Mysterious Screaming From Bike

by davecochrane   March 10, 2014  

Over the last few weeks my Fuji Team Pro 2009 (Ultegra) has started making a hellish screaming noise, mostly in descents, mostly in the big ring, and oftentimes when freewheeling. My chain was pretty mucky, so I took it to my excellent LBS to see if it was something beyond that. He seemed to think the freehub was ok, despite there being a very slight ability to generate power by turning the crank backward. Today, about 70k into an 85k club ride, the scream appeared briefly once more. Totally mystified.

Anyone got any suggestions as to what is causing the noise?? Is is time to try someone else's wheels??

7 user comments

Oldest firstNewest firstBest rated

Shot bearings can make a lot of noise, but any mechanic should be able to spot them almost immediately.

What are your wheels?

My eyes prefer Celeste, my bum prefers titanium.

Jack Osbourne snr's picture

posted by Jack Osbourne snr [304 posts]
10th March 2014 - 0:55

like this
Like (5)

If you've still got the stock Mavic Aksium wheels on it, there's your problem I think. It's the Mavic death squeal.

Mavic freehubs have a nylon bushing in them, and this wears out over time. You can't see the wear but it's enough to cause fiction at high speed, creating drag, a horrible noise and even shifting problems. The hub bearings that are in there can be fine, the bushing is the problem. Replace the freehub body (I found one for£30ish on eBay, easy job for a reasonably confident home mechanic) and your problem will go away. You need some 7wt mineral oil too, keep it topped up to prevent the same issue reoccurring.

mintimperial's picture

posted by mintimperial [18 posts]
10th March 2014 - 10:43

like this
Like (6)

mintimperial wrote:
If you've still got the stock Mavic Aksium wheels on it, there's your problem I think. It's the Mavic death squeal.

Mavic freehubs have a nylon bushing in them, and this wears out over time. You can't see the wear but it's enough to cause fiction at high speed, creating drag, a horrible noise and even shifting problems. The hub bearings that are in there can be fine, the bushing is the problem. Replace the freehub body (I found one for£30ish on eBay, easy job for a reasonably confident home mechanic) and your problem will go away. You need some 7wt mineral oil too, keep it topped up to prevent the same issue reoccurring.

Those are indeed the wheels I have - thanks for the info. I'm considering a new set of wheels anyway as this lot have had to be rebuilt once already post-crash.

davecochrane's picture

posted by davecochrane [88 posts]
10th March 2014 - 10:45

like this
Like (6)

you can buy "upgrades" that replace the bush with a bearing ...

https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rj...

??

still on the 3rd switch-back of Bwlch !

posted by therevokid [679 posts]
10th March 2014 - 13:39

like this
Like (5)

If it's mostly on descents. If thats fast descents it might be you!

posted by paulrbarnard [96 posts]
12th March 2014 - 20:23

like this
Like (7)

paulrbarnard wrote:
If it's mostly on descents. If thats fast descents it might be you!

+1!

posted by NickK123 [59 posts]
12th March 2014 - 20:40

like this
Like (6)

I get a mysterious screaming on fast descents. Is okay. Bike's fine.

The Mavic Death Squeal sounds entertaining though.

posted by Argos74 [261 posts]
12th March 2014 - 20:48

like this
Like (5)