Your thoughts on SRAM's new DB 8 brakes

[longpete]

I bought the CANYON striven underdog with DB8 brakes as I wanted my bike black not green. The first 3 rides the brakes worked ok but not good as you have to push very hard in order to get an acceptable brake performance. Yesterday I was the first time in the alps in Grindelwald and I had a horrible experience during a long down ride.... 1st you get spasms in fingers and arms when you have to squeeze the brakes. After 2/3 of the down ride my back brake lost completely the pressure and I was lucky that on the right side was only gras as I turned right with 50 Km/h and jumped off the bike... nothing haamppend to me beside some minor blessings... the brake pressure was completely soft for 1/2 hour and came back partially again. It is a brandnew bike with brandnew brakes. This brake is dangerous and not constrcuted for Enduro or Downhill EMTB.... I will exchange my DB 8 brakes against Shimano, Magura or Acura... need first to study the latest test. SRAM DB 8 is dangerous and you risk ur life with it.

System weigth? Diameter rotors? Did you bleed the brakes? Possibly brake pads glazed. How did you use the rear brake?

 

[longpete]

To balance such negative report, and because Internet attracts more negative comments than neutral/positive, I leave my comments from last 800km with this brakes on similar ebike:

The longest descent I've tried is around 1000m descent over 9,5km, and never had any problems with the brakes.
[Meaning "no problems", as: vague bite position, lack or changing locking power, lever pressure.
I do have a problem, and already comment on it, that is basically pad drag! It's really annoying!]

The only problem, is that rear brake pads have almost no meat left, and had to change front pads to rear brake and vice versa until the new sintered arrived. This was around 700km.

Until now, no bleed needed.
Lever hasn't move, besides the normal adjustment due to pad usage.
I live at low altitude (around 30m) and ride the ebike up to 1200m high. Highest altitude was around 1300m something
So no high altitude things (Over 2500m, when you really start to notice changes on everything).

From what you describe, it would be wise to have a bleed on both brakes, but I wouldn't bail out, and would just pump it until I had some pressure (so many times happen to me, on Shimanos old design...).

But I understand that if you don't have confidance, change is required!

Pad drag is worse than Magura MT 5. Rotors are too light.

 

[Mario Antony]

Pad drag is worse than Magura MT 5. Rotors are too light.

Yes, disks could be thicker...

Side note / opinion:
In coming years we'll have thick rotors (probably between 2.5 and 3mm. Motos have >4mm!).
This will help on long descents, and also probably we'll be riding 240/250 front and 220/230 rear.
Hope this "upgrade" comes without speed limit and the 25kg weight limit that some think it's heavy on full power emtb.

These beasts (full power) aren't bikes/mtb, and the sooner people move on and actually embrace the Full Power Ebike stuff, manufacturers will start selling actual emtb full power machines (double crown/real brakes/internal gear box/around 80/100km range in middle settings).
But for the moment, nothing like embrace and enjoy what's available

 

[barry162]

I have contacted yesterday Canyon and they want to analyze the brakes as they want to find out the root cause of it... which is the right way as it also could be an assembly error or a material error... they said, they will exchange the brakes and send my one to an lab. Canyon said this for them necessary as they have to understand if this was a single case or if it was systematic failure.

 

[RiderOnTheStorm]

I have contacted yesterday Canyon and they want to analyze the brakes as they want to find out the root cause of it...

@barry162 thanks for sharing your experience! Curious to hear what the manufacturer says about it. Keep us posted!

 

[COrider]

I have the DB8’s on a new Orbea Wild and so far they are good. They aren’t very refined looking but I don’t much care about that. They don’t have the same power as shimano XT’s which is the only thing I have to compare them to, but they are better than I expected.

I’ve only put 25 miles on them so I’m uncertain how they will hold up. I intend to get out to a trail with much longer sustained descending on Friday. I’ll report back on how they handle it.

 

[COrider]

I got a good ride in on the DB8’s today. Right at 3000 feet/914.4 meters of climbing/descending with multiple hits in the mid 20 mph/32.18 kph range and a top speed of 28 mph/45 kph. The brakes honestly did really well. No noticeable fade and I feel like they modulate decently well and allowed for some late braking coming into the corners when traction allowed. So far so good. For the sake of providing all info I weigh about 160 lbs/72.6 kg ready to ride. I’ll keep updating as I get more time on them.

 

[COrider]

Couple more rides and I’m experiencing some pad drag. I’ve re-centered them twice but as soon as everything starts to heat up it shows back up. It seems like 200mm rotors may need to be thicker? I’m just guessing on this.

My test period with these brakes is quickly coming to an end. I have new wheels coming with 6 bolt hubs and I will need to buy new rotors. I’m thinking of making the switch to new brakes with the new rotors. Not because the DB8’s are bad brakes. Mainly because I have no self control when it comes to bike parts.

 

[COrider]

Ok, one more report on these brakes. I got a long ride in today and they are really solid. I have the rotors centered much better. I was getting a tiny bit of contact on the rotor but it only occurs when everything is hot after extended stretches of descending at speed. I believe the rotor is warping a tiny bit from the heat and brushing the pads. As soon as they cool down a bit they are back to good.

I wanted to elaborate on that because before I mentioned “pad drag”. That almost implies that it’s due to the caliper and it’s definitely not. These are really solid brakes as far as I am concerned.

I’ll be able to compare them soon to the Hayes dominion A4’s that showed up with the fed ex truck today. They certainly aren’t necessary as I really like the DB 8’s. When I ride my bike I’m always amazed at how perfect it is. When I’m not riding my bike, I’m feverishly researching the internet looking for the perfect next part that I don’t really need.

 

[wenna]

Ok, one more report on these brakes. I got a long ride in today and they are really solid. I have the rotors centered much better. I was getting a tiny bit of contact on the rotor but it only occurs when everything is hot after extended stretches of descending at speed. I believe the rotor is warping a tiny bit from the heat and brushing the pads. As soon as they cool down a bit they are back to good.

I wanted to elaborate on that because before I mentioned “pad drag”. That almost implies that it’s due to the caliper and it’s definitely not. These are really solid brakes as far as I am concerned.

I’ll be able to compare them soon to the Hayes dominion A4’s that showed up with the fed ex truck today. They certainly aren’t necessary as I really like the DB 8’s. When I ride my bike I’m always amazed at how perfect it is. When I’m not riding my bike, I’m feverishly researching the internet looking for the perfect next part that I don’t really need.

If you want a bit more distance between the pads and the rotor you can bleed the brakes using a little thicker bleed block.

 

[COrider]

If you want a bit more distance between the pads and the rotor you can bleed the brakes using a little thicker bleed block.

That’s a neat idea. I would imagine the thickness of an old bank card combined with the bleed block would do the trick.

 

[R3Z3N]

Modulation for me : the further the lever is pulled the more power comes. No modulation: you just have to pull the lever harder with more force but the lever is not really moving, just pulled harder. Dosing is very difficult. I have big hands and like two finger levers. DB8 has modulation, al lthe magura's have (prefer MT5 but also ride MT4 and MT7 and even the Louise Fr is stil a nice break). Also have XT, sometimes unpredictable. Winter breaks : the price of shimano brake pads is very good. DB8 : was going to replace them with mt5(had an extra pair lying around) but decided to keep them. Curious about the rotors longevity. Sram's weak point. If they don't come wit the bike (so you have to pay for them) SLX and certainly MT5 are a better choice in my opinion. Don't know the price point of Magura in the US. In Europe set MT5+180 mdr rotors+adaptors les than 150 EUR.

Actually both are wrong to an extent. Modulation is the feeling from initial pad contact to full lockup, and how that power ramps up (or back). Little modulation means it is harder to control little applied brakes to full lock and vice versa. Handfuls of modulation means it is easy to control how much brake force feels to be applied. Pad choice matters heavily here.

This is NOT defined by the lever pull distance. In a perfect hydraulic system, from initial pad contact to full lockup, the lever will not pull further. Sadly due to orings, pad compression, brake master flex, caliper flex and hose expansion, we have quite a bit of lever pull AFTER initial pad contact.

However, the human body is terrible at feeling distance, but rather much more superb at determining differences in force required for an action.

Changing pads will be the easist method to change modulation. However, to get more POWER means using smaller master and/or bigger caliper pistons at the con of giving the rider LESS resolution to feel the difference between initial pad contact and lockup. This is exactly why Codes/DB8s have so much modulation feel: because they are down on power and we have to pull MUCH MUCH harder with 1 itty bitty finger that can only pull 59.5 ± 21.4 N. Then that also means brakes like the Trickstuff Maxima, Hope Tech 4 V4, Hayes Dominions give LESS resolution due to the human factor. As stated by these 3 companies, reducing friction and pad choice is huge in giving modulation feel back to the rider.


This is why race cars use manual brakes and are designed to have an input of ~350lbs of force, and cars sold for the road 60lbs. I can control my race car brakes MUCH more, though physical exertion is high enough that I have to workout my legs just to stop the car. Comparing that to my autocross stock car with assisted brakes, much less resolution to get maximum braking potential, but much physically easier to push my leg in, meaning for more chance to get it wrong. The reason we choose higher power brakes, is not for the modulation, but because our itty bitty fingers get super tired and need a beer to open.

 

[R3Z3N]

If you want a bit more distance between the pads and the rotor you can bleed the brakes using a little thicker bleed block.

However shortly after riding due to piston rollback, it will be as if one bled the brakes with the thinner rotor instead of thicker bleed block. This is why we have reservoirs with bladders, as the pads and rotor wear, bite point should in theory stay consistent. However as they approach extreme ends of wear, the pistons extend further and are supported less by the caliper block, which cants the pistons ever so slightly upon braking, causing the rider to feel less modulation. Also, heat soak then may start to be a problem for rotor, pads, pistons and caliper body. (as is the case for Codes....)

 

[BIG-DUKE-6]

Maybe bike manufacturers started using Sram's DB8 this year as an alternative option (to shimano for example) due to supply chain shortages.

Looks like major bike stores (in europe) are selling these DB8 brakes as well.

I believe this is accurate

 

[BIG-DUKE-6]

Here is a 200 mile update on my DB8s
I’m 220 5-11” and am riding an Orbea Wild with the 750 battery.
My average XC speed is usually right around 13 mph so these brakes are getting a workout. Once I got the rotors bedded in it took 2 finger squeeze to get the tires to lock up. Now at 200 miles the brakes have gotten noticeably squishier and it takes a full squeeze to get the tires to lock up . I think this is a good brake system for the lighter XC/Enduro rider. For the bigger/ e-bike/ both like me. You might want to step it up to a more powerful system. Super cross lol

 

[Stihldog]

I was directed here by @Dax for some more information on the DB8’s.

This brake system came standard on a new Fuel EXE 8. My initial intention was to change these to MT7’s. (Full disclosure, I only have experience with MT7’s, MT8’s , Shimano XT, and some Tektro).

I’m glad I had an opportunity to use these DB8’s before I read the pros and cons in this thread. Good info btw. I was skeptical of the Sram braking system, especially for these mid to low-end brakes. (I mean affordable $$).

However after using them, and getting use to them, I found the power and modulation fairly good for a lightweight eMTB. I’m gonna keep these, but I wouldn’t install a set on my FF Rail. I might find that the stopping power and effortless feel just isn’t there. But I like the DB8’s on my lighter eMTB (Fuel EXE).

But…SRAM might be coming out with a new (heavy duty I assume) brake model in the next week or so. Either that or my source is unreliable. (Some guy that knows about this stuff).

 

[Mario Antony]

I was directed here by @Dax for some more information on the DB8’s.

This brake system came standard on a new Fuel EXE 8. My initial intention was to change these to MT7’s. (Full disclosure, I only have experience with MT7’s, MT8’s , Shimano XT, and some Tektro).

I’m glad I had an opportunity to use these DB8’s before I read the pros and cons in this thread. Good info btw. I was skeptical of the Sram braking system, especially for these mid to low-end brakes. (I mean affordable $$).

However after using them, and getting use to them, I found the power and motivation fairly good for a lightweight eMTB. I’m gonna keep these, but I wouldn’t install a set on my FF Rail. I might find that the stopping power and effortless feel just isn’t there. But I like the DB8’s on my lighter eMTB (Fuel EXE).

But…SRAM might be coming out with a new (heavy duty I assume) brake model in the next week or so. Either that or my source is unreliable. (Some guy that knows about this stuff).

Are those HD brakes to be used with DOT or "olive" oil?

 

[Stihldog]

Are those HD brakes to be used with DOT or "olive" oil?

Hahaha …no. The new sram brakes use mineral oil. The mineral oil has a green tint …apparently.
Blue tint or royal blood is Magura
Red tint is Shimano.
All mineral oil. Not baby oil.
Dot fluid has a short shelf life.
Olive oil is good on salads.

 

[arTNC]

Are those HD brakes to be used with DOT or "olive" oil?

Olive oil...just like Shimano. What I've always like about this oil is the ability to pull over to the side of the trail on a long ride, break out my backpack stove, and boil up a little pasta using this fine, quality olive oil. Very healthy and refreshing on a long ride.

But seriously, I'm finding the same results as Stihldog. I was disappointed at first as my Rail 7 is supposed to have a lower level set of Shimano 4-piston brakes which I know from experience work quite well. I also have XT 4-piston brakes on another big hit emtb.

This was traced back from our shop to Trek that it was a supply chain issue. My Rail is a Gen 2 2022 model. However, after riding with these brakes for a few weeks at least every other day...my main local trail is only 10 miles from my home...I'm decently impressed. I ride aggressively in Bosch Turbo mode with a VOLspeed tuning unit, and we have a few fast, longer, steep descents. No fade, no squeal, no change in level travel, and no great effort on the levers for full power. I haven't found an issue with them yet.

Hopefully this weekend I will be riding this bike for the first time out at our off road club ranch where we have all kinds of off road events, and it has about 100 miles of single track. While this part of Texas isn't the Alps or the Rockies, it has some gnarly, fast descents off of very tall mesas. So this will be more of a test for the ultimate performance of these brakes.

 

[Mario Antony]

Olive oil...just like Shimano. What I've always like about this oil is the ability to pull over to the side of the trail on a long ride, break out my backpack stove, and boil up a little pasta using this fine, quality olive oil. Very healthy and refreshing on a long ride.

But seriously, I'm finding the same results as Stihldog. I was disappointed at first as my Rail 7 is supposed to have a lower level set of Shimano 4-piston brakes which I know from experience work quite well. I also have XT 4-piston brakes on another big hit emtb.

This was traced back from our shop to Trek that it was a supply chain issue. My Rail is a Gen 2 2022 model. However, after riding with these brakes for a few weeks at least every other day...my main local trail is only 10 miles from my home...I'm decently impressed. I ride aggressively in Bosch Turbo mode with a VOLspeed tuning unit, and we have a few fast, longer, steep descents. No fade, no squeal, no change in level travel, and no great effort on the levers for full power. I haven't found an issue with them yet.

Hopefully this weekend I will be riding this bike for the first time out at our off road club ranch where we have all kinds of off road events, and it has about 100 miles of single track. While this part of Texas isn't the Alps or the Rockies, it has some gnarly, fast descents off of very tall mesas. So this will be more of a test for the ultimate performance of these brakes.

For the type of descents I have over this side, I find then more than adequated - as writen on previous posts.

And being fair, brakes only have to stop ±100kg at less than 60km/h.

I need to find out piston diameter on Db8 lever & Shimano's lever.
Would like to try a pair of Shimano levers (Shimano SLX M675) I have in the garage collecting dust.

 

[Jamie78]

For what it's worth, I've had the db8s on a couple bikes now and on my new heckler.

I tried switching to Shimano levers and found they are way more powerful, but less modulation.

I don't mind then, but prefer a bit stronger engagement. I'll likely add Shimano levers again as they came with my heckler.