Emergency notice of KEIZER centers

[Jason B.]

Keizer wheel failure

A Keizer aluminum wheel failed on Thursday, June 12 during testing of the 2013 Texas A&M FSAE car. The wheel had a center design which Keizer supplies to FSAE teams using 10” wheels. The left rear wheel failed during a right hand corner. Fortunately, there were no injuries and minimal damage to the car.

Texas A&M purchased eight new 10” wheels from Keizer in 2011 and used them on the 2011 FH car & the 2012 & 2013 FSAE cars. Texas A&M has not done a lot of off season testing and driver training since 2011. After the failure, the seven remaining wheels were tested with dye penetrant and all spokes on all wheels had cracks. There is no visible damage to any of the wheels that would cause stress concentrations to initiate cracks. In retrospect, it is obvious that the wheel center does not have a very large section modulus in the direction that supports bending during cornering.

All three cars weigh about the same - 350 to 375 pounds plus driver. The 2011 & 2012 cars cornered at about 1.5g. The 2013 car has an aero package to generate downforce and grip & corners at excess of 2.0g.

Make McDermott
Department of Mechanical Engineering
Texas A&M University
College Station, TX 77843-3123

Jason Brelsford
Project Manager 2013
Texas A&M University

Here are the links to pictures of the failed wheel and another that had the dye penetration test performed on it when we got back from testing.

https://www.dropbox.com/s/y4fl...06-12%2017.13.24.jpg (https://www.dropbox.com/s/y4flx3waod3ecir/2013-06-12%2017.13.24.jpg)
https://www.dropbox.com/s/l8dq...06-12%2017.13.43.jpg (https://www.dropbox.com/s/l8dqa9ungg5v3wc/2013-06-12%2017.13.43.jpg)
https://www.dropbox.com/s/kxb7...06-13%2012.08.25.jpg (https://www.dropbox.com/s/kxb7hbus3n0plfk/2013-06-13%2012.08.25.jpg)

[Owen Thomas]

Bump so people see this and check their wheels.

Also: bummer, hope you guys figure something out before next week. Good luck!

[acedeuce802]

That sucks to hear. Do you have any pictures of the failure?

[MKakli]

Bump so folks see this.

We run Keizers but with 13" wheels. One of the Florida teams at MI approached us warning us that another Florida team had the same centers and they failed at the spoke.

[MCoach]

Originally posted by MKakli:
Bump so folks see this.

We run Keizers but with 13" wheels. One of the Florida teams at MI approached us warning us that another Florida team had the same centers and they failed at the spoke.

California 2011, a team running the 13" Kesiers saw a failure of the magnesium center at the hub.

From trying to find suitable wheels, it seems the word is that Keiser's centers are the week spot on both 13" and 10" wheel designs. Has anyone looked into official word on this.

We recently tore down and inspected our wheels this season to check for cracks before going out for testing.

[Moop]

We(Waterloo) were running a set of 13" Keizer CL0s last year and had one of the front wheels fail on track at the root of the spokes. We did dye penetrant testing as well on the other wheels and found cracks at the roots of the spokes

[Jason B.]

Originally posted by Moop:
We(Waterloo) were running a set of 13" Keizer CL0s last year and had one of the front wheels fail on track at the root of the spokes. We did dye penetrant testing as well on the other wheels and found cracks at the roots of the spokes

That is exactly the same issue. I'm trying to figure out how to get some pictures up.

[Jason B.]

Originally posted by acedeuce802:
That sucks to hear. Do you have any pictures of the failure?

Links to the pictures are now up.

[mdavis]

Originally posted by MCoach:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by MKakli:
Bump so folks see this.

We run Keizers but with 13" wheels. One of the Florida teams at MI approached us warning us that another Florida team had the same centers and they failed at the spoke.

California 2011, a team running the 13" Kesiers saw a failure of the magnesium center at the hub.

From trying to find suitable wheels, it seems the word is that Keiser's centers are the week spot on both 13" and 10" wheel designs. Has anyone looked into official word on this.

We recently tore down and inspected our wheels this season to check for cracks before going out for testing. </div></BLOCKQUOTE>

This is probably the Florida team cracked wheel: http://sphotos-b.xx.fbcdn.net/...5822_574135116_n.jpg (http://sphotos-b.xx.fbcdn.net/hphotos-ash3/540925_434974096565822_574135116_n.jpg)

Given that it came from USF's pictures from their Florida Invitational last year.

That being said, we talked to Georgia Southern last year at Lincoln and we saw the barrel of their wheel being out of round by a solid 3/4" at 1 point on the wheel. With their packaging it looked alright (they didn't seem to be pushing the limits of what you can fit inside a 10" wheel) but with our current setup, there's no way it would work.

We went away from Keizer this year, and I'm glad we did. We've had issues with our wheel supplier too, but they aren't nearly as bad as things seem to be with Keizer.

[Ben A]

Oh shit....


we just bought our first 10 inch rims this year from Keizer. I hope they don´t fail.

Is there an other better 10 Inch supplyer?

Is there an offical statement from Keizer?

I would be very angry if one of these rims fail, especially on the events. we bought just 12 rims thats not very cheap for our team. When they say there are for use in FSAE i would think they were strong enough and don´t fail under normal conditions.

Is there any Team who did an FEA calculation with the rims to show the hot spot in the rim to keizer or here in the forum?

Thank

Ben

[tromoly]

Originally posted by mdavis:
This is probably the Florida team cracked wheel: http://sphotos-b.xx.fbcdn.net/...5822_574135116_n.jpg (http://sphotos-b.xx.fbcdn.net/hphotos-ash3/540925_434974096565822_574135116_n.jpg)

Any idea which Keizer wheel that team was using? It looks very similar to the CL-1's our team is currently using, has me wondering what shape our wheels are in.

[mdavis]

Originally posted by tromoly:
Any idea which Keizer wheel that team was using? It looks very similar to the CL-1's our team is currently using, has me wondering what shape our wheels are in.

I have no idea. I just remember seeing the picture looking through their albums awhile back.

[Jason B.]

Originally posted by Ben A:
Oh shit....


we just bought our first 10 inch rims this year from Keizer. I hope they don´t fail.

Is there an other better 10 Inch supplyer?

Is there an offical statement from Keizer?

I would be very angry if one of these rims fail, especially on the events. we bought just 12 rims thats not very cheap for our team. When they say there are for use in FSAE i would think they were strong enough and don´t fail under normal conditions.

Is there any Team who did an FEA calculation with the rims to show the hot spot in the rim to keizer or here in the forum?

Thank

Ben

To my knowledge, our professor spoke with Keizer and they said that the web section where our wheels broke has been re-enforced. They have known about this problem, but I do not know the exact model or time in which they implemented the change. If the centers were purchased recently, you should be okay. I would still recommend a dye penetration test. It's non-destructive and can erase any doubts as far as competition goes.

[Buckingham]

Is there any Team who did an FEA calculation with the rims to show the hot spot in the rim to keizer or here in the forum?

You mean that you cant tell just from looking at them that that is EXACTLY where they are supposed to fail? Lowest cross sectional area and stress concentration at the radius which usually has more tool marks.

If you make them thicker, they are still going to fail ... it will just take longer.

Ive ran a set of kodiaks that failed the same way on all 4 wheels after 2 years. Wheels are consumable items.

P.S. how much do those hex head bolts weigh? Oh nevermind... its not like they are rotating mass at a 8"? Diameter...

[DKellett]

Hey guys,

Brief intro, I am a member of Queen's Formula, from Queen's University in Kingston, ON. As a designer, my focuses are frame and wheel package design. My other responsibilities are physical and driving testing and driver ergo.

Onto my point, if teams who had failures also have recorded the number of driving hours on the components in question, these numbers could be useful to other teams who run/are thinking of running these components.

Thanks,

[tromoly]

Bump up for safety.

We had a Keizer CL-1 wheel fail yesterday during an autocross event, the wheel did not separate from the vehicle but every spoke on the split five-spoke wheel center was cracked completely through, the driver was traveling approximately 10 mph when the wheel cracked and safely pulled off course. Looking at the other three wheels after returning to school every wheel center had cracks ranging from hairline fractures to substantial cracks in several spokes. We are estimating the wheels have approximately 30 hours of use, including two Michigan competitions, a few days of testing, and one autocross.

The wheels were ordered March 2012, earlier this year we ordered an additional two wheels which have a different wheel center design and are yet unused, attached below is a picture showing the difference in the wheel center design.

http://img163.imageshack.us/img163/5108/jdfv.jpg

[Kevin Hayward]

A good time for all teams on these wheels to start looking at designing their own centres. Starting with an existing wheel as a base it is easy to analyse and then make marked improvements. One of the few places where you can do a great back to back analysis of an existing commercially available item, and clearly show how you have improved the design.

Of all the centres available to purchase you can generally improve on a number of areas:

- Cost / manufacturability
- Strength
- Stiffness
- Weight
- Attachment method

In most cases you can improve all at the same time with a little work. Most of these wheel centres are very badly designed and do not account for the direction of the loads very well. With most centres I have seen they focus primarily on lateral strength, and do not behave well with torque and vertical loads added. Lateral stiffness also tends to be horrible.

From a very simple analysis the shape of the wheel centre above is pretty ordinary. Why would you want a solid rectangular cross-section on the spoke when a C-Section or T-Section would be a much better use of material? hy does there need to be anywhere near the amount of material in the hub? Ideally we want to see more uniform stress, put the material where it needs to work. Is a centre lock the best use of material? The bigger your attachment radius the less material you will need. Also looks like excess materail around the rim attachment points, and I'm not sure that countersunk heads are the best idea. If the offset is well considered you can probably mill a good centre from thick plate from one side. This looks like it has had both lathe and mill operations (at least the one on the right).

In the end this centre is difficult to make, not strong, not stiff, and heavier than it needs to be. If a student designed this centre for their final thesis it wouldn't be a good mark.

Kev