Review SRAM HS2 220mm Disc

Ian986

Active member
Apr 21, 2021
108
43
Surrey
Product Image:
ACB223E2-7E7D-431B-842D-AAC3A12B8A50.jpeg


Product name: SRAM HS2 220mm Disc
Price paid: 50
Score (out of 10): 1

Review: I bought a pair of these discs just after they came out, I also purchased a pair off code RSC brakes too.

I can honestly say this is the worst brake disc I have ever purchased within in a week started rubbing when hot ! It has got worse and worse it is completely fine when cold soon as it gets hot rubs and squeels

I went in to my local bike shop and they agreed was not right , but because I did buy from them they have to send it back to sram and I have to pay postage to try to get sorted under warranty but would be without a front disc so can’t ride bike. Have to make most of British summer while you can.

i spoke with sram and was a little sympathetic but said have to go back to supplying dealer if they call sram would probably replace it, but has to be done through them. I bought from bike inn as they seemed to be only place that had them in stock at the time , shocking customer service, all you get is automated reply saying send disc back. I sent lots of emails but was not interested. I will never buy from them again.

Here is a link to video of cold disc and hot disc here the noise it makes.



Let me know what you think
 

Jeff H

Well-known member
May 19, 2019
205
200
San Jose, CA, USA
I swapped the Centerline rotors for HS2 on my ‘22 Levo Expert with Code calipers first thing before even bedding in the brakes.
I now have almost 400 miles on the bike and since day 1 no rubbing, no warping, and much quieter than the centerline rotors on my ‘19 Levo. LOVE ‘EM!

Having said that my buddy put them on his ‘19 Levo also with Code calipers and they rub as you described. In his case it might be an installation issue (not retracting the pistons fully) or maybe his calipers need some TLC. My other thought is it has to do with the bite point adjustment on his RSC levers which you also have (my RS levers don’t have that). He hasn’t looked into it yet but I wonder if the bite point adjusters are supposed to be set a certain way when installing new rotors or pads?
 

St4nley

Well-known member
Subscriber
Nov 17, 2020
160
328
Derbyshire
I swapped from centrelines to HS2 also, not impressed at all with them, not worth the money to upgrade.
 

KnollyBro

E*POWAH Elite
Dec 3, 2020
894
2,219
Vancouver
Product Image: View attachment 94161

Product name: SRAM HS2 220mm Disc
Price paid: 50
Score (out of 10): 1

Review: I bought a pair of these discs just after they came out, I also purchased a pair off code RSC brakes too.

I can honestly say this is the worst brake disc I have ever purchased within in a week started rubbing when hot ! It has got worse and worse it is completely fine when cold soon as it gets hot rubs and squeels

I went in to my local bike shop and they agreed was not right , but because I did buy from them they have to send it back to sram and I have to pay postage to try to get sorted under warranty but would be without a front disc so can’t ride bike. Have to make most of British summer while you can.

i spoke with sram and was a little sympathetic but said have to go back to supplying dealer if they call sram would probably replace it, but has to be done through them. I bought from bike inn as they seemed to be only place that had them in stock at the time , shocking customer service, all you get is automated reply saying send disc back. I sent lots of emails but was not interested. I will never buy from them again.

Here is a link to video of cold disc and hot disc here the noise it makes.



Let me know what you think
What kind of pads are you using? What happens if you back off your pad contact point adjuster as your rotor may slightly bent? You could try rubbing alcohol on the rotors to clean them and lap the pads with some 400 grit sand paper on a flat surface. Personally, I use Magura MDR-P 220mm front rotors (they make the coolest "TING" sound when they are cooling down!) and only have a noise issue with rotor squeal when they get wet. They still stop great! I also use metallic pads as ceramic pads wear out way too fast.
 

Ian986

Active member
Apr 21, 2021
108
43
Surrey
I am just using the standard pads that came with the codes. I would like more power but the work well enough for what I do.

The adjustment Bite point is wound out otherwise rubs even more when gets hot.

I have ordered a Magura floating disc hopefully that cures it.

I am so disappointed in SRAM and Bike Inn

Every part of my bike is Sram and rockshox I have upgraded every part, so it is not like a I am a SRAM hater. just want people to know these disc are rubbish don’t waste there money on them.

I did wonder if the heat dispersal paint the use is only on every other arm so maybe that causes the disc to warp
 

Swissrider

Well-known member
Nov 1, 2018
364
382
Switzerland
I’ve got the same set up as you and have had the same problem, with the same irritating noise. I think that the problem is that this disc is thicker than the standard one (I think 2mm instead of 1.8mm) so the brakes are more sensitive to correct adjustment. I have to use a torch and make sure that the rotor is precisely centred between the pads. Also, the pistons need regular maintenance. With the heat generated the gunk on the pistons gets hardened onto the pistons and one needs to carefully extend them as much as possible (I block three of them and extend the fourth) and use lots of brake cleaner and a soft wire brush to thoroughly clean them. I think that the noise is caused by one area of the rotor having more brake pad material deposited in one spot so there is a little more friction, enough to cause the vibration which makes the noise. It’s not that the rotor is warped. You can see that the rotor is straight but at one point it slows down because of uneven brake pad deposits. You might notice that if you drag the brakes very slightly the noise goes away. I have found if you clean the rotor very thoroughly and then re-deposit the pad material on the rotor you can get rid of the spot that causes the problem. I use Swisstop ebike specific sintered pads and these come with comprehensive instructions on how to break in pads and rotors. I know it’s all a bit of a pain but once sorted they work well and the pads last for ages.
 

KnollyBro

E*POWAH Elite
Dec 3, 2020
894
2,219
Vancouver
I am just using the standard pads that came with the codes. I would like more power but the work well enough for what I do.

The adjustment Bite point is wound out otherwise rubs even more when gets hot.

I have ordered a Magura floating disc hopefully that cures it.

I am so disappointed in SRAM and Bike Inn

Every part of my bike is Sram and rockshox I have upgraded every part, so it is not like a I am a SRAM hater. just want people to know these disc are rubbish don’t waste there money on them.

I did wonder if the heat dispersal paint the use is only on every other arm so maybe that causes the disc to warp
Sorry to ask, but can you see a warp in the rotor when you shine a light between the pads and rotate the rotor past them? It seems strange that your brakes have so little tolerance in pad contact area that backing out the adjuster does not provide enough space for the rotor to spin freely between the pads. As @Swissrider has mentioned, it is most likely a piston that is not retracting/pushing evenly and his method of isolating one piston at a time after cleaning the area thoroughly should sort it out. A brake lever bleed after resetting your pad contact point adjuster to the center of its travel could give you some added clearance but if the rotor is not warped, the pad contact area has a tight tolerance and one of your pistons is not moving freely, a different rotor won't solve your problem.
 

thewrx

Member
Sep 4, 2019
187
71
US
I agree on point above that when you bleed your brakes, stick the rotors in the oven for a few min so they are warm (not scalding hot) and then bleed accordingly.

i think this is more an issue with the lack piston travel (aka code brakes suck imo, and the 2 cylinders in the caliper and mc arent matched optimally). Also with thicker rotors and 4 separate pads (helps with deflection=better) alignment is more important as your tolerances are tighter.

I actually like those rotors, for a 1 piece rotor, and normally I dislike everything code/sram when it comes to braking; and the lack of mineral oil just ensures I will never use them ever. Magura FTW! (TRP, XTR, and Hope) are a close second.
 

Alexbn921

Well-known member
Sep 27, 2021
545
508
East Bay CA
A lot of theory's.
Bigger rotors have a larger diameter, so the same angular deflection results in more movement.
Rotor thickness has NO impact on pad distance, unless they are physically max out in the calipers. Yours are not.
Contact adjust rarely if ever sets the pad spacing. Only when the lever engages the transfer port and starts to pressurized the system.
Crappy bearings will let the hub rock slightly causing rub. I swapped out the stock bearings to NSK and it made a significant difference in lateral run out.

ALL rotors come slightly bent out of the box
NO mounting surface is perfectly flat.
Add this together and you need to true your rotors after installation. Perfectly true rotors heat more evenly, don't defect as much and have more room to move. Warped rotors heat the high spots first and rub right away.

A torque wrench is your best bet at preventing heat warping. Make sure that you creep up on full tight to evenly load the bolts and mounting surface.

Make sure that all your pistons are clean and move freely. The best way to do this is to remove the pads and cycle all the pistons several times until they all move smoothly. This needs done even on NEW brakes. Cycling them lets a small amount of brake fluid lube the seals.

For alignment, loosen the caliper and squeeze the brakes. Then tighten the bolts. Next look at the alignment and adjust ONLY 1 bolt on the caliper at a time to perfectly center it.

Your rotor is most likely not defective. I personally don't like Sram rotors.

PXL_20220630_164141049.jpg
 
Last edited:

rod9301

Member
Oct 10, 2020
160
94
US
I’ve got the same set up as you and have had the same problem, with the same irritating noise. I think that the problem is that this disc is thicker than the standard one (I think 2mm instead of 1.8mm) so the brakes are more sensitive to correct adjustment. I have to use a torch and make sure that the rotor is precisely centred between the pads. Also, the pistons need regular maintenance. With the heat generated the gunk on the pistons gets hardened onto the pistons and one needs to carefully extend them as much as possible (I block three of them and extend the fourth) and use lots of brake cleaner and a soft wire brush to thoroughly clean them. I think that the noise is caused by one area of the rotor having more brake pad material deposited in one spot so there is a little more friction, enough to cause the vibration which makes the noise. It’s not that the rotor is warped. You can see that the rotor is straight but at one point it slows down because of uneven brake pad deposits. You might notice that if you drag the brakes very slightly the noise goes away. I have found if you clean the rotor very thoroughly and then re-deposit the pad material on the rotor you can get rid of the spot that causes the problem. I use Swisstop ebike specific sintered pads and these come with comprehensive instructions on how to break in pads and rotors. I know it’s all a bit of a pain but once sorted they work well and the pads last for ages.
What do you mean by. Redeposit the pad material?
 

Swissrider

Well-known member
Nov 1, 2018
364
382
Switzerland
When you get a new rotor you have to break it in, which involves depositing pad material on the rotor. This greatly increases the friction and how well the brakes work - see photo of instructions from Swisstop. If you come to a complete stop during this process there is a risk of depositing a thicker deposit of pad material which will increase the friction at that point so if the brakes are rubbing slightly at this point there is enough friction to cause vibration and the noise. It can go away with time but best solution is to remove all pad material with brake cleaner and very light emery paper and re do the rotors.
E9EC47B9-EBE9-4FE8-BAF0-91555A6A80F7.jpeg
 

Swissrider

Well-known member
Nov 1, 2018
364
382
Switzerland
I forgot to add that pads have to be worn in too, by the same procedure. If you use the pads gently at first there is risk that they glaze over and don’t work well.
 

R120

Moderator
Subscriber
Apr 13, 2018
7,819
9,190
Surrey
I have been running 223mm Galfers for about 3 years now, and have found that firstly when installing new pads you will get a bit of rubbing until everything beds in properly, and secondly that the there is a significant difference in performance based on the fork they are attached too.

I originally ran them on a Lyric, which needed quite a big adapter off the 180mm post mount. I found the brakes went out of alignment often, especially after a hard days riding. One thin that made a big difference was installing torque caps on my wheels. You could feel the effect of the bigger disc twisting the fork under hard breaking, and then you would start to get rubbing.

I then swapped over to a Zeb, which have 200mm post mount as standard, and the difference was night and day. I have only had to realign the clappers when changing pads, and the extra stiffness of the zen means they can handle the forces better.

Long and short is that if you are having issues and are running a RS Fork, I firstly would definitely try torque caps, they are cheap and for me made a noticeable difference, and that on smaller forks especially where a bigger mount is required, I would not bother running them.
 

Ian986

Active member
Apr 21, 2021
108
43
Surrey
Wow lots of replies thank you for all the advice.

To be honest I let the shop work on my bike.
The disc Is Definitely warped. When I got the disc it was fine. It Has got worse with time. Unfortunately trying to video and hold bike up is hard when on the trails.

When the new disc comes in I will get them to check the pistons too.

I have Zebs and do have Touque caps too. The wheels and Hubs are hope which are 6 months old and new calliper discs and wheels all fitted at same time.
 

R120

Moderator
Subscriber
Apr 13, 2018
7,819
9,190
Surrey
Thats a solid set up, would not be expecting the disc to warp unless you are riding like Ameury Pierron every day!
 

Ian986

Active member
Apr 21, 2021
108
43
Surrey
Thats a solid set up, would not be expecting the disc to warp unless you are riding like Ameury Pierron every day!
I am just a normal guy! only riding been riding a year so far from profesional.

I tend use back brake to scrub of speed when going too quick.
 

militantmandy

Well-known member
Jan 18, 2022
399
369
Tweed Valley, Scotland
I've had 2 sets of HS2s, all 4 of which were bent from new to varying degrees. With some patience and a bit of swearing I got them all true or close enough. They've been fine since. However, the Galfer versions are as good if not better and half the price (and only 50% were bent from new!), so I wouldn't buy the SRAMs again.
 

Ian986

Active member
Apr 21, 2021
108
43
Surrey
I am no Sam Hill Maybe because I have his pedals on my bike make me better lol

Here are the trails I ride I am not the slowest but I am no where near the faster riders. I am 50 so hurts when I fall off.

 

Stihldog

Handheld Power Tool
Subscriber
Jun 10, 2020
3,164
4,388
Coquitlam, BC
Good advice here on brake setup and issues.
I have a bit to unpack here since 5 of us use Mt7’s on our Trek Rails. 220mm bolt on rotors f/r but some are slowly changing the rear back to 203mm as the 220mm wear out. I’ve only seen one of those rotors look like a potato-chip but I was able to straighten it out. One guy has the “ting-ting” sound. Another has a squeak. Another sounds like a train. Mine are fine …thank gawd! Another uses one set of pads a year. Most of us use the Magura Performance pad. One guy orders pads from whoever has the best price. I keep 4 sets of Magura Prerformance pads in stock …just in case.
Regarding the beefy Zeb forks; that’s good news. Last week some big rocks scratched up my Lyric upper tube. I was thinking about the 160-170mm Zeb but I want the model that lines up to the steering tube(no step or offset) on the Rail. The Zeb fork sounds like it’s better suited for the 220mm rotor.
(btw…why does it feel like I’m herding cats)😉
 

KnollyBro

E*POWAH Elite
Dec 3, 2020
894
2,219
Vancouver
When you get a new rotor you have to break it in, which involves depositing pad material on the rotor. This greatly increases the friction and how well the brakes work - see photo of instructions from Swisstop. If you come to a complete stop during this process there is a risk of depositing a thicker deposit of pad material which will increase the friction at that point so if the brakes are rubbing slightly at this point there is enough friction to cause vibration and the noise. It can go away with time but best solution is to remove all pad material with brake cleaner and very light emery paper and re do the rotors. View attachment 94344
I am not reading anything that says that pad material is deposited onto the rotor in the instructions you provided. I have always understood the purpose of bedding in rotors and pads to be like lapping to surfaces to create a very smooth and even contact point. The purpose of the slots on the rotors are used to reduce out gassing of the pad compound which causes glazing at high temperatures, to help cool down the rotor thru convection (which is dependent on surface area so slots may be counter productive) and to shave off a small amount of brake pad on each rotation to ensure on "perfect" contact area. Pads glaze when the surface areas have not been properly lapped, which is what you are doing in the bedding in process (as well as heating up the pads to out gass them), and then go blasting down a hill and drag your brakes until the out gassing desposits pad material onto the rotor which can not be cleared off by the slots. This is why rear brake are more likely to covered in a black film of out gasses material compared to front brakes. Riders over use their rear brakes by dragging them causing them to build up more heat. If your rear rotor is just a shiney as your front rotor, you either have good braking technique or you rarely use your brakes!
 

KnollyBro

E*POWAH Elite
Dec 3, 2020
894
2,219
Vancouver
The steel rotor doesn't do any actual braking. It almost 100% pad on pad material transferred to the rotor surface.
I am not following what you mean. If I understand you correctly, rotors would never wear down/out. For instance, Shimano Icetech rotors have an aluminum core with a layer of steel on both sides of the rotor to improve heat dissipation but when the steel wears down (rotor thickness of less than 1.55mm), the rotor needs to be replaced.

rotor.jpg
 

irie

E*POWAH Elite World Champion
Subscriber
May 2, 2022
2,219
2,152
Chichester, W.Sussex, UK
I've had 2 sets of HS2s, all 4 of which were bent from new to varying degrees. With some patience and a bit of swearing I got them all true or close enough. They've been fine since. However, the Galfer versions are as good if not better and half the price (and only 50% were bent from new!), so I wouldn't buy the SRAMs again.

Few weeks ago got a Sram HS2 220mm rotor. When it arrived I checked it by laying it flat on both sides on a dead flat piece of plate glass. The rotor was and still is absolutely true.

Broke it in (front brake) carefully with Discobrakes semi-metallic pads. As said elsewhere, didn't like the noise and performance of the pads.

Cleaned the rotor, cleaned then put Shimano D03S resin pads back into my MT420 caliper, broke it in again, and all good.

* reason I wanted a larger rotor is not because I'm a riding god, but to reduce finger pressure because I have arthritis in my hands :(
 

Alexbn921

Well-known member
Sep 27, 2021
545
508
East Bay CA
I am not following what you mean. If I understand you correctly, rotors would never wear down/out. For instance, Shimano Icetech rotors have an aluminum core with a layer of steel on both sides of the rotor to improve heat dissipation but when the steel wears down (rotor thickness of less than 1.55mm), the rotor needs to be replaced.
All rotors wear. The surface of the rotor holds the pad material that creates the friction. At a microscopic level its not smooth, but has peaks and valleys. There is quite a large amount of pressure and heat at the pad/rotor interface and both make contact with each other causing wear. Metallic pads have much harder material that tends to dig into the surface, while organic does not.
 

Gyre

Well-known member
Jan 25, 2021
629
420
Pasadena, CA
shouldn’t one piece rotors cool faster and dissipate more heat being the same metal? I have a mdrp and it’s heavier than my thicker trickstuff HD rotors. I mean 20 grams doesn’t matter but still.
Yes, but the theory with two-piece rotors is that the thick aluminum carrier should better resist warping (at least up to the rivets).

FWIW, I'm trying HS2s and MDR-Ps. Both of them need truing occasionally. The HS2 is much quieter when it doesn't rub. MDR-P is kind of noisy with its large slots, but doesn't need truing as often. Just some anecdotal input.
 
Last edited:

irie

E*POWAH Elite World Champion
Subscriber
May 2, 2022
2,219
2,152
Chichester, W.Sussex, UK
Yes, but the theory with two-piece rotors is that the thick aluminum carrier should better resist warping (at least up to the rivets).

FWIW, I'm trying HS2s and MDR-Ps. Both of them need truing occasionally. The HS2 is much quieter when it doesn't rub. MDR-P is kind of noisy with its large slots, but doesn't need truing as often. Just some anecdotal input.

How long have you been using a HS2 rotor and how long have you been using a MDR-P rotor? Would be interested to know the frequency with which you have had to true the HS2 rotor and the frequency you have had to true the MDR-P rotor? And are they both front or rear?
 

Gyre

Well-known member
Jan 25, 2021
629
420
Pasadena, CA
How long have you been using a HS2 rotor and how long have you been using a MDR-P rotor? Would be interested to know the frequency with which you have had to true the HS2 rotor and the frequency you have had to true the MDR-P rotor? And are they both front or rear?
About 2 years on MDR-P (originally 220/220, now 220/203) and 6 months on HS2 (220/220). MDR-P needed attention early but after its initial “break in” (a dozen big rides or so) I haven't thought about them much. Front MDR-P currently has a tiny bit of rub (almost imperceptible), back rotor a little worse. HS2 has significantly worse rub and it gets noticeably pronounced after a big descent. Keep in mind that I'm not controlling for confounding differences like piston stickiness, so YMMV.
 

KnollyBro

E*POWAH Elite
Dec 3, 2020
894
2,219
Vancouver
So your rotors make a little noise when they get hot or wet, you can always change your pads to an organic type if it bothers you. I am using the stock Code RSC metalic pads on an MDR-P 220mm on the front and an IceTeck and find the front rotor doesn't make any noice unless it gets wet and the rear, which gets baked all the time (I sand off the baked on black stuff with 150, 220 and 400 grit emery cloth a couple of times a season), will make a little noise when it gets hot. I can live with that as long as its working. Its not like I depend on the rear brake and I probably drag it too much anyways. As for the warping, are they really warping from heat (I don't see how they would only warp in one spot) or are they getting bumped and bending? It not like they are getting any where hot enough and cool unevenly to warp. I am not even sure if pouring water on a hot rotor would warp it.
If you are bored, you can watch a video where they try to cook a rotor.
 

Downhillr

Active member
Jul 2, 2021
255
130
SF Bay, California
I am just using the standard pads that came with the codes. I would like more power but the work well enough for what I do.

The adjustment Bite point is wound out otherwise rubs even more when gets hot.

I have ordered a Magura floating disc hopefully that cures it.

I am so disappointed in SRAM and Bike Inn

Every part of my bike is Sram and rockshox I have upgraded every part, so it is not like a I am a SRAM hater. just want people to know these disc are rubbish don’t waste there money on them.

I did wonder if the heat dispersal paint the use is only on every other arm so maybe that causes the disc to warp
Couldn’t agree more about _ _ _ _Inn (looong story, suffice to say lousy service, no follow-up, thank goodness for bank card coverage).
I swapped to HS2, no problems in nearly a year on them, plenty of long, steep descents as well in CA & Oregon mountains using Code RSC. I’ve switched out pads to MTX “ Gold” versions… better bite, less fade. When pads are cold or cold/wet there is some squeal, goes away after couple stops.
 

EMTB Forums

Since 2018

The World's largest electric mountain bike community.

536K
Messages
26,730
Members
Join Our Community

Latest articles


Top