Tom A. wrote:
BigBoyND wrote:
longtrousers wrote:
10 years ago when disc brakes starting to appear more and more I read an article where overheating of discs was discussed. At the time that was a problem: sandwiched discs where the adhesive layer would melt in descents. Is this with disc-brakes still an issue: overheating on long steep slopes when being heavy (I weigh 190 lbs) or have the discs become better in the last 10 years. How is it with the diameter of the discs: can you mount smaller or bigger discs when needed.
Never heard of the issue you describe, or even the use of adhesives, vs all-metal construction. Brake rotors may be new to bikes but they have existed in motorcycle applications for much longer.
The overheating danger comes from boiling your brake fluid, not damaging rotors, which may warp but won't fail before the fluid boils. Larger rotors will absorb and dissipate heat better, but enough to make a practical difference.
You can fit different rotor sizes with adapters, to a point. On road/tri frames it is usually limited to 160mm or 140mm. You shouldn't get in trouble with 160mm unless you weigh a lot and drag tour brakes down a long descent. There may be some spacers you can buy to fit larger rotors but it really isn't necessary. The main benefit to larger rotors is brake leverage.
The issue is with Shimano Ice-Tech rotors, in that the aluminum center of the steel-aluminum-steel "sandwhich" reaches a point where the material becomes thixotropic (not melted, per se, but more like a "jelly" state). Tour Magazine in Germany was able to get them to fail...and quite spectacularly, as well IMO. Of interesting note is that the rim-braked bike actually was navigating the course faster than the disc bike...until the disc failed during the simulated "panic stop"...doh!
Thanks that was the article I meant. So not adhesive as I remembered wrongly, but aluminium in the center of the sandwich. Anyway, maybe those discs have been improved in the meantime.
Last edited by:
longtrousers: Oct 20, 22 22:09