I think part of the problem is most people have no idea what the Fit's rear suspension actually looks like. I can't find the Fit trailing arm pic in my photobucket, but here is what the CRZ's trailing arm looks like (it's virtually identical to the Fit's).

All I'm asking, is somebody please explain how attaching a rod the size of your finger to a beam the size of your forearm is going to reduce flex???? The design of the rear trailing arm is basically a massive sway bar.

 

Found the pic of the Fit's rear beam...I sure would like to know if these are swappable (and what the weight difference is).

 

Let's move the discussion to the suspension subforum:

https://www.fitfreak.net/forums/2nd-...ml#post1043177

 

it isn't but what the torsion beam does is twist if even just a little bit. the trailing arms are connected to the rest of the car's frame. so the from the front of the suspension to the back is: front of trailing arms connected to frame by bushings, the axle beam and then the rear of the trailing arms where the springs and shocks are seated. the basic way is to picture it as a ladder without the other side connected to the rungs.

it would look like this:
_________________
| | | | | | |

picture the rungs as the trailing arms. without the other side, the rungs are fee to flex up and down. what a sway bar does is add another side to the "ladder".

so it looks like this and it's much more solid and won't flex as much:
______________________
| | | | | | |
-------------------------

i don't even have MSpaint on this work computer.

 

Ninja edit...I really don't understand what you're trying to say there with the "rungs of the ladder." There is a single cross beam and two components to the rear trailing arm (front, rear). Maybe if you use the appropriate terms your implied message will be clearer. Regardless, let's move the discussion here:

 

The Progress RSB is cheap. Buy one and then do a review instead of bench racing/theorizing whether it will work or not. You can spend the rest of your life using diagrams and computers, but truth is in the actual results. I put one on my wife's car and we both agreed the car is much more stable and drives considerably better.

My favorite part about it and the way I can tell it does make a difference is in the ability to get the rear to rotate. Before the bar there was no hope, but with it I can go in deep, let off the throttle, and get the rear to loosen up enough to get a nice slide through the turns. Might not mean much to others, but we live in the mountains and can really take advantage of the slight change.

 

I do plan to invest in one eventually. I actually popped in here because I read your post before the ninja edit...in for pics of the 500 rwhp beast

 

It's just your typical fox body Mustang...TFS heads & intake with a Paxton Novi 2000. The parts list is way too long, but those are the major items. Brakes from a '95 Cobra and completele aftermarket suspension make it driveable. Even without a single factory part, it can't get around a turn as well as the Fit. It just gets to and from the turns MUCH faster

 

Any reasony why?
(does it have anything to do with rear disc conversion?)

 

If the cross-beam in the rear axle were truly a tube, it would be phenomenally stiff, and probably no need for a supplemental bar.
However, it ain't a tube. It's actually more of a C-section (maybe closer to a horizontal V-section: >) with the open end facing forward.
With this design, the torsion stiffness of the cross-beam is closer to the twisting resistance of a couple of pieces of flat sheet steel connecting the trailing arms; much lower than that of a tube. So the additional torsional stiffness of a solid 19mm piece of spring steel would not be un-noticed.

 

the progress bar works as advertised. it is not a scam. ive had it on the GD and it did wat it was suppose to do.

 

I agree with this man. Before I bought the 2012 Honda Fit Base, I was driving my Corolla--it has a thick torsion beam in the rear AND a factory RSB sandwiched in-between. Based on the hype about thicker bars, I bought a thicker TRD bar that replaces the factory bar----it made NO difference whatsoever!

It was a waste of money...
That was for the COROLLLA.

ON THE OTHER HAND, WHY DID THE FIT SPORT INCLUDE ONE FROM THE FACTORY BUT THE BASE UNIT DID NOT COME WITH ONE??????

HONDA ENGINEERS LIKELY THOUGTH IT WOULD MAKE A DIFFERENCE...

 

No, they likely put it through serious modelling and then testing. Auto makers don't just take guesses. The rear sway bar on the Fit works to strengthen the weak factory rear beam. Think of it as a brace more than a sway bar, but it does make a difference.

To the degree that lift off oversteer is possible with the bar.

 

You're probably right----I wish I had gotten the Honda Fit Sport.

I bought my 2012 Honda Fit Base with 135K miles on it for 5,000 which 3 weeks ago felt like a decent deal---it's beginning to feel less like that because the car is really loosy goosy, the suspension is very wallowy. I'm going to have to modify it.

Of course it lacks the rear sway bar in the rear, the Progress may help a little but I think the factory unit is likely superior. Also the Sport just looks better.

 

The Progress bar is an upgrade over the factory bar and likely less expensive. Any bar is an improvement though. The factory rear beam flexes quite a bit.

 

The comment about them not working is 100% false. I installed them in both my 2nd gen and 3rd gen Fit's. I noticed a huge difference changing lanes at freeway speed with a load in the car. Or in the switchbacks driving on country back roads. Great upgrade for under $200 shipped.

 

I think, with my non-existent understanding of physics and whatnot, that this is the best way to describe a rear anti-roll bar's function for the Fit.

 

😂😂😂 Yeah agreed

 

Thank you for sharing, it is very helpful to me

 

I've recently installed the Progress RSB on my otherwise entirely stock Fit. Very noticeable difference. Car is significantly more planted in turns and doesn't have nearly as much body roll. It is very much like a 'reinforcement' for the torsion beam which still gives it the effect of a traditional swaybar.