Need help diagnosing bike problem!

Just got back from a good days riding but problem is becoming more apparent:
When I’m not pedalling and going above about 10mph a ‘brrrrrrrr’ sound starts after about 3 seconds, which vibrates the bike.
At first I thought it was something catching on the rear disc, but it happens whether the brake is on or off and I cleaned them out this morning and pads have plenty of life.
It also sucks the upper part of the chain right down below the chainstays and pulls the rear mech up so its almost touching the chainstays.
I’m guessing the cassette mechanism is fecked?
Help! 😯

Sounds like your bike is starting to try and be a fixed wheel? So your freewheel may need servicing? I am sure someone with actual experience and knowledge will be along soon though.

Sounds like the free hub is dragging, could be either the grease being really think due to the low temperature, could try riding the bike after it has been in the warm for a few hours, if this doesn’t cure it then contamination or mechanical failure of the free hub is likely 😡

PS what hub is it?

its a mavic crossride factory rear wheel. if i needed to replace inner parts i’ve got a buckled mavic aksium race wheel i could salvage hub parts from? hmmmmm 🙄

Could be the jockey wheels need replacing.

dound like freehub problems the, rear mech being pulled up is probably due to the chain coming under tension. Strip down (it not you) and have a look, watch out for flying innards, should be pretty obvious if it’s full of gunk or if the grease is comtaminated or if it is fecked.

If it was jockey wheels would that only make a difference when pedaling, not freewheeling?

yeh jockey wheels r fine anyways. sounds like im gonna have to take it apart and have a little look. if it looks too scary i’ll take it to the lbs.
cheers guys!

my guess is it is a Mavic hub. ou’ve got death rattle so its effectively buggered.

My mate had the same in his cross max wheels but as he’d just spend a fortune on bearings etc, he persevered and “made” a washer that goes in there somewhere. Sorry I can’t be more descriptive.

if this is the case, mail me, I’ll put you in touch as he seems to have fixed his.

hub could be stressed – too much pud over crimbo..