SRAM vs Shimano hydraulic disc brakes - which is better

[BugsBunny]

Does any one know which is "better" between SRAM and Shimano for their current line up of hydraulic disc brakes. I understand that there are various models between them, but lets say at the equivalent "Ultegra" and "Dura Ace" level - how do they compare?

[MichaelB]

Can of worms opened !!

The brakes at each level are essentially the same - same fluid, dimensions, pads etc. Where each level differs is colour, weight and sometimes features (lever adjustment, free stroke adjustment, different spec pads - resin vs sintered and or finned).
Sometimes there are physical differences, such as the latest DA9100 levers are a different shape to the RS685, but they are different model cycles.

They will all work the same, but many will say the DA ones work better, but that's because they invested in them and they can't be wrong.

I have RS685 levers and Zee calipers - would DA levers and Saint calipers be any different ? I wouldn't notice any difference.

Same would go for SRAM as well.

[Toyopet]

Better in which way? Feel, maintenance, aesthetics, power?
I’ve not used SRAM so can’t comment on them.

One of my road bikes has Shimano Ultegra level hydraulic discs.
It's two years old and has done over 20,000km.

Pros:
No maintenance required so far apart from replacing worn pads and rotors.
I bought a bleed kit just in case, but haven’t found the need to use it yet.
Uses mineral oil instead of DOT, so less likely to corrode nearby components if it leaks.
I believe SRAM brakes use DOT fluid and are a little more expensive when it comes to pad replacement

Cons:
Lever throw is hard to adjust to where you want it.
Lever always seems close to bottoming out on the bar.
I know of others who have had oil leakage problems with their Shimano brakes.

[Duck!]

Ergonomically I find Shimano better, which is an unfortunate let-down on SRAM's part, because their brake lever shaping has always been better (in my opinion at least), but the large reservoirs have a very squared-off cross-section, with a sharp edge that digs into the base of your thumb when on the hoods; Shimano's more rounded profile fits more naturally in the hands.

In terms of operation, Shimano have a more linear feel; you squeeze harder and more happens at the caliper. Both have tuned their brakes differently to MTB models so there is more modulation (control) and less outright grunt, but SRAM have taken it further, to the point that they feel kind of dead. Some of that comes down to pad compound though; SRAM specify resin (organic) pads, where Shimano offer both resin and metallic. Metallic pads offer improvements in both overall power and modulation, but the downside is they lack bite when cold.

SRAM brakes use DOT fluid, which absorbs moisture, resulting in degraded brake performancewhen pushed hard (lowered fluid boiling point, therefore increased risk of vapour lock and brake failure). Therefore they need to be bled periodically to maintian performance.

Mineral oil used in Shimano does not absorb moisture, therefore maintains consistent performance, and in theory never needs bleeding.

Both offer lever reach adjustment, but not all models have stroke adjustment.

Finally it's also worth considering the shifting system you prefer, given that both functions are integrated in the levers.

[am50em]

Mineral oil used in Shimano does not absorb moisture, therefore maintains consistent performance, and in theory never needs bleeding.

I read that this means water accumulates at the bottom in the calipers and causes corrosion and the water boils???

[Duck!]

It's an unproven hypothesis. The idea being that because water is denser and does not mix with oil, any that does get into the system will pool at the lowest point.

However, the oil at the seal boundary effectively provides a water-repellant barrier, and in more than 13 years as a professional mechanic I have never seen a single mineral oil-filled disc brake displaying even the tiniest hint of water ingress, so I'm calling it a load of bunkum.

[JPB]

Mineral oil used in Shimano does not absorb moisture, therefore maintains consistent performance, and in theory never needs bleeding.

I read that this means water accumulates at the bottom in the calipers and causes corrosion and the water boils???

This is one of the reasons why DOT graded brake fluid is used in cars. The principal of hydraulic systems is that fluid cant be compressed. Any pressure applied at the brake pedal or lever is transfered to the piston in the brake caliper.
IF there is water in the system AND the brakes get hot enough to boil the water, the water turns to steam which can be compressed when the brakes are applied lowering the force applied at the caliper.

[Tim]

The inability to readily buying SRAM parts cheaply fom overseas would determine my choice.
Shimano at good prices and availability fom Wiggle, Merlin, Evans etc or paying top dollar for SRAM from local, high priced suppliers.
Easy choice.

[warthog1]

The inability to readily buying SRAM parts cheaply fom overseas would determine my choice.
Shimano at good prices and availability fom Wiggle, Merlin, Evans etc or paying top dollar for SRAM from local, high priced suppliers.
Easy choice.

lay down misere

[Duck!]

Mineral oil used in Shimano does not absorb moisture, therefore maintains consistent performance, and in theory never needs bleeding.

I read that this means water accumulates at the bottom in the calipers and causes corrosion and the water boils???

This is one of the reasons why DOT graded brake fluid is used in cars. The principal of hydraulic systems is that fluid cant be compressed. Any pressure applied at the brake pedal or lever is transfered to the piston in the brake caliper.
IF there is water in the system AND the brakes get hot enough to boil the water, the water turns to steam which can be compressed when the brakes are applied lowering the force applied at the caliper.

As I said above though, I have never seen any actual evidence of it happening, therefore it must be considered an extremely improbable scenario.

On the other hand, DOT fluid brakes with undue care to maintenance have proven themselves to be more troublesome many times.

[am50em]

Good to know. Thanks Duck!

[baabaa]

Best or better? Best is you choose the SRAM or Shimano road levers you want to do your shifterings but get some Hope 4-piston calipers to do the stoperings....
http://www.hopetech.com/product/rx4-caliper/

[JPB]

As I said above though, I have never seen any actual evidence of it happening, therefore it must be considered an extremely improbable scenario.

On the other hand, DOT fluid brakes with undue care to maintenance have proven themselves to be more troublesome many times.

I agree Duck, the forces required to stop a car are much greater than stopping a bike. I can't see the issues of extreme heat build up occurring, especially seeing our discs and calipers are in the open air, not shielded inside a wheel rim.

[am50em]

Just for reference, this was the article I read
http://www.epicbleedsolutions.com/blog/ ... neral-oil/

[ball bearing]

I have seen two Sram disc brakes seize up. I have been using Shimano discs on my MTB bikes for 15 years without any trouble. I can also buy Shimano online from anywhere in the world - try that with Sram.

[BugsBunny]

Thanks guys... some really good feedback.

From the above points, I think the main factor for me would by the oils used. Living in a high humidity place like Hong Kong, the DOT 5 fluid used by SRAM might lead to more frequent bleeding due to moisture absorption.

I've been discussing this with a few of my riding buddies, and they've introduced a new dilemma to me. They are suggesting that given that we like to take off the handle bars and pack our bikes into bike cases for long trips, there is a risk of it bleeding - and so now they are recommending *mechanical* flat mount discs! What do you guys think? Mech disc or hydro disc? Is the chance of oil leaks really a significant point - given that I do like to take my bike on overseas trips.

[RonK]

From the above points, I think the main factor for me would by the oils used. Living in a high humidity place like Hong Kong, the DOT 5 fluid used by SRAM might lead to more frequent bleeding due to moisture absorption.

This really is a non-issue. Modern braking systems are not open to the atmosphere so moisture absorption is minimal. Even on motor vehicles the replacement cycle for DOT brake fluids is 2 years or 40,000kms.

Same goes for corrosiveness - DOT brake fluid is mildly corrosive, but in my first career as an automotive technician I wouldn't care to guess how many times I spilled brake fluid on car paintwork. Spills wash away with water easily.

There may be various legitimate reasons for choosing a particular brand or type of brake, but brake fluid type is not one of them.

[Calvin27]

+1 to SRAM being bum holes and geoblocking australians.

Aside from that DOT fluid is the devil (in bikes at least) and I still can't trust sram after a generation of avids.

[ft_critical]

Hello all,

Bumping an old thread. I have SRAM HRD Red brakes on a CAAD12. I find it exceedingly difficult to get the brakes aligned so there is no rub. If I do the skewers (QR system) up tight, it is impossible to eliminate rub.

It would be awesome if someone had some thoughts on anything I can do. I am considering changing the calipers to the Hope ones for example, if that is a better caliper.

Thanks,

[Calvin27]

Hello all,

Bumping an old thread. I have SRAM HRD Red brakes on a CAAD12. I find it exceedingly difficult to get the brakes aligned so there is no rub. If I do the skewers (QR system) up tight, it is impossible to eliminate rub.

It would be awesome if someone had some thoughts on anything I can do. I am considering changing the calipers to the Hope ones for example, if that is a better caliper.

Thanks,

I don't think you can just change calipers like that without some hydraulic wizardary- it has to match the levers. I don't know if hope even makes a drop bar brake lever...?

[DarrylH]

The problem is unlikely to be the calipers. The problem I have had is that on some hubs the clamping surface on the end of the axles is not perfectly square. If you put the wheel in and align the calipers all is good - until you put the wheel in next time with the axle rotated to a different position. Watch the caliper closely as you close the quick release and you will see it move as the fork aligns to the off square clamping surface. If you can get a cone spanner on the lock nut on the axle, clamp the QR and spin the wheel, if it rubs, loosen it and rotate the axle until you find a position where it runs clear. The only guaranteed fix I have found is through axles. But that needed a new bike.

[Calvin27]

I've always used the wheel on method of aligning brake calipers. Chuck the wheel on and tighten as you would normally. Then hold the brake lever firmly but not super tight and screw the caliper bolts in place. This is from years of swearing at bb7s lol.

[ft_critical]

The problem is unlikely to be the calipers. The problem I have had is that on some hubs the clamping surface on the end of the axles is not perfectly square. If you put the wheel in and align the calipers all is good - until you put the wheel in next time with the axle rotated to a different position. Watch the caliper closely as you close the quick release and you will see it move as the fork aligns to the off square clamping surface. If you can get a cone spanner on the lock nut on the axle, clamp the QR and spin the wheel, if it rubs, loosen it and rotate the axle until you find a position where it runs clear. The only guaranteed fix I have found is through axles. But that needed a new bike.

Thanks Daryl, I will play around as you suggest.

[ft_critical]

I've always used the wheel on method of aligning brake calipers. Chuck the wheel on and tighten as you would normally. Then hold the brake lever firmly but not super tight and screw the caliper bolts in place. This is from years of swearing at bb7s lol.

Thanks Calvin, yes I do the wheel on alignment as well. I took it to Clarence St Cyclery in Sydney and asked them to make it all work together. But as soon as I braked once or twice it all seemed out of alignment. It is not massive, but I can here the brush of the discs against the pads. Honestly, it makes me think I am using precious watts. I am someone who can't really afford to loose even 1 watt.

[trailgumby]

SRAM has not in my view ever made a successful hydraulic brake. SRAM (previously Avid) are subject to a much higher rate of problems and difficulties in use. Bleeding Avid/SRAM mountain bike brakes is typically painful. The press associated with each new SRAM brake release typically talks them up (they need the advertising dollars no doubt), but a few months further on the truth comes out from non-media users in the wild (ie, retail customers) and the news is never good. Duck! can confirm, but the most common warranty fix for SRAM brakes is to install Shimano.

SRAM just don't seem to have their testing act down pat; it always seems like they treat early adopters as crash test dummies, and we saw this again with their initial hydraulic road brake release - pretty much had to be taken off market while they worked out a fix.

Duck! has already described the pain associated with SRAM using hygroscopic (water absorbent) DOT fluid. Shimano "mineral" oil has none of these dramas and is reported to have a higher boiling point than anything SRAM uses anyway.

Shimano by comparison just works. Problems are rare.

It's such a shame. SRAM/Rockshox suspension components are pretty good. It beats me why they seemingly can't translate that success to their brakes.