Originally Posted by
Kabuto
I've seriously considered swapping out the 160mm front rotor on my Tern Verge X11 for a 180mm rotor for the extra heat absorption, because the 160mm rotor overheats quickly on any serious descent and makes a horrible squealing sound until it gets a chance to cool down after finishing the descent and riding on flat ground for a bit. I never have that problem on a full size road bike with 160mm rotors. Just with 451 wheels that obviously are spinning much faster compared to a 700c bike at the same speed.
The fact that the wheel spin faster has no influence on the amount of heat to dissipate.
The amount of heat to dissipate depends of the weight of the loaded bicycle + percentage and length of descent.
If the 700c bike and 451 bike have the same total weight and ride on the same descent, there will be the same amount of heat to dissipate. Actually, with a well designed rotor, the fact that the rotor spin faster should improve the cooling.
I had also horrible noise, with a Tern with the same Tarsus fork as the Verge X11 and a Magura Storm SL.2 rotor and with other bikes with Shimano Ice Tech rotors. It came from the type of disc mounted, the Magura vibrates and the Shimano Ice Tech have some deformation when hot (which is bigger when the rotor is bigger, my 205mm Ice Tech rotor made more noise than my 160mm Ice Tech rotor), I changed the type of rotor and the noise disappeared.
For the Magura Storm SL.2, I replaced it with a Magura MDR-C and for the Shimano Ice Tech, I replaced them with plain steel Shimano rotors.
The fact that the a rotor can make noise due to vibration and that a specific rotor design can avoid that is explained on the Magura website:
https://magura.com/en/EUR/bicycle_tu..._mdr-c/p/mdr-c
Originally Posted by Magura
Thanks to the stiffening ring, it is also very vibration-resistant and therefore quiet.