RMD,
Can you send me a picture of your brake lever? I want to see what Orbea supplied with your H15. During covid, Orbea was switching brake parts due to Shimano supply problems. I want to confirm you have the BL-M6100 Deore brake lever.
I see that you reside in the USA. Do you reside near Orange County California? If so, I'd be happy to check the bike out in person.
Okay....let's work the problem:
Looking at your pictures, I don't see any obvious "In Your Face" issues. The pads look okay. The caliper adapter is orientated correctly. The brake rotor looks good. Everything should work.......but it's not.
We can agree that the horrible hammering noise when you apply the front brakes is not normal. Something is hitting, grabbing, and jerking when you apply the brakes. The million dollar question, what is causing it?
1) I know from personal experience that it's very easy with the Fox 36 fork, to push the caliper adapter over a bit too far, towards the rotor. This may cause either the caliper or the adapter to make contact with the brake rotor rivets. When riding and or coasting you won't hear a noise. However, when you apply the brakes, the caliper pistons may be pushing the rotor over enough to make contact with the caliper adapter or brake caliper.
Remedy: Remove the two caliper bolts and carefully examine the caliper adapter and the brake caliper. Look for any shiny spots on the adapter or caliper which will indicate one or the other is making contact with the rotor. Re-install the caliper bolts. Insure the caliper adapter is pulled as far as possible away from the rotor. Re-center the brake caliper over the rotor and tighten the bolts. Visually inspect everything as you spin the front wheel to see if the caliper or adapter is too close to the rotor.
2) Examine the outer edge of the brake rotor. Feel it with your fingertips. Does it feel smooth? Is there any scoring, scratches, or burring that you can feel on the leading edge of the brake rotor? If so, your rotor may be bottoming out against the caliper. This is a long shot, but it's possible the caliper adapter or fork post mount may be machined too short by a millimeter or so. This will cause the caliper to not be spaced out high enough to clear the rotor. I recognize this is a long shot and you would likely hear a rubbing noise while spinning the front wheel, but we are trying to eliminate potential causes.
Remedy: If you feel scratches or burring on the leading edge of the rotor and consistent with bottoming out against the caliper, you will need to first measure the caliper adapter with a Vernier Caliper. Compare your measurement against the caliper adapter you have used to space out the rear brake caliper. If both adapters are the same, then you may have an issue with the fork's post mount not being machined correctly. You will need to use a very thin shim/washer to space the caliper out enough to prevent the rotor from bottoming out. This is highly unlikely, but I've encountered it before.
3) Confirm, that the 203mm RT-EM600 rotor which you mounted on the rear is braking smoothly with no hammering or noise issues? Yes? No?
If the RT-EM600 rotor is working fine, then this leads me to suspect that the 203mm RT-MT800 Ice Tech front rotor is possibly not playing well with the Deore two piston front caliper or possibly the G05S-RX brake pads. You may need to switch to the much softer GO3S-RX resin brake pad.
There is an easy way to confirm if the Ice Tech rotor is conflicting with the caliper. Swap the 203mm RT-EM600 rear rotor with the RT-MT800 front Ice Tech rotor. They are both 203mm rotors so no switching of caliper adapters is required. I realize the motor won't work with the magnet missing from the rear rotor. You don't need the motor to pedal down the street and test the front and rear brakes.
After switching both rotors, pedal down the street and test both the front and rear brakes. Has the noise disappeared? Has the hammering noise now migrated to the rear brake? Is the front brake still making a hammering noise despite having switched the rotors?
Shimano's compatibility chart for the BR-M6100 caliper states the Ice Tech RT-M800 brake rotor is compatible with the M6100 two piston caliper.
However, when you look at the specification chart for the M6100 caliper, Shimano recommends that the RT54, RT56, RT64 or RT66 be used. These four rotors have a narrower surface band as compared to the Ice Tech rotor. My guess is that the two piston caliper may not provide enough braking pressure to grab, hold and stop the larger surface area of the Ice Tech. I'm not a friction engineer, so this is just a guess. Regardless, Shimano recommends that the above four rotors be used with the two piston Deore caliper. I do know that four piston calipers provide more braking pressure as opposed to two piston calipers.
Do you still have your original RT64, 180mm brake rotor that came on the front of your bike? It would be interesting to see what happens when you remove the 203mm caliper adapter and mount the 180mm rotor back on the front wheel. Does the hammering and jerking go away?
In the picture of your front brake caliper, I did note that the cup and cone washers on your caliper mounting bolts are reversed incorrectly. Below is a Shimano diagram showing how the cup and cone washer should be orientated in relation to the caliper bolt. The cup and cone washers allow the caliper to pivot and be tightened down to an angle so that the brake pads are square and true to the face of the rotor. While it's unlikely, it's possible the reversed washers could be binding and are not allowing your caliper to be set true and center to the brake rotor. It's a real long shot, but what the hell, it's something to look at.
Here are the brake specifications for the 2022 Rise H15. You will note that Orbea offered a 203mm rotor upgrade option which included four piston M8120 XT calipers. I have to wonder if it's possible much of your hammering problem stems from the Deore two piston caliper not providing enough braking pressure to fully stop and hold the 203mm rotor when hard braking the front tire? The hammering may be the caliper releasing and trying to grab and hold the 203mm rotor???
I realize everybody has a budget and you can only do what you can do. However, if you have the financial resources, I very much encourage you to ditch the two piston Deore calipers and go with Shimano's four piston "BR-MT520" caliper. The BR-MT520 caliper is the
exact same caliper as the Deore BR-M6120, but is matte black in color. The BR-MT520 is a direct bolt on and requires no modification to your Rise. The BR-MT520 caliper can be purchased for about $55 per caliper. With the Black Friday sales kicking in, you can likely pick up the calipers even cheaper. Four piston calipers will offer a better braking experience.
As a side note, one of my riding partners has a Rise M20. We mounted 203mm rotors on the bike and Shimano BR-MT520 four piston calipers. We kept the stock Deore brake levers. My buddy weighs 260 pounds. He has no problem stopping his Rise, even on technical chunky downhill.
Shimano Deore BL-M6100 brake lever
Shimano Deore BR-M6100 two piston caliper. Your Deore caliper is an "OEM" manufacturer only version without the Deore labeling.
Deore BR-M6120 four piston caliper at $70.
Shimano BR-MT520 four piston caliper at $55.
Conclusion:
After trying the above suggestions, let me know what your results are. We can go from there. As I mentioned above, if you live in or near Orange County, I'm happy to work on and help you out with your braking issue. Send me a private message and I'll give you my address.
Be safe,
Rod
