Baer Track 9" rotor - axle hub diameter?

[BlownYenko]

I'm ready to order some replacement axles for my 9" shortly. When ordering axles, I have the option of specifying the axle flange diameter and axle hub diameter.

For the Baer rear rotors, it seems that 5.9" is the popular axle flange diameter option to fit inside the rotor, but I never see any mention of ordering the axle hub/stub diameter to make the rotor hub-centric without a need for a spacer ring.

Is there any reason for this?

Fumbling around in the dark with a splintered old ruler, it seemed my Baer rotor hub was 2.75". Has anyone measured theirs? To make it functional, I'd really like to make sure that measurement is perfect. I've searched this forum and most of the gazillion pages that came up on a Google search, but came back with nothing.

Thanks for any assistance!

[Apogee]

Odds are the center bore on the rotor is nominally either 70.3 or 70.5 mm [2.768" or 2.776"]. Without knowing the exact rotor you're using, I'm hesitant to tell you what to cut the axles at, however we suggest 2.776 for C5/C6 rear rotor apps as the rotors tend to run 2.782 to 2.787 for the most part. In my experience, most axle manufactures will standardize on the 70.5mm [2.776"] dimension if you specify a GM 5x4.75 wheel pattern for an early application unless you specify otherwise.

I'd suggest getting a better measurement of your rotor even if it means buying a decent set of calipers. Most auto parts stores seem to have a pair of calipers behind the counter, so ask around and you might save some coin...although a good set of calipers is something every auto mechanic should own IMHO.

Tobin
KORE3

[BlownYenko]

Thanks Tobin - that's excellent information. Turns out that the default 70.5mm that you thought is indeed what I need.

Cheers,
Craig