistance and you do need to keep adjusting the set up ???

Thanks..

古強者死神

Those are hydro correct?

I think maybe its a matter of bleeding the line for correct pressure. There might be some pressurized air in there or somthing.

with mechs sombody said they had to clean out there calipers because they were sticking so that might be the case too, so maybe taking them apart and cleaning+lubing them will elminate that problem.

Im no expert so these are just my educated guesses.

Riles

They were bled well recently & are new so they do not need a clean..

I can try bleeding again - you may be right as there is not much else it can be I guess..

Hope Mono Mini's are hydraulic.

blue_neon

No you dont need to re-bleed them. The pistons shouldn't retract ALL the way back in but there should be a gap on either side of the rotor? Did you re-center the caliper?

It dosn't matter whether you switched pads from the back into the front, i've done it and no problems they are the same pads. You most likley just need to re-lube the piston with the fluid that is in your brake lines. I'm not too farmilier with Hopes so i can't comment.

mx_599

you can try to carefully bend open the retractor spring a little to gain more retractor spring preload

mx_599

....and you can try to reshim the caliper in the "opposite" direction of the rub. just slightly with the thin Hope shims or shim stock you buy from a hardware store or soda can i have heard of using if you cannot afford the hardware stuff.


....and you might want to open the master cylinder up top when you have the pistons where you want because i am not sure if a slight vacuum can ever be created.


.....and you can make sure the pistons are not all dirty.

LowCel 

Have you had your brake tabs faced? It is possible that they are very slightly out of line. If nothing else that has been suggested has helped you might want to try that.

Also, I have to ask. Why do you remove your brake pads when you clean your bike? Once I install mine I never remove them until it is time to replace them again.

The Great Stonk

1stly, how new are they ? are they post or IS mount ? new hope minis are now IS mount to make setting up and allignment easier, not requiring any shims.

the problem may be caused by un faced mounts, remove the mounting braket from the fork/frame and see if their is a 'halo' around the hole where the paint has been removed, if their is still paint there, you need to get your mounts faced.

swapping pads between front and rear can cause problems, but, only really when your pads are old, where one set may be worn more then the other. bare in mind also that the discs will bed in to a certain set of pads, so swapping the set around will mess with the feel of your brakes untill they bed in again to the differend rotors.

have you balanced the pistons ? - find out which piston isnt retracting far enough away from the rotor and push it back while gently squeezing the lever, this will cause the other pad to move slightly more, and the one your puishing back will tend to move slightly less (when brake is pulled) you will have to recenter the calpier after doing this.

N.B. - be carfull when pushing pistons and pads back, the pistons are made of a soft heat dissipating material that will damage easily, and you dont want big dents and scores in the surface of your pads now do you!

Riles

thanks for comments

- I will try a re-shim (again) first and maybe look at centering the pistons if one is quite far out..

I now suspect they probably need to be faced (I didn't know brake mounts needed facing also) i did notice it was rubbing more to one end of the rubbing pad & that could be caused by uneaven paint ?

Also, comment from LowCel - how do you clean the pads then when they get dirty - just pull a cloth or towel between them ? I would prefer to leave them in once I get them set up right.

LowCel 

I've really never needed to clean them. The rotor does a pretty good job of keeping them clean. I believe I have taken a rag between them once just to get some of the brake dust off to see if the pads needed replaced. Seriously, how dirty can the pads get?

That's pretty bad, in close to four years of using disc brakes I've never had the need to clean the pads. Hmmm, oh well, if it ain't broke...........

mx_599

don't be afraid to get them wet! a spinning wheel and running water will get the rotor, pads, and caliper clean.

achc

i have two sets of hope myself...and other hydro disc brakes on my other bikes...i found that hope is the only one that have the rubbing problem...i have tried hayes hfx9 and avid juicy 7 and none of them have rubbing issue

but my hope m4 is a pain in the @$$ to setup and after two years i have installled them...they are still rubbing...i guess becuase of its long (4) pistons caliper setup it has....the mono mini seems to be better

blue_neon

My nine's are driving insane with the rubbing! When nicley set up there fine, but they seem to need A LOT of fiddling...well mine do anyway!

Chrizz

make sure your wheel is in properly - i had problems for a while, but it turned out that the wheel was about 5mm away from being fully clicked in