Grinding hubs to take 308mm discs

[Adrian]

I need to replace the front rotors on my '94 V6 and I really fancy fitting the <a href="http://www.clubcalibra.net/forum/showthread.php?t=10129&highlight=308mm%5dVectra" target="_blank"><a href="http://"http://www.clubcalibra.net/forum/showthread.php?t=10129&highlight=308mm"" target="_blank">Vectra</a> GSI ones that normcoupeturbo supplies</a>. I found a "How to" guide...

<a href="http://82.34.51.160/sytemsandsoftwaredevelopment/systems/automotive/How_to/Cavalier3/288or308mmbrakes.htm" target="_blank">http://82.34.51.160/sytemsandsoftwaredevel...308mmbrakes.htm</a>

...that has a video of a grinder being used to shave 5mm off the hub to get the disc to fit on the earlier hubs (on a Cav). It looks a bit scary, but then I'm a bit of a chicken. Anyone else been here, bounced off of it or gone ahead and done it?

[Cheater2k]

just use the 5 stud hubs, no grinding needed

[Cheater2k]

they look nice behind 17 inch wheels to, i have these on my cally turbo, lol

[jayl645]

at the end of the day its only really thin metal and dosent do a lot any way,
i would go for it and grind it off,
it will look well nice when there on!!,
jay

[Cheater2k]

this is what they do look like

[Cheater2k]

forgot to add the picture [img]/smile.gif[/img]

[Tim2001]

Cheater he has five stud hubs but the earlier varient which was fitted with the smaller disks. Rather than grinding like that i would consider removing the hubs and find a machine shop to lathe them down for you

[Cheater2k]

Or fit the ventra hubs with the calli barings, i think thats how mine were done, no grinding was done either way.

[Adrian]

<!--QuoteBegin-Cheater2k+--><div class='quotetop'>(Cheater2k)</div><div class='quotemain'><!--QuoteEBegin-->Or fit the ventra hubs with the calli barings, i think thats how mine were done, no grinding was done either way.<!--QuoteEnd--></div><!--QuoteEEnd-->

Aha! Vectra hubs on Calibra bearings... sounds interesting, getting a bit technical though. The 5mm that needs to come off is only 2.5mm off the radius, but what concerns me is that from a mechanical point of view...

...With the hub fiting snugly in the back of the rotor all the braking force is transferred equally to the shafts of the five studs (and retaining screw) but if there's any gap between the hub and rotor I can imagine some uneven loading on the studs (I'm amazed that they're able to take the shear forces as it is!)

Am I thinking about this too much? (Usually my greatest downfall)

[Tim2001]

Not thinking too much on mig they have spigot rings for sale for when adapting to the larger brakes from the much smaller varients. If the hubs are machined properly you should have no trouble.