I got my road bike back yesterday after putting it in to be serviced cos it needed it and there was a noise/vibration coming from the back wheel when I free wheel above 20mph but not every time. Shop said nothing needed on the service but did find a loose bit at the cassette. Noise sorted, Eh no.
I took it out today and after about 20 miles the noise came back. It sounds like instead of the normal tick,tick tick of a freewheel there is a zzzzzzzzzzzzzz noise that you can feel vibrating through the pedals. If I turn the pedals it goes back to normal but only for a wee while. I have Sram Rival groupset and Mavic wheels if that helps.
Any ideas before I take the bike back to the shop?
Thanks in advance.

My guess would be the Mavic freehub needs some oil in. You get a weird kind of buzzing and then a high pitched noise when descending if it’s a bit dry.

Dead easy to do, don’t use grease, just thick oil and don’t drown it.

Thanks #crikey I should have asked the shop if they did that. I did the Tour O the borders sportive a few weeks back in grim conditions and had to ford a burst river en route, could be the freehub was washed out clean.

It only tends to make itself known when riding along; it’s difficult to spot on a stand, and your history suggests it’s likely.

You probably don’t need to take it back, just work out how to get the freehub off and dollop some oil in there.

I’ve a few Mavic wheels, so I can’t remember exactly, but it’s really dead easy; in cooking terms it’s about an omelette level!

It’s the bushing at the inner end of the freehub. You’re supposed to use mineral oil to lubricate it. I used castrol lhm as that’s all I had that was deffo mineral oil!

Thats handy to know. Cooking I am quite good at, but everything I know about bike maintenance could be carved on the back of an asprin with an axe.

What Mavic wheels?

The bomb proof Mavic Aksium wheels.

Put Mavic freehub service into Google; videos to follow!

Cheers 🙂