CB 9 wagon-specific rotor over hub conversion parts question

[oldcarguy6547]

Need to replace a slightly warped front brake rotor on my 91 wagon - since both rotors will be replaced, the hubs have to come off anyway & it has 130k miles on the original front bearings, will probably do a rotor-over hub conversion with new hubs and bearings at the same time.

According to the info in the rotor-over-hub-conversion sections of the brake upgrade stickies, 98-99 Acura 2.3CL front rotors are the same diameter as wagon rotors (282 mm) and only slightly thinner (23 vs 25 mm) - am I correct in thinking that wagon front brakes can be converted to rotor-over-hub by replacing the original Accord hubs, bearings & rotors with 98-99 2.3CL parts and using the original wagon calipers?

Have gone through the hub-over-rotor conversion sections of the brake upgrade stickies and threads a couple of times, don't see any any reference to this specific issue addressed anywhere.

[oldcarguy6547]

Update / revision to the above wagon rotor-over-hub front brake conversion question....

Found a post indicating that 1st gen Acura CL 3.0 (V6) front rotors have the same diameter / width / lug circle dimensions as wagon rotors (282mm dia / 25mm thick / 4x114.3 lug circle) - hopefully this means that the only parts needed to convert 4 lug wagon front brakes to rotor over hub are 98-99 CL 2.3 hubs and 3.0 rotors.

Can anyone verify whether this is correct?

[CyborgGT]

Kinda late to reply, but I seem to be in your same shoes. I want to keep 4-lug for now, but still do an ROH conversion when I replace my brakes and bearings. Looking at rotor specs on Rock Auto:

CB9 front rotor:
- thickness: 25mm
- diameter: 11.1"/282mm

'98 2.3 CL:
- thickness: 23mm
- diameter: 10.24"/260mm

'98 3.0 CL:
- thickness: 23mm
- diameter: 11.1"/282mm

'94 Prelude VTEC:
- thickness: 23mm
- diameter: 11.1"/282mm

Looking at the same brand of rotor for the Prelude and CL 3.0, they use different part numbers. There are some fraction-of-a-millimeter differences in certain measurements, but the main difference seems to be in where the set screws are located on the rotor hat, assuming the photos at the links are accurate and not just stock images. So I'd base my choice on where my set screw holes appear to be on the hubs we go with, and I still need to look into whether the 2.3 CL hubs still apply to us wagons...

Centric 12140037 for 3.0 CL:
- Center hole [hub] diameter: 64.2mm
- Outside diameter: 281.7mm
- Overall height: 47.3mm
- Stud hole diameter: 12.6mm
https://www.rockauto.com/en/moreinfo.php?pk=2033508&cc=1313323&pt=1896&jsn=440



Centric 12140034 for '94 Prelude VTEC:
- Center hole [hub] diameter: 64.1mm
- Outside diameter: 281.8mm
- Overall height: 47mm
- Stud hole diameter: 12.8mm
https://www.rockauto.com/en/moreinfo...t=1896&jsn=790

[oldcarguy6547]

Honda Parts Now lists the same O.E. part number (44600-SM4-020) for both left & right front hubs for all CB7/9 versions (90-93 DX/LX/EX coupe/sedan/wagon, manual & auto trans), so 2.3 CL hubs should be compatible with wagons.

Assuming that's correct (and as you mentioned) the key should be insuring the set screw holes on 3.0 or Prelude rotors align with the threaded holes in the CL 2.3 hub.

Rock Auto lists 2.3 CL hub & bearing sets from two manufacturers, one of which (GSP) lists specs for the hub center flange as 64 mm. Based on that info, if both the '94 Prelude VTEC & 3.0 CL rotor set screw holes align with the CL 2.3 hub, the .1 mm difference between Prelude & CL rotor center bores probably isn't critical - think I'd tend to go with the Prelude VTEC rotor's tighter .1 mm (.0039") clearance between the hub and rotor center bore.

[CyborgGT]

Well, since you're looking at being active here, this forum has officially died (the owners don't seem to want to sell to active older members) and a new one has just been started at projectcb7.com. Only a few of us are there so far, and a handful more are active on the CB7Tuner Discord (ProjectCB7 also has a new Discord), but we're trying to find other CB guys and bring the new forum to life. I've recently ditched Instagram, and I'll be clearing out my account there soon and leaving one final post to direct other CB guys to the new forum. Discord isn't very friendly for looking through older material, but at least it's lively enough to get quick feedback. Over time, I assume a lot of the tech info from here will be transferred over to the new forum as we all work on our cars in real time.

[oldcarguy6547]

Thanks for the info / update as to this forum's status (figured something of the sort was happening when the site's security certification lapsed & there was no response to queries directed to the admins) & the "heads up" regarding the projectcb7.com site - I'll log on there and get signed up. Too bad whomever owns / controls this site has no interest in passing it on to folks who'll keep it alive & current - will be a pity if all the accumulated info & knowledge here is lost.