Mystery Monoshock for Tamiya Frog

[tacomancini 11]

This appeared on eBay as an "Unbranded" monoshock and on the bag was "Frog Suspension" written in sharpie.  It came with a rear sway bar and resembled the Parma setup I've seen on here with a few key differences.  Instead of mounting to custom upper suspension arms it uses L brackets that mount on the front of the suspension.  This looked pretty suspect but I was intrigued by the mystery of the brandless hopup so I decided to make it part of my "Mach II" setup.  Plus, with the re-re Frog being my first real RC build (I'm late to the game) I wanted to experience first hand the fun of leaky vintage dampers and all the quirks that come with a monoshock.  

After figuring out how to keep it from binding everything up I found that it offered some unique benefits.  I have the CRP suspension arms with the metal bushing in the holes which really go a long way to reduce slop so it was great that this setup doesn't require the special upper arms that other frog monoshocks do.  Also the L Brackets seem to add to the stability of the suspension and because the damper relies on the internal springs of the Frog I was able to use much softer You-G springs that came from the kit that's too pretty to use at this stage.  

I'd love to hear if anybody has any idea where these might have come from.  They are so similar to the parma setup that I wonder if maybe they were an earlier variation, but I know companies like dirt burners have also done a frog mono setup.  Regardless it's been very fun putting these together so if anyone has critiques, tips or experiences they'd like to share I'd love to hear them.  I'm going to give this setup a go while the you-g independent dampers wait in the wings for a bit.  I'm still a terrible driver.  

 

 

 

[Pablo68 741]

Looks very interesting, but I really have no idea.

Better to be late than never I always say.

[tacomancini 11]

Totally agree!  Thanks for taking a look.

[KEV THE REV 2238]

Very interesting , looks great , would a Frog body still fit on at the front ? . I haven't played the video yet so maybe you've explained it

[tacomancini 11]

It fits but you have to remove the damper to put it on.  Definitely a little bit of a pain.

[Juggular 4429]

That was interesting.  I like your voice. (lol... is it weird to say that?)  

"Tah-me-ya" is correct.  

As you noted, if it takes 2 seconds for the shock to stop, (& it extends only half way), I would say that's too stiff.  My rule of thumb is that a tire should recover from a bump in half a second or so.  What you could do is to drain most of the oil and leave just a drop or two for lubrication.  I did that for light M-06 touring chassis' front end.  Because the front is so light on M06, the friction from o-rings was enough. 

(Even with light oil, M06 would jump over a bump, instead of soaking it up. Now without oil, it soaks up without oscillating. Putting in oil isn't the end goal; it is soaking up the bumps. As far as I'm concerned, I don't care if stopping oscillation is done by o-ring or oil.)   

I wondered about the swaying effect, and you showed it.  If it sways too much when cornering, you could remove the springs, and use it only as a shock.  Not many people complain about the spring rate on Frog, but they do complain about lack of shocks.  Yours solves it.  It looks like it needs some adjustment, but tinkering is half the fun.  

Would you keep us posted? 

 

[graemevw 819]

It does look a little over damped to me, but i like the set up.

As for the voice, easy to listen to 😂

My other half says you sound like Conor Oberst (whoever that is) who is from Omaha. Anywhere near you?

[Frog Jumper 3123]

I've seen a rear sway bar like that.  With the small tab thingy and the short wire, rather than the round thingies and long wire we usually see with the Parma and You-G rear sway bars...  But for the life of me, I can't remember the manufacturer (if I ever knew it) and I can't find it online...  I thought maybe Trinity, but its not...

And I've never seen a front mono-shock like that.  I like the L-Arms - its a neat touch...  But you'll have to play with the action in order get it right...  But I wonder if you'll ever get over the sway effect the mono will give your car...  Fun stuff! 

Honestly, the sway concern at the front, and the PITA factor in removing the body, has kept me using 2 independent shocks...

Terry

 

[Nicadraus 4281]

When I had a Frog (converted from Brat) back in the 80s, I always wanted to improve the suspension. I replaced the rear shocks with the auluminum but the springs were too hard while the fron suspension was too soft. I thought of doing something similar to this but didn't have the resources (lack of materials, tools).

It's nice to see this and it works. Good job!

[jeekelemental 528]

Taken inspiration also from that mono-shock seen on the Net and with the intention to keep the original horizontal damping scheme, during the years I've made some "experiments".

First attempt:

<a href="http://tcphotos.net/image/Ie3u"><img src="" alt="brat001.md.jpg" border="0"></a>

 

[jeekelemental 528]

Second:

<a href="http://tcphotos.net/image/Ifjt"><img src="" alt="brat002.md.jpg" border="0"></a>

[jeekelemental 528]

Final:

<a href="http://tcphotos.net/image/I9dx"><img src="" alt="brat004.md.jpg" border="0"></a>

 

<a href="http://tcphotos.net/image/IzSl"><img src="" alt="brat003.md.jpg" border="0"></a>

[tamiyanerd 2]

The momoshock  is a You-g item resold in the states by Parma.  It came with upper control arms with a 90° cantilever. Very similar to this item by Dirt Burners

[tacomancini 11]

On 11/6/2019 at 4:49 PM, Juggular said:

That was interesting.  I like your voice. (lol... is it weird to say that?)  

"Tah-me-ya" is correct.  

As you noted, if it takes 2 seconds for the shock to stop, (& it extends only half way), I would say that's too stiff.  My rule of thumb is that a tire should recover from a bump in half a second or so.  What you could do is to drain most of the oil and leave just a drop or two for lubrication.  I did that for light M-06 touring chassis' front end.  Because the front is so light on M06, the friction from o-rings was enough. 

(Even with light oil, M06 would jump over a bump, instead of soaking it up. Now without oil, it soaks up without oscillating. Putting in oil isn't the end goal; it is soaking up the bumps. As far as I'm concerned, I don't care if stopping oscillation is done by o-ring or oil.)   

I wondered about the swaying effect, and you showed it.  If it sways too much when cornering, you could remove the springs, and use it only as a shock.  Not many people complain about the spring rate on Frog, but they do complain about lack of shocks.  Yours solves it.  It looks like it needs some adjustment, but tinkering is half the fun.  

Would you keep us posted? 

 

Thanks so much!  I've got a voice like sandpaper but I use a good mic that smoothes it over a little.  

That half second makes a lot of sense.  Whats interesting is that if you keep one wheel touched down the other side is much quicker with the return.  Much closer to under a second.  I think this is part of the distributed force of the mono shock complicating things. Regardless I agree that the damper is too stiff, and after doing some reading it seems that if the ride height is lower, the potential for see saw and rolling is increased.  So a softer damper ideally should better match the springs, increase ride height and have a faster recovery.  

With regards to the stock front springs - I thought that since the frog has essentially gotten lighter in re-re form (no AA's, ESC, one servo) the stock front springs are perhaps a bit strong if originally specced for a heavier frog.  My first build in stock form didn't compress much when dropping the front.  I took inspiration from Tokai RC Factory on Youtube.  That person was suggested cutting one ring off of each spring to soften the front suspension: 

 

 

I tried that first, and it was definitely softer.  It is just the you-g seemed softer and smoother still so I couldn't resist using it.  

I have the three softest Tamiya Oils on order, but what you say is the truth; its not about using oil for oil's sake, but getting the best results, and if that means a lubricated friction damper so be it.  

Will definitely keep yas posted.  

[tacomancini 11]

On 11/6/2019 at 5:13 PM, graemevw said:

It does look a little over damped to me, but i like the set up.

As for the voice, easy to listen to 😂

My other half says you sound like Conor Oberst (whoever that is) who is from Omaha. Anywhere near you?

Thanks!  I like Bright eyes.  I'm in Pittsburgh, door to Middle America maybe?  

Looking to soften up the dampening with lighter oil or perhaps little to no oil.  

[tacomancini 11]

On 11/6/2019 at 6:59 PM, Frog Jumper said:

I've seen a rear sway bar like that.  With the small tab thingy and the short wire, rather than the round thingies and long wire we usually see with the Parma and You-G rear sway bars...  But for the life of me, I can't remember the manufacturer (if I ever knew it) and I can't find it online...  I thought maybe Trinity, but its not...

And I've never seen a front mono-shock like that.  I like the L-Arms - its a neat touch...  But you'll have to play with the action in order get it right...  But I wonder if you'll ever get over the sway effect the mono will give your car...  Fun stuff! 

Honestly, the sway concern at the front, and the PITA factor in removing the body, has kept me using 2 independent shocks...

Terry

 

 

On 11/6/2019 at 6:59 PM, Frog Jumper said:

I've seen a rear sway bar like that.  With the small tab thingy and the short wire, rather than the round thingies and long wire we usually see with the Parma and You-G rear sway bars...  But for the life of me, I can't remember the manufacturer (if I ever knew it) and I can't find it online...  I thought maybe Trinity, but its not...

And I've never seen a front mono-shock like that.  I like the L-Arms - its a neat touch...  But you'll have to play with the action in order get it right...  But I wonder if you'll ever get over the sway effect the mono will give your car...  Fun stuff! 

Honestly, the sway concern at the front, and the PITA factor in removing the body, has kept me using 2 independent shocks...

Terry

 

That's a good hint!  Gotta be one of the classics right you-g, parma, trinity, cup, dirt burners etc.  But maybe a first stab at a solution by them?

I'm hoping the independent springs will help in some part to resist the sway.  I also read on the forums here that keeping it as close to a fully extended damper helps reduce the see-saw, so gotta aim for a higher ride height.  Perhaps with lighter oil.  

Agreed on the PITA for the removal of the damper every time the body comes on/off.  Maybe there's a quick release solution, like a shaft and a little pin?  The flip side might be that I only have one damper to maintain since these older solutions need TLC.

By the way, love your threads on this forum!  I've followed all the stuff you did to your frog and your comprehensive list of hop-ups.  CRP arms too I see at least one point.

[tacomancini 11]

On 11/7/2019 at 11:26 PM, Nicadraus said:

When I had a Frog (converted from Brat) back in the 80s, I always wanted to improve the suspension. I replaced the rear shocks with the auluminum but the springs were too hard while the fron suspension was too soft. I thought of doing something similar to this but didn't have the resources (lack of materials, tools).

It's nice to see this and it works. Good job!

Thank you, I think I have a long way to go.  Including learning how to actually drive the thing.  

I can't find it now but I thought the same Youtube channel Tokai RC Factory had a rear suspension solution that involved using red tamiya racing shocks from the OP-163 pack.  I can't find the video now though for some reason.  They fit on the rere brat/frog rear shock using the supplied but unused suspension parts.  That's what I'm gonna do as I rebuild the rear end next.

[tacomancini 11]

On 11/8/2019 at 2:54 AM, jeekelemental said:

Final:

<a href="http://tcphotos.net/image/I9dx"><img src="" alt="brat004.md.jpg" border="0"></a>

 

<a href="http://tcphotos.net/image/IzSl"><img src="" alt="brat003.md.jpg" border="0"></a>

That's beautiful stuff.  I have much respect for custom fabrication solutions.  I have no idea how guys like you come up with stuff out of the blue.  It seems like with the push rod/strut? ... you may have less drag or build up of additional friction.  How did it wok out for you?  I assume you removed the internal springs.  It looks like ride height is about at the highest position which would potentially counteract the see-saw rolling.

 

BTW, there's a guy on the Facebook group "Tamiya ORV type chassis" that recently posted pics of his custom monoshock.  He mounted the pivots in the middle of some of those custom aluminum cnc'd arms and used a Frog/Brat re-re rear shock.  I take a snap, or link it but I'm not sure about the rules on that.

[tacomancini 11]

20 hours ago, tamiyanerd said:

The momoshock  is a You-g item resold in the states by Parma.  It came with upper control arms with a 90° cantilever. Very similar to this item by Dirt Burners

Ah, so you think it might have been's You-g's predecessor to their independent dampers with the crossover line?  I've seen that Dirt Burner's pic on the web, I wonder how that particular damper worked out.  It looks like it rely's on internal springs but has a shorter but wider capsule.  I'd guess it has a larger diameter piston that could be drilled out for softening.  Of note my mono shock has such a small diameter piston that it really couldn't be drilled out or notched to soften its behavior.  

[tamiyanerd 2]

I have this monoshock along with the arms.  Got it some 15 plus years ago on ebay, but i recall seeing it new in package in my LHS back in 1988.  It was sold by Parma.  You-g, i believe  was the original manufacturer,  and their products got rehashed into other brands such as Diamond, Mugen, Panda, and Parma.  The monoshock dampers design architecture  is vey You-g, down to the parts.  I collect  the You-g hop-ups and their many reiterations, and from what i can deduce, the item predated the dual front dampers from the Frog with the interconnecting silicone tube feeding damper oil  between the dampers.  Though the hop-up is for the Frog, my guess is that the item was originally  intended for the Tamiya Brat as the damper interferes with body removal on the Frog and looks like it would easily get damaged in a roll over.  That and the Brat was the 1st ORV Chassis.

[jeekelemental 528]

On 11/10/2019 at 12:48 AM, tacomancini said:

That's beautiful stuff.  I have much respect for custom fabrication solutions.  I have no idea how guys like you come up with stuff out of the blue.  It seems like with the push rod/strut? ... you may have less drag or build up of additional friction.  How did it wok out for you?  I assume you removed the internal springs.  It looks like ride height is about at the highest position which would potentially counteract the see-saw rolling.

Thanks 

I came to this solution after many attempts (only thought and actually built): the first concern a more classic double vertical dampers but, considering the short suspension arms and the resultant much short lever arm,  that configuration, IMO, doesn't added the handling I figured so I've started to surf the web looking if anything was done in the good old days.

The first mono-shock design made only adding an alluminum triangular arm parallel to the original arm is my version of the You-g/Parma one but to work well it needs a specific damper and I wanted to put in a standard one. So I've added i kind of push-rod: unfortunately it wasn't enough.

After years (because it took years) I decided that it was the time to finish this project so (considering that all my CR01's cantilevers during it's heavy modifying were in surplus) I reach the final result with    enough push to manage a standar damper. Of course the internal springs have been removed.

The car handles more ore less like a Citroen 2CV and it's what I was looking for, it looks a bit overengineered but, sometimes, Tamiya do the same so I consider it a kind of (natural) evolution of the specie.

[tacomancini 11]

So here's a video update taking into account the great feedback so far from you guys.  I just got a set of the Tamiya super soft oils to test in the monoshock next.  I had a little setback though with the brand new chassis I was building on.  I'm not sure if I used too much force, got a bad one, or the locktite is to blame.  

Also I'm looking for any tips or tricks you guys may have for setting up these older types of dampers.  So far its still leak free, but has that slight notchy behavior and wants to retract the piston like a spooked turtle.  

 

 

[tamiyanerd 2]

Saw this on ebay

[tacomancini 11]

On 11/18/2019 at 5:02 AM, tamiyanerd said:

Saw this on ebay

Thats very cool and timely.  So that would probably be the later Parma right?  It's interesting that a coilover spring is used rather than depending upon the internal springs.  I wonder what the reasoning was with regards to that.  Also the ends are cylindrical and un-tapered in comparison to the ones I am working with.  

BTW gave you a shout out in the vid above ^^^

I just ruined another ORV chassis.  This one splintered in another critical location, the front nose.  I am now convinced that in my attempts to be more thorough I've been sabotaging things by using good ole fashioned Loctite Blue.  This time multiple cracks in the front revealed a slight blue oozing beneath.  So no more loctite anywhere near the ORV frame.  It's a bummer because its really difficult to get to the front mounting to check for loosening without disassembling the entire front suspension.  I wanted to use thread lock for that reason, as well as on the other screw into metal spots including the rere chassis cross bars that replaced the MSC plate and on the four screws that mount the gearbox. No more.   

If anyone is selling a dark gray chassis from the new Black Monster Beetle or Blue Brat please let me know.  

[Kayak 43]

Super glue, automotive silicone sealant and even good old fashioned wood glue are alternatives that work fairly well.  Loctite made a plastic specific compound (pretty sure it's #425 and has a name associated with it).  Super glue can be a bit tough to break/loosen, wood glue is great as long as it's not getting wet.  Sealant comes in a lot of colors and just a little on the bolt threads really works well and is pretty easy to disassemble.

  Found out the hard way (long ago) that locktite disintegrates plastic when a bikes body panels began falling off after using thread locker... the molded in brass inserts fell out of the plastic... still secured to the screws.