35 replies to this topic

[DionJ]

All the talk about going back to harder tires, lower offset wheels etc. Why not instead have a supplier build and the rules accept an optional front hub with real replaceable bearings that are up to the task? We do this with bump stops and suspension pieces. Initial cost might be higher, but less frequent replacement/ repacking and dnf's would make that up fairly quickly...

[Brian Ghidinelli]

Is this just a game of moving the failure around though?  What starts failing after that?  

[Jim Drago]

Who puts up the 25k or more in development money? What do we do when the first version is no better or worse than what we have? It is easy to throw out these ideas, but implementing them may be harder than we think. 

Jim

[davew]

Everything Jim said. Plus, If I develop the new bearing, what is to stop Joe Blow from copying it and not having any development costs. By the time patent is approved Spec Miata will be no more.

 

I like the idea, just doubt the feasability.

 

dave

[Parity]

Rather than chasing failure ad infinitum, wouldn't it be easier to tweak tire compound/construction to be a little more forgiving? Even if a little grip is sacrificed you retain low cost and reliability of the class. As we've seen, tire contracts come and go so I would hate to see rule changes for something that may go away with the next tire.

[Bench Racer]

A similar issue raised it's ugly head (IIRC breaking hubs and wheels flying off) in the early 2000's with the 1st gen Mazda RX7 SCCA production cars. The bearings in those hubs were not an issue, they were tapered rolller bearings with seperate outer races. There was meat and space to redesign. They cured the issue with redesigned front hubs/brake rotors. With the OEM hubs, they did all the similar on track stuff SM drivers do at faster speeds.
 

kcraceware.com

 

EP Mazda RX-7 front hub/rotor assembly.  Direct replacement for '84-'85 GSL-SE front brakes.  Designed to be used with the stock Mazda bearings, seal, and dust cap.  Hub is billet aluminum and can be supplied with your choice of metric or SAE wheel studs.  Hub also comes with the bearing races already installed.  Rotor is heat treated and has directional vanes.  Uses stock caliper.  This assembly is vastly superior to the stock, one piece, cast iron hub and rotor, as well as being 5+ pounds lighter.

 

[LarryKing]

Do we even know that the bearing failures are a result of the tire size/compound?

[davew]

I think it is a pretty logical assumption, that since we have gotten faster, we have gotten harder on hubs. More HP does not effect hub life.

 

Tires are a consumable. they only last so long. Where as wheels, hubs etc are (or should be) a rarely replaced item. So changing tire design/manufacturer/size/compound is a much more palatable expense.

 

When you think about the big picture, our hub issue is a very small expense/hassel when compared to any other class.

 

Dave

[ChrisA]

-edit-

 

Tires are a consumable. they only last so long. Where as wheels, hubs etc are (or should be) a rarely replaced item. So changing tire design/manufacturer/size/compound is a much more palatable expense.

 

When you think about the big picture, our hub issue is a very small expense/hassel when compared to any other class.

 

Dave

A lowed grip compound would probably be the best route, if the instances of failure continue with the SM7s. A narrower tire may not work optimally on the 7" width wheels we run, which is about perfect for 205s.  And, I doubt there would be much market demand for our old, slightly heavy 15x7 wheels if a new size was required.

[AW33COM]

Yet, there are those who do not destroy hub bearings no matter what.  Explaining that one would be the first step to improvement. 

[FTodaro]

I think it is a pretty logical assumption, that since we have gotten faster, we have gotten harder on hubs. More HP does not effect hub life.

Tires are a consumable. they only last so long. Where as wheels, hubs etc are (or should be) a rarely replaced item. So changing tire design/manufacturer/size/compound is a much more palatable expense.

When you think about the big picture, our hub issue is a very small expense/hassel when compared to any other class.

Dave

Look at my misplaced post in the mid ohio thread and tell me that bearing quality control is not a factor, comparing the before and after effects of tires. Tires as the cause is only relevant as a cause if all other factors remain constant. That is what we have to figure out or we are just chasing our tail.

[LarryKing]

Front bearings have been a weak link for the 12+ years I've raced SM, even when everyone was on Toyos. Frank's approach seems much more logical than just assuming "it's gotta be the Hoosiers."

[ChrisA]

Frank & R.G, good points. However, routine maintenance and occasional replacement of the hubs is not as big a deal to me as the flange failures. Those usually cause damage beyond the hub and could lead to driver injuries. The cause of this problem needs to be remedied, if these failures continue to appear. 

[steveracer]

Yet, there are those who do not destroy hub bearings no matter what.  Explaining that one would be the first step to improvement. 

 

Good point.

 

The only failure I've had was the one I brushed the K rail with.

 

Better balls, better grease, repack once a year whether they need it or not.

[Jim Drago]

Front bearings have been a weak link for the 12+ years I've raced SM, even when everyone was on Toyos. Frank's approach seems much more logical than just assuming "it's gotta be the Hoosiers."

 

Agreed! these hubs were NEVER meant to be raced in the first place.  

Jim

[Mike Collins]

Driving style has a lot to do with failures.  

 

Also has anyone ever measured a 205 hoosier vs a 205 toyo???  A 225 toyo is the same as a 205 hoosier.  A 195 Hoosier would fit on our current rims very nicely.

[Bench Racer]

Good point.

 

The only failure I've had was the one I brushed the K rail with.

 

Better balls, better grease, repack once a year whether they need it or not.

Not trying to negative, did you miss the post that Mazda's new suoer duper hubs failed out east this past weekend? I have not had a hub failure either. Maybe I have the most supreme hubs made or maybe I don't put an equal load on my hubs that failed hub drivers do. What about the hubs that have had the hub flanges fracture.

[Bench Racer]

Agreed! these hubs were NEVER meant to be raced in the first place.  

Jim

There is a message within this message.   We'll need to wait for the next FasTrack.

[Jim Drago]

Not trying to negative, did you miss the post that Mazda's new suoer duper hubs failed out east this past weekend? I have not had a hub failure either. Maybe I have the most supreme hubs made or maybe I don't put an equal load on my hubs that failed hub drivers do. What about the hubs that have had the hub flanges fracture.

 

Mazda Super duper hubs are nothing special and nothing than many havent done for years.  There are many many factors that come into play, curbs, towing, driving style, tires, towing and strapping, grease used and one of teh biggest is under torqued hubs for those trying to get the car to roll easier.  If the huib is under torqued, it will fail VERY quickly. 

 

 

No hidden meanbing in my post, we have no plans to develop or allow alternative hubs at this point in SM, not even talked about. You may see member input on 195 tires soon though

[Jamz14]

Good point.

 

The only failure I've had was the one I brushed the K rail with.

 

Better balls, better grease, repack once a year whether they need it or not.

Ah I new month and I can post again!! Though I am blowing my wad kinda early.

 

Repack once a year whether they need it or not??!!! Yikes. Am I the only one that inspects and repacks after every weekend and sometimes during the weekend? Also, last year I bought a hub from mazda and out of the box the race surface had some fairly large pits in it. I only discovered this because I do repack every race weekend. Maybe the issue isn't limited to ball tolerence but the race material. Personally I am not concerned about the front hubs. If I had my choice for a redesign it would be on the rears. Granted they don't seem to have the problem of the fronts, but nor can I easily service and inspect them like the fronts.