# CAADX Vibration on braking



## D'Artagan (Mar 15, 2012)

Hi everybody and sorry for my english...
Last year I bought a Cannondale CAADX and discovered a problem with the front brake when the pressure of my tire is around 30psi.
The problem is caused by the brake fixation. It seems that the bore is not sufficiently precise on the Tektro CR720.
Does anyone have this problem and solved it?
Can you advise me in choosing new brake?
Thanks in advance.


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## tihsepa (Nov 27, 2008)

Is the cable hanger on the fork crown or on top of the head tube under the stem? 

My cross bike did that with the 720's and I switched to TRP mini v'ees and the problem was solved.

I have heard that you can get a hanger that mounts to the fork crown and cure it that way. My understanding is that flex in the fork causes the brake pressure to fluctuate and cause this chatter. Mounting the hanger on the fork not on top of the headset cures this.


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## metoou2 (Mar 18, 2009)

You are experiencing "fork shudder". Google it, there is plenty to read.
What 'tihsepa' said above is correct. If the housing stop is up on the top of the head tube you will always get shudder. If the housing stop is mounted down on the fork crown the shudder is all but eliminated.

There are some odd effects going on when using canti-lever brakes on the front of a bike.
Any of the v-brakes will stop the shudder as well.

I discovered a way to stop it using a brake arch from the old style Mag 21 Rock Shox, but it is more than I want to explain here.


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## D'Artagan (Mar 15, 2012)

tihsepa said:


> Is the cable hanger on the fork crown or on top of the head tube under the stem?


Yes the cable hanger is on top of the head tube...



metoou2 said:


> You are experiencing "fork shudder". Google it, there is plenty to read.
> What 'tihsepa' said above is correct. If the housing stop is up on the top of the head tube you will always get shudder. If the housing stop is mounted down on the fork crown the shudder is all but eliminated.
> 
> There are some odd effects going on when using canti-lever brakes on the front of a bike.
> ...


Ok I will google it,,,
I will try to mount the housing stop down on the fork and if it's not good for me I will put mini V-brakes
Thank you very much for your answers, it's really appreciate.


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## D'Artagan (Mar 15, 2012)

Hi again!

I'll put V-Brake but I don't know the type of my 105 shifters...
On the TRP site we can see "For newer Shimano levers, you'll want to choose venerable CX9"... Why? What it changes?
=> TRP CX8.4 or CX9

What about Tektro RX5, RX6?

My CAADX is dated of 11-01-2011 (dd-mm-yyyy).

Can someone help me?
Thanks in advance.


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## metoou2 (Mar 18, 2009)

Call Lance at TRP
He is very helpful
650.965.4442


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## D'Artagan (Mar 15, 2012)

Ok thanks but it's an international call... if nobody can help me, I will


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## tihsepa (Nov 27, 2008)

I run the 9's with 5600 levers. I have a friend that rund them with 7800 levers. They both work fine. I have very good modulation and very good power. They do have to be set up dead on or they will rub if the wheel is out of true. I understand the 8.?'s offer a little more clearance when released but less power. I love mine and will never go back to cantis. 

I dont know about the Tektro models but there are some that will work the same without the TRP flash. The 9 and 8.?'s are the lencth of the lever in cm's so compare specs. Your 105 levers will work with either it is just up to you how you want them to feel.

They are powerful brakes.


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## kneejerk (Feb 2, 2007)

just one of the possible characters of "rim brakes", cantilever brakes can take some fine tuning to eliminate some issues, otherwise switching to "mini-V brakes" should improve things, 

with some use the brake shudder should deminish, also... trying different brake pads can help.... also, changing the spring tension and cable pull angles can help,


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## tihsepa (Nov 27, 2008)

kneejerk said:


> just one of the possible characters of "rim brakes", cantilever brakes can take some fine tuning to eliminate some issues, otherwise switching to "mini-V brakes" should improve things,
> 
> with some use the brake shudder should deminish, also... trying different brake pads can help.... also, changing the spring tension and cable pull angles can help,


You are right. There are ways to reduce it but not eliminate. It is caused primarily by the flex in a fork. The one sure fire way I have seen is by going with a steel fork. This gets rid of it almost all together. :thumbsup:

I have NO shutter at all with my mini v's. None. Also brake modulation and preformance are greatly improved. 

OP. Dont forget to get the noodles with adjusters. The adjusters are nice to have.


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## D'Artagan (Mar 15, 2012)

Thanks for your answers, I ordered the CX8.4 this morning. I will give you my feedback as soon as possible!


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## D'Artagan (Mar 15, 2012)

I tried many things before creating this topic but none has eliminated the shudder. 

The CX8.4 integrates a barrel adjuster.


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