Is their any options other than using clevises

[ram rod2]

Are their any viable options for attaching radius rods to front bat wings other than using clevises? I know a lot of builders have no issues with using them but they scare me! I have considered using four bar ends or rod ends sandwiched between two bat wings.It seems to me that rod ends will give you more range of motion. Not to sure if you realy want that? Using the rod ends would no doubt require the use of a panhard bar.

 

[2old2fast]

With a transverse front spring , the clevis' do not control lateral movement of the front axle , the spring tension controls that . If you're running coilovers , then you need a panard rod , still the clevis' do not control lateral movement..
dave

 

[ellis8500]

I use rod ends on both ends of all 8 bars in my 4-bar setup. I do not have a front panhard bar. The car tracks straight; does not show evidence of bump-steer and is very stable in turns. I do not have sandwiched batwings; they are not needed.

 

[ram rod2]

I use rod ends on both ends of all 8 bars in my 4-bar setup. I do not have a front panhard bar. The car tracks straight; does not show evidence of bump-steer and is very stable in turns. I do not have sandwiched batwings; they are not needed.

I will be using hair pin radius rods not a four bar set up.

 

[ram rod2]

With a transverse front spring , the clevis' do not control lateral movement of the front axle , the spring tension controls that . If you're running coilovers , then you need a panard rod , still the clevis' do not control lateral movement..
dave

Thanx Dave
I was under the false impression that a front panard bar would keep the front end from shifting and putting side load on the radius rods.i.e clevis. I understand that they are not designed for side loading or for controling lateral movement.

 

[2old2fast]

So you're still scared or are you not scared ???
dave​

 

[ram rod2]

Dave

I guess what it boiles down to is that if the front suspension is set up right then clevises are adaquate.
That's as far as I am willing to go. I guess I will go with the clevises and stop trying to reinvent the wheel!

 

[choppedtop]

Here are some interesting reads from early posts. https://tbucketeers.com/threads/front-panhard-bar-yes-or-no.8824/

 

[ram rod2]

Here are some interesting reads from early posts. https://tbucketeers.com/threads/front-panhard-bar-yes-or-no.8824/

Thanx
That was some interesting stuff!!
Realy liked what LKE and Bat had to say. Pretty much in line with what I had always understood with respect to use of a pan hard bar!
I did note that in one post their was another failure of a clevis. So here we are full circle again! Back to my original post.
Is their any viable options for attaching the radius rods to the batwings other than using clevises?

 

[ram rod2]

Sorry that was a heim failure not a clevis but the question still stands.

 

[2old2fast]

With the failure rate of clevis being in the 1/10th of a percent category , and them being used in a non fail safe situation , my moneys on them being fine.
dave

 

[fluidfloyd]

Sorry that was a heim failure not a clevis but the question still stands.

ram rod2...I am one that does not care for clevis for several reasons. I know I'll get a number of disagreements but that's why it is a discussion forum. The biggest problem with using a clevis is knowing the quality of the part and it's application. A number of people machine these parts and some import them. As in all fasteners I make sure of where they come from and what the material specs are. Just because a bolt is marked grad 5 or 8 doesn't automatically make it good. Lot's of off shore stuff that is on the very low end of the minimum rated strength level. Chinese stuff is always suspect. When used in the wrong application in a suspension component then Murphy's Law can and will apply. Clevis use is just as critical. They are not designed to take side loads for any reason. They are normally us for adjustable linkages, push-pull links etc. To use them to locate a front axle requires everything to be on the money. Here is what you need to look for.

Quality Clevis: The clevis should be of a known source of quality. Ask where it came from and the material/strength info. The bottom of the slot should be a radius cut equal to the slot with. (.375 slot = .1875 radius). Absolutely no square cornered slots!

Bracket Material: The bracket should be of a thickness that is a slip fit into the clevis slot. Just enough clearance to slide in without having to force it. Side clearance or slop should be a minimum. When you tighten that through bolt the clevis should not be forced or pinched together. Use thin shims if necessary to obtain a close fit.

Clevises should never be used in a 4 link type of suspension If you use a 4 link you need to use a double shear bat wing with a rodend bearing or a rubber or poly style bushing. I know some do us a single bracket but that puts the fastener in a bending load. As long as you don't exceed the yield strength of the bolt all is well. It's those sudden impact loads from curbs, pot holes etc that can spike the fastener hard enough to yield or bend it.

Clevises can be used with hairpin type radius rod designs but they don't like side motion. I know the argument of spring shackles keeping things centered. While that is true to some degree spring shackles are not close tolerance devises and usually have some slop in them. That is why I feel it is necessary to use a track locator. The longer the better.

As always, there will be some that see things differently and that is their right. Do your research and think about all the motions taking place then go with what you think is right. At the very least choose the very best components you can afford. You can skimp or even cheat on some parts in a car build but suspension, steering and brakes are not in that group ever! Hope this will give you some insight and something to think about. Good luck with your project.

George

 

[EX JUNK]

Very well said, George.

Jim

 

[2old2fast]

while i agree w/what george said , I'll add this caveat...using speedway as an example , even if you knoww all the right questions to ask , the likelyhood that you'll get an educated answer is somewhere between slim & none , I'll guess that would be true of most if not all hot rod suppliers..... so then what , don't buy the part ,.... don't build the car......??? few , if any of us home builders know the right ? to ask or have the time to research each & every part we use , I'll agree that you need to be informed , but going w/what is normally used isn't all bad ..
dave

 

[ram rod2]

With the failure rate of clevis being in the 1/10th of a percent category , and them being used in a non fail safe situation , my moneys on them being fine.
dave

Dave
The way I see it is the use of a pan hard bar/ track locator is a little insurance that the clevises will not be subjected to side loading?Then theirs the issue of the 3/8" throu bolt. scary
Their has to be a better way?

 

[ram rod2]

thanx George
this is good stuff!!

 

[2old2fast]

You wouldn't be an engineer perchance ? Every one I know suffers from "paralysis by analysis "
dave

 

[ram rod2]

You wouldn't be an engineer perchance ? Every one I know suffers from "paralysis by analysis "
dave

Dave
No I am not an engineer but I am for sure "paralysis by analysis"

 

[fluidfloyd]

Very well said, George.

Jim

Thanks Jim. Coming from you carries a lot of weight at my house. If I'm not mistaken I was thinking you might have single shear brackets on the rear chassis brackets. If so. I didn't mean to upset anyone's design cart. Big enough bolts can and do overcome bending forces. It's those big torque numbers and sticky tires that bend things. In the front end I feel these bending issues are more of a problem due to several things. Usually the bolt diameters are much smaller. The single batwing bracket is usually 3/8" thick allowing very little bearing load surface. Hole sizes are either laser/waterjet cut and sometimes are slightly over sized to the bolt OD. That allows the bolt to twist in the batwing which can egg shape that hole. I have always drilled holes just undersized then reamed to fit. Hairpin units are flexible by design and in my opinion should not be used to attach shocks to. I realize this might be over thinking or even anal thinking but I have been called and accused much worse. Just the industries I have hung out in over the last 50 years have inbred me into that world. And it really takes no more time to apply those standard to these cars then doing it quick and dirty. Looking at your car and your son's should be a must do by anyone starting out on their first build. Another one to study is Hotrod 46 and his roadster. I had a chance to really look it over at Spirit's Bucket Bash some years ago and it is well thought out and executed like yours. Hope this clears any mud in the water. Take care!

George

 

[fluidfloyd]

while i agree w/what george said , I'll add this caveat...using speedway as an example , even if you knoww all the right questions to ask , the likelyhood that you'll get an educated answer is somewhere between slim & none , I'll guess that would be true of most if not all hot rod suppliers..... so then what , don't buy the part ,.... don't build the car......??? few , if any of us home builders know the right ? to ask or have the time to research each & every part we use , I'll agree that you need to be informed , but going w/what is normally used isn't all bad ..
dave

Dave...The clevis quality can usually be solved by going to the drag racing world. Most chassis builders have good sources for them ang buy 4130 clevises. When it comes to standard nuts and bolts just go to a MSC tool catalog and look trough it. All bolts will have the manufactures name. Look for a known brand and source it out. I see the name Hillerman on a lot of pre-packaged fasteners from Home Depot, auto parts stores and Fastenal. All from Taiwan. I buy bulk by the pound bolts from Tractor Supply and use them for tooling and mock up assembly. Later I replace them with either quality standard bolts or Aircraft AN or NAS fasteners. Then I sleep reasonably good that night. Just some insight from my cluttered mind!

George