Vibration mystery - freewheel hub

[J9 mtbfanatic]

Hi, has anyone had a persistent freewheel hub vibration (particularly with Mavic wheels), that disappears for only a short time (e.g. one long or two short rides) after lubing? I eventually tried to solve the problem by having my freewheel hub replaced 2 weeks ago, and vibration is worse than it was before. What do I do next? (It is most definitely the rear freewheel hub, as the vibration only occurs when freewheeling fast downhill, and disappears when I pedal downhill regardless of speed).

[Capricorn]

if you lift your rear wheel, and spin it, does it wobble?

[J9 mtbfanatic]

if you lift your rear wheel, and spin it, does it wobble?

 

Nope, I just tried - looks fine. And there is no play in it either, seems solid if I try to wiggle it sideways.

[Noshow]

This is a common issue with Mavic hubs - they use a PTFE bushing in the freehub body rather than a bearing. It wears out quickly if you don't keep it lubed. It's more of a howl than vibration?

 

It sound like yours has worn too far so the housing has worn narrowing the diameter, so a new freewheel with a new bushing still won't fix it.

 

The only fix I know, which doesn't require a full new hub, is the hubdoctor ebay shop which sells either replacement PTFE bushings to put in the old freehub - they do an oversized one for your situation if the actual hub housing has worn.

 

Better still, they do a bearing which fits in place of the PTFE bushing which should last for ever and doesn't require such frequent lubing.

 

They are pretty cheap, and much cheaper than a new hub and/or a new feehub body - you'll have to do it yourself or get a friendly mechanic to do it.

Edited October 14, 2013 by Noshow

[Hennie VR]

I have Mavic SLR on my MTB and also had the same problem. I now service them regularly. I have replaced a cracked freebody previously and have another cracked one now and have vibrations again. Also check the bearings. I have now replaced my hub bearings with bearings from Bearing Man and will give it a go to see if its better than the ones the LBS use.

[J9 mtbfanatic]

This is a common issue with Mavic hubs - they use a PTFE bushing in the freehub body rather than a bearing. It wears out quickly if you don't keep it lubed. It's more of a howl than vibration?

 

It sound like yours has worn too far so the housing has worn narrowing the diameter, so a new freewheel with a new bushing still won't fix it.

 

The only fix I know, which doesn't require a full new hub, is the hubdoctor ebay shop which sells either replacement PTFE bushings to put in the old freehub - they do an oversized one for your situation if the actual hub housing has worn.

 

Better still, they do a bearing which fits in place of the PTFE bushing which should last for ever and doesn't require such frequent lubing.

 

They are pretty cheap, and much cheaper than a new hub and/or a new feehub body - you'll have to do it yourself or get a friendly mechanic to do it.

 

Thanks, I am passing this on to my friendly mechanic! Yes it is definitely a howl, good description. I hope fellow cyclists know it is my bike and not me.

[MrJacques]

Typical Mavic issue, I've had my freehub do that as well, a vibration and a howling sound. Lubed it with fork oil which I had on hand for servicing my fork. Or Wynflon, can't remember which of the two I used.... but it has been silent for a long time now. Not the recommended oil for it, but I figured that it was already broken, so I didn't have much to lose.

 

As Noshow stated, it's the nylon bushing running dry which will cause it to wear out even faster than it normally would. Only Mavic knows why they didn't put a proper bearing in there, it would have been much better.

 

If you aren't scared of diy, get some finish line green (ptfe) to lube it, but for the long term the kit is the best option. Google for Mavic and Hub Doctor.

Edited October 14, 2013 by Jacquers

[Bobbo_SA]

I have a unused / sealed Hub doctor Pro kit, although its been pending the finalization of the sale for over a month now, I'll contact the gentlemen again and see whats happening, if he does not confirm I'll PM you.

[J9 mtbfanatic]

I have a unused / sealed Hub doctor Pro kit, although its been pending the finalization of the sale for over a month now, I'll contact the gentlemen again and see whats happening, if he does not confirm I'll PM you.

Thanks!!

[Organic]

I had this too. I almost crashed I got such a fright. Search for 'Mavic Squeal of Death' on the net for more details. I bought some special Mavic freehub oil from the bike shop (about R150 for a lifetime supply if I remember correctly - they had to order it), took the thing apart, cleaned it, lubed it, reassembled it, and it was fine. There are videos on YouTube, and it's quite simple to do.

 

The freehub actually looked well lubed and pretty clean when I opened it up, so I suspect it was just a speck of sand or something that caused the problem.

 

Not the best design.

[fabs]

Hello J9.

 

I think I had exactly the same problem.

Before trying any complicated fix, get some Q20 and spray inside your hub.

My problem has gone away completely.

[johannrissik]

If you don't freewheel they don't make the spine-chilling noise........