New bike question
Last Post 06/07/2019 09:20 PM by Bill H.. 7 Replies.
Author Messages
mondonico

Posts:158

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06/04/2019 09:00 PM
Purchased a so called fitness bike for Christmas. Its a Cannondale Quick Carbon. Have been been using as my commuter Got on eBay for 700 and fits my needs. Came with sora nine speed , disc brakes, and full carbon frame. My question is it has been very quiet on the way to work in the early morning. As it has gotten warmer in Nr. CA. on the way home it has started to make a high pitched sound like a tuning fork. I assume it has something to do with the front disc brake expanding as the heat goes up thru the day and resonating thru the fork. It stops when I gently apply the front break. Just one of those things and wonder if anyone else has had this happen.
mondonico

Posts:158

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06/04/2019 09:01 PM
Thats front brake of course.
Orange Crush

Posts:4499

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06/05/2019 10:47 AM
It sounds like the zinging sound I often get when riding a wet gravel path and fine clay grit get stuck in disc brakes. Given that this is not the situation you are in, can you slightly loosen the brake and get rid of sound that way? This also sometimes happens when I get new brake pads and things are adjusted too tight.
longslowdistance

Posts:2881

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06/05/2019 05:37 PM
Which brake brand and model? Some adjust only one side, so stopping the singing may require two steps: back off the pads and move the caliper slightly to recenter.
mondonico

Posts:158

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06/05/2019 06:44 PM
Thanks for the responses. I believe they are Shimano M315 hydro disc, 160/160mm. Lower end model and something I have never used before so I have not even looked into how to adjust. I can gently ride the brake and the noise stops and after about a mile it seems to go away. So I would also say its the pads rubbing on the disc. Just a strange sound I had never heard until it started getting hot. And I also assume it has something to do with the carbon fork acting like a tuning fork. It puts out a b flat tone. Just kidding. But I'm sure it has some equivalent to a musical note not just white noise. And it gets louder the longer I go not faster without hitting the brake. Can get very loud so its not something just within my hearing. Could also be a one off thing that is affected by the carbon layup and would only grind on every other bike.
Cosmic Kid

Posts:4209

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06/05/2019 08:30 PM
Try inserting a chisel in between the pads and then gently rotating the chisel to spread the pads and push the pistons back. If you had accidentally activated a brake lever when the wheel was out of the dropouts, the pads can extend and not retract.
Just say "NO!" to WCP!!!!
longslowdistance

Posts:2881

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06/07/2019 10:36 AM
A really clean chisel, so the pads don't get contaminated.
mondonico

Posts:158

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06/07/2019 09:20 PM
So its been much cooler here and I did slide a knife on both sides of the disc between the pads.
Don't know how you would get a chisel in there. But its been much better the last few days. Thanks to all for your advice


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