something wrong or am I just lucky?

[matty b]

He I had a pair of c5 discs delivered to the shop and I was suprised to see that they appeared to fit perfectly on my hubs without having to machine the hubs at all. They sit flush on the hubs and the center doesnt seem to cause any problems either. Everyone says the have to machine the outside edge of their hubs but I have ample clearence the way it sits. So did I mess up or do I have the only set of hubs that will fit a c5 disc with no problems????

[matty b]

i assume this is normal?

[jaybee]

What car? It's my understanding that most if not all 5 lug Chevrolets down through the years use the same pilot hole diameter as well as the same lug spacing so there you go.

[matty b]

What Im talking about is the outer diameter of the hub. Every place that sells C5 disc brake conversions says that you need to trim down the outer lip of the hub to fit the inner face of the C5 rotor and apparently it wasnt necessary on the hubs I have so I was asking if this is some strange coincidence or if something is wrong cause i didnt have to trim the hubs.

[MrQuick]

Make sure you measure it. It can be deceptive. It will mount but not fully seat and the problem might not be evident till it is torqued down and driven. Most offen a chamfer is all that is needed.

[matty b]

whats the advertised spec on the inner face of the rotor? I can easily measure the hub but the rotor is a little trickier. From what Ive read, the hub needs to be 5.9" so Ill measure that. Its crazy though cause it really appears to be sitting nice and flat, maybe Ill put some grease paint on the hub and see if it fully transfers to the rotor. Thanks for the input.

[MrQuick]

Yep, 5.9 is correct.

Make sure you post your findings. Maybe you found a hub that works without machining.

Now that I think of it, I think machining just applies to cut down rotor hubs.

[Apogee]

Yep, 5.9 is correct.

Make sure you post your findings. Maybe you found a hub that works without machining.

Now that I think of it, I think machining just applies to cut down rotor hubs.

Most of the OE A/F/X drum hubs I've seen have had a 6.15" outside flange diameter and virtually no chamfer on the face. The center pilot register diameter of the hub has never been an issue as it is the GM standard 70.5mm. We always suggest cutting down the hubs to 5.94" OD with an 1/8" x 45 degree chamfer so that all C5/C6 rotors will work without question. The C5 rotors vary by manufacturer with respect to how much room there is inside the hat for the hub...some are fully machined and easily fit unmodified hubs but most only machine the bare minimum. The C6 rotors with their heat-dam design have much less room inside the hat and will require the chamfer noted above to clear the fillet radius inside of the hat where it transitions into the heat-dam.

Tobin
KORE3

[matty b]

yeah these are c5 rotors, ordered for a 2003 vette (doesnt matter but anyways) and the hubs are from a 70 chevelle with drums. My buddy Al at Chevyland gave me a few pairs of hubs and spindles plus a pair of wilwood disc brake brackets that were laying around. I put grease paint on the hub and set the disc in place and ran some lugnuts down on it to make sure it was nice and tight then took it apart and it was without a doubt toucing. Also there is at least an 1/8th inch of machined material surronding the outter circumerence of the hub so in reality the hub could be almost a 1/4 inch wider and still sit flat. I guess I am lucky with this set of rotors but from the sounds of it, it may be a different story the next go round.

[rwhite_692]

Make sure you measure it. It can be deceptive. It will mount but not fully seat and the problem might not be evident till it is torqued down and driven. Most offen a chamfer is all that is needed.

Yes, What MrQuick said...and you should only need to go down to about 6.030" diameter to do the deed...

[Apogee]

Yes, What MrQuick said...and you should only need to go down to about 6.030" diameter to do the deed...

Just don't ever think of swapping to C6 rotors because they won't fit with the specs given above.

Tobin

[matty b]

if i change the rotors I will be going to 2 piece wilwood rotors and I will cut em down at that point but for now I dont feel like doing that if I dont need to. My plan of attack at this point is to buy a set of the kore3 caliper brackets and then buy a pair of radial mount 4 piston calipers and the radial mount adapter brackets for a c5 from wilwood. Cool too cause the 4 pistons look like 6 pistons just missing the middle piston. So as of now just gotta order up everything else and get going with my front brakes. Thanks for all the inout guys!!

[rwhite_692]

Just don't ever think of swapping to C6 rotors because they won't fit with the specs given above.

Tobin

Right.... He asked about the C5 Rotor...