dannylightning

when i turn sharp or lean the bike (GT Avelance 1.0 ) i hear a noise from the rotor rubbing the caliper. if i grab the front tire and yank on it i can watch the front rotor move from side to side in the caliper and touch each side of the break pads, so it seems something is flexing some place and it should not be.

i tore down the wheel hub, cleaned it all up, greased the bearings, thew it all back together and everything is tight, it cant be the axle flexing in the hub unless something really weird is going on. i know if i take the wheel off and pull on the forks right about where the wheel bolts on the forks seem to have some flex. its got a low end rock shock on it that came with the bike, there does not seem to be any adjustments on there that are not plenty tight. i am guessing its the forks flexing but the caliper is bolted to the fork and it does not seem to be moving, i only see the rotor moving to the left and right when i jerk the front wheel back and forth..

anyone ever have anything like this going on. the bike is only a few years old and i only ride it around the neighborhood it has never been crashed, jumped or abused in any way.. i have noticed it doing this since i got it and i finally decided to try to do something about this, yesterday i tried to see why it was doing this, i removed the front tire ( quick releqase ) to try and see what was going on. i had to re position the caliper and everything because when i took the front wheel off and put it back on it was rubbing really bad. had my friend look at who has been building bikes for years for a living and he has never seen something like this going on.

fietsbob

It Breaks? Into how many pieces ?

dsbrantjr

Did you adjust the bearings or just "throw them together"? Loose bearing adjustment will allow the wheel to move in relation to the axle.

dannylightning

the bearings are loose in the hub, there not sealed bearings or anything like that, just a bunch of loose balls setting in the hub . ( in my bmx days we had nice sealed bearings in the wheel hubs )

i took a tool and pushed on all the the loose balls to get them in the right spot and so they were nice and tight together. i am pretty sure everything is correct with the bearing placement. i do not think its he axle moving in the hub which seems like the logical thing to be causing this.

i guess there is always the option that this is just some kind of weird vibration that i am hearing, but i sure sounds like its coming from the front wheel and it sounds like a vibration but at times you hear a a sound like if you were to take a screwdriver or something and scrape it across the rotor and than that metal sound rings out for a second. was thinking about maybe just removing the front caliper and riding around to make sure the sound stops.

mrFreel

If the wheel bearings are adjusted properly so the wheel has no side play on the axle then I would guess that the front fork is flexing between the drop out and the caliper mount.

mike

dannylightning

this is what i am thinking but it does not seem like that should happen. i have never had forks with shocks on them before so i do not know anything about them.. i do not really see the point of the shocks, part of my has been thinking about replacing them with solid forks. i might have to take this down to the bike repair shop and see what they think but if i can figure out how to fix it on my own even better.

dsbrantjr

It sounds like your answer is "no, I didn't adjust the bearings".

I would suggest that you do so. Here is a procedure to follow: Cone Adjustment You will need the proper size of "cone wrench" to do this.

From the procedure: "If the cones are not screwed on far enough, the bearings will have "play": the wheel will be able to shake back and forth on its bearings. This is an unpleasant sensation, and may cause control problems."

It will also allow your brake (not break) rotor to move in relation to your brake pads, which can cause rubbing.

cale

It's the shock, IMHO. That's more likely to have changed, not the position of the cones. I don't generally remove everything from the axle when I overhaul the hub. That's just asking for trouble.

A worn shock. A cheap, inadequately braced shock could produce the symptoms described.

dannylightning

I just watched a video for a cup and cone hub and it appears i have everything adjusted the way it should be..

dannylightning

rockshox tora 302 would be the forks on my bike. not sure if those should be good or not

cale

I don't know the model but shocks can develop problems over time with loss of oil and/or leaky seals.

dannylightning

well i just read a thing about when shocks need work. its saying if the lock does not work 100% that is a sign there is a problem my forks have a very slight amount of travel when i have them locked, not much but i can get them to compress slightly. well it sounds like i might need to get the shocks serviced. it also said to have them done once a year. that i was not aware of.

wesmamyke

If we are talking more of a light zinging noise and not a hard scraping it's pretty common. I had good luck with one of those DT swiss twist on quick release skewers. You can really crank them tight and almost completely eliminates the noise.

dannylightning

it was more of a light zinging sound, till i took the wheel off and put it back in a couple times yesterday, and next thing i know the caliper and rotor were actual rubbing and making a nasty clicking sound, it left marks on the rotor where you can see where the rotor rubbed the caliper, not the pads but the caliper, i adjusted the caliper a few times and well now its more of a buzzing vibrating rubbing type sound now and its every time i turn sharp or lean, i am also hearing it when the bike starts going fast down a hill and i am just riding straight. i don't know what the deal is. this is my fist mtn bike so its all new to me. bmx bikes were so much easier to deal with lol.

one thing i did notice today, my rotor is slightly warped, it might wobble back and fort 1mm, maybe 0.5mm when i spin the front wheel and watch the rotor spin.. it very slightly wobbles. it is so slight its probably not the issue but i figure i should mention it.

bikeman715

To me it sound more of a warp disc . this should help . Park Tool Co. » ParkTool Blog » Rotor Disc Service and Installation

dannylightning

yes, it appears to be slightly warped but i am not sure that is actually my issue here but i do see its only around 15 bucks to buy a new rotor so i might give that a try..

cobba

Rotors can be trued.

https://www.youtube.com/watch?v=0fosSuyiCDE

FBinNY 

Try a simple experiment. Mount the wheel and tighten the skewer. Jiggle the rim to ensure there's zero play at the hub. Now hold one fork strut and pull the rim towards it. Odds are you can pull the rim enough to make the disc appear to move in the caliper. In reality the fork is flexing and the caliper is moving over.

No easy fix to making a cheap fork more rigid, but maybe you can open the brake a bit more if there's enough lever travel.

In any case, there's virtually no added friction or power lost in slight incidental contact of the disc in the caliper. Many auto brakes have no positive way to ensure zero cntact when the brakes are off, and you can often hear the chirp, chirp as they pull away from a light. So, if it's just the occasional chirp on turns, it may be annoying, but that's all it'll be.

dannylightning

thanks, i will give that a try,, i have never been good at getting bent things straight but that looks simple enough

cobba

Installing the QR skewer properly?

https://www.youtube.com/watch?v=YTLgcEViRo0

dannylightning

well so far all 3 people i have showed all seem to say it looks like the forks flexing.

anyone know of some good forks that do not cost a load of money and do not have any shocks. i always have my shocks locked, i do not care for the suspension, i do not ride off road trails and what not since my back is not doing so great. these i just stick to riding around and getting exercise

dannylightning

my skewer does not have any washers, it does have 2 springs on it but no washers. is that a issue ?

cobba

No, not all qr skewers have washers.

https://www.youtube.com/watch?v=p0m2Jdfl8To


A rotor rubbing when cornering is something that I've heard of before, it sometimes comes up om mountain bike forums.
Suspension forks with standard qr skewers can have a bit of torsional flex, the lower legs on a suspension fork are only joined together by the arch on the top of the lowers and the axle at the bottom.

I suspect that a cheap low end suspension fork wiill have more torsional flex then a better quality fork.

Worn bushings in the lower legs could also contribute to fork flex.

If don't like this noise when cornering maybe get a better fork or a fork that uses a 15mm or 20mm thru axle, the lower legs on forks with larger axles are much stiffer then ones with the standard 9mm QR.

A fork with a larger axle will require a new hub to suit.

dabac

I've been quite happy with a Mosso fork off Ebay. Make sure to get the appropriate axle-to-crown length though.
Using discs, you don't need to worry about if it's a 26" or 29er fork.

dannylightning

well the rotor is straight as its gonna get, i have adjusted the position of the caliper a few times. I made sure the brake pads are as far apart as they can be. i moved the skewer so the locking clamp was on one side and than i moved it to the other side. no matter what i do i get this buzzing, grinding sound,

as of right now even a light turn is making the noise, something sure seems to be flexing way to much, the caliper does not seem to flex, wheel i pull on the wheel as far as i can tell the rotor is moving not the caliper so i am not sure if that would cancel out the idea that the forks are flexing or not., something is flexing though, i am about 99% sure that is what is going on.