Hello! Go easy on me if this question seems stoopid!! But i've struggled to find the answer for myself. Essentially, I want to find out if Hope Mono M4 Floating Rotors are compatible with all Hope Mono M4 calipers? i.e. Are there Mono M4 calipers which are not compatible with floating rotors? I am trying to elimnate the variables which relate to the poor braking power of my rear disc brake (Mono M4s). I have bled the caliper as carefully and thoroughly as I am able. I have taken out the pads and cleaned them and roughed/evened them with a file. The pads are from Discobrakes.com – these may be the problem – any expereince? However, I feel that the most likely problem might relate the floating disc. I've not had it long. I have cleaned it with degreaser and used Juicelubes disc brake spray on them to perhaps remove any coverings from manufacture or recent riding, but there has been no improvement.

I should add that I have Mono M4s that came on a Marin Attack Trail 2007 (no sniggering!) which were once powerful if a little wooden.

Any expert help welcome! Wonder if anyone from Hope reads this…

I'm not too sure of the answer to your problem but try ringing Hope in the morning – they were extremely helpful when I rang them about some second hand brakes I bought off here.

Disco pads are shyte. All Hope brakes can be used with the correct rotor – either Mini/M4, M6 or V2 – be it floating or fixed.

Thanks, sounds like a pad swap could be the next option.

Any recommendations on brands and compounds?

Hope Sintered, surprisingly enough work pretty well with Hope brakes!

What sized rotors? If they are 180mm check that is correct as they do a 183mm version too. To be honest though it sounds more like duff pads.

Superstar kevlar pads are pretty good, bite a bit more than the Hope Sintered pads imo.

Im liking superstar Kelvar pads too at the moment, Goodridge sintered are also pretty good.

I find the Hope sintered pads very good – made by EBS. Plently of bite and seem reasonable long lasting. Also included in the price is a new spring and pin which you don't get with the others

EBC red compound for extra bite and fairly good longevity, or goodridge sintered for fairly good bite and extra longevity.

I have had problems with floating rotors in the past, they just don't seem to have good friction. They were the only hope rotors I had tried at that point and thought it would be all of them, but have put on a none floating saw tooth rotor recently and it is excelent. So I don't know if they were from a bad batch or if there is an inherent design flaw with hope floating rotors.

I have had problems with floating rotors in the past, they just don't seem to have good friction.

The braking track is identical on the floating and fixed rotor. It's probable that there was another issue, perhaps set-up related, which caused your problem.

Nope, changed pads, bleed them several times, put on goodridge hoses, it wasn't untill I replaced the disks that they started working effectivly. Well actually i bought a whole new set of brakes, formula the ones, had some issues with them also, and happened to try the hope brakes on the formula rotors, and they were great.
I would say that the rotors I had a problem with were made of a different material from the ones I now have, either there was a change in production, between the purchases or the floating rotors use a different material or the wrong material was used for a batch, but I asure you they were not the same.

MSP – Member

Nope, changed pads, bleed them several times, put on goodridge hoses, it wasn't untill I replaced the disks that they started working effectivly. Well actually i bought a whole new set of brakes, formula the ones, had some issues with them also, and happened to try the hope brakes on the formula rotors, and they were great.
I would say that the rotors I had a problem with were made of a different material from the ones I now have, either there was a change in production, between the purchases or the floating rotors use a different material or the wrong material was used for a batch, but I asure you they were not the same.

contaminated rotors?

I think my next step should be to try some Hope sintered pads. I've just bought them and will update if this works.

I'm confident the calipers are bled correctly (bled them again this evening) and the floating rotor is true and attached to correct torque.

I'm running 180mm discs front and rear. The rear is the least powerful. My bike came with 180mm fixed rotor on the front and 160mm fixed rotor on the rear. After the rear crumpled on a bit of Dartmoor granite I bought the 180mm as I thought it might add more bite when braking. I have seen it suggested that 160mm rotors on the rear is actually most desirable (heat issues excepted, is there any substance in this claim? And why would that be the case?

Have you centred the pistons? There is a very easy to follow video on Hopes website that shows you how. Boy does it help…

If it helps mine are M4 and i use Hope sintered from CRC. Buy 4 sets and they last forever.

prob pads, the standard discobrakes ones I had on my formulas lasted less than an hour in peaks grit
and that was after a right struggle to fit them (too thick)
learnt lesson on the really cheap pads now
most of them are all made in same place anyway and just imported and repackaged and quality control doesnt seem so good in my experience so people that say one cheapo brand is better than the other possibly just got a bad batch of one brand

Have used both Hope Mono Mini and V2 brakes with both hope floating rotors and generic aftermarket fixed rotors (swopping wheels across various bikes) and never noticed any difference in performance from the different rotor

+1 for the "centering pistons" comment above.

This really can turn piss-poor lever feel into mighty modulated braking!

Get over to Hope's website and check out the video(s).

Well worth investing the 5/10 minutes it'll take.

iain1775 – Member

"prob pads, the standard discobrakes ones I had on my formulas lasted less than an hour in peaks
grit"

The standard discos are organic, sounds like what you had wasn't a cheap pads issue, just a wrong pads issue. Not really a fan of Disco myself, I use Superstar which are about the same price and have performed better for me, but doesn't really sound like their fault here.

Floating rotors cool more effectively. That's their primary function. in UK conditions it's hard to get to get brakes up to decent temps unless you drag the brake down long descents. So i reckon you've got temerature issues. You're not getting enough temp into the pads, and only heating enough to polish the friction material. That in turn just polishes the rotor, creates more heat, and less friction and hardens the polished surface on the pad. You get into a negative spiral of more power = more heat & less friction from there.

Scuff the rotors with some abrasive sandpaper or dremel type sanding disc, clean the pads with Swarfega to get rid of the polished surface, and ride fast down a big hill. Put in a big stop, and repeat about 8 – 10 times.
If things don't improve, try new pads and do the big hill thing to bed them in. Or just ride Afan or The Peak district in the wet.

I dunno if anyone has pointed this out, but the technical advantage is in the name, "floating" rotors. They are made out of an alloy, that, when it reaches a certain speed, the centrifugal forces on it give it "lift", counterbalancing its weight. It doesn't actually "float", that'd be stupid. but it is, technically "weightless".

Probably duff pads. I nominate skyline's poet for BS of the week

I dunno if anyone has pointed this out, but the technical advantage is in the name, "floating" rotors. They are made out of an alloy, that, when it reaches a certain speed, the centrifugal forces on it give it "lift", counterbalancing its weight. It doesn't actually "float", that'd be stupid. but it is, technically "weightless".

I've got to assume this is a troll… it's Kevevs post for BS of the week

Advantages of floating rotors are that they handle heat expansion better (more evenly, so potentially less warping), and that the float improves performance if the pads or caliper are fractionally offcentre, or if the rotor is slightly warped.

Rotor materials being the same, I don't see how a floating rotor can dissipate heat faster than a non floating, in fact I'd have thought it would get up to temperature faster.

you've cleaned your rotor with degreaser – thats your first mistake. That combined with crap pads and you will have a reduction in performance, couple that lot with pistons not centred and you've got a lot to work with. I'm running mono m4's with floating rotors with no issues-apart from slight noise from my superstar pads in the wet but for less than a fiver a set i expected that. Clean your rotors with something alcohol based- meths or buy a specific disc cleaner (not a motorbike one).

Fit the new pads first.

As above, you have probably polished some residue onto the disks. Get some 120 grade oxide paper (not sandpaper) and give the braking surface of the disk a really good workout so there is almost no shine left. Doesn't look nice but trust me it will disappear after the first couple of brake applications

Kevevs – Member

I dunno if anyone has pointed this out, but the technical advantage is in the name, "floating" rotors. They are made out of an alloy, that, when it reaches a certain speed, the centrifugal forces on it give it "lift", counterbalancing its weight. It doesn't actually "float", that'd be stupid. but it is, technically "weightless".
You're not serious ARE YOU?

I dunno if anyone has pointed this out, but the technical advantage is in the name, "floating" rotors. They are made out of an alloy, that, when it reaches a certain speed, the centrifugal forces on it give it "lift", counterbalancing its weight. It doesn't actually "float", that'd be stupid. but it is, technically "weightless".

Brilliant I hadn't thought of that, I'm off to fit some motorbike floating rotors, with any luck I'll be weightless enough to float up the hills

… and that the float improves performance if the pads or caliper are fractionally offcentre, or if the rotor is slightly warped.

This does not apply to Hope's floating rotors. Stricly speaking, they're just two-piece, not floating, as the braking track is held firmly in position by the rivets. Although there is sometimes a tiny amount of axial play, there is zero lateral movement (which is typical of automotive floating systems).

Northwind – whatever compound I would have expected them to last more than two gentle descents down farm tracks (and yes I bedded them in etc)
The Discobrakes pads where shite.
Shite to fit
Shite in use

"in peaks grit" were the magic words though. Soft compound pads don't last at all with that sort of conditions.

heh! floaty light 🙂