# Is "rotor rub" under turning or hard pedaling common?



## sgtrobo (Aug 19, 2014)

So the bike:

2012 Salsa Fargo (with road BB7s, 180/160mm F/R)

me:
*picture of 255# chubby former powerlifter*

I hear a heavy rotor rub under the following circumstances:

1. when I start to ride, I put my left foot on the left pedal and pedal once to get going, then swing my right foot over the bike. I hear heavy rotor rub until I'm centered on the bike, then it goes away.

2. When I turn corners and lean into the corner, I'll hear some obvious rotor rub.

3. when I stand and hammer. this agitates me because I go through a lot of heavy gravel on the way to work during my commute (well, I purposely go through the gravel, but dammit it's fun!) and it frequently requires some hammering to power through

4. When I have done many miles or finished a climb, I will stand with pedals at 6 and 12 o'clock, alternating with my left foot at 6 o'clock, then my right foot at 6 o'clock, to stretch out all my stuff. Definite rotor rub

I've tightened the QR as best as I can, taken many steps to ensure that the wheel is centered. I don't think anything is out of true because it doesn't make that noise when I'm NOT in those situations (i.e. just pedaling along in a straight line)

now it seems that I'm causing an inordinate amount of wheel flex, or is it possibly something else causing this deliciously agitating noise?


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## andrewkissam (Jan 3, 2014)

Wheel flex shouldn't effect the position of the brake rotor as the rotor is fixed to the hub which will remain true even if the wheels flex or bend. My thought is that it is just frame flex, especially for a man of your size.


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## sgtrobo (Aug 19, 2014)

well bloody hell, one of the reasons I went with a Fargo is because it's beefier than a normal road-type of bike. It's supposed to be a cargo bike! Steel and all that! *grumble*


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## HitmenOnlyInc (Jul 20, 2012)

I may have missed it but is the rub on the front wheel or the rear?


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## sgtrobo (Aug 19, 2014)

it's the front, sorry.

from what I am reading, it might be the fact that I have a big butt and a QR system on the Fargo that might be the culprit


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## andrewkissam (Jan 3, 2014)

HitmenOnlyInc said:


> I may have missed it but is the rub on the front wheel or the rear?


That's actually a good question. All forks have a degree of torsional flex, even the nicest ones. If the fork is twisting under your weight it will cause the front caliper to rub against the rotor or vice versa. The front brake is much more likely to rub than the rear, as the rear triangle should be pretty solid.


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## HitmenOnlyInc (Jul 20, 2012)

andrewkissam said:


> That's actually a good question. All forks have a degree of torsional flex, even the nicest ones. If the fork is twisting under your weight it will cause the front caliper to rub against the rotor or vice versa. The front brake is much more likely to rub than the rear, as the rear triangle should be pretty solid.


This is what I was getting at. Being a big boy is causing flex in his fork, thus the rubbing. Nothing to worry about really IMO.


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## sgtrobo (Aug 19, 2014)

so it's just kinda noise, not a bad thing, just agitating?

grumble


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## fishwrinkle (Jul 11, 2012)

get a fork with a 20 or 15 mm axle. you may have to get endcaps for the hub if applicable or a new front wheel to fix that problem. or just live with it, it's not going to kill ya, well maybe. j/k


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## slapheadmofo (Jun 9, 2006)

I'd be pretty surprised if we can't get BB7's to run without rubbing on a rigid fork; if your flexing it, it sure isn't going to be by much. The QR isn't really going to be a concern with a rigid either (or did you change the fork from stock?). 

Are the brakes adjusted and positioned 'right'? Rotors straight?
You might find the caliper is sitting so one pad is riding really close to the disc making it more likely to rub; take a good look and make sure the disc is as centered as possible between the pads. Make sure your pistons the retracting all the way too. Things can get dirty/worn/out of adjustment etc.

I'm not sure what the difference between road and mtn BB7's is, but IME, some brakes allow more 'running room' than others for the rotor. Maybe the road versions are designed to run tighter?

Hub in adjustment, not sloppy at all?

I dunno, just throwing stuff out there...


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