Juicy 7 Help

[akern2]

Alright everyone,

I have a set of Juicy 7's on my bike and recently got a new, larger rotor for the rear. I installed and "adjusted" (squeeze lever while bolts are loose, then tighten bolts) the brake. Now i'm getting stopping power, but it's bare minimum. The pads don't seem like they are grabbing the new rotor at all.

What i think is going on its that the rotor hasn't had a "groove" formed in it yet so the stopping power at a minimum.

Any thought or suggestions? Do i need new pads? Could this be completely done and worked out by Saturday? (my life sorta depends on it cause i'm shuttling on saturday)

Thanks,
John

Edit: I got a Roundagon rotor in 185mm, prior rotor was a G2 Clean Sweep in 160mm.

[atlantis]

You did change the mounting bracket right for the new rotor size?

I suspect it could also be breakin on the new rotor also, when I put on my latest J7 upgrade it took a good 20-30 solid stops for breaking to really maximize.

[akern2]

yeah, i have the right mounting bracket.

I'm going to swap the rotor for the G2 clean sweep. I've talked to the guys over at G-town cycles and they'll gladly do that for me. (i would suspect them to cause i bought the rotor there).

[DaveG]

yeah, i have the right mounting bracket.

I'm going to swap the rotor for the G2 clean sweep. I've talked to the guys over at G-town cycles and they'll gladly do that for me. (i would suspect them to cause i bought the rotor there).

I'd sand the pads lightly and then clean w/ alcohol, then ride them. It will take a few good stops to bed in.

[langer]

I'd sand the pads lightly and then clean w/ alcohol, then ride them. It will take a few good stops to bed in.
Yup. Find a steep hill and do a few hard stops...not such much to send yourself otb though! :D After sanding the pads and cleaning rotors with alcohol, the stopping should get better with each run. That's what I did when I switched out my front to a 185...made a world of difference on my 29er.
-jon

[tuba_transport]

I'd sand the pads lightly and then clean w/ alcohol, then ride them. It will take a few good stops to bed in.
brake cleaner on the pads or cook them over an open flame holding them with pliers to cook off whatever got on them

[sevenforty]

I have a set of Juicy 7's on my bike and recently got a new, larger rotor for the rear. I installed and "adjusted" (squeeze lever while bolts are loose, then tighten bolts) the brake. Now i'm getting stopping power, but it's bare minimum. The pads don't seem like they are grabbing the new rotor at all.

You can try the playing card trick too. Just stick some some playing cards or index cards between the pads and rotors and run through what you previously did. I generally have good luck aligning the pads / rotors this way.

[rsosborn]

What i think is going on its that the rotor hasn't had a "groove" formed in it yet so the stopping power at a minimum.


i'm not a bike disc expert but on motorcycles and sport cars, this is the case.
if you see a car with very open wheels (or spokes) and see the disc, there's grooves from variances in rotor/pad density. most car/bike shops will only replace pads and rotors at the same time, or at least re-face (turn) the rotors, so they seat against new pads.

like i said, i'm no bike guru. i guess you can replace bike pads and bike rotors seperately. i would think it would take a hell of a break in period to get the faces adjusted to each other and any real friction back.