Rotoflo owners needed here.

Hello! Ok it whas rubber in ,no i dont have rubber tree can i find that on
ebay too ?
Have you the old soft rubber in your dampers or you have restore with
new fluid ?
Yes i like the look on them. I have plans to this on my 32 5w in 50s racer style.
Maybe best to heat them up little and try to get the arms to move and
see what happen before i try to take them down.
Thanks. Jan

 

Yes i get the arms to move now and they looks to work ,i see the rubber in it
move when i swing the arm so maybe best get them a chance on the car
before i take them down.

 

Here is how the makers describe them, in an ad from 1949 ...


WHAT IS ROTOFLO AND HOW DOES IT WORK?

"Plastic-Solid" shock absorbing is exclusive to Rotofo. It is a special NON-LIQUID filling which is forced by powerful pneumatic pressure into the body of the shock absorber. There is "squeegees" into every part of the Rotoflo mechanism, forming a "Plastic-Solid" buffer which gives a strong resistant "flow" to every movement of the outer arm, thus "cushioning" both car and rider against road shocks on the worst surfaces. The revolutionary Rotoflo has only ONE moving part, no valves, NOTHING TO GO WONG. The chamber is impervious to the entry of grit and foreign bodies. This completely obviates the possibility of failure or siezing up."

http://www.gracesguide.co.uk/wiki/Image:Im19491007Autocar-Universal.jpg

 

Thanks SimonSez that whas very nice and helpful information , fun to see this old
publicity too.


On my dampers are one shaft 1/2 inch longer out than the other.

Have they different shaft size on the A2 dampers ?

 

Hello! Are here any Rotoflo owner know anything about the shaft output
sizes ?

 

I got a pair off Ebay a few months ago. I'm going to run them on my 27 roadster on 32 frame. They are really stiff, I need to put them on a vise to see if I can move them.

 

Some info I've learned since my last post:

One rebuilder says he uses windshield setting tape in his. He dis***embled and shoved it as full as he could with the pliable tape. I haven't tried it yet.

Another rebuilder says he uses urethane like used for casting molds. He sent me a sample but I haven't tried it yet.

Another guy (maybe I read this on the HAMB?) said if the rubber was still in your shocks, you could soften it by putting a few drops of thinner through the hole in the middle of the shaft. Maybe mineral spirits would soften the rubber? I haven't tried this yet either.

I've since bought another set of four that are completely apart with no rubber in them. They'll be a good set to experiment on.

 

Awesome, I'm going to open these up soon. Do you have pictures of yours on your car?

 

All eight of mine are sitting in boxes on the shelf.

 

I was able to free my pair of A2s up. Now I have to weld the biscuits for the flathead so I can mount them.

Posted using the Full Custom H.A.M.B. App!

 

These pdf files should enlighten you all a little more. http://www.gracesguide.co.uk/Universal_Dampers

It seems the Rotoflo dampers were manufactured by Universal Dampers, Cranmore Boulevard, Shirley, Solihull, Birmingham (this is the town Hamber Mart [Holden] lives). They do come up for sale, often in very poor condition, on the UK Ebay web site. Beware, they can be expensive to repair and re-service.

Here's a link that confirms the use of 'uncured synthetic rubber as the resistance material' - http://archive.commercialmotor.com/article/24th-february-1950/61/increased-range-of

This company maybe able to help you, though they are based in England - http://www.vintageandcl***icshockabsorbers.co.uk/

Another similar 'cylinder' type damper you might want to lookout for are Luvax (though problems with the original Luvax [according to many experts] is that the internal chamber is made of Mazak which is prone to cracking)[FONT=Verdana, Arial, Helvetica][/FONT], these are re-buildable and do use a damper oil/fliud that can be serviced/replaced.

Hope this helps.

 

And... this Norwegian Guy says he was gonna use a silicone replacement in his Rotoflos. I haven't read the whole article, yet, but maybe you wanna get in touch with him as the build was started back in 2007 - http://www.earlyford.no/phpBB2/viewtopic.php?t=1971

 

I have dis***embled some of mine and installed oillite bushings in the egged out holes in the housing where the shaft comes through.



You can see part of the bushing sticking out. I decided to leave it long since it will give more holding power to the shaft. Also note how the pair of shafts on the polished shocks are longer than the unpolished one in back. Maybe there were a couple (or more) varieties of the A2 model for different cars?

I have not replaced the rubber in these yet. Mike In Tuscon was going to research the consistency and try to find a replacement goo when he has time. I gave him a sample of the goo from one of these shocks.

 

Alchemy, did you ever come up with with replacement goo for the rotoflo shocks?

 

I have not. They are still sitting on the shelf with nothing inside them.

 

Thanks to the sample that alchemy sent me, we determined that the material is a natural rubber. Last year, I only had a set of NOS Rotoflo shocks and I didn't want to destroy those with testing. Since then, the NOS shocks are on our 32 roadster and work very well. I also found some worn out ones from somewhere in Europe that I bought. They need bushings like alchemy installed in his. I need time to work on this but other stuff gets in the way. There appears to be a way that the original manufacturers filled the shock body....I am not familiar enough with natural rubber to know if it exists in a flowing, liquid state so it can be "poured" into the body OR if solid, packed into the body somehow. There is an adjusting screw at the center of the lever arm, this appears to serve to compress the material to affect the damping response. We do know that the material is a solid that is much like chewing gum consistency. Will post more if I find any info. Mike in Tucson

 

If I had to chew it my jaw wouldn't last ten minutes. I'd think it's closer to a dried-out tube of RTV.

Post up pics of your roadster Mike.

 

I just found a really useful post here from last year that has the patent details of the rotoflo, posted by @RAREBIKE.

Here is a link to it ...
http://www.jalopyjournal.com/forum/threads/roto-flo-shock-absorbers.965323/

The patent states: "the medium is uncured or unvulcanized natural rubber, devulcanized rubber, " Government Rubber Styrene," or other synthetic rubber coming in the category generically known as Elastomers, the medium retaining its plasticity, between a temperature well below zero and 200 F. and completely filling the spaces in the chamber which are unoccupied by mechanical parts. Suitable Elastomers include poly-chloroprenes, butadiene, acrylonitrile copolymers, isobutene diolefin copolymers, silicone rubbers, organic poly-sulphides or thioplasts."


Here's a couple of non-hardening sealants I found online that might be worth trying ...

SikaSikaLastomer-711 is a high solids, non hardening, non-drying, non-oxidising butyl sealant

Tremco Acoustical/Curtainwall Sealant is a single component, non-skinning, non-hardening synthetic rubber sealant.

 

here tis, before aluminum heads

 

SimonSez, thanks for the suggestions....we are trying to find the local distributor so we can buy some material to try. The Tremco stuff looks especially promising. The 1,000,000 cps viscosity seems about right. I may need to mail the sample to Alchemy if he has a shock body that is serviceable....mine are not yet. Will update this posting when I get the material purchased.

 

Here are mine on my roadster, I hope to be on the road soon. Shocks have really good resistance and bounce when I jump on the front end

 

Great looking T Al!

 

http://www.rosta.us/

here is an industrial version that could be aapted. Ugly as sin, but....

 

Found the material that SimonSez spoke of....in stock in Phoenix. Now I just gotta get up there are buy some of it to test.

 

Any opinions on using the lever shocks that were used on TR6's in the same application?

 

I have had some luck putting them in low temp boiling water for a time approx 10 mins, then quickly bolting a them to the vice to get movement. Some of the large size ones were still reluctant to perform well, but we got 4 of the small ones working well with sufficient resistance . They have performed well in our 32 3w for the last 7000 Mls.

 

Fortunateson, those Triumph shocks have been used on a few hot rods. They are hydraulic and you can still get the seal kits. I have seen them polished also, but am not sure about the range of lever lengths available. Rotoflo shocks were introduced after the war, probably in response to all of the hydraulic shocks that leaked.

 

Good point about the lengths avaiable. I have a few sets
I acquired while working on my TR6. I guess I'll just go and see if they would work.