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Having specified these on my new build, they're ok but aren't turning out as good as I'd hoped. On moderate trails I'm finding myself braking earlier than I'd like to, and at times putting a second finger on the front lever to apply more force. Before I start fiddling with them much more I'd appreciate some advice please.
I think these brakes should be adequate for my needs; I'm a 70kg rider on a mid-travel 29er trail bike, I'm not fast, nor do I typically ride steep or sustained downhills. That's why I specified 4-pots as a bit of a luxury but didn't spec up to Codes. They're definitely better than all other brakes I've tried before (SRAM and Shimano), which is to be expected given those were all entry-level.
Reach adjustment is set to put them 5.8cm from the bar at rest, this requiring 8 clicks from furthest-out on the rear brake and 3 clicks on the front. With that adjustment, they become what I'd call firm when pulled moderately to 3.2cm; a stroke of 2.6cm. Ideally they would become firm at 3.6cm (3/0 clicks, stroke of 2.2cm), allowing my finger to continue applying more force further through the stroke due no not becoming weaker due to bending, but this would put them too far out at rest (6.3cm). Contact adjustment exists to solve this exact problem, but it's already all the way "out" on the lever (pads all the way in). There's about 1.5cm of lever travel before I can hear/feel any braking action at the wheels on a clean disc when in the workstand, but I do hear them sometimes in muddy conditions for a bit until they clean up.
The root problem though may be why I need to apply such force to the lever in the first place. It's not like I'm pulling really hard, just more than I'd like to, and it'd be nice to have the confidence that rapid deceleration is available should I need it. To give some examples, 25km/h on a 15% gradient into a tight bend and I'm braking early, and to lock the front for an endo around a tight corner needs serious sudden provocation.
They've been this way since new, both ends are the same, they're consistently like this every ride from start to finish, and they don't get better with pumping the lever. I have a feeling this is how they're supposed to be, rather than anything being wrong with them.
Rotors are 200/180mm so plenty, pads are original organic ones.
Things I've checked: caliper alignment, glazed pads/rotors, uneven pad wear.
Things I've tried: cleaning everything and bedding in again (exactly the same).
Things I've read about on here:
* replace pads with (semi)sintered
* bleed them
* bleed them with the contact adjuster in the middle of its range
* advance the pads against a pad spacer (not sure how this achieves anything, given the spacer is 2.4mm and the disc is 1.85mm)
* lubricate the pistons
* replace with Codes/Shimano/Magura
Any advice much appreciated, thanks.
Definitely try them with different pads, Uberbike Race Matrix seem to reference point.
Are any of the pistons lazy ??
Try different pads, ensure pads are properly bedded in. I have G2 R on my big bike (160mm full sus) and I weigh about 80kg with no issues of a lack of power.
If you haven't bled them then I would do that first. Whilst they are new, they might have been built some time ago so a bleed would be in order.
If you adjust bite point all the way in, so pads furthest away and bleed without resetting pistons there will be less lever throw. If you have guessed it right you won't spend 2.5 months fighting against the pads rubbing on the rotors and making every ride feel like a resistance training effort!
Lack of power has nothing to do with lever throw really. Except that when brakes need bleeding they’re down on power and the lever feels bad.
IME the free stroke thing on SRAM brakes isn’t that useful - the adjustment seems to go from ‘acceptable’ (default, same as on the R brakes) to ‘bad’ without bracketing the position I like. I could live without that adjustment, but you can’t get the servo lever without the extra dial IIRC so IMHO the RSC brakes are worth paying extra for.
Perhaps you can bleed them to get around this problem as DickBarton says.
Unless you have exceptionally weak braking fingers, there shouldn’t ever be a need to use two fingers on modern MTB brakes.
If the brakes feel fine but theres no power, it’s probably a pad thing. If the lever feel is inconsistent, bleed them. If you can’t tell, maybe take them to a bike shop.
I don't know how different G2's are to Guides, but my SRAM brake setup system is to...not bother until a good deal on a Shimano or Magura brakeset shows up.
Mine are currently just about OK, although the rear lever doesn't return properly if it's a bit warm out...but from fighting with SRAM brakesets in the past I know it's a lost cause 😁
Definitely try them with different pads
Will do.
Are any of the pistons lazy ??
No, just checked this.
Try different pads, ensure pads are properly bedded in.
My technique has been 20 near-stops from ~10mph on a slight hill, followed by 10 near-stops from ~15mph, doing both ends at once. I doubt if finding a longer hill so I can do it all in one go (keeping the temperature up) rather than three uplifts would improve things. Or doing one end at a time. Before the re-bed, I cleaned the discs and pads with IPA, rinsed with water, rubbed the pads together a bit, and lightly roughed up the discs with fine sandpaper. Ended up same as before.
I have G2 R on my big bike (160mm full sus) and I weigh about 80kg with no issues of a lack of power.
Great. Not using stock organic pads I guess?
If you haven’t bled them then I would do that first. Whilst they are new, they might have been built some time ago so a bleed would be in order.
I see, yes. Any particular symptom prompt this recommendation? The feel is fine once they bite (not "mushy"), they're consistent, and pumping them makes no difference. I'm inclined to try pads first.
If you adjust bite point all the way in, so pads furthest away and bleed without resetting pistons there will be less lever throw.
Will keep this hack as a near-last resort. I don't want them so close to the disc that the slightest bit of muddy water makes them catch.
Lack of power has nothing to do with lever throw really.
Yes, this is what I was getting at with the root problem comment. I'm only needing less lever throw to keep my fingers in the strongest part of their range of motion, to compensate for the power issue.
IME the free stroke thing on SRAM brakes isn’t that useful – the adjustment seems to go from ‘acceptable’ (default, same as on the R brakes) to ‘bad’ without bracketing the position I like.
Exactly, it'd be better if that default position were in the middle of the adjustment range.
I could live without that adjustment, but you can’t get the servo lever without the extra dial IIRC so IMHO the RSC brakes are worth paying extra for.
I believe you can - the RS models.
If the brakes feel fine but theres no power, it’s probably a pad thing. If the lever feel is inconsistent, bleed them. If you can’t tell, maybe take them to a bike shop.
It's the power, the lever feel is fine.
As someone with plenty of experience of G2's who's also about 20kg heavier than you...
Change the pads... Stock organic aren't up to much, but SRAM's own Power pads are good, and there's various aftermarket alternatives with differing results too.
Move the levers further in board... If you can get a 2nd finger on the lever, the lever isn't far enough inboard. Moving them inboard will increase your mechanical advantage on the brakes, you'll be able to apply more pressure at the pads for a given force at the lever because you're now pulling the lever further from its pivot. You will worry that you will need the option of a 2nd finger to pull the lever hard enough, but trust me you won't need it once your index finger is pulling right on the end of the lever blade instead of half way along it... An added benefit of this is that you'll be able to wind the lever reach in a couple more clicks, and you may bring the free stroke adjuster back into play too. 👍🏻
Stock organic aren’t up to much, but SRAM’s own Power pads are good
Just had a look around, according to Bikerumor the stock pad is the "Quiet organic" rather than the "Power" organic.
Move the levers further in board… If you can get a 2nd finger on the lever, the lever isn’t far enough inboard
The levers are right where they are; to put two fingers on I have to shift my index finger inwards.
I’ve run guide R’s a lot in the past (now on Code R’s) with the same size rotors as you and they’ve been fine. The G2 RAC should have more power - I’ve certainly never had to use 2 fingers. At the time I’d have been 80-83kgs. Run on a 170f/160r enduro bike and a 140mm travel fork hardtail.
I reckon it’s time for a pad change more then anything else. I’d try Uberbike Race Matrix or E-Matrix for a cheap fix. I’d say the E-Matrix have more bite in the dry but Race Matrix is a better all rounder in UK weather.
Either that or (if you can find some) the Sram sintered pads - they’ll definitely be more expensive though.
I remember a wet day at BPW and absolutely chewing through Sram standard organic pads right back to the plates. Would not use them again.
I don’t know how different G2’s are to Guides, but my SRAM brake setup system is to…not bother until a good deal on a Shimano or Magura brakeset shows up.
Great. A downgrade will really help.
For the bedding in part - do the brakes individually so they both get a really good working over...I've always found if I bed them in together that I need to do more bedding in stuff as the pads don't quite get their bite.
The Bleeding Edge tool makes getting a really good bleed and lever feel so simple. Doddy has some good YouTube vids on the bleed process and how to set the lever and bite adjuster when you do this...
Failing that if it's a good bleed without a soft or spongy lever, change the pads out.
Similar to above I have G2 rsc and am about 83kg and had no problems, currtnely running uber bike race matrix pads and they're spot on. I'd try changing pads first, and possible rotors - I'm always a bit dubious about rotor cleaning fluids and stuff like that..often seem to make things worse.
If you do end up bleeding, it's really straightforward and seems easy to get a good result, but I'd try pads first for sure.
I believe you can – the RS models.
Hmm, looks like you're right. I was thinking of Codes which seem to be only available as R or RSC (at least, aftermarket sets).
I don’t know how different G2’s are to Guides
Pretty much identical. I have a G2 rear and Guide front and they feel identical. Apparently the G2s don't do this, though:
the rear lever doesn’t return properly if it’s a bit warm out
...which is not too difficult to fix with a lever teardown. But super annoying.
Fitted a set of Fibrax semi-metallic.
All problems sorted; great power, lever reach at rest/bite same as before which is now fine given less force required. Just as quiet too, at least in these summer temperatures. The power difference is just night and day. I bedded each end in separately for good measure.
I don't understand why SRAM ship with such poor pads. Gives a poor impression of their products and tarnishes their brand. Maybe I'd understand for the lower-grade Level series, but they sell these as "mini-Code".
Great. A downgrade will really help.
It's funny. I've had experience of juicys (shite), codes (really shite) and guides (average).
And then XT (fantastic), SLX (fantastic) and Magura, albeit on a borrowed bike (fantastic).
…which is not too difficult to fix with a lever teardown. But super annoying.
Just shite 🙂
Ive had deore x2 fail, SLX levers fail x3 levers 1x piston which cracked in half during braking, 2x XT levers fail, 2x Saint levers fail spontaneously at the same time. None of my SRAM ones have yet.
Just REALLY shite 🙂
Oh, I forgot about the wandering bite point. This was the turd icing on the turd cake 🙂
That’s why I specified 4-pots as a bit of a luxury but didn’t spec up to Codes.
This is where you went wrong. You can try all the 'fixes' you want, but ultimately, you need to buy some Codes.
just wanted to share this for future reference. Just done the pre purge fix from the Sram service manual and it has fixed both the excessive lever swing and crap performance of my G2 R brakes. P7 onwards in here:
i'm still running the original organic pads and they are working like a dream at the moment. Maybe worth doing a few times a seasons just to resent the pistons.
Sram brakes 'un-shited'...for the moment 😉
the pre purge fix from the Sram service manual
Interesting. What is that supposed to achieve within the brake? It looks like it would just shift fluid backwards and forwards between the caliper and lever reservoir and maybe lube the pistons a bit?
Hard to say.... you can see how unevenly the pistons come out when you do it but I wouldn't say that changes much as you repeat the process. I guess the pistons advance a bit further than they would under normal use with the pads in so maybe that helps free them up a bit. I had to realign both calipers afterwards so it clearly does change the positions of the pistons.
They specifically say not to lube the pistons from the outside which I have seen recommended elsewhere.
As for reducing lever swing....maybe when the pistons are better aligned some of the spare fluid comes out of the reservoir into the system?...if that's how it works
My Levo SL came with same brakes as OP and my experience was pretty much identical. I persevered for 6 months and then swopped them out to 2021 XT 4 pots which so far are miles better in every way.