Mavic Cosmic Elite Bearings

mitchgixer6

Hi all

More of a curoisity than anything else tonight. I recently bought a second hand pair of Mavic Cosmic Elite wheels. Getting round to cleaning them I wanted to take the freehub off to give it a proper clean out. Not thinking much of it as I knew the wheels utilise sealed cartridge bearings so none of the hassle of adjustment that you get with cup + cone. Seems I was wrong!!

It took me a wee while to fuigure out how to get the freehub off, but got there in the end. I did wonder why one of the end caps had the notch for a cone spanner, but didn't think much of it until later. I put the assembly back as I would normaly with sealed bearings and just tightened both caps up fairly tight. Spun the wheels to check everything and the bearings weren't spinning! 'Oh' I thought!

So a quick web search and I dug out the Mavic technical site and onto this http://www.tech-mavic.com/tech-mavic/technical_manual/data/mavic_tech.php

User: mavic-com
Password: dealer

Turns out you need to adjust the 'expandable bearing support' which leads to the bearings having the correct adjustment. The tech doc says tighten it up then back it off half a turn and then tighten with the 17mm spanner and cone spanner.

Now, this seems to me to be a step backwards to me. As I said before any other time I've worked with sealed bearings on wheels it's designed just to be tightened up and away you go. Why, oh why have Mavic introduced this adjustment system? It took me ages of backing it off the half turn and then testing it on the bike, but each time I had play in the wheel! This is just as bad as cup + cone! In the end I settled for about 1/4 turn back from tight to eliminate the play. My thinking that there's not actually any pressure exerted on the bearing apart from the axle touching the inner race???

Anyone any ideas why they use this system? Also read that the 'expandable bearing support' is a one use item and should be replaced every time the axle is removed, regardless of whether the bearings were replaced. Is this necessary? Also I'll now need to buy some Loctite 243 to put it back together properly! :roll:

Thanks for humoring my rants!

ugo.santalucia

The adjustment system give you tolerance, which otherwise you don't have and need to rely on perfect fit of all the components. It is not a bad idea

mitchgixer6

Yeah fair do's, never thought of that. What about the replacement of the bearing support? Is it necessary? Will I do any damage to the bearings if the cap is slightly too tight?

Thanks Paolo.

ugo.santalucia

mitchgixer6 wrote:

Yeah fair do's, never thought of that. What about the replacement of the bearing support? Is it necessary? Will I do any damage to the bearings if the cap is slightly too tight?

Thanks Paolo.

They will run with more friction and wear out quicker

mitchgixer6

So should I treat them the same as cup and come bearings then? Set them with play when the qr is half closed which goes away when fully tight?

ugo.santalucia

If that's what your QR does, then yes