Hardness of Hubs for 1988-1991 civic/crx....just a tidbit of info for ya!

[jisu009]

Ok.... After a long ordeal with various hubs that are offered for this application, here is a little bit of info. OEM Honda hub: -Consistant specs and tolerances -Rockwell of 18.2-18.8, which converts into a tensile strenght of around 118,000 PSI -This is considered "soft" or annealed steel. OPM Hubs: -Inconsistant specs and tolerances (based on the three hubs I had mic'd out) -Consistant Rockwell of 31, which converts into a tensile strenght of around 141,000 PSI -This is a "harder" steel that has been heat treated to raise the Rockwell So, after all of this "messing with hubs" I ended up running the OEM units becasue the issues with tolerances with the OPM units. Just a little "tidbit"....

This ad is not displayed to registered or logged-in members. Register your free account today and become a member on Honda-Tech!

[Tyson]

can you provide numbers please? i dont question your judgement, i just would like to make my own analysis on your numbers on these since i am runing opm hubs as well.

[ZygSpeed]

I have heard of people cryo treating the OEM CRX hubs in the past, for similar (durability) reasons.

[jisu009]

Cryo is a different process...it will only raise the Rockwell a point or two. It is mainly used to restructure the molecules and eliminate the inconsistencies in the metal....it yieds a more consistant product.....

Heat treating is used to substantially raise the Rockwell.

I believe ideally you could cyro heat treated hubs to eliminate the inconsistencies that heat treating may cause.....

So here is a question:

Who here has actually had a failure issue with an OEM hub?

[RexRacer19]

After five years of twice a month autocross and about 8 track events, I have not had a failure with my OEM hubs.

However, I have seen a failure just this last May at VIR. It was at a Driving School on an H4 preped Civic HB. I have been considering the hardened units because of the "common failure" hype. Seeing one fail kind of got me thinking a little more about it.

Are the hardened hubs custom made or are they OEM units that have been heat treated? It almost seems they would be even more expensive if they were custom machined.

[jisu009]

Originally Posted by RexRacer19

After five years of twice a month autocross and about 8 track events, I have not had a failure with my OEM hubs.

However, I have seen a failure just this last May at VIR. It was at a Driving School on an H4 preped Civic HB. I have been considering the hardened units because of the "common failure" hype. Seeing one fail kind of got me thinking a little more about it.

Are the hardened hubs custom made or are they OEM units that have been heat treated? It almost seems they would be even more expensive if they were custom machined.

The ones from OPM are custom machined from heat treated stock.

[phat-S]

Seen two fail on the same weekend on the same track in the same race, both lost a drive wheel. First one parked it off of South Bend at VIR, the other lost the wheel coming into Roller Coaster and went straight off the track through the grass on three. Both cars/guys were pretty lucky. Sorry I don't have any failure stories first hand as we change FL bearings every 6 races, FR for every two FL. Hubs get checked during bearing change. Currently have a set of OPM hardened hubs. Started with them and ran an OEM when the HHs weren't available.

[rice_classic]

Jisu: have you asked Rick or Steve or any of the other ITA guys what hubs they use?

I think I *might* remember Jim Leithauser (guy who built my ITA crx) saying that he used OEM hubs but changed them every 2 years.

just a thought.

[CRX Lee]

Originally Posted by jisu009

OPM Hubs:
-Inconsistant specs and tolerances (based on the three hubs I had mic'd out)
-Consistant Rockwell of 31, which converts into a tensile strenght of around 141,000 PSI
-This is a "harder" steel that has been heat treated to raise the Rockwell

Care to elaborate on the tolerance problem that you had? Is it a physical dimensional issue from machining and did it have any effect on the use or it it a stength or hardness issue effecting function?

I have seen one catastrophic LF hub failure at Road Atlanta many years ago on the ITA Civic that Whitney later owned. I ran OE hubs on a number of CRXs until I replaced them with OPM units but never had a failure or reason for concern.

[metalworker]

I too would like to know what kind of problems you ran into and how long ago were the units purchased?

I can't figure out if you are slamming a product or giving info.

[H5Civic]

Saw one fail last year at the BeaveRun Hyperfest on an H4 Civic Si HB. Chris Stiffler and I were crewing for the guy that weekend and Chris had said that it was caused from lack of brake cooling ducts and therefore the heat from the brakes is what made the hub fail. Just my $.02 worth.
Sam

[Tyson]

Originally Posted by jisu009

Who here has actually had a failure issue with an OEM hub?

i've had two failures, one week apart on original hubs and after i had unsmartly replaced just the bearings. i had originally considered the bearings as the original failure mode (bearing grease not up to snuff, expanding and stressing the hub). however i think the age and stress of pushing the bearings in/out creates enough stress on the hub it cant take any more racing. so the hubs are a veritable failure point.



when i received my HH from OPM, they had some obvious markings from mishandling, but im not too concerned with it. OPM told me they were the last ones on the shelf at the time, and i still feel more confident with OPM than OE.


Modified by Tyson at 2:23 PM 7/2/2004

[phat-S]

Originally Posted by Tyson

OPM told me they were the last ones on the shelf at the time, and i still feel more confident with OPM than OE.

So you were the bassard!!! Because of you, we had to race on OEMs for a while last year.

[Tyson]

(actually this was 2002)

[Black R]

wow, what else does OPM make?

Perhaps custom knuckles to go with those hubs?

[Tom Blaney]

You are correct about the initial hardness of the OEM hubs, that is why I use Honda factory hubs and have them hardened and stress relieved. Since I base mine on the factory unit I solved the fitment issue, and the hardness is increased a little higher than OPM's, so the units will last longer.

Trust me on this one because I lost two fenders in the coarse of two years before I went out and did the research and had my mcahine shop locate the right facility that can treat them properly. I purchase a 88 CRX/Si that had the other guy's hubs (and some spares) with them after 3 races at Lime Rock the left front hub failed at the radius behind the flange. Chaucked it up to experience bought a new set from OPM, and within a few more races same failure same result.

I now sell my own version of the hubs, and as others can contest, I ran the old car for another season and then have run the new car for a couple of years with the same hubs (including the 12 Hours at the Point) with no failure and have not had any reports of failure from the 20+ sets that I sold to my customers. Yes some things are a little more expensive, but that's because I want the parts to work and my race clients to be safe.

You can review them at http://www.sbmsinc.com/race_shop.html . As with everything else I sell, I have used them personally and suffered through the development process until I get it right.


Tom Blaney