Trek Allant+ 9.9S Front Rotor - 203mm?

[Kraveylicious]

I’ve got a Trek Allant 9.9S which has a carbon fork. It comes stock with 180mm rotors front and rear. I’m planning on upgrading the front to 203mm as I have a very long, steep downhill to get out of my neighborhood and I often have a hard time stopping safely at the bottom. It’s not uncommon for me to blow through the stop sign simply because the 4-piston 180mm brakes don’t have enough power (much squealing can also be heard). I’ve also already swapped to metallic pads for better stopping power.

Is there any concern with running a 203mm rotor on a carbon fork that originally came stock with 180mm (no adapter required for 180mm)? Bike + rider + gear is about 250 lbs.

 

[fooferdoggie]

You should have better braking than that. I can stop without issue on 22% grades. Our tandem we need 203 as it’s about 400 pounds.if they are squealing then you need to clear the rotors and maybe the pads. They could be glazed

 

[Kraveylicious]

You should have better braking than that. I can stop without issue on 22% grades. Our tandem we need 203 as it’s about 400 pounds.if they are squealing then you need to clear the rotors and maybe the pads. They could be glazed

I've checked the pads, sanded them down, sanded the rotors, cleaned both with alcohol. The pads look ok when I take them out to clean them. The rotors don't have any discoloration from excessive heat. So if its not the rotor, then maybe the Shimano MT520 calipers aren't up to the task.