Extreme engineering question! RIDGID?

I was wondering if you could build a ridgid rear suspension hotrod? I see it done all the time with motorcycles, but could it be done with a car? This is a question for pure spectulation. I have wondered this for a while ,and feel confident there are people on here that have the knowledge to tell me one way or the other. Please try to back up any thoughts with real world knowledge instead of just writing off the question with one or two words, if you can. Thank you for any help you can give me with this question.

 

I imagine it would ride a tad rough.

....as in you'd be coughing up your spleen after a 30 minute drive.


I once drove a truck with a shackel rusted fast on ONE rear spring. That means that it wasn't moving and the spring was not working. In other words that axle was mounted solid on ONE side.

It just about beat me to death.

 

OK, before we get on to the practicalities (or lack thereof)...WHY?

The problem is that the only springing medium is the tires, and they are uncontrollable. So you either run really low profile tires and the car is a skaty brick, or you run balloons (more trad.) and it bounces (think Top Fuel dragster on shutdown).

 

I've seen it done, rear axle welded solid to the frame, usually for racing but I've seen a couple of street versions.

For a purpose built race car, it's OK, but for a road car, it's lazy. Not only would it provide a terrible ride, but it would put unnecessary stresses on bodies and ch***is, and may cause welds and other joints to fail over time.

But then again, I don't think I've ever seen anyone do it with any real design in mind, they're usually slapped together, so it might be do-able with some really good design insight. My question would be, why would you want a ridgid rear suspension hotrod?

 

Ridgid rears on cars don't work nearly as well as ridgid rears on bikes. Anyone who's riden in one describes it as "race only", not to mention there are alot more parts to rattle loose on a car, and you can't easily see them like you can on a bike.

 

drag car=ok
street car=ouch

while driving my old '71 chevy pickup the trailing arms rusted through and broke on me, so I made my own out of tubing and needed the truck to go to work after the weekend, so instead of making all the spring and shock mounts I just drilled and bolted it to the framerails with a rubber bumpstop in between...it looked cool as hell, backend lowered down with big tires out back...kinda g***er looking if you squinted your eyes...but the 2 mile drive to and from work was enough to make me want to shoot someone...it was insane how rough that ride was, and that was with 31 inch all terrain tires aired down...the only time I'd ever do it again is on a drag car, period...

 

My buddy Paul's original 50's drag Model A has a solid mounted axle. Between that and the drums on the rear only, it makes it a real handful to drive.

But that's the point. It is a full on drag race car.

I know he's thought about changing it before, but it has been that way for 60 years, so he just ****s it up and wear a kidney belt.

 

I appreciate all the replies so far. All the things that have been mentioned seem to ring true. I guess the only thing I was thinking about, with the ridgid rear in mind, was really cleaning up the back end of a car. I know on bikes the ridgids can really look streamlined because of all the extras you eliminate by doing it, but it looks like the trade off just wouldn't be worth it. May be there would be some way to hide the suspension and keep the ridgid look, and that is more where my thinking should go.

 

I wouldn't even attempt it.. you would rattle yourself and the car to pieces..

 

no suspension.

 

Why the hell not? do it and give us a report!

 

Two things you've overlooked so far.....

1) Making a typical car intended to run a suspension into a rigid will transfer all the stress into other parts of the car. Fatigue will occur and so will catastrophic failure. Bad idea.

2) You can't compare this to a race car like a fuel dragster. The ch***is on those types of cars is designed to BE the suspension. They have a known flex for the intended loading and also a designed life span before fatigue becomes an issue. See above.

We recently had a customer contact us to evaluate a ch***is he had bought. He had a pretty serious door slammer, but wanted to go a little quicker and be more consistent, so he took his motor out and sold the car. Then he bought a used dragster ch***is to put the motor in. Imagine his surprise when we pointed out all the stress fractures that covered that ch***is from one end to the other. Solid suspension cars are for limited use in controlled conditions. If you don't have a well prepped track free of pot holes, dips and curbs, you can't even begin to predict how long it might last. Why go there?
I saw an interview with Carrol Shelby the other day. When he chose the ch***is for his original Cobras, it was the cheapest thing he could fit the Ford truck motors into. It said it was flimsy as all get out, so they stuffed more and more tire under it until it started to handle. He used the soft ch***is as part of the suspension, but he didn't remove the suspension. Later, they got better suspension parts and improved the ch***is they put them on.

 

Try quarter elliptics,flat look good ride.There was a Bonnevile coupe lettered Sharp Equipped and Chrismans Garage, cirque 55 or so. the photos show no rear susspension.It's a leed for a look see.

 

you're gonna crash! when you hit a pot hole the *** end is gonna bounce all over the place especially at high speeds.plus you're ding your rims

 

There was a propeller driven car built years ago that had no suspension. I forget what it was called. It was real slow. Like 0-30 in 3 minutes. Real loud and sandblasted everything behind it. Talk about bumpsteer.

 

Ridged frames, like you said, are built for looks rather than function. Old bikers will not get on a ridged because it'll beat the hell out of ya. If you try to apply this to cars, your comparing apples to oranges. You usually can't see the suspension on cars so you not going to impress anyone. Why not make it comfortable to ride in. The more comfy, the more your going to drive it, right? Nobody wants to ride in a kidney crusher.

 

seams like a good way to have a ****ty handling, wheel hopping, rim bending unsafe piece of **** car. I think the purple people eater had a rigid rear, but it wasn't intenede for alot of street if I remember. cool looking car though.

 

Scratch
Problem is that a car weighs a lot more than a bike. So you end up with a ton of unsprung weight. That equals very poor handling and brakeing.

If you work the the tires size and air pressure you can probably get it to the point that it is tolerable but it will never handle or brake well. What will happen if you get it to the point that it doesn't skitter all over the road when you go around a corner is that it will mush out on you and you'll have really slow response to your steering wheel movements.

But what the hell, go ahead and prove me right.

 

Ever ride a lawn mower across a bumpy yard in top gear at full throttle? Times 100 I'm sure......no thanks.

 

On a bike you can also stand a little and use your legs as a sort of "suspension" for your body. Tough to do in a car.

 

Ignorance is bliss, just don't ask anyone to ride in it, or even "share" the road with it.

 

I've got one, ala "the Boneshaker" old lakster, haven't driven it on the road but I can imagine laughing and laughing with my friends as we drive into HELL

 

Speednazi,you are slower then me.That thing ain't done yet?
Post a picture on this thread.
Paul's Model A,has rigid mount rear end,followed him on the Swindlers pocker run.Center steer and hand brake(rear only) he had fun.
Anyone have pictures? Rolf?

 

This car is the one I was talking about..

 

just put up the old thread on the board, btw the 28 banger roadster is going up for sale

 

I tried to explain, but some guys just won't listen. I did not intend to do anything past building this car in my mind. This was pure and simple speculation. I was pretty sure it wasn't a good idea because I haven't seen any before. However, I just wanted some reasoning behind it in order to gain a good working knowledge of why ridgids work on bikes and not cars. Once again some guys can turn anything into an argument. Thanks to all those who backed up why it's a bad idea with something other than a smart *** comment.

 

Ever try to LEAN a car through a turn...

 

The altered with the solid mount rear is our car... and no, you can't drive it on the street very far without having your *** cramp up from all the pain inflicted on it from all the jarring.

I mean... a trip around the block will have your *** hurting for days!

So... I'd say... no... unless the car is just a fairgrounds cruiser...

Sam.

 

My bike has a shock on both front and rear. Cannondale, that is.

I hear the cave men didnt have suspension on their cars though. They were stupid too.

Race car= whole different story.

If your building it just for looks, it would look neat for sure, but why bother hanging all the ugly rear end suspension on it, and cluttering up the engine bay with all the weird lines of an engine? Smooth it all away (literally ALL), call it air, show it off to all your buddies! Hell, you dont even have to do any work, Ill sell you some of my air in my driveway for a few hundred bucks and you can show everyone how clean it is. Just send me the check. Buhwhahahahahahah!

 

I worked on a model A on 32' rails with a welded in rear, it was a salt flat car though, we were supposed to put a ford 9" in with a four link. I quit before then. Even for that application I wouldn't suggest it. You have absolutely no adjustability, suspension travel, and will probably break your frame, rearend, and loose a couple of nuts and bolts along the way. Your only suspension at that point is within your tires. The only benefit is that it just may make some poor gal's ***s flop out in the p***enger seat.