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Discussion Starter · #1 ·
Yesterday after a relatively easy ride, both my Guide RE and my wife's Guide R got real grabby. The trail was clean, dry, and not technical at all. No hardcore brake heatups or anything. Her brakes became grabby early on in the ride and she locked up the front a few times and it almost through her off. Mine became grabby as I was rolling up to the car after the ride. I'm talking instant on/full power when you barely apply lever pressure. It was a 4.5 mile ride and pretty flowy. Her bike is a few months old and maybe 50 miles. My Evil is a few weeks old and some good/fun 50 miles on it. lol

After driving home, both seemed better when I was rolling them into the garage from the bike rack.....
 

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This "grabby" sensation you speak of is usually a good thing. Your brakes are well-tuned if the rotors aren't rubbing the pads and making noise. My advice would be to learn how to modulate your braking efforts. If you can't seem to get used to it, you can pop out the bleed screw on the lever end squeeze your lever in just a tiny bit to allow a smidge of fluid to come out and replace the screw. IMO, get used to the amazing brakes you have. It sounds like you hardly have any time on these bikes, so get out there and ride more before tweaking anything.

If its a serious issue, bring the bikes in where you bought them and the shop should help you tune them to your liking.
 

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Discussion Starter · #3 ·
This "grabby" sensation you speak of is usually a good thing. Your brakes are well-tuned if the rotors aren't rubbing the pads and making noise. My advice would be to learn how to modulate your braking efforts. If you can't seem to get used to it, you can pop out the bleed screw on the lever end squeeze your lever in just a tiny bit to allow a smidge of fluid to come out and replace the screw. IMO, get used to the amazing brakes you have. It sounds like you hardly have any time on these bikes, so get out there and ride more before tweaking anything.

If its a serious issue, bring the bikes in where you bought them and the shop should help you tune them to your liking.
I came from Shimano brakes and can modulate grabby brakes with no issue. These became uncharacteristically grabby for SRAM. Instant full on/suspension compressing/insta stop power. Very, very little lever movement. So no, I "don't need to learn to modulate my brakes". Just because these bikes are newer, doesn't mean I am. And if it was just the bakes finally fully bedding in, why did the grabbiness go away after the ride home?

My wife is always light on the brakes as she rides slow and cautious anyway. Just a strange scenario that two different people, on two different bikes, with two different riding styles, and both bikes brakes suddenly behaved differently on the same ride. Dusty conditions caused it maybe?
 

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I was gonna ask, did they magically morph into Shimano brakes?

I've had dusty conditions make brakes more grabby, but not as extreme as you describe. Very little lever movement sounds weird too. And that it went away after the drive home, weirder still. And on the two bikes!!! Maybe some really light powdery dust that built up in the caliper somehow? That's the only thing I can think of.

Older Guides (it's been a few years now) had this problem where the lever piston would expand causing the piston to stick. This would hold the lever in and the brakes lighly on or nearly on. Your issue sounds different. And of course, the fact that it happened on two bikes at the same time out of the blue kinda rules that out.
 

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Short-Change-Hero
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Sounds like they have finally bedded in fully and are now at max power. I used to ride Shimano SLX M675s which I considered absolutely awesome brakes. They had great feel, modulation and power. New bike has Code R brakes on them and have been having some other issues but they feel great when they are working. I have noticed that at time the bite point can wander some after they have "warmed up", which may be what you are feeling.

Have you adjusted the lever throw at all? (also known as the reach adjustment)
Have you changed pads recently or are they the stock SRAM pads?
How far does the lever move before you feel the brakes starting to engage? This can be done while rolling down the street, just pull slowly on the lever until you can feel them starting to grab.
 

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Discussion Starter · #6 ·
I was gonna ask, did they magically morph into Shimano brakes?

I've had dusty conditions make brakes more grabby, but not as extreme as you describe. Very little lever movement sounds weird too. And that it went away after the drive home, weirder still. And on the two bikes!!! Maybe some really light powdery dust that built up in the caliper somehow? That's the only thing I can think of.

Older Guides (it's been a few years now) had this problem where the lever piston would expand causing the piston to stick. This would hold the lever in and the brakes lighly on or nearly on. Your issue sounds different. And of course, the fact that it happened on two bikes at the same time out of the blue kinda rules that out.
That's sounds believable and hoping what happened. Guess I will just keep an eye on them and see how it goes. The two other bikes in our group yesterday had Tektro hydro and Tektro mech brakes and did not have the same issue.
 

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Discussion Starter · #7 ·
Sounds like they have finally bedded in fully and are now at max power. I used to ride Shimano SLX M675s which I considered absolutely awesome brakes. They had great feel, modulation and power. New bike has Code R brakes on them and have been having some other issues but they feel great when they are working. I have noticed that at time the bite point can wander some after they have "warmed up", which may be what you are feeling.

Have you adjusted the lever throw at all? (also known as the reach adjustment)
Have you changed pads recently or are they the stock SRAM pads?
How far does the lever move before you feel the brakes starting to engage? This can be done while rolling down the street, just pull slowly on the lever until you can feel them starting to grab.
Stock resin pads. No lever adjustments.
 

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These became uncharacteristically grabby for SRAM. Instant full on/suspension compressing/insta stop power. Very, very little lever movement.
And if it was just the bakes finally fully bedding in, why did the grabbiness go away after the ride home?
This IS the same symptom that many of the "older" SRAM Guide brakes had with the piston expanding and holding in place. The fact that it was this way during your ride, but stopped being this way when you got home (after the brakes had cooled down for whatever reason) is the typical characteristic of the issue. It swells when heated up, cools off and feels normal again.
Take it to your LBS if your bike is new enough and hopefully they will help you out.
 

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Discussion Starter · #9 ·
This IS the same symptom that many of the "older" SRAM Guide brakes had with the piston expanding and holding in place. The fact that it was this way during your ride, but stopped being this way when you got home (after the brakes had cooled down for whatever reason) is the typical characteristic of the issue. It swells when heated up, cools off and feels normal again.
Take it to your LBS if your bike is new enough and hopefully they will help you out.
Good to know!! Yes, both bikes are under warranty still. Her Stumpjumper being 3 months old and my Evil being 1 month.
 

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SRAM has been supplying replacement levers for free based on serial number (on the bottom of the caliper) even for bikes out of warranty, but they solved the problem a few years ago. With such new bikes it's unlikely the levers are the problem. Your LBS can check the serial number range and get replacement levers from SRAM. If you bought the bikes there, they'll probably not charge for the install.
 

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I'd say it's one of two things

  1. the brakes have bedded in (the pads have "keyed" with the disc). If the lever travel is the same, then this isn't what's happening.
  2. the good ol' SRAM lever issue has hit both of you. it typically manifests in warmer weather. If the brakes now engage with less lever travel, then this is the issue. This fault appeared in 2016, and it's still occurring on MY2019 brakes...

    This 4 page thread is one of the threads about it on MTBR...:
    https://forums.mtbr.com/brake-time/...aced-under-warranty-1011229-post12614901.html

    You should be able to warranty them.

Best of luck!
 

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One thing overlooked here - this is also the symptom of a DOT brake system that might need bleeding. The water expands more than the brake fluid when it warms up, and can get to a point where it actually locks the wheel while the bike is just sitting in the garage if it gets hot. I'd suggest trying a full flush and bleed on both brakes before you warranty them for the piston problem. I think a lot of people started having problems with Guide and Level brakes and assumed it was the piston problem and forgot - what you're describing used to happen all the time with Elixir brakes when they needed a flush and bleed. In spite of some other threads floating around here, flush and bleed any hydro once a year for best performance and longest life.
 

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One thing overlooked here - this is also the symptom of a DOT brake system that might need bleeding. The water expands more than the brake fluid when it warms up, and can get to a point where it actually locks the wheel while the bike is just sitting in the garage if it gets hot. I'd suggest trying a full flush and bleed on both brakes before you warranty them for the piston problem. I think a lot of people started having problems with Guide and Level brakes and assumed it was the piston problem and forgot - what you're describing used to happen all the time with Elixir brakes when they needed a flush and bleed. In spite of some other threads floating around here, flush and bleed any hydro once a year for best performance and longest life.
Great advice regarding regularly flushing and bleeding DOT brakes (and add in a good piston clean too).

However, the op stated that the bikes are a few weeks old, and a few months old. This should not be happening brakes that are effectively new, unless they are NOS...and these don't sound like NOS brakes.
 

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SRAM has been supplying replacement levers for free based on serial number (on the bottom of the caliper) even for bikes out of warranty, but they solved the problem a few years ago. With such new bikes it's unlikely the levers are the problem. Your LBS can check the serial number range and get replacement levers from SRAM. If you bought the bikes there, they'll probably not charge for the install.
My LBS just replaced the levers on my 2 year old Code R brakes after I dropped my bike off for a brake bleed after a weekend in Telluride. Never knew about the recall. The mechanic said that there are still about 1/3 of the brakes that were affected by the recall that need to fixed. Thanks for the info!
 
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