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  1. #1
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    How To Shorten Sram Guide Lever Throw:

    I've been running Sram Guide brakes pretty much since they came out. I'm a big fan of the brake's power and modulation, but I prefer a short lever throw. I have 2 sets of Guide RSC brakes (one older style and one newer style with the Bleeding Edge) and I've been experimenting with way to reduce the lever throw. (The contact adjust really just increase the lever throw.) After trying different methods, I finally found the real solution.

    So here's how to dramatically reduce the lever throw on Sram Guide Brakes (and probably other brands):

    Basically, you're going to over fill the brakes with brake fluid by pumping out the pistons before you bleed them. If you have contact adjustment, dial it all the way IN. Do NOT push the pads/pistons back into the caliper, in fact you can push them out a bit further if you wish. Bleed the brakes as normal WITHOUT a bleed block. Make sure you you pump the lever a few times to fill the caliper with fluid.

    If you have the newer Guides with the Bleeding Edge port, you don't have to do full bleed or even remove the pads. Just connect the syringe to the lever, push fluid into the line. No need to open the caliper port, just make sure you can see the pistons sticking out. Make sure you squeeze the lever a few times and then bleed the system of air (push syringe down, then pull back and get all the bubbles out).

    Once that is done, push the pads all the way back in and dial your contact adjust back out. Squeeze the levers a few times to let the system reset. Now you have the badass brakes with a short lever throw!
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  2. #2
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    That works right up until your brakes get hot enough and the fluid has no where to go. Locks the wheels, Blows a seal, brake failure.

    Sorry but this is a very bad idea. System is specifically designed to account for fluid expansion when it heats up. Since your giving it no where to go there is only one place it can go. Push the pistons out and start pushin fluid past the seals.

    If you want shorter lever throw, buy shimano brakes.

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  3. #3
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    Quote Originally Posted by RAKC Ind View Post
    That works right up until your brakes get hot enough and the fluid has no where to go. Locks the wheels, Blows a seal, brake failure.

    Sorry but this is a very bad idea. System is specifically designed to account for fluid expansion when it heats up. Since your giving it no where to go there is only one place it can go. Push the pistons out and start pushin fluid past the seals.

    If you want shorter lever throw, buy shimano brakes.

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    Ah, yes. The 'ol buy Shimano response.

    I've been doing this for the last year on
    Plenty of looong downhills. No problems whatsoever. The Guides are designed to deal with fluid expansion and have a large master cylinder that can accommodate the extra fluid.
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  4. #4
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    Except you flat out just said above you over filled them. Lever reservoir is designed for a specified capacity, brand has no bearing on it. Over fill any brake much, they leak. 100% guaranteed. Cant defy physics.

    The shimano response was relevant as you wanted short throw.

    Otherwise I would have said Hopes are worth a look.

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  5. #5
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    While I think exploding and utter failure is overly dramatic, I suspect when they get warm you'll be needing to reset your setup like this (if not, you got lucky and/or only barely overfilled). If the extra work is worth it for lever feel, I say go for it. I have enough to do.

    Also, buy Shimano. It'll fix everything.

  6. #6
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    I've shaved my bleed block down a 1/32" or so to get a bit more fluid in. What I find works best is simply pumping the brakes sans rotor to move the pistons out further. Obviously not so much you can't get the rotor back in or have excessive drag.
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  7. #7
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    Quote Originally Posted by RAKC Ind View Post
    That works right up until your brakes get hot enough and the fluid has no where to go. Locks the wheels, Blows a seal, brake failure.

    Sorry but this is a very bad idea. System is specifically designed to account for fluid expansion when it heats up. Since your giving it no where to go there is only one place it can go. Push the pistons out and start pushin fluid past the seals.

    If you want shorter lever throw, buy shimano brakes.

    Sent from my SM-G950U using Tapatalk
    The fluid capacity of a disc brake system is not static. When the pistons are pushed in (as when you bleed them) they have minimal capacity. The capacity EXPANDS as the pistons move out of the caliper. The master cylinder and Sram's Piggyback Reservoir is designed to allow for varying amounts of fluid in the lever. So, when you put more fluid in the system the only real result is that the pistons will not be able to retract all the way into the caliper. The positive result of this is that the pistons/pads site closer to the rotor. The negative result is when the brake is extremely hot they may pump out a little. But you're not going to blow a seal unless you drastically overfill the system, which is difficult to do. I'm adding a few extra CC's (if that much) to the line.
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  8. #8
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    Actually the volume of the system is static except the reservoir itself. The ONLY time the volume changes is as the pads wear down. To maintain same distance to the rotor, fluid moves from the reservoir into the system itself.

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  9. #9
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    I tried a few different methods to achieve the same result and even talked to a SRAM rep that said the overfilling *could* be done to get a shorter lever throw, but may result in the wheel locking up when hot. What ended up working for me in the end were beer can shims between the piston and pad. Cut open a can, trace the pad, cut it out, poke a hole in the top for the pad retaining bolt, and voila. One behind each pad gets a super short throw, but I've also used a shim behind just one pad to get the feel I liked (just adjust your caliper accordingly). I've used this method on Guide R, RSC, and Elixir brakes, all with success. Anywhere from single digit temps to 95+ degrees. XC to downhill trails. No complaints at all and you don't have to bleed your brakes in any special way.

  10. #10
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    Guys, I have the opposite problem. My front lever stroke is much shorter than my rear brake and grabs early. The rear lever has a nice range and modulation. How to I increase the lever range and make the front lever less grabby. Thanks.

  11. #11
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    Quote Originally Posted by sasquatch rides a SS View Post
    I tried a few different methods to achieve the same result and even talked to a SRAM rep that said the overfilling *could* be done to get a shorter lever throw, but may result in the wheel locking up when hot. What ended up working for me in the end were beer can shims between the piston and pad. Cut open a can, trace the pad, cut it out, poke a hole in the top for the pad retaining bolt, and voila. One behind each pad gets a super short throw, but I've also used a shim behind just one pad to get the feel I liked (just adjust your caliper accordingly). I've used this method on Guide R, RSC, and Elixir brakes, all with success. Anywhere from single digit temps to 95+ degrees. XC to downhill trails. No complaints at all and you don't have to bleed your brakes in any special way.
    This is awesome!
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  12. #12
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    Quote Originally Posted by dcr1 View Post
    Guys, I have the opposite problem. My front lever stroke is much shorter than my rear brake and grabs early. The rear lever has a nice range and modulation. How to I increase the lever range and make the front lever less grabby. Thanks.
    You could probably just open the port at the lever and let a bit of fluid drip out. Close it up and check the throw. Lather, rinse, repeat until desired results.
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  13. #13
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    Quote Originally Posted by sasquatch rides a SS View Post
    I tried a few different methods to achieve the same result and even talked to a SRAM rep that said the overfilling *could* be done to get a shorter lever throw, but may result in the wheel locking up when hot. What ended up working for me in the end were beer can shims between the piston and pad. Cut open a can, trace the pad, cut it out, poke a hole in the top for the pad retaining bolt, and voila. One behind each pad gets a super short throw, but I've also used a shim behind just one pad to get the feel I liked (just adjust your caliper accordingly). I've used this method on Guide R, RSC, and Elixir brakes, all with success. Anywhere from single digit temps to 95+ degrees. XC to downhill trails. No complaints at all and you don't have to bleed your brakes in any special way.
    So this is once reply that has me interested. Can you provide some more details? any pics you have of this? Really hopeful this can fix these brakes for me!!

    It seems the brake would just readjust (similar to having a new set of brake pads that are thicker and I would be back having the same problem.

  14. #14
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    Yeah... this isn't how brakes work. The extension/retraction of the pads is a result of the deformation of the piston seal. It's an o-ring with a square cross section. As the system is pressurized and the piston moves outward, the square is deformed into something resembling a parallelogram. When the pressure is released, the o-ring returns to its original shape, pulling the piston back with it.

    The amount of retraction is the same every time. You can phony it up by overfilling or adding shims, but as soon as the pad wears down sufficiently, the retraction will be exactly as it was originally.

    To minimize lever throw, make sure there is NO air in the system. That's as good as your going to get, unless you want to play around with your brakes every few rides.

  15. #15
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    I think my only option is to be willing to pull the wheel every once in a while and advance the pistons by squeezing the lever. Did that this morning and got the feel I want. I know it will go back over time but this effort only takes about 3 min so if I had to do it weekly it still wouldn’t be that big of a deal.


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  16. #16
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    Quote Originally Posted by dcr1 View Post
    Guys, I have the opposite problem. My front lever stroke is much shorter than my rear brake and grabs early. The rear lever has a nice range and modulation. How to I increase the lever range and make the front lever less grabby. Thanks.
    Very late reply, but that's what the contact adjust dial is for on the RSC's.
    Rolling on 29", 650b, 8.3" and 23mm

  17. #17
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    To update, I've been riding with my brakes like this for 3 mons with some big, brake testing decents and they've been fine. Actually, perfect. My Guides perform exactly how I want them to. YMMV.

    Oh, and 6thelement, the contact adjust only really increases lever throw. Some folks like it short.
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  18. #18
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    Nice, actually worked without issue so far. Pleasantly proved wrong on that, maybe Sram is truly starting to get brakes figured out. Though getting upset over a shimano suggestion wasnt necessary. Valid solution considering Srams track record.

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  19. #19
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    Quote Originally Posted by RAKC Ind View Post
    Nice, actually worked without issue so far. Pleasantly proved wrong on that, maybe Sram is truly starting to get brakes figured out. Though getting upset over a shimano suggestion wasnt necessary. Valid solution considering Srams track record.

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    So you tried the "overpressure" idea? May be my next move if so.

  20. #20
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    Few more questions on this. Above mentioned the bleeding edge port but said you don’t use this. The process is to simply attach the one syringe to the lever and “charge” it. I assume when I unscrew it it may make a bit of a mess but guess that’s ok. Do I do this process with the wheel on or need to have the pads all the way touching and no rotor between. Thanks!


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  21. #21
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    Quote Originally Posted by jasondbikes View Post
    Few more questions on this. Above mentioned the bleeding edge port but said you don’t use this. The process is to simply attach the one syringe to the lever and “charge” it. I assume when I unscrew it it may make a bit of a mess but guess that’s ok. Do I do this process with the wheel on or need to have the pads all the way touching and no rotor between. Thanks!


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    I did it w/o the wheel in. Either way is probably fine. If you want a really short lever throw, pull the wheel and pump out the pistons a bit then top off the fluid and bleed the lever.
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  22. #22
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    The reason this works- same reason for the beer can shim- is that the pistons are free/the piston is stuck.
    You aren't gaining anything by overfilling, but you do gain by pushing the pistons out of their normal (stuck) position and stowing them again. It only takes 1 sticky piston to increase your lever travel.
    Bottom line, on SRAM Guide brakes, exercise your pistons a little. They will work better. Bleed as normal if required/as desired.

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