Hubs with disc mountings, ok to use without disc?

[vlgi]

Hi,

I'm looking to get a replacement rear hub, the freehub has some play, and one of the cones has some heavy pitting, I've been looking around and most of the hubs I am interesting have a disc mounting, I am intending to use rim mounted V breaks.

My question is, does it matter, will the hub be fine to use even if it has a disk mounting on it for a non disc brake wheel?

Thanks in advance.

[Bill]

Yes if it was first intended for the bike you have then getting another with the disc mounting would be fine.

[vlgi]

Intended for the bike?

Not really sure what you mean, I have a Mavic X139 rims, I was going to reuse with a new hub, a 8 speed hub, new cassette and chain.

I take it the hub width would be the same but with the disc attachment would it mean the side opposite the freehub would be more dished than I currently have it with a hub without the disc mounting?

Thanks

[Bill]

(07-20-2010, 07:57 AM)vlgi Wrote:  Intended for the bike?

Not really sure what you mean, I have a Mavic X139 rims, I was going to reuse with a new hub, a 8 speed hub, new cassette and chain.

I take it the hub width would be the same but with the disc attachment would it mean the side opposite the freehub would be more dished than I currently have it with a hub without the disc mounting?

Thanks

Oh I misread what you stated earlier, sorry. That is a possibility, just wait to see if one of the others have better advice on this.

[trevgbb]

If you are rebuilding the wheel yourself, check that the essential dimensions of the new hub are the same as your old one, that is, OLD (over locknut dimension) FD ( flange Dia.) and the PCD ( pitch centre dia) for the spoke holes, the FTF (flange to flange), and the same no. of spokes. I would suggest you replace these, in any case.
If you look at the Novatech web site, you can see how all these dimensions interact.
http://www.novatec.com.tw/novatec/english/tec_d_c_data.php

[vlgi]

Hi thanks for the answers and information.

So I've looked into this again, I think the answer is essentially no, for a drop in hub replacement, which I guess is what I'm looking for, a hub with a disc attachment will not have the same geometry to allow me to just drop it in, however with new spokes and ensuring the correct number of holes, it may be possible to rebuild the wheel with the disc hub.

So I've been looking for the information on the current hub, its listed as the Shimano FH-MC18, seems is the Alivio hub, can't find the FTF or other stats however I am assuming FTF is the distance between the two flanges along the axle, and PCD is the distance between two opposite spoke holes around the edge of the flange.

So I got out my ruler and it seems the FTF is around 57mm and the PCD is about 45 which tallies with the figures on the PDF from Joytech's non disc hubs, the disc hubs have different FTF and PCD and a different offset (whatever that is, I'm guessing offset is some measurement possibly from the cone/flange to the end of axle on the same side [edit] Or not, looking at it I think maybe its the difference between the centre to the flange on the freehub side and the centre to the flange on the other side.)

Anyway throwing caution into the wind I bought a cheap Shimano Deore non disc rear hub with 32 holes. So I'm hoping Shimano machines its hubs similarly. (FH-M590 in-case you are wondering, couldn't find info on this one either)

So we'll see what happens when all the bits arrive, and whether I manage to build the wheel. I'll let you know what happens, unless it all goes horribly wrong, which it might

Thanks again.