Cleaning mavic freehub

[gl20]

Hi all. Any tips on the following appreciated.

Had my Mavic ksyrium wheels a few years now and the freewheel hub now makes a groaning sound when I freewheel. This only happens at medium or higher speeds and goes as soon as I pedal, even if just soft pedalling. So I assume it’s the freewheel hub needs a service/clean.

I’ve watched some gcn videos on how to clean the hub and have just dismantled ahead of cleaning it tomorrow. I wanted to take a look first and make sure I was able to get it apart. All good so far but it’s not obvious to me what would be causing the noise.

I will follow the GCN steps but just posting to see if there’s anything you think I should focus on or look out for. Just trying to avoid doing all the steps and then finding I’ve not cured it.

Thanks.

[gl20]

One other thing to add. When I removed the nut that allows you to then lift off the hub, I discovered that the small lip attached that is part of the nut (which I assume sits in the drop out) has snapped way from the nut. Having reassembled I note that this piece would remain static relative to the dropouts (I think) whether pedalling or freewheeling. Just point that out in case this could be the culprit?

[jfdi]

They're simple enough just strip clean and reassemble. Ensure oil used is mineral oil. Other oils may cause the rear seal to swell which will then drag causing the chain to drop when freewheeling. Ask me how i know. Thankfully you can buy replacement seals.

[jfdi]

The groaning may be the infamous "Mavic howl of death" (google it) caused by the rear plastic bush in the freehub. There's a guy in the states sells slightly tighter bushes on Ebay allowing you to sand down the aluminium hub for a good fit. Just watch out for customs charges on it. I got stung for an extra £15 (including the post offices cut) as the total was something daft like 3 pence over the allowed threshold.

[gl20]

Thanks. Mineral oil should be arriving tomorrow.

Is it best to leave the bearings alone? I’ve seen some comments suggesting lifting the seals and cleaning them

[gl20]

jfdi said:

The groaning may be the infamous "Mavic howl of death" (google it) caused by the rear plastic bush in the freehub. There's a guy in the states sells slightly tighter bushes on Ebay allowing you to sand down the aluminium hub for a good fit. Just watch out for customs charges on it. I got stung for an extra £15 (including the post offices cut) as the total was something daft like 3 pence over the allowed threshold.

Funny. When I was reading up I heard it described as a Mavic screech, so discounted that. But ‘howl’ is a fairly apt word for what I’m hearing. Either way, will pay close attention to the bush and see if I can sort without replacing.