After 10 years and over 15,000 km of commuting in all weather conditions, I’ve tested both the Shimano BR-M375 and the Zoom DB680.
One of them nearly left me without brakes on a downhill. The other has been running for 6 years without a single cable failure.
If you're considering mechanical disc brakes for commuting, here’s what actually matters.
Why I chose mechanical and not hydraulic?
The bike came with integrated brakes / shifters. I wanted to update from V Brakes for a very simple reason and is not the lack of power. I ride my bike in all seasons and in all kinds of weather. In the rain rim brakes eat aluminum rims like cake. Fed up by this I decided to switch to disc brakes.
Because I didn't want to change the shifters on the bike (they are combo unit brake - shifter) instead of getting hydraulic I went the other route and go mechanical brakes. I didn't purchased the Avid BB7 as it was not easy to get at a decent price. It was more expensive than hydraulic systems, and I felt it was not worth it. I could just get for the same money new hydraulic brakes + shifters.
My first contact with mechanical disc brakes was in 2016 when I installed the Shimano Altus BR M375. After 4 years and 8.400 km I switched to the Zoom DB680 in 2020.
In total I ran the two systems for 10 years and 15.400 km. Because of this I feel I have enough experience to say the good and the bad. Shimano was on the bike for 4 years and 8.400 km while the Zoom DB680 is still on the bike after 6 years and 7.300 km and counting.
My experience with Shimano M375 caliper after 4 years and 8400 km
Shimano BR M375 like most mechanical brakes on the market has only one moving piston and a fixed one. To compensate for pad wear you can move inward the fixed caliper. But when the pads are worn in this is not enough, as the distance between the moving piston and the rotor is high, and you have a lot of travel without engagement. The second option is to reposition the caliper and do the adjustment from the fixed piston. I had to do a lot of readjustments and sometimes it was not enough. So to limit the number of times I had to move the caliper I shortened the travel of the piston (clamping the cable higher). But this caused another very annoying issue, cable snaps. Because the construction of the caliper and the way the position the cable gets when the pads are worn causes the cable to bend repeatedly and finally it snaps. Clamping the cable higher exacerbated this issue. I had enough of this cable snaps as I was changing one almost every month and at some point while descending a hill I felt the cable snapping and the travel of the lever extending as more and more strains would snap. I managed to stop but the entire back brake had only 2 strands left.
Even though the brakes are robust and powerful the disadvantages were too big for me.
I researched dual piston mechanical calipers. At that time locally there were not many options, at least not my budget, so I bought the Zoom DB680 dual caliper from Aliexpress.
Zoom DB 680 after 6 years on the bike and over 7.000 km
I was always very hesitant about Chinese brakes and I did a bit of
research before buying them. My biggest concern was the reliability of
the system as it is extremely important to have a reliable braking
system.
One thing that speaks for itself, the brakes are durable and reliable. Even though I had doubts at the beginning about this topic, longevity and reliability.
My first experience with them was mounting on the bike. This was not an experience without issues. I had to file one of the calipers clamping holes as it wasn't aligning properly with the disc. Not a good start. Also there was not that much material that could be removed, so I filed carefully.
But after installed they worked really good. Comparing the braking with the Shimano caliper the action is very different.
First, they have a lighter action, you don't have to exercise as much force in the brake lever.
Second the braking is not as powerful as the Shimano, but plenty enough. And the delivery of the brake force is much more linear and forgiving. Even if you grab a lot of front brake it won't throw you off the bike, they have a progressive feel. For extreme stuff probably they are not a good option, but for most people and especially for commuting I think this is a very good thing.
For example with the Shimano I had to pay attention to my braking so I would not lock the back wheel. With the Zoom DB 680 is much harder to do it. If you grab a lot of brake you can feel how it increases progressively the braking force and when you are at that point you can back off just a little tiny bit. Many would say that this is a weak brake, and they would be right, but I think it is absolutely genius. Of course the experience might vary, I am a heavy rider 90kg + bike + occasional baggage well over 100 kg total mass.
Since switching to the Zoom I never had a cable snap on me again.
Dual piston mechanical brake are better than single piston ones. Adjusting the brakes is much more easy to do. You will need an allen key, I would prefer to be able to do this without tools but for the price you can't ask for everything. Being able to adjust the pads without a key would be awesome, even on the side of the road... (but on the other hand the BR M375 uses an allen key as well).
Both pads can be adjusted independently so once you put the caliper on position you never have to readjust it. Both pads move in grabbing the rotor the same time, making the pad wear more equal. But I found that sometimes after adjusting the pads they would back off a tiny bit giving more travel in the lever. To address this I took them out of the caliper and placed thread locker on the threads. This solved the problem but it was not easy getting them back in position.
The brakes have barrel adjuster, combined with the adjuster from the shifter you can run the brakes quite a lot before needing to adjust the pads.
Another plus is that the caliper uses the Shimano pad, which is very popular and easy to replace.
Final verdict on Zoom DB680 caliper
If for some reason you don't want to have hydraulic brakes, and you mainly use your bike for commute or for casual riding, then yes. It is a perfect brake for this kind of riding.
It works, it is progressive (i consider this a huge benefit, to grab a lot of front brake and fly over the bar), reliable I had it for 6 years and over 7000 km and it is very affordable. Back in 2020 I payed for a set of calipers 23€ or 26$. Of course the prices increased but they are reasonable. At the time of writing this post I could find on Aliexpress 2 calipers + 2 rotors price including shipping 39€ or 45.5$. It uses the Shimano bs01 pad which is easy to replace.
Quick comparison table
| Shimano BR-M375 | Zoom DB680 |
|---|
| Piston action | Single | Dual |
| Power | High | Moderate |
| Modulation | Aggressive | Progressive |
| Maintenance | High | Low |
| Cable issues | Yes | No |
| Best for | Easy XC | Commuting/Recreational |