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Discussion Starter · #1 · (Edited)
I just installed a set of new sram code Rs, front + rear, along with new 200mm centerline rotors. I installed everything according to sram's user+service+bleed manuals. I trimmed the rear hose and bled the rear with a sram bleed kit, and worked the syringes back and forth until there were absolutely no air bubbles.

A couple of weeks ago, I installed sram G2 Rs, but thought they didn't have much power. I did not trim or bleed those, reading that they come pre-bled from the factory. So I just mounted and zip tied for 1 ride. Wasn't impressed.

I purchased the G2 Rs because the Tektro's that came with my Vitus Sentier 29 were pretty horrible.

Subjectively, the Code Rs w/ new 200mm rotors don't seem to have even as much power as the G2 Rs with 180mm rotors, and those didn't seem to have even as much power as the stock brakes on my old Giant Sedona DX (also Tektros). So far, I've tried 4 sets of brakes and neither of the more expensive brakes (for me), the G2 Rs or Code Rs seem even as powerful as the stock Tektro's from my $450 hybrid Giant.

The most likely cause is probably user error and perhaps I installed something incorrectly. However, I was pretty meticulous about it and spent about 3 hours installing, trimming, and bleeding the Codes. It's possible I could have something set wrong as well.

I've read over and over the sram Codes are supposed to have a ton of stopping power. They seem pretty wimpy at the moment.

One theory, is that the piston spacer was still present while performing one of the last steps, which is to pump the lever a few times before removing the lever syringe. Also, I may have had too big a spacer in there (the bleed kit comes with 3 or 4 different sizes). This may have led to not enough fluid in the system when I replaced the bleed screw in the lever. However, the front brake also seems underpowered, which I did not bleed and installed as it came from the factory. There's quite a bit of travel in both levers before they start to bite, and I'd have to floor either one to get it to lock up, if it even could.

Based on your experience with sram (or maybe any) brakes, or specifically Code Rs, does this sound familiar to anyone? Does anyone see a point where I may have made a mistake? Suggestions/advice/things to check to increase power?

Thanks.
 

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Run Guide RE's on 2 of my 4 mules and I love em.

They're as good, if not better than the Code R's on one of the other rigs.

Sent from my Asus Rog 3
 

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My bike came with the Guide T brakes. The first time I used them, coming from the XT, I thought I was having a brake failure. But, after about 20 minutes, I really was used to them and now think they're good brakes. I ended up putting them on my wife's bike because she needs the better modulation of SRAM brakes and put XT's back on my bike, but I like both quite a lot. I'm 165 pounds in Northern Utah, so 3000 ft descents are pretty standard.

I wonder what you mean by the phrase "lack of power", though.
Does it take excessive gripping force to stop?
Is it just too much modulation?
Do they fade in the descent as they get hot?
Can you pull the lever to the bar?
Edit: It sounds like there's a bit of this, which suggests an imperfect bleed. If the bleed block fits, it's not too big, I'd say.
Do they flat out not stop you?
Is it a problem in wet, dry, both?
There are 3 pad compounds, but any of them should be sufficient.

What pads are you using and have you tried different pads compositions?
 

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Discussion Starter · #4 ·
My bike came with the Guide T brakes. The first time I used them, coming from the XT, I thought I was having a brake failure. But, after about 20 minutes, I really was used to them and now think they're good brakes. I ended up putting them on my wife's bike because she needs the better modulation of SRAM brakes and put XT's back on my bike, but I like both quite a lot. I'm 165 pounds in Northern Utah, so 3000 ft descents are pretty standard.

I wonder what you mean by the phrase "lack of power", though.
Does it take excessive gripping force to stop?
Is it just too much modulation?
Do they fade in the descent as they get hot?
Can you pull the lever to the bar?
Edit: It sounds like there's a bit of this, which suggests an imperfect bleed. If the bleed block fits, it's not too big, I'd say.
Do they flat out not stop you?
Is it a problem in wet, dry, both?
There are 3 pad compounds, but any of them should be sufficient.

What pads are you using and have you tried different pads compositions?
Thanks for the reply.

By 'lack of power', I mean that, yes, I have to pull the lever farther than I would expect to feel the brake apply any friction and, when I do, it's not as much force as I would expect. I haven't measured, but I would say that I can pull the lever maybe 70% to the bar before feeling anything, then would have to continue to the bar (or nearly, fingertip touches the shifter) to come to a stop, and this would be just coming down a neighborhood road with a slight downward grade, and only about an 1/8 of a mile or 600', dry. I would not feel comfortable taking them on any descent currently.

I would not describe it as modulation, since the bite, or contact point, doesn't happen until late in the lever travel.

I have only ever used the stock pads for the 4 sets of brakes I've tried. I've read this is one area that can be adjusted for better performance, however, even the stocks should do better than what I'm seeing.

The bleed kit comes with 3-4 block sizes. I didn't use the smallest, or the largest. It certainly could be a flawed bleed, however, I don't know how. It isn't that complicated a process once you go through it, and like I said, there were zero bubbles. I pumped the lever, tapped, moved the caliper around to orient it differently.

Pondering hydraulics, I am thinking there may simply not be enough fluid. I came across a video in another thread on the Code Rs where the guy adds fluid from the caliper end, with some trial and error, to get the pressure at the lever right. I may try this. Sram's directions say not to push fluid from the caliper end b/c fluid pressure may dislodge the seal, however, I should be able to simply hold it on with my other hand.
 

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It sounds like a bleed issue. I had similar results with a friend's bleed up front, but he had a leak at the master cylinder seal that introduced air.
I used the largest bleed block that would fit in. The small ones were labelled for a different brake and the large one was clearly too large to fit in.
Just to be sure, this is a nice guide, as I guess you've probably seen:

I like GMBN for these sorts of videos:
 

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Does your brake have lever travel adjustment? Some brakes have them and some don't. It's usually a screw on the lever assembly. If you do, try changing it to the shortest travel mode. You will need less lever movement to engage the brakes. Brake force will not change, but they will feel different.
 

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If your new codes came with sintered pads it takes awhile to be them in, and they have to heat up before they really start to bite.

I bleed mine with the pads in that way the fluid is the right amount for where the pads are. When I used the bleed block it left too much lever travel because the pads take up much less space than the bleed block. If you do bleed with the pads in be careful removing the bleeding edge tool and cover it with a rag or something.

I had the same issues as you and after I realized all of the above they’re working great. I run the code R on my hardtail and the rsc on my full suspension


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Discussion Starter · #8 ·
Does your brake have lever travel adjustment? Some brakes have them and some don't. It's usually a screw on the lever assembly. If you do, try changing it to the shortest travel mode. You will need less lever movement to engage the brakes. Brake force will not change, but they will feel different.
Thanks. The Code Rs have reach adjustment but not contact point adjustment.
 

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Discussion Starter · #9 · (Edited)
If your new codes came with sintered pads it takes awhile to be them in, and they have to heat up before they really start to bite.

I bleed mine with the pads in that way the fluid is the right amount for where the pads are. When I used the bleed block it left too much lever travel because the pads take up much less space than the bleed block. If you do bleed with the pads in be careful removing the bleeding edge tool and cover it with a rag or something.

I had the same issues as you and after I realized all of the above they're working great. I run the code R on my hardtail and the rsc on my full suspension

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Thanks. I think you're right about the bleed block being larger than the pads which, therefore, leaves too little fluid in the system.

Actually, I'm going to re-bleed the system with the pads in. I tried the pressurizer method (for lack of better name) and it definitely helped, but the logic of the way you did it makes sense to me and I think it seems like a more benign way to achieve the same thing.
 

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Discussion Starter · #10 · (Edited)
It sounds like a bleed issue. I had similar results with a friend's bleed up front, but he had a leak at the master cylinder seal that introduced air.
I used the largest bleed block that would fit in. The small ones were labelled for a different brake and the large one was clearly too large to fit in.
Just to be sure, this is a nice guide, as I guess you've probably seen:

I like GMBN for these sorts of videos:
After doing the pressurize method from the caliper, I think this may be what's going on, and related to socalrider77's comment above. If one follows the sram bleed instructions exactly, as I did, and understanding this may only be true for these exact brakes, maybe only the exact specimen I have (accounting for part-to-part variation), using the medium bleed block (which appeared to be the smallest of those available), will leave the pads excessively far from the rotor so that the lever must be pulled excessively far before the pads touch the rotor and begin applying force.

The tolerance here is very small. Once I installed the caliper syringe and added some pressure (while closing the tool with the other hand), I got the rear lever to engage with 1/4" less travel, which improves the feel quite a bit. The front lever I was able to make engage with 1/2" less travel. The key was pressure, or more correctly, more fluid in the system, which pushes out the little part (I don't know what it's called) the lever contacts to begin pressurizing the line, so that the lever contacts it earlier in its travel.

This added fluid only reduced spacing between the pads by less than half a millimeter on either side of the rotor. That's how little will make a difference. IMO, sram's bleed procedure is flawed. Toward the end, the instruction is to pull the lever syringe to create a vacuum, then push it in to pressurize the system, then remove the syringe and replace the bleed screw. At the moment the syringe is removed, before the screw is replaced, the system is exposed to atmospheric pressure and, therefore, is not pressurized above atmospheric. So if the pistons are spaced too wide by a bleed block that is larger than the pads would need to be to closed on the rotor w/o excessive lever travel, once you replace the bleed block with the pads and pump the system, it will actually go slightly less than atmospheric.
 

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Thanks. I think you're right about the bleed block being larger than the pads which, therefore, leaves too little fluid in the system.

Actually, I'm going to re-bleed the system with the pads in. I tried the pressurizer method (for lack of better name) and it definitely helped, but the logic of the way you did it makes sense to me and I think it seems like a more benign way to achieve the same thing.
I've done the pressure method from the caliper before as well and bleeding with the pads in works better. Pressure method equalizes itself after a couple rides and doesn't work as well

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If you didn't spend 20 minutes at the start of your first ride purposefully bedding in your new brake pads, you get the ol' "XYZ brakes suck, they have no power". Especially since you find that both G2 and Codes are weak.

Bed in those brakes.
 

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After doing the pressurize method from the caliper, I think this may be what's going on, and related to socalrider77's comment above. If one follows the sram bleed instructions exactly, as I did, and understanding this may only be true for these exact brakes, maybe only the exact specimen I have (accounting for part-to-part variation), using the medium bleed block (which appeared to be the smallest of those available), will leave the pads excessively far from the rotor so that the lever must be pulled excessively far before the pads touch the rotor and begin applying force.

The tolerance here is very small. Once I installed the caliper syringe and added some pressure (while closing the tool with the other hand), I got the rear lever to engage with 1/4" less travel, which improves the feel quite a bit. The front lever I was able to make engage with 1/2" less travel. The key was pressure, or more correctly, more fluid in the system, which pushes out the little part (I don't know what it's called) the lever contacts to begin pressurizing the line, so that the lever contacts it earlier in its travel.

This added fluid only reduced spacing between the pads by less than half a millimeter on either side of the rotor. That's how little will make a difference. IMO, sram's bleed procedure is flawed. Toward the end, the instruction is to pull the lever syringe to create a vacuum, then push it in to pressurize the system, then remove the syringe and replace the bleed screw. At the moment the syringe is removed, before the screw is replaced, the system is exposed to atmospheric pressure and, therefore, is not pressurized above atmospheric. So if the pistons are spaced too wide by a bleed block that is larger than the pads would need to be to closed on the rotor w/o excessive lever travel, once you replace the bleed block with the pads and pump the system, it will actually go slightly less than atmospheric.
The point of pushing in on the plunger before removing isn't really to "pressurize the system", even though they use those terms - as you correctly point out. It just follows the step of creating the vacuum just prior to removing the syringe. Otherwise, it would pull in air upon removal.
You do have to cycle the lever after bleeding, though.
But, by all means try the process with pads in and wheel/disc in place. It may add that little bit of fluid you need.
As long as you're careful not to get fluid on the pads/rotor, I don't see how it can hurt to try.
And it works for others, as they've pointed out.
 

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Discussion Starter · #14 ·
If you didn't spend 20 minutes at the start of your first ride purposefully bedding in your new brake pads, you get the ol' "XYZ brakes suck, they have no power". Especially since you find that both G2 and Codes are weak.

Bed in those brakes.
Noted. I'm not too familiar with bedding but think I understand the concept and it makes sense. None of the installation videos I watched mentioned bedding. It'll be embarrassing if it turns out to be something simple like that that I overlooked, but I'll admit to it just the same. :)
 

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Noted. I'm not too familiar with bedding but think I understand the concept and it makes sense. None of the installation videos I watched mentioned bedding. It'll be embarrassing if it turns out to be something simple like that that I overlooked, but I'll admit to it just the same. :)
Have you gotten more than 20 minutes of braking in while riding? That'll bed them in. If not, and you didn't bed them in, that could be it.
 

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Have you gotten more than 20 minutes of braking in while riding? That'll bed them in. If not, and you didn't bed them in, that could be it.
Nope. Braking for bedding in and braking during any type of general trail, park, downhill or path riding is very different.
 
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It's really not that different.
This isn't "Apollo 13" after all.
Yeah I agree. Unless he is always riding in the wet I dont see how it would be different to just bedding in through normal riding. I bed my brakes but I dont believe in it. Kinda like despite being athiest I apologise for my sins once a year so I only ever have one years worth of sins to make up for, just in case…
 

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brakes will NOT work properly on fresh pads and rotors

never touch the rotors or pads,

clean the rotors w alcohol anytime you are working on brakes etc, even just removing a wheel and reinstalling or washing your bike.

as for the amount of fluid in the system.... the reservoir has a rubber diaphram that collapses as fluid is used up. the seals on the pistons are designed to retract the pads so they dont drag.

overfilling a reservoir keeps the seals partially extended and can shorten the movement needed to engage rotors. less lever travel, until wear takes over and things work with normal tolerances again

fill your brakes from the bottom syringe with no plunger in the top syringe. lever adjusters open all the way. best to remove calipers and push pull from bottom to remove air while rotating calipers in odd positions to get it all out.

seal up the system and ride.

resin pads usually require a cool down period after bedding in to get full grip.

dont soak resin pads with alcohol or brake clean and ride. it softens the pad and ruins them until they have flashed off and dried overnight.

a vacumn allows entraped gas to escape a fluid. i dont understand the clamp the lever thing overnight for a best bleed. it does make the bubbles smaller.

a stab on these brakes should send you over the bars when working well.
 

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The point of pushing in on the plunger before removing isn't really to "pressurize the system", even though they use those terms - as you correctly point out. It just follows the step of creating the vacuum just prior to removing the syringe. Otherwise, it would pull in air upon removal.
the rubber bladder needs to be expanded after pulling fluid at the lever. otherwise the reservoir is pretty much empty. so pressurize to make sure its full.

because you can rupture the bladder by over pressurizing or pulling too much vacumn i dont do this at all. or perhaps changing terms to say gently remove fluid and any air by pulling on the plunger and then gently refill the reservoir by pushing fluid back into the system.

in fact i feel pusing fluid from the caliper syringe with the plunger in the lever syringe could cause damage if the plunger sticks in the syringe. causing an over pressure and tearing the reservoir bladder or damaging the seal at the reservoir.

best to leave the plunger out at the lever syringe.
 
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