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SLX M665 brakes for DH?

MarkDH

Monkey
Sep 23, 2004
351
0
Scotland
Pretty much just the question in the title, anyone use SLX brakes with 203mm rotors for regular DH use? My old style Saint brakes are getting a bit sloppy and I need a set for a hardtail build anyway, so I was thinking of retiring them onto that.

Originally I was going to get the new Saints, but they are a wee bit pricey for my budget at the moment. A couple of mates have them and say they are really powerful, almost too powerful in fact. I never had issues with power on the old Saints, so I'm wondering if the SLX brakes will be roughly comparable? I'm pretty average in terms of both weight and speed, so I thought I might get away with it, but I do take a holiday in the Alps and ride Ft. Bill a few times a year which is were the Saints would have the edge I suppose.

Buying from chainreaction I could get 3 sets of of SLX for less than a pair of Saints, so they are a fair bit cheaper, but I don't want it to be false economy and wish I had gone for the full bhuna.

Any thoughts?
 

pajamas

Chimp
May 23, 2009
14
0
My girlfriend ran the SLXs and 180mm discs for a couple of seasons including several stints in the alps and she loved them. Pretty slick looking aswell.
 

scottishmark

Turbo Monkey
May 20, 2002
2,121
22
Somewhere dark, cold & wet....
I've been thinking about getting the same brakes Daly. Was originally thinking about 2011Codes but they're even more than Saints!

SLX and XTs are supposedly 25% more powerful than the old version (M765/M800) so they should be grand. Ford's used XTs for 3 years or so and gets on fine with them....and you know he likes to abuse kit!
 

Gary

"S" is for "neo-luddite"
Aug 27, 2002
7,536
5,470
UK
A mate has them on his XC bike (with wee rotors) and they're more powerful than anything I've ever had on any bike.
 

MarkDH

Monkey
Sep 23, 2004
351
0
Scotland
Yeah I was thinking they will be plenty good enough for 99% of the time, it was just that 1% where they might cause an 'oh f*ck' moment where you wish you'd gone for the Saints! I'd forgotten that people used to use old style XT's on DH bikes as well (weren't they practically the same as old Saints?), so if the new ones are more powerful then... yeah. Of course Penman I could just let you guinea pig them for me. ;) Kinda want this hardtail build finished soon though, brakes are all I'm needing. :S

Udi, thinking about it, I have known a disproportionately high number of Marks in my time!
 

Gary

"S" is for "neo-luddite"
Aug 27, 2002
7,536
5,470
UK
a curry.. not even a very hot one

Mark, can't believe how much you worry about things.. I must have a good 3 - 4st and 10yrs on you and rarely have brakes that work well (usually on the last slither of friction material and probably needing a bleed) and still ride stuff you won't! almost all the brakes out these days are amazing just get them bought!
 

norbar

KESSLER PROBLEM. Just cause
Jun 7, 2007
11,346
1,587
Warsaw :/
Mineral oil on smaller brakes?(ie not saint/gustav) I wouldnt trust them for the alps or anything longer.
Maybe get saint calipers and slx levers? Look around. I got my saints <300$ new.
 

RayB

Monkey
Jan 31, 2008
744
95
Seattle
SLX 665's are the exact same as the XT 775's, minus tool-less free-stroke adjustment at the lever. They're also a different colour. Calipers are exactly the same.

Both made in Japan. Both feel identical.
 

norbar

KESSLER PROBLEM. Just cause
Jun 7, 2007
11,346
1,587
Warsaw :/
Eh? Lots of people used M800 Saints for years without issue, why shouldn't SLX's work just as well?
Lots of light people who didnt do long runs. All the people I know on them were happy at first but then prefered their new other brakes that faded less.

Any 2 pot brakes that arent v2s, ones or gustavs (ie power wise in the realm of 4 pots) fade unless you use a high quality dot 4/5.1 fluid. In case of mineral the boiling point is close to 70deg lower. Thats 25%
 

j-posch

Monkey
Jun 25, 2007
122
0
Lots of light people who didnt do long runs. All the people I know on them were happy at first but then prefered their new other brakes that faded less.

Any 2 pot brakes that arent v2s, ones or gustavs (ie power wise in the realm of 4 pots) fade unless you use a high quality dot 4/5.1 fluid. In case of mineral the boiling point is close to 70deg lower. Thats 25%
I have found the opposite of what you are saying and I live in the alps. Friends still having problem with new hopes fading and my older saints have been flawless and really reliable. I have used a lot of brakes and always go back to shimano. Best by a country mile in my opinion. Think I might try the Deore or Slx for this season.
 

norbar

KESSLER PROBLEM. Just cause
Jun 7, 2007
11,346
1,587
Warsaw :/
I have found the opposite of what you are saying and I live in the alps. Friends still having problem with new hopes fading and my older saints have been flawless and really reliable. I have used a lot of brakes and always go back to shimano. Best by a country mile in my opinion. Think I might try the Deore or Slx for this season.
What hopes? What year? Hopes have problems but not due to fading but crappy builds and them failing. M4s fade but those are trail brakes. V2s + proper fluid will fade much much later than most brakes. Ive tried Xts and SLXs and they are not the most fade resitant brakes, my oros with rbf 600 faded much less.
 

scottishmark

Turbo Monkey
May 20, 2002
2,121
22
Somewhere dark, cold & wet....
Lots of light people who didnt do long runs. All the people I know on them were happy at first but then prefered their new other brakes that faded less.

Any 2 pot brakes that arent v2s, ones or gustavs (ie power wise in the realm of 4 pots) fade unless you use a high quality dot 4/5.1 fluid. In case of mineral the boiling point is close to 70deg lower. Thats 25%
sorry, not buying that one. i know several people that have done seasons or live in the alps and Saints (M800s) have been the brake of choice over Hope 4-pots

Ive tried Xts and SLXs and they are not the most fade resitant brakes, my oros with rbf 600 faded much less.
stop dragging them then ;)

Baring in mind that both myself and the other Mark weigh about a bag of sugar each, they'll likely be absolutely fine
 
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norbar

KESSLER PROBLEM. Just cause
Jun 7, 2007
11,346
1,587
Warsaw :/
sorry, not buying that one. i know several people that have done seasons or live in the alps and Saints (M800s) have been the brake of choice over Hope 4-pots



stop dragging them then ;)

Baring in mind that both myself and the other Mark weigh about a bag of sugar each, they'll likely be absolutely fine

Did you read my post? Ive said V2s and not m4s (the 4pots - these are bad) . I was talking about v2s - the big 2 pots. The m4s - 4 pots as Ive said in my previous pots ARE WEAK but they are trail brakes. Its closer to running XTRs or Magura Martas.
 

Udi

RM Chief Ornithologist
Mar 14, 2005
4,915
1,200
Norbar -
You have the wrong idea here. Brake fade has nothing to do with fluid, ~95% of the time.

The only way fluid is really going to cause fade is if it boils, and then your lever will come to the bar and you will have no brakes. Aside from that the only thing it can do is get thicker or thinner, which won't really affect anything but lever feel.

Brake fade will be a result of pads, rotor size, and obviously the greater the overall power of the brake, the less fade one will notice (as they will still be good at their worst).

Bicycle brakes are not reaching temperatures that require RBF600, you're just throwing away money in my opinion, any super-DOT4 fluid will work fine. Just for the record I've done a stint in the alps on shimano brakes and had no dramas whatsoever.

The M800 saints are in my opinion (and also ridemonkey's apparently, see their long-term review) THE most reliable brake ever made, bar none. The new saints are more finicky, but have a lot more power on tap. I'd quite confidently say that any issues with those brakes are user-related (bleed, which unlike other brands you only really need to do once, and pad/rotor choice, contamination, etc).

I am also interested in where you obtained your data regarding the boiling point of shimano mineral oil since I don't think it's something they disclose. It's just that if mineral oil really boiled, I'm sure guys like Gee Atherton would be having a bit of trouble winning world championships. :)

Edit - according to this post, mineral oil has a BP of 260-330°C, vs. RBF600 at 216-312°C.
 
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4130biker

PM me about Tantrum Cycles!
May 24, 2007
3,882
447
Anyone actually have these on their dh bike? (slx m-666) they've caught my eye, and I do like shimano...
My budget is fairly low- seems like saint is out of my price range, but a basic code r, or elixir, or slx are basically my options. 200 pounds w gear, currently running old saint m-800, but would like more all out power when needed. Any input is appreciated.
 

4130biker

PM me about Tantrum Cycles!
May 24, 2007
3,882
447
Ps- Id be using 8" rotors with any of these options.
Also just realized this thread was for older slx- I'm talkin the current m-666 over here!
 
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Rocko

Chimp
Jan 11, 2009
56
2
Currently I have m675 slx, it's far the best brake I ever had on my DH bike. Previously I had elxir 9 and r. The r was better, but as good as the shimano.
M666 is almost just the same as the m675, the colors are different.
22mm pots (the overall surface is larger than in a code) plenty of power, always consistent bite point.
Short levers make them very comfortable.
I wanted to buy XT, after a few reviews I decided I don't really want to pay for the stroke adjustment.
 

Rocko

Chimp
Jan 11, 2009
56
2
Zee was 225&#8364;, the SLX 140&#8364;. It's just roughtly the same. :D

Since I know what these SLXs are capable, don't see any reason to change.
 
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Sandwich

Pig my fish!
Staff member
May 23, 2002
21,031
5,921
borcester rhymes
I've got XTs on the way for my DH bike project. I've felt SLX 666/75 on the trail, and they were every bit as responsive as my saints, but I can't comment on DH performance or fade as of yet.

The ONLY reason I chose XT over SLX is that Nashbar had them for $106, and Jenson price matched. The end cost vs. SLX was like $16 more, but the XTs were retail packed with metal and resin pads. You have to be careful where you buy your SLXs from, as some places are selling OEM packs and only include certain pads, like metal/no-fin or resin only.

Best deals are 89$ at blueskycycling for SLXs with resin pads and fins, and Jenson has XT fronts for 99$ with metal pads and no fins. You can find other ones here or there.

There's really no difference between the two besides the bite point non-adjuster, and forged lever blades instead of cast (or something) but the metal fin pads got me.

$200 for a set of XT brakes (the best in the business right now) is pretty easy to justify compared to some used-ass and haggard codes or half a formula/hope setup. Bluesky also has zee for $150 if you feel like partying.
 

ZoRo

Turbo Monkey
Sep 28, 2004
1,224
11
MTL
So where can I get front and back XTs or SLX with metal finned pads for a good deal? Jenson has a good price on XT but it's only for the fornt right??
 

Sandwich

Pig my fish!
Staff member
May 23, 2002
21,031
5,921
borcester rhymes
no wheahs...

XTs come in at 129 at nashbar now (sale go byebye), and most SLXs come in at 89 with resin only. Jenson's 99 dollar setup comes without fins but with metal pads.

There are some $99 SLX sets on ebay, but I'm uncertain what pads they come with.
 

amishmatt

Turbo Monkey
Sep 21, 2005
1,263
396
Lancaster, PA
I wore out the original, metalic finned pads, on my XT's last summer. Replaced them with metal, non-finned pads, and can't tell a difference.

Granted, I'm not riding super long runs or anything (Mountain Creek), and I'm using Avid rotors as well, but for my use, I can't say the fins did anything.

Still love the brakes though, and I want a second set for my trail bike.
 

Sandwich

Pig my fish!
Staff member
May 23, 2002
21,031
5,921
borcester rhymes
I've heard that before, and I wouldn't kick a set of non-finned pads out of bed, but for $6 more I get finned pads, olives and barbs, and a backup set of resin pads if the metal ones squeel.

PLUS, lots of people have a different interpretation of fade and such. How fat are you and what brakes did you come from? I'm fat enough where I've experienced minor fade on saint 810s, so I'm always hesitant to believe people when they say their single pot Juicies are plenty powerful for everybody.
 

amishmatt

Turbo Monkey
Sep 21, 2005
1,263
396
Lancaster, PA
I'm 185, was on Juicy 7's and Elixir CR Mags prior. Aside from lever feel, the XT's are better in every way.

I'm not saying the finned pads don't do anything, just that I didn't notice a difference in my application.

Never spent any real time on dual piston's, but the cost/performance ratio of the new XT's has me satisfied.
 

schwaaa31

Turbo Monkey
Jul 30, 2002
1,431
1,018
Clinton Massachusetts
After spending 3 years on Elixir CR's and a year on Juicy 7's, I switched to SLX brakes on my DH bike. The SLX's are better in every way. I was surprised at how good they were for DH, especially for the price.
 

Rocko

Chimp
Jan 11, 2009
56
2
For the finned pads: I can't believe that they can make miracle. If the caliper heats up, it won't dissipate heat faster. In use I can't imagine it dissipates heat sensibly faster, before the caliper heats up, and the fluid starts "boiling".
 

Sandwich

Pig my fish!
Staff member
May 23, 2002
21,031
5,921
borcester rhymes
I think the idea is that the heat moves into the sink/radiator before it moves into the piston and then into the fluid. The concepts in ice tech seem to marry well depending on what pads you're using. I think resin pads keep more heat in the rotor, and metallic pads transfer more heat to the caliper. So, the alloy sandwich rotor doesn't inherently make sense with the metal pads, and I can't imagine the resin pads transfer a huge amount of heat to the radiator.

Still, none of this matters if you aren't really heating up the pad. I've heated up hope dh04 pads to the point that they deglaze themselves from the backing and fall off. Those were terrible brakes, and these are supposedly actually designed by an engineer using "sciency ****", so the whole "dissipating heat" thing isn't quite as necessary as it would be on a garbage brake.
 

amishmatt

Turbo Monkey
Sep 21, 2005
1,263
396
Lancaster, PA
I was running Avid G2 Clean Sweep rotors in 203/185 with my XT 785 brakes. Shimano 203mm post mount adapter in the front, Avid 185 IS mount rear.

I had the Avid rotors and adapter, but needed a post mount adapter for the fork, so I bought Shimano. It all worked together just fine.

My new rear wheel was built on a Saint hub, so I'm now running a cheap Shimano SLX 180mm centerlock rotor with the same Avid adapter. Works fine as well.
 

toowacky

Monkey
Feb 20, 2010
200
4
Pac NW
I was running Avid G2 Clean Sweep rotors in 203/185 with my XT 785 brakes. Shimano 203mm post mount adapter in the front, Avid 185 IS mount rear.....
Thanks, I had these types of questions, too. SLX (Shimano) seems inexpensive unless you've only run Avid and then would need to factor in rotors/adapters... but sounds like there are some scenarios that will work.