Shimano SLX brakes and which rotors?

alexthebear

I have decided that I dislike my Avid elixir 3s on the Camber and I want to swap over to Shimano. This isn't up for debate so please don't tell me how much you love yours or what I'm doing wrong with mine thanks.

As this will be the first set of brakes I have bought in some 10 years I'm after some advise on, well, pretty much everything . I think I've narrowed my choice down to SLX m666 / m675 as they are bang in my price range and going by reviews and thoughts of a few guys I've spoken to, are as good power wise as XT just without the free stroke adjustment which is not something I'm likely to need anyhow.

As they do not come with rotors I'm asking which ones people have had success with and which ones to avoid, also do they have to be specific to match the finned pads that come with the brakes? Also on the note or rotors, as I am replacing the whole kit would I benifit from increasing the size from 180f / 160r to 203f / 180r? I'm doing a lot of uplifts and will be doing even more so over the summer with it currently being 80% of my riding.

Also will I need to buy adapters for the calipers to fit my frame and forks (I have a 2011 Spesh Camber specs)

Once again cheers in advance for any info or advice

jimothy78

No-one's going to disagree with your choice of SLX brakes - they're awesome.

As for rotors, stick with the sizes you have now and you won't need to change adapters (they depend on rotor size, nothing else). Later on you can always up-size if you decide you need to, but see how you get on with the extra stopping power the new brakes give you first.

morepower

Chain Reaction may still have some Shimano Ice tech rotors on offer... I have swapped my Avid rotors for Ice techs and I have to say they have made a real difference. I did also increase from 185mm to 203mm but still it was a significant improvement..

alexthebear

jimothy78 wrote:

No-one's going to disagree with your choice of SLX brakes - they're awesome.

ha ha yeah cheers, just read enough threads to know what was coming

jimothy78 wrote:

As for rotors, stick with the sizes you have now and you won't need to change adapters (they depend on rotor size, nothing else). Later on you can always up-size if you decide you need to, but see how you get on with the extra stopping power the new brakes give you first.

Ah ok cool, I thought that it was depending on brand rather than size so yeah I'll stick to the same size if it keeps the cost down a bit

alexthebear

morepower wrote:

Chain Reaction may still have some Shimano Ice tech rotors on offer... I have swapped my Avid rotors for Ice techs and I have to say they have made a real difference. I did also increase from 185mm to 203mm but still it was a significant improvement..

Is that keeping your original Avid calipers and now running them with Shimano rotors? I'm changing out everything for Shimano for a number reasons but thanks all the same.

Anyone running superstar rotors with these brakes?

raldat

I am not going to tell you not to change your rotors as you may well have valid reasons for wanting to, but I put Deore brakes on my 29er last year that came with Elixr 1s. I kept the Avis G2 rotors, 180/160 front/rear and I could not be happier with performance.

Up to you of course and depends on usage but that is my experience.

Enjoy your new brakes. You will I am sure...

jonnyashworth

I run my SLX brakes with 183mm hope saw rotors and hope mounts they work perfect and look stunning.
Will shimano brakes work okay with the avid cup and cone washer system?

The Northern Monkey

No, your new brakes should come with new bolts and washers. The cup/cone are avid only.

alexthebear

Cup/cone system refers to the multiple adjustment washers on the calipers?

The Northern Monkey

I'm assuming so!

Chunkers1980

Yeah. Works as a discription. But conical washers is their name.

alexthebear

Chunkers1980 wrote:

Yeah. Works as a discription. But conical washers is their name.

Ideal cheers, I can now sound like I know what I'm talking about

jimothy78

Actually, the Avid ones are called "CPS" (Calliper Positioning System) washers

Chunkers1980

What about when they are used to position brake pads on cantis and vs ;-)

Cqc

What's wrong with the avid rotors? There's no reason to swap them out.

alexthebear

Cqc wrote:

What's wrong with the avid rotors? There's no reason to swap them out.

Sort of the question I was asking to begin with, would the G3s I have now be suitable for the Shimanos?

morepower

alexthebear wrote:

morepower wrote:

Chain Reaction may still have some Shimano Ice tech rotors on offer... I have swapped my Avid rotors for Ice techs and I have to say they have made a real difference. I did also increase from 185mm to 203mm but still it was a significant improvement..

Is that keeping your original Avid calipers and now running them with Shimano rotors? I'm changing out everything for Shimano for a number reasons but thanks all the same.

Anyone running superstar rotors with these brakes?

I have kept the Avid Elixr 5 calipers... The problem for me is not a huge one and they feel OK at the moment so dont need bleeding. I am running Uberbikes Race matrix pads in the front and the rears are just the original Avid pads which I will swap for Uberbike ones. I may change the calipers at some point but for now I dont feel I need to in the short term.

The problem with the Avid calipers I think is they flex too much. That flex allows a very very small amount of air into them over time and they need bleeding. The other problem with the flex is that they do not transfer all of the power from the master cylinder to the pads... I dont seem to have the same problem with squealing like many have complained about but I do think you swapping the calipers is a good idea for a maintenance free (well as free as you can get) brake.

The ice tech rotors seem to do all they claim and I have not had a problem with any brake fade. I went to 203mm purely as a cheap fix to get a better brake. It has worked so for now I will use them and think about what calipers to run possibly later in the year.....

cooldad

alexthebear wrote:

Cqc wrote:

What's wrong with the avid rotors? There's no reason to swap them out.

Sort of the question I was asking to begin with, would the G3s I have now be suitable for the Shimanos?

Yes, rotors, unless they are ultra lightweight lacy things, or pointless floating rotors, make minimal difference.

morepower

Rotors can make a difference but here is the problem. Most dont know the difference in how they work. Most are made of stainless steel which is not the best brake disc material as it has a lower coefficient of friction than say cast iron. So they use the machined shapes and holes to add friction by having sharp edges which actually work by shaving the pad surface. As the pads and rotors wear that sharp edge dulls over time and the brakes lose their power too... Pad wear is usually very slightly biased due to disc rotation to bite a little more on the edge which the leading edge on the disc profile will bite. The wear is just a fact of life.

I cannot say for sure but I think Shimano use a material more likely seen in motorsport which is a swedish steel and actually a cast stainless and has a more granular nature to the steel. It is heavier so by using a alloy spider to mount the rotor it brings the weight back down but should increase brake efficiency and rely less on the machined shapes sharp leading edges...

I may be wrong but I do know Swedish steel works very well for brakes and unlike cast iron does not become brittle and can be used thinly without risk of breakage.

I was an importer for a brake manufacturer for about 7 years and got to learn a lot about how to make brake systems work. But my back ground was not MTB it was motorsport so I am not trying to push brake components for any cycling company. Just pointing out discs can make a big difference in performance and pad life too....

The Rookie

Never come across stainless brake discs, they all rust quite readily.

alexthebear

Well going on my current brakes I think my rotors are made of Brie lol

I have the 6 bolt fixing rather than the centre lock type so I'm thinking that the SLX-zee standard will be fine for my uses for now. crc rotors

The Rookie

Just leave your Avid discs on there, they will work just fine.

lostboysaint

Good decision to go with the SLX calipers, truly excellent. As has been said, stick with the Avid rotors. It's not the rotors that feel that they are made of cheese, it's the hydraulic system that's engaging the pad with them!

morepower

The Rookie wrote:

Never come across stainless brake discs, they all rust quite readily.

The Avid ones seem to be stainless but heat and metalic residue from pads will contaminate the discs. The cast stainless discs on my motorcycle are covered in rust but I know it is all residue from the carbon fibre pads which do actually contain iron to retain heat in the carbon matrix of the disc. So depending on quality some my find rust is more contamination from pads and effects of heat with that residue.

The Rookie

The avid ones rust, fact, its not residue, but then low grade srainless rust (surface, it won't become a structural issue), a fact you seem unaware of.

morepower

The Rookie wrote:

The avid ones rust, fact, its not residue, but then low grade srainless rust (surface, it won't become a structural issue), a fact you seem unaware of.

My old rotors are the original ones from 2010 on my bike. No rust at all none on the spokes of the disc. Yes I know low grade stainless will rust over time..... I was an engineer that made parts for F1 for almost 20 years.... The avid discs on my bike were not low grade. The problems lie with properties needed to make the discs and how they bend or resistance to bending and its ability to spring back to its original form. Cheap discs may use a lower grade of materials to keep its sprung properties as heat will make the metal less likely to spring back. Good discs use a good material that has to be stabilised and and stress relieved so when it is ground flat it will stay flat when it gets hot and still keep its sprung properties if it takes a hit.. Cheap materials cannot do both and will rust due to the composition of that steel.

If you want to go down the grades of steels and their properties you will see how many variations there are and add in heat treatments you can make a steel do many different things but costs go up...

I would still reccomend the Shimano Ice Techs as an option for someone looking at new discs.