Let’s not forget the potential for weight saving.
Plastic bushes are likely to be several grammes lighter than rubber encased steel 
If they work much the same as the originals without squeaking, rattling or creaking but look a little prettier and are one or two grammes lighter, I will be happy.
If there is a detectable improvement of any kind, I will be thrilled
I have them, they do work.
Yes, I can confirm they do too. I bought some from Skidnation, blue to match Laguna blue. However, I’ve found that listening to all advice in these forums has made the most difference in terms of getting rid of or reducing shakes and rattles - the bushes helped, as did tightening up the toolkit and the spare, as well as fitting brake anti rattle shims. All of these together have made a difference, so thanks all for the advice!
Well, all of the above so I’m very pleased.
Theyre not beautifully made though and appear to be 3d printed.
They come oversize and need sanding to fit but once done, all the creaks and groans from the folding roof disappeared and the car does feel more confident and less squirrelly.
Thumbs up.
Back in the thread a fair way I mentioned I’d 3D printed a pair of these and thought there was a general improvement in the feel of the car after fitting and left them on. After that, a few of weeks ago I had the Eibach -30mm coils fitted (and full geo setup) and have got used to the more direct feel of the car.
When I first fitted the printed door bushes I was aware they were not tight in the cups; not loose, but they slid in without sanding so I made a pair .3mm wider and could feel these were a quite solid fit to the sides of the cups. I did a (roof up) run over roads I know well including our far from perfect approaches to the village and the result was the ride felt the same but there was a lot of squeaking and rattling from the roof I didn’t have before; quite unpleasant.
I then gave my original rubber bushings a good squeeze in a vice as suggested by Saz9961 somewhere up the thread. There are signs of contact on these but no visible wear. When I drove the same route the rattling had gone and the ride felt smoother on the rough surfaces, riding better over the irregularities.
Going back to my original printed pair, these seemed to be a half-way house. Rattles on a rough road were gone but there was a greater feeling of the road surface transmitted through the body than with the OEM rubber bushes.
Try reaching across with your left hand and pushing a couple of fingertips against the gap between the vinyl trim at the top of the door and the front of the roof well while driving on a rough road. With both the printed bushings and the OEM ones I can feel a very very slight squashing and release; about the same with both types of bushing.
My overall opinion is the plastic bushes definitely do make a difference to the feel of the car but it may be more about how much of the road vibration is fed into the upper part of the car rather than any great stiffening effect. Yes, probably minimally stiffer to transmit the vibration but not in any way enough to affect handling. I’ve now reverted to the OEM rubber bushings for what I feel to be a smoother ride.
I suggested not squeezing the bushes, but the squeeing cup (Mazda calls this the Dovetail)
The Dovetail/cup
That sounds rather irreversible, although I suppose you could always buy new cups if necessary.
Yep, so you did. Sorry about that, Saz.
Should have re-read your comment.
Interesting.
I think a sliding fit is what you would be looking for, an interference fit seems too tight to me.
With my sliding fit bushes, I personally find that the car does feel sharper, more solid and the steering feels more direct with tighter turn in.
It now feels like the car I expected it to be, the handling was a little disappointing before.
The fact that the new springs combined with plastic bushes make the ride over-harsh suggests to me that maybe the new springs rely on chassis flex to give an acceptable ride and are just too stiff without it
All in all, I find the bushes do live up to the claims but in hindsight, I think I should have gone for the Cobalt delrin bushes rather than the ABS 3d printed ones and I still might.
All subjective of course but even if it’s all in my mind, that’s alright because I’m definitely enjoying driving it more and that’s what counts.
Done a few more miles with the OEM rubber bushings and decided I prefer the 3D printed ones I made originally. Very noticable difference in long sweeping curves where the car feels more solid on the road than with the rubbers. (This is on a different route to where I was doing a comparison before.)
There is some sacrifice in terms of ride smoothness with the plastic bushings and yes I’ve been faffing about too much with these and changing my opinion, but overall I feel I now prefer these to the OEM variety.
What plastic did you do your 3D printing with, may I ask?
Now I’m convinced that they actually do work as claimed, I’m definitely tempted to ‘buy twice’ and get a pair of the Cobalt Delrin bushes from Moss. The ABS 3D printed ones are showing signs of scuffing.
I printed these in PETG which is a modified version of the plastic used for most fizzy drink bottles etc.
Very similar properties to ABS but a lot easier to print with. ABS is what Lego blocks are made of.
Delrin is a more resilient than both these and a machined block is always going to have better wear resistance and dimensional rigidity than a 3D printed bushing.
Just squeezed my cups yesterday (bored so thought let’s have a play) must admit it’s taken a few rattles away the door is tight now before you could just let the door go and it would shut, now you have to help it with a little shove.
The Cobalt bushes are 25 quid plus postage of something like 8 quid.
The 25 is fine but the 8 is not for such small items, so I got some machined Delrin bushes from a guy called Rob Bate.
Great quality and the same 25 quid but no postage charge and you get stainless flanged bolts thrown in.
Buy cheap buy twice for the just send it version but I was sceptical if they would work.
Now I know they do, Rob Bate is my recommendation.
Tried to tell many this!
Don’t you fret now. They are lovely darling. 
A swift calculation based on 8000Nm/degree chassis torsional stiffness does suggest that about 25% of the movement at each wheel, relative to the driver, is the chassis twisting. That’s with 6kg/mm springs. So I wouldn’t say that the ride relies on the chassis, in fact, that would not be a good way to do it because the chassis motion is relatively undamped, compared with the suspension.
Sorry to resurrect a two year old thread; I should have checked the dates!
