mkroger1981

I just put a new set of Zipp 404 NSW's on my Cervelo P3 with Continental 5000 tires. When I'm pedaling and push on my right foot, I hear a bit of a whoosh sound(bit like a jet engine). Its only when I press on my right foot. I've confirmed it is coming from the rear wheel(sound goes away when I take it off and returns when I put it back on). I don't hear it when coasting only when applying downward force with my right foot. I'm fairly certain that the sound isn't from any rubbing of the tire on brakes or the frame(I would think that would make a sound all the time), and I never hear it when coasting. I'm pretty sure its coming from the hub but can't be sure. I wonder if this is the normal sound of the "Cognition Hubset". I find it very odd the sound doesn't happen when I push on my left foot, only my right...

Wondered if any riders out there had any experience/thoughts with this...

mkroger1981

Replying to my own thread. I feel a bit silly, but I did discover the issue. What was happening is there was a slight "wobble" on the rear wheel and would I would pedal on the right, if I was pressing hard enough to make the wobble occur, the wheel was kissing the brake-pad just a little and producing the sound I was hearing. I took the bike to my local mechanic who installed the wheels and when the wobble was corrected, the sound was resolved. Thought I would share just in case anyone else ever experiences anything similar.

TrojanHorse

Excellent! Welcome to the board... when you get to ten posts, let's see a pic of that bike.

Wildwood 

Good posts. Problem described well. Problem resolved easily by someone knowledgeable.

Welcome to Bike Forums

031

i know the sound you are describing, I hear it on my rear wheel also but not sure what it is. At first, I thought it was the brake shoes rubbing but upon close inspection, it's not. Let me know if you hear of anything.

mkroger1981

If you think it sounds like the brake, take another look. The thing that was throwing me was, when I would get off my bike and spin the wheel, no sound, so I figured can't be the brake. The issue was when I was ON the bike and pressing on the right pedal, it made the rear wheel wobble a bit and hit the brake pad.

One way you could test this, AND BE CAREFUL IF YOU DO, is totally open up the brake on the wheel that you think is making the noise. Then ride around(knowing you only have a single brake) and see if the noise goes away. If it does, you can probably assume you are getting a bit of a wobble on your wheel as well. If so, I think you might need a bike mechanic(I did) to fix the wobble.

Good luck! Let me know if this experiment works for you!

aclinjury

and how was the wobble fixed??

jadocs

It’s not wobble, it’s frame flex under load.

031

i don’t think my wheel wobbles, just made some noise. probably caused by the dimples on the face. the wheels are properly adjusted but my problem now is a “crack” on the brake track that zipp considers “cosmetic”

i dont want to hijack your thread but i’ll post pictures when i reach 10 posts

mkroger1981

Yes, that is a better description, I think that’s his my mechanic phrased it. Also, the fix was they tightened something in the hub and opened the brakes up(just a tiny but).

mkroger1981

No worries, my problem is solved. Good luck!