Hope Mono Mini - Seems to always be "on"

bobmij7 · June 2007

I have just fitted my mono mini onto my new forks (2005 66s).
Now, when I ride the brake seems to always be clamping down on the rotor. It isnt forceful so you cant notice it when riding but its pushing on enough so that the rortor gets warm!

There is absolutely no space between the pads and the rotor.
The lever seems to be fine too. It bites alright. If anything it could be a little more sharp.
The pads are also new.

Any ideas?
I'm in quite a pickle.

Thankies,

James

The whole story.

I got the hope brake off ebay. At the time i had dirt jumper 2s. the pads were crap and I was in Scotland at the time. I bought some new pads at "The Hub" bike shop at Glentress. The guy who worked there said he would fit them for me, he did, and everything was good! The brake worked niceley.

I just got the 2005 66s and fitted the brake (obviously using the same hope rotor and same wheel). I have used, what i like to call, washers to put the brake in line with the rotor. The problem was that for some reason, withing the 10 minutes between taking the brake of the old forks and putting it on the new one the pads seem to have closed together. I could hardly even get it on the rotor without pushing them open with a knife.

So now, the pads just seem to be pressing against the rotor at all times.

I do know that when you press the lever without a rotor between the calipers it can close the pistons, so i didn't do that!

I'm going to have a fiddle with the brake and try and re-align the caliper.

http://www.pinkbike.com/photo/945659/

whyamihere · June 2007

Check the alignment, then ride it, let it bed in, if there's still a problem, then let us know. Many problems with new brake installations like the one you've described fix themselves as you allow the brakes to bed in.

extreme__dude · June 2007

it could be if you've put new pads in that you have to let some fluid out of the reservoir and, when you pushed the pistons in to fit the new pads, the reservoir filled up, so now there is nowhere left for the excess fluid to go

<center>pinkbike</center>
<center>new frame [:D]</center>

whyamihere · June 2007

You never have to let fluid out of the reservoir to fit new pads. Post something like that again and I'll ban you.

Snapper · June 2007

Whyamihere it really does happen quite often. I see it quite often when people have tried to DIY service there brakes. I have even seen some not so great bike shops do it. Its very simple to do. If you have toped a brake system fluid up when the pads are very warn you can literally over fill the system. This is ok when you have warn pads but when you stick new pads in you simply cant push the pistons out far enough. This is because there is no place for the extra brake fluid to go that you have introduced in to the system. Some times it can be so marginal that its only noticeable when the fluid heats up and expands.

mmm_pie · June 2007

Most likely an allignment problem.

Have you used any shims mounting the caliper?

not working

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by haleybunny

Sometimes it overheats. You have to make sure it's in a ventilated place all the time.
<hr height="1" noshade id="quote"></blockquote id="quote">

whyamihere · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Snapper

Whyamihere it really does happen quite often. I see it quite often when people have tried to DIY service there brakes. I have even seen some not so great bike shops do it. Its very simple to do. If you have toped a brake system fluid up when the pads are very warn you can literally over fill the system. This is ok when you have warn pads but when you stick new pads in you simply cant push the pistons out far enough. This is because there is no place for the extra brake fluid to go that you have introduced in to the system. Some times it can be so marginal that its only noticeable when the fluid heats up and expands.
<hr height="1" noshade id="quote"></blockquote id="quote">Ah, yes, if it's been bled by someone after purchase. I was assuming it was a factory bleed. Apologies for any confusion.

rubber side up · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Snapper

Whyamihere it really does happen quite often. I see it quite often when people have tried to DIY service there brakes. I have even seen some not so great bike shops do it. Its very simple to do. If you have toped a brake system fluid up when the pads are very warn you can literally over fill the system. This is ok when you have warn pads but when you stick new pads in you simply cant push the pistons out far enough. This is because there is no place for the extra brake fluid to go that you have introduced in to the system. Some times it can be so marginal that its only noticeable when the fluid heats up and expands.
<hr height="1" noshade id="quote"></blockquote id="quote">

Most brake manufacturers design the brake system so you dont need to do that. so i wouldnt reccommend it.

<hr noshade size="1"><center><blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by EvilAlex

Something round here tastes bad. Could be plain old bad taste.
<hr height="1" noshade id="quote"></blockquote id="quote"></center>www.mtb-bitz.co.uk - Bitz for you & your mountain bike. pinkbike

extreme__dude · June 2007

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by whyamihere

You never have to let fluid out of the reservoir to fit new pads. Post something like that again and I'll ban you.
<hr height="1" noshade id="quote"></blockquote id="quote">

a bit harsh i would say. just trying to give advice based on my own experiences, and i shall continue to do so...

as snapper says you can over-fill the system if its topped up when the pads are very warn and the pistons are all the way out...i have (foolishly) done it before hence i feel i can make the comment. maybe i should have said to give it a bleed if that would have made you happier...but i doubt it...

<center>pinkbike</center>
<center>new frame [:D]</center>

maximus44 · June 2007

i had a similar problem with my avids on marzocchi, it sounds like its not aligned properly, space it out with shims.

Dmr goes here

bobmij7 · June 2007

Please read "the whole story"

are there two pistons on hope mono minis? If so it seems as though one it fully "out" and the other is pushed in (Towards the caliper).

http://www.pinkbike.com/photo/945659/

bobmij7 · June 2007

extreme_dude, please explain wot you mean. I don't understand! when i pushed the pistons in to fit the new pads?

http://www.pinkbike.com/photo/945659/

Snapper · June 2007

If it was me I would;

centre calliper body not pads.

Pump leaver 5 times.

See how that is.

If that was close do some fine adjustment with alignment.

If it did not work;

Take pads out.

Give calliper good clean and spray with some light oil.

Bleed brakes.

Give calliper good clean and spray with some light oil again.

clean off all oil including what's inside. Use a clean rag. You want no oil left at all.

pop pads back in.

centaur calliper. Not the pads but the calliper body.

Pump brakes about 5 times.

see if that works.

May need fine adjustment on alignment.

(oil is to clean remove all brake cleaner and help pistons move freely. You must not get any oil on your pads)

bobmij7 · June 2007

hmm, i've NEVER done anything like that before. not much experience with hydraulics.
Is there anyway to do it without bleeding them? I don't want to have to loose any brake fluid. i want to clean them and tweak them as best i can without interfering with the internal fluid.

wud it cost much at a bike shop?

(thanks 4 youre help guys)

http://www.pinkbike.com/photo/945659/

Snapper · June 2007

Think where I works charges œ8.50 for a full brake setup. That is front and rear brakes. If you have to have the brakes bled I think that's œ12 a brake. Its not that much really. Best to see if you can do the alignment your self. if that does not work it sounds as if a shops your best bet. phone up the ones round you and so who does a good price.

bobmij7 · June 2007

Thanks Snapper.

I'll start phoning around.

http://www.pinkbike.com/photo/945659/

bobmij7 · June 2007

How do I remove the pads?
I know you need to reove the clip thing and the pin but it looks hard to get the pin out without permenantly bending it!

http://www.pinkbike.com/photo/945659/

mmm_pie · June 2007

Bleeding isn't as bad as it sounds though, especially with modern hydros.

And you have to bend the split pin to get the pads out. But you can re-bend it when you put them back in (or buy a new split pin).

not working

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by haleybunny

Sometimes it overheats. You have to make sure it's in a ventilated place all the time.
<hr height="1" noshade id="quote"></blockquote id="quote">

bobmij7 · June 2007

Well,
I had a go today.

I removed the pads (was easy eventually).
I gave everything i could see a wipe with a dry cloth. Then i pushed both pistons into the caliper so they were as far back as i could get them (I did it with a plastic tyre wrench so not to damage them)
Then i aligned the caliper so the rotor was exactly central.
then i put the pads back in properly and squeezed the lever a couple of times...
What i found was, one piston just pushes out and stays out (It then scrapes the rotor) and the other presses the rotor them moves back, ut only very slightly.

I think that the main problem is the piston that doesnt retreat.

Any ideas?

I think i'll take it to my LBS on friday as i have exams all of next week

But, basically I have done exactly what it says in the hope manual. The brake is supposed to compensate for the size of pads and rotor...so I think it could be one of the pistons.

http://www.pinkbike.com/photo/945659/

mmm_pie · June 2007

Check that the reservoir is topped up, but I think you may need to bleed them.

not working

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by haleybunny

Sometimes it overheats. You have to make sure it's in a ventilated place all the time.
<hr height="1" noshade id="quote"></blockquote id="quote">

Hope Mono Mini - Seems to always be "on"

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