Bicycle Mechanics - Hubs and Wheels and Bearings, oh my!

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DonTx
07-30-02, 12:43 PM
This question relates to my wheels, I am riding on a set
of Mavic Classics SSC with the Mavic FTS-L hubs. They seem very
tough and ride nicely, however at least once during each ride I get the feeling that my brake is dragging on the rim. I know its not the brake because I release the quick release and it still happens. Normally if I stop and roll the wheel I feel no difference in the rolling resistance but the bike rolls normally after that. My
thoughts are that it is in the hub, I opened up the hub to take a
look but I did not get very far, basically I removed the cassette,
and the left side cap. The bearings seemed to be in the right place and the axle turned smoothly. Although the rear axle turns with some resistance, this may be a characteristic of the hub design. My understanding is that this type of Mavic hub has a "low friction ring in the hub that replaces the bearing that functions only when the wheel is in freewheel mode"(quoted from Mavic's web site). I am not sure exactly what this means.

I do not want to return the wheels under warranty because intermittent problems usually just get more frustrating under warranty. Where can I find service information on these hubs, Mavic seems somewhat protective about this information. I would like to be able to lubricate the freehub but I do not know how, I think that may help. Especially helpful would be a drawing of the internals of the hub and a procedure for overhaul. How does one get information on Mavic hubs.

Also any thoughts on this problem not related to the hubs would also be helpful, for example am I feeling the flex in the wheel, or perhaps something in the bottom bracket.

As always Thanks


mechBgon
07-30-02, 05:55 PM
My 2 cents' worth: it seems unlikely that the hub could be generating enough friction to noticably slow the bicycle, without nuking a bearing in short order. Does the wheel coast smoothly when clamped into the frame with the QR? Presumably your wheels came with the Mavic bearing-adjustment tool needed to adjust bearing preload if necessary.

If a freehub is generating friction when the rider coasts, it will attempt to rotate with the wheel and "push" the chain toward the crank, which doesn't turn since the rider is coasting. The derailleur cage's tension breaks the freehub body loose after a moment, and the chain rebounds with a slap. Because this would occur if your freehub were generating a lot of resistance, and you didn't mention a slap-slap-slap of your chain, I don't think that's the answer either.

DonTx
07-31-02, 10:14 AM
Wheel spin freely when clamped in the frame, rear wheel has a little more resistance than the front. I fooled around with the adjustments a little bit but that made no noticable difference. No chain slap either. I am going to put the bike on the trainer and see if the problem appears.