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Discussion Starter #1
I've got Guide RSC brakes on my Pivot M4c with 180/160 rotors. The mountains have melted out so I've gotten in some sustained steep descents and am looking for more power. The good news is the RSCs didn't fade away to nothing nor did they pump up. There was a bit of fade part way down but it didn't get any worse the remainder of the descent.

What's bugging me is I was having to use two fingers and pull pretty hard which I don't recall having to do w/ XT 785 180/160 setup under the same conditions. The XTs seemed to have more power.

I've got the XOTR-M pads in the RSCs which I think are the metallic pads.

Any suggestions for improving power of the RSCs?

TIA!
 

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damned rocks...
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2,550 Posts
Hi,

You can upgrade your front rotor to 203mm and if you have clearance your rear to 180mm.
This will give you around 20% boost in brake power.
Other than that unless you get some really nice pads or change your brakes, I don't know how you can get more power.
 

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C__Corax
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384 Posts
bigger rotors, organic pads(wont last as long as sintered) sure you have a good bleed?
my guides are flawless, 1 finger, 180/160, on a 150mm trail bike, 180# rider.
 

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WillWorkForTrail
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What rotors are you using? I can see where there could be some affect from certain types of rotor, but I'm at a loss as to why you would have to pull so hard. My Guide R's will lock up my 29er with one finger using 180/160. Could your pads or rotors be contaminated? As suggested, larger rotors would give you more power, but it seems to me something else is amiss if you can't lock up both wheels with one finger.
 

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Discussion Starter #5
I'm using the centerline rotors and I weigh 180-5# riding. I went over the bars once following my son when he braked abruptly but I wasn't prepared. Twice now tho on steep extended singletrack techie descents where I'm on my brakes continuously i have to resort to 2 fingers and pull hard.
 

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high pivot witchcraft
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4,312 Posts
Not trying to sound like a fanboi (I will readily slam components I own if they deserve it) but I suspect there may be something wrong with your set up. My Guides are truly 1 finger operation. And like another poster has said, God himself could not have designed a better lever. XTRs (IMHO) are stronger, but do not have nearly enough modulation for my liking. And when I say stronger, what I mean is that I have to pull the lever ever so slightly less with one finger than I do with the Guides.

The Guides are Whistler Double Black proven (personally). Not much steeper or longer descents than what's found there.
 

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damned rocks...
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Cotharyus, they work normally most of the time. Just on the steep stuff that I have to pull hard.
Hi,

I don't have the Guides, but by what people and magazines say, it seems to be a consensus that they should at least be as powerful as the XT, so you should have more than enough power to stop/slow your bike with one finger.
Unless you have some problem with your brakes or they are fading you shouldn't have to use two fingers.
Out of curiosity, how much do you weight?
A friend is thinking of buying the Guides, he weighs ~75 Kg(165 lbs) and he has tried my XTs with 203F/180R on really rough and steep stuff and loved the power, I told him about the Guides and MT5/7. But if the Guides don't have enough power I guess he will chose other brakes.
 

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Discussion Starter #10
Aglo, Agreed, according to tests and what others say (see above) the Guides should be as good at XT. But that's not my experience... but mine probably have a problem. I weigh 180-5# riding and have 180/160 centerline rotors.

That said the MT5 are more powerful than XT or Guide according to the test found in this issue of Enduro mag: Back Issue | Grouptest: Six of the best disc brakes | ENDURO Mountainbike Magazine
And the MT5 are lighter.
 

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WillWorkForTrail
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Cotharyus, they work normally most of the time. Just on the steep stuff that I have to pull hard.
This, to me, indicates you're getting fade. If that's the case, the answer is, possibly, a combination of things. First, technique. Don't drag your brakes if you aren't using them. They need a chance to cool off some. Brake aggressively, then release. Alternate front and rear brakes. Second, you may be an ideal candidate for larger rotors. More power means less time on the brakes, and a greater thermal mass means the rotor at least won't get as hot as quickly, which should keep heat down in the caliper too.
 

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J-Flo
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One possible solution may be to move your brake levers so that your finger hits more towards the end of the lever and you have more leverage, therefore more power.

Coming from XTs (slightly more powerful), I was used to planting my finger closer in on the lever. The same finger position on Guides took noticeably more work and made my fingers tired on a long downhill (Downieville). Moving the levers way in, farther from the grips than I am used to, actually feels better after a short adjustment and makes up for most of the difference so I no longer have to squeeze that hard. Just back from a week in Whistler and Squamish and the Guides (both on my bike and the rented DH bike on the one day we spent at the bike park) were simply terrific.
 

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One possible solution may be to move your brake levers so that your finger hits more towards the end of the lever and you have more leverage, therefore more power.

Coming from XTs (slightly more powerful), I was used to planting my finger closer in on the lever. The same finger position on Guides took noticeably more work and made my fingers tired on a long downhill (Downieville). Moving the levers way in, farther from the grips than I am used to, actually feels better after a short adjustment and makes up for most of the difference so I no longer have to squeeze that hard. Just back from a week in Whistler and Squamish and the Guides (both on my bike and the rented DH bike on the one day we spent at the bike park) were simply terrific.
Doesn't everyone already do this? The root word of leverage is lever. Apply force anywhere else but the end of the lever and you are not taking full advantage.
 
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