Al rotor - braking power

[smusante]

Anyone have experience using aluminum rotors? I have Shimano XT brakes - using XT resin pads and Al rotors. First 45 min ride just softly used brakes (as suggested in Stan's info doc), then started to use them... after about an hour still poor braking power, esp. the front brake - would have to really grab it with multiple fingers to get the wheel to stop. Do they just need a longer break-in period? Experience to share? Advice? (when I use regular steel rotors and my reg brake pads the wheels stop on a dime)

[DaveG]

Anyone have experience using aluminum rotors? I have Shimano XT brakes - using XT resin pads and Al rotors. First 45 min ride just softly used brakes (as suggested in Stan's info doc), then started to use them... after about an hour still poor braking power, esp. the front brake - would have to really grab it with multiple fingers to get the wheel to stop. Do they just need a longer break-in period? Experience to share? Advice? (when I use regular steel rotors and my reg brake pads the wheels stop on a dime)


Also, are these new pads or the ones that you were already using? If they're used pads then I'd get a new set (of whatever type is needed) and try breaking them in again.


Just curious though, why Al rotors? That seems like a bad place for al.

Dave

[Nick]

Yikes - Those Alu rotors scare the hell out of me.
I remember a year or so ago seeing someone after a race who was running those. Both his rotors had shattered after a longer DH.

I think the extra grams are well worth it.

[smusante]

Thanks for the replies. yes I'm using special pads with the aluminum rotors. It's getting a bit better the more I ride/use them but still not stopping on a dime. I emailed with the guys from NoTubes and they said to give it more time so I'll be patient.

Yea, Nick, I remember that same incident but I'm not going to riding these rotors in races with long downhills - just for the non-epic sorts of races like those around NoVA, some of the MASS races etc. I've got steel rotors for Michaux and Kyle's races for sure.

If anyone else has experience with these rotors do let me know. Thanks!

[jmblur]

general tip for rotors to break 'em in faster is to slop on some really silty (not sandy) mud (create your own out of trail dust if needeD) and just grind it in there. Works like a charm...

but aluminum rotors? I dunno - brakes are one component I really like a nice high FoS on...

[walsh]

general tip for rotors to break 'em in faster is to slop on some really silty (not sandy) mud (create your own out of trail dust if needeD) and just grind it in there. Works like a charm...

??????? :confused:

[jmblur]

it helps "burn in" the rotor - the extra friction and grinding serves to decrease the break in time.

Using silty mud prevents you from gouging up your disk with sand particles. Clay works just as well. Your disc will look shiny still macroscopically, but the silt will help wear in microscopic roughness that improves your braking.

Its nothing that doesn't happen normally when you "break in" your rotors, it just shortens the time it takes to get to this point.

That said, I've only ever done this with steel rotors - aluminum you might want to just do the traditional way.