SRAM's recently launched Guide brakes have been well received, possessing performance and reliability that are a marked improvement from the previous Elixir line. By ditching their TaperBore master cylinder and going with a cam activated cup seal and port system, SRAM was able to create a brake that has earned praise for its excellent modulation and lever feel. Now, just over a year after the Guide brakes were first announced, SRAM has a new addition to the line, the Guide Ultimate.
The Guide Ultimate's lever body internals are the same as on the standard Guide but the blade is made of carbon fiber, and titanium hardware is used for further weight savings. The use of carbon and Ti isn't the real story though – it's the new caliper, which received a complete overhaul as part of SRAM's goal to develop a brake with an extremely high level of consistency, one that maintained the same lever feel throughout a run, no matter how long or steep the trail.
Guide Ultimate Brake Details• Intended use: all-mountain / trail
• New S4 four piston caliper
• Heat shield in caliper for reduced fluid temperature
• Titanium lever hardware
• Increased pad pocket
• Uses same pad shape as standard Guide and Trail brakes
• Weight: 360 grams (front brake, includes rotor, hose, clamp, adapter and all bolts)
• MSRP: $288 USD per wheel
• Available May 2015
•
www.sram.com
Updated Pistons: To help achieve their goal of creating a brake with even better consistency, SRAM uses four aluminum pistons in each caliper. This reduces the likelihood that a misaligned piston will apply uneven pressure to a brake pad, and helps reduce seal wear. Instead of being completely machined from aluminum, there's an insulator in the center of each piston to help dissipate heat, while the surface of each piston is also covered with tiny grooves that are meant to help improve rollback, the speed that they return to their original position after the lever is released.
Improved Heat Management: Excessive heat buildup is the enemy of disc brakes, and companies go to great lengths to try and keep temperatures in check for as long as possible. To that end, SRAM has come up with a simple yet supposedly very effective heat sink that is located just in front of the brake pads. The horseshoe shaped piece of stainless steel channels heat away from the pads, and SRAM's in-house testing found that this created a 20°C reduction in running temperature. The shape of the caliper itself has been altered as well – the pad pocket (the portion of the caliper where the pads sit) has been widened in order to increase the amount of airflow between the rotor and the pads for additional cooling.
New Rotors:The Guide Ultimates come with new Centerline X rotors that are up to 20 grams lighter than the standard Centerline rotors. The use of a two piece design is the reason for this weight reduction, with the seven arms of the rotor mounted to an internal carrier. Two piece designs can occasionally develop play over time, leading to an annoying 'kathunk' that feels like a loose headset when the brakes are applied, but SRAM say that they took special care when designing the interface between the outer and inner portion of the rotor to keep this from happening.
Simplified Bleeding Procedure: It's fair to say that nearly anyone who's ever bled a set of brakes has one time or another dropped a miniscule bleed screw and watched it immediately roll under a bench, an event that's usually followed by a good amount of cursing and maybe some hair pulling. To help prevent temper tantrums, SRAM has developed a trick new bleed adaptor that should make brake maintenance much easier. The adaptor pushes into a port on the caliper, and then the anodized knob is back off slightly, allowing fluid to be pushed from the syringe through the caliper to the lever. Bleeding the Guide Ultimates is extremely simple, and requires fewer steps than what was required for any of SRAM's previous brakes. The new adaptor will be included with every Guide Ultimate brake set.
Riding Impressions | I was able to get out for a short ride on the new Guide Ultimates, but as fun as the rolling, berm filled trails of Rotorua were, there wasn't enough sustained braking to determine whether or not the new features make a difference in the consistency department. They did work well throughout the entire ride, with the excellent balance of power and modulation that the Guide brakes have become known for, but there wasn't a noticeable difference in lever feel or performance from the standard version. That's certainly not a bad thing, and once they're available we'll get a set in for review, at which time I'll be able to take them on steeper trails with enough vertical to give them a proper evaluation, including giving the simplified bleed procedure a try. - Mike Kazimer |
It would make sense with their history of unsatisfactory brakes!
However I've only heard good things about them in the past year or so. Maybe (hopefully) they've stepped up they're game.
the obvious choice was Shimano SLX. Inexpensive, extremely effective, very reliable.
The general consensus here in the UK is that if your new bike comes with Avid's then ok, you'll put up with them
As soon as you get a problem you dump them for Shimano brakes.
And if paying out of your own pocket for new brakes, its gonna be Shimano?
Avid always seem (as an aftermarket brake purchase) - overpriced, overcomplicated, unreliable
As a mechanic I've dealt with way too many warranty claims on Elixirs to ever buy them out of my pocket - you get good warranty support from SRAM which is important because you will need it.
I am sure the new Guide brakes have merit but its gonna take a lot of work to earn the trust of consumers burned by the Elixir experience?
for the average consumer, by the time you've paid for the replacement parts and the labour time for a wrench to do the work, its costing as much or more than just buying a new MC (master cylinder i.e. brake lever) or caliper from Shimano and then you have a whole fresh end of the brake.
The lack of rebuild kits for sheemano is troubling. The fact that they don't need them for years is nice. It is like old Chevy vs old Toyota. Used to be harder to find import parts for cars, but old Japanese cars took you 300,000 miles almost trouble free when american was lucky to go 100,000.
average consumer is not rebuilding hydraulic brake systems. They just want a mechanic to fix their bike for them. This costs time and money.
I've been a workshop manager for some of the leading bike shops in the UK, and have dealt with 100's of warranty claims on Avid brakes, very few on Shimano
yes Shimano have nothing like the levels of OE penetration that Avid have (due to SRAM's low OE pricing) but Shimano brakes seem to run and run until they fail, whereas Avid develop issues either out of the box, or degrade in a season
DOT: better performance at high temps, doesn't have that inconsistent feel resulting from water pockets in the mineral oil.
I'll stick with DOT thanks.
www.bikerumor.com/2013/04/11/tech-speak-brake-fluid-break-down-and-implications-for-road-disc-updated
www.rotorburn.com/forums/showthread.php?13473-Magura-oil-substitute
www.maximausa.com/product/brake-fluid
Also- brake line casings are not brand specific. You can run Shimano hose on a SRAM system and vice versa, so not sure what you're trying to point out there.
Seriously? !?!?!
Whoa.
I run hopes. None of this dropping parts and special bleed adapter trash. Turn the screw, bleed it, tighten and done.
As a side note I was watching On Track with Curtis Keene and he has his tech bleed his brakes after every day to alleviate this dead spot.
As for fade due to temperature I ended up making my own custom screw on extension for my master cylinders which basically doubled the amount of fluid. I also ordered new (dry) lines and seals and switched to 5.1 fluid. No more fade. (On my older brakes).
Also: Positioning the RSC as the top model last season, only to come out with a "completely new" version comes across a bit 650B.
Back up support and spares are brilliant in the UK for Hope.
The power and lever feel have always been excellent all the way back to the old O2 and C2 units and they have simply got better as time goes on.
Working as a bike mechanic I get to play with all sorts of different setups and the one thing I will say is that as yet NO Avid (lets face it that's what these are) have as yet been able to hold a candle to a set of Hopes.
However to be fair I will reserve judgement on these units for when I get a set through my doors.
In other words, that rotor is.....................
But they took so long to get right ...... like 5 bleeds ?? All downtime on riding...
hopefully this wont be the case with these ..... or the standard version.
i felt some at the London bike show and in terms or build quality id say they are poor. the lever feels tacky cheaply made. (standard guides)
if i had the money and need to buy new brakes id have 2 options really.
Hope tech 3 levers with v4 calipers or shimano slx both have good build quality and reliability on the sides not to mention a lot easier to bleed and get right.
My question is, how are these rotors going to cool any more efectively than the old ones?
So that's how.
The biggest performance gain will be the horseshoe heat sync inside the caliper body near the pads.
It is a wonder you don't see cooling fins on high end steel rotors instead of alu spiders. Cooking finds all over the whole apaeatus might make the most a sense, unless it needs to get to a optimal heat to work properly.
Shove them up your ass AVID.
Shimano: shut it Avid. You're drunk. Go home.
forums.mtbr.com/weight-weenies/xtr-race-brakes-vs-xtr-trail-brakes-weight-savings-real-740626.html