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Discussion Starter · #1 ·
I picked up a Rockhopper SL Base from my LBS a short while ago and have had a chance to put some mileage on. While the bike as a whole is fantastic the brakes are causing me a bit of trouble.

It came with Tektro Auriga Pros and these rotors:



The power is definitely there but I get a relatively pronounced vibration from the rear any time I use it. Performance doesn't seem to be affected but it is really getting annoying considering the vibrations translates into any body part that is is contact with the bike at the time.

I've taken it to the LBS I picked it up from and they did some adjustments but the problem still persists.

I'm a newb at discs/hydros so I'm hoping someone could at least point me in the right direction for solving this.
 

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First I've heard of a Spec. vibrating. I know Gary Fishers are known for it, like the HiFi. You can try organic pads and see if it helps but it might be something you can't solve.
 

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Discussion Starter · #3 ·
Mount Dora Cycles said:
First I've heard of a Spec. vibrating. I know Gary Fishers are known for it, like the HiFi. You can try organic pads and see if it helps but it might be something you can't solve.
That certainly would be tragic considering how nice the bike really is. Anyone else with an SL frame experience this? If I'm not mistaken the entire Rockhopper SL lineup should share the same frame.
 

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meow meow
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i think its a combo of the breaks and the rear end. you can try new pads and if it still persists and is really bugging you you can try a new brand of break.
 

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It's not the brake. Had a friend with a similar issue, turned out to be a crack at the dropouts.
 

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Discussion Starter · #6 ·
I spent some time outside with the bike and some tools tonight and I can't for the life of me get the vibration to go away. I tried reversing the pads (so the pad was on the opposite side of the rotor) and swapping front to rear. There was absolutely no difference throughout any of it.

I also tried re-centering the calipers but still the problem persists.

When the LBS tried to resolve the vibrating they said they gave it their best shot. Should I give them another crack it at? Would it be appropriate to ask them about alternative solutions like replacing the brake system? If so should I ask for a discounted rate?
 

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You could try and see if tightening up the quick release helps. I get some vibration on my front end if my quick release isn't tightened enough.
 

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Discussion Starter · #11 ·
rdickens48 said:
You could try and see if tightening up the quick release helps. I get some vibration on my front end if my quick release isn't tightened enough.
Tried that one too. Caliper, quick release, adapter, etc is all tightened down.

EDIT: To give you a better idea of what I'm talking about it's bad enough that I can feel the vibration in handlebars and saddle. Sound wise I'm not sure what I could compare it to but it will drown out someone's voice riding next to me.
 

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I have had similar problems with the rear Tektros on my Mongoose. It seems to come on with dirty rotors after riding the flats alot. The best I have found to mitigate the issue is to clean the rotors with IPA and the get them really hot. I ride up the step slope in front of my house and then ride back down applying the the brakes. After the rotors are way to hot to touch the vibration goes away for a few more rides. Getting the brakes really hot seems to clear up the vibration more than just cleaning.
 

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I still say it's the frame. As others said, it might be "normal" on some other kind of bikes but not yours. The frame either has an invisible crack, or it's just plain faulty. It's fully covered by warranty.
 

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Discussion Starter · #15 ·
Thanks for all the info and advice!

I did try getting some speed down a long slope and then applying the rear brake with authority but that didn't seem to do much either.

For those thinking that there is a crack in the frame: would I be able to see this crack? Where would it likely be?
 

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I hate rock gardens
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MNiceGuy said:
Even though I've owned it more than a month and put ~200 miles on it?
Absolutely.

Hell, 99% of LBS let you try a seat out for 30 days with the option of returning/swapping it...

:thumbsup:
 

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Discussion Starter · #17 ·
TwinBlade said:
Absolutely.

Hell, 99% of LBS let you try a seat out for 30 days with the option of returning/swapping it...

:thumbsup:
I plan to call them up this morning. This particular LBS has been very good to me so far so I have high hopes.

Just to clarify some information:

The vibration I mention isn't a shuddering like one would expect from a damaged/warped rotor. This actually sounds like something is making the frame resonate. Also, the RPM of the wheel doesn't seem to affect the pitch but it does affect volume.
 

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Discussion Starter · #18 ·
I dropped the Rockhopper off at the LBS I bought it from and who serviced it for the brake issue previously. I have my own thoughts and feelings but I'd like to bounce some of the information of someone else.

The tech took the bike for a spin and agreed the rear brake was rubbing/squealing obnoxiously and it was one of the most pronounced examples he'd seen. He proposed changing the rotors to another design. I'm not one to go against the recommendation of someone much more experienced than myself so I accepted the diagnosis. The only problem is that the LBS wanted to perform this upgrade (to Avid rotors) at my cost. When I disagreed with this they said they would give me $20 per Tektro rotor coming off and then I would just have to pay the difference. The train of thought from their perspective is that the brake is fully functional it just has a very obnoxious side-effect. Since the part isn't functionally defective it's not a matter of warranty replacement or anything along those lines.

I then asked how we would proceed if the new rotors didn't solve the issue to which I was told they would try new pads (again at my cost). If that didn't work we would have to start replacing the braking system itself.

Facts to consider:

1. The bike was purchased 6/04
2. Has already been in service for the same issue at the same LBS
3. I bike fairly regularly and I'm a little disappointed to have it stuck at the shop again.
4. It's a 50-60 min drive to the LBS
5. I don't want to pay out to have brakes that don't squeal like crazy and vibrate every body part in contact with the bike.
6. This LBS has been very good to me throughout my 'return to cycling'
7. My girlfriend and I have dropped about $2300 total at this LBS for the bikes, gear, and roof rack.


What are the thoughts here?
 

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I hate rock gardens
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Show them the receipts and ask them if the nominal cost of brakes is worth them losing another $2300 in business.

That is total BS IMO. They are nice because you just made a couple months rent for their building. Of course, I am saying this for what I would do.

2 hours in gas in my truck would be about $20.

Then again, I don't at all mind getting sh!tty with someone when they are jerking me around. You are getting jerked...pretty bad too.
 

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Are the brakes new to the bike?

If not then here is something to consider; 6 year old bike and the problem just started and the mech thinks it's a rotor design problem? WTF was he smoking? Did you ask about checking the frame, frame warranty etc?
 
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