Re: Polyurethane Puch Swingarm Bushing

EH 📣FCC of the QCB /
342D4AD3-1576-4493-80F6-5BFB819ED23E.jpeg

just checked chart, seems when radial plane corresponds with good ball bearings it makes better, especially with oil dampening,

Re: Polyurethane Puch Swingarm Bushing

Jesse Stephenson /

Here's a crazy idea, I make some of these, hand them to people that are very hard on swingarms like trick riders, and track racers and then I ask them if it's better or worse and then I try different designs, materials, ect.. idk maybe I won't even run FEA or draw free body diagrams either because it's mopeds. But like the intellectual negging is fun though.

Re: Polyurethane Puch Swingarm Bushing

I always enjoy kooks that have minimal knowledge of engineering concepts playing madlibs with technical terms. I'm not sure who the intended audience is, but it's good for a laugh.

Re: Polyurethane Puch Swingarm Bushing

Dirty30 Dillon /

> classic carl jepsen wrote:

> -------------------------------------------------------

> IMHO oil damper are always better than friction dampers.

This isn't your opinion lol, this is well known fact.

It's like saying: "IMHO, a Formula 1 car is faster than a Prius."

Re: Polyurethane Puch Swingarm Bushing

cool idea.

I think someone across the pond makes an external conversion. Goes thru the pedal shaft and uses bearings?

Re: Polyurethane Puch Swingarm Bushing

can I be the control for "installed but rarely ridden"?

EDIT: i have tendency to take sharp corners faster than i should, the "wobbly" back-end on my magnum slows me down. its not firmly planted like my mototoilette.

> Jesse Stephenson wrote:

> -------------------------------------------------------

> Here's a crazy idea, I make some of these, hand them to people that are

> very hard on swingarms like trick riders, and track racers and then I

> ask them if it's better or worse and then I try different designs,

> materials, ect.. idk maybe I won't even run FEA or draw free body

> diagrams either because it's mopeds. But like the intellectual negging

> is fun though.

whaaaat? you mean science? that never works. (edited)

Re: Polyurethane Puch Swingarm Bushing

Jesse Stephenson /

Yea, I think VDM or Puch shop sold a swing arm conversion that mounts to the pedal shaft to reduce all that bad motion and it's just bolts into bushings iirc. Which is great but then you have to remove pedals and sort a foot position. Plus it's expensive. I'm trying to develop an in between. Maybe I need some zero point energy?

Re: Polyurethane Puch Swingarm Bushing

i'm excited to try this out!

My Maxi has an MLM swingarm and one of the treats spoke wheels and it feels soft, like the wheels don't stay truly inline, while cornering compared to my Tomos (which has a swingarm sorta like what y'all are talking about here this one!!! https://www.puchshop.de/en-gb/psr-race-swingarm.html )

Re: Polyurethane Puch Swingarm Bushing

Geeking out about things can be fun too!

Anyway this is a rad idea and I hope testing goes well.

Re: Polyurethane Puch Swingarm Bushing

Yeah this is awesome! Even a slight improvement would be huge! Thanks for heading it off!

Re: Polyurethane Puch Swingarm Bushing

I don't know about the MLM but the stock swingarm is a noodle. I'm running a modified chrome robot and it makes a huge difference. I put the OEM replacement bushings in all my puchs but it's still way soft.

It's a great idea for a stock bike but ride behind someone with one and the lateral twisting is crazy. My dubs maxi rides about as well as I think a maxi can, with better forks and shocks to handle the extra weight, but it's hard to even predict what a stiffer/better bushing could do.

Re: Polyurethane Puch Swingarm Bushing

> Graham Motzing wrote:

> -------------------------------------------------------

> I'm running a modified chrome robot

What's that?

Re: Polyurethane Puch Swingarm Bushing

EH 📣FCC of the QCB /

> b to the eff wrote:

> -------------------------------------------------------

> > Graham Motzing wrote:

>

> > -------------------------------------------------------

>

> > I'm running a modified chrome robot

>

> What's that?

https://www.treatland.tv/puch-robot-wide-swingarm-chrome-p/puch-robot-chrome-swingarm.htm

The old robot swingarm from treats.

Adam funny you say that because my MLM swingarm, with a stock bushing is a noodle. But the robot swingarm on Jon’s Tribute pinto is stiff as a board, but has way to beefy shocks that may be compensating for any bushing problems.

No matter how you slice it this is a great idea. (edited)

Re: Polyurethane Puch Swingarm Bushing

I have the MLM magnum swingarm

Less noodly than stock, but still noodly. (edited)

Re: Polyurethane Puch Swingarm Bushing

Yeah the robot is really weird, mine was welded crooked AF, I had to put it in the vise and reef on it with a cheater bar to tweak it into shape. Then I changed the spacing on my axle since I was running a fatty tire and had to bend the ears where the axle bolts in to make it all clamp gooder. I think I cut off the shock mounts and moved/beefed them up too? Then I machined hard urethane into custom bushings for the shocks which was dumb in hindsight should have just bought better shocks.

I dunno it works good now. Bike actually rides and handles totally decent with me and my wife like 300+# of meat on it, plus camping gear, etc. Having a full clevis on the lower shock mount I think helps a lot.

Re: Polyurethane Puch Swingarm Bushing

My MLM is also crooked and the axle slot was 2mm too wide. Made spacers to hold the axle in place while torquing dwn nuts, one end up, one end down, To compensate for the crookedness. (edited)

Re: Polyurethane Puch Swingarm Bushing

Jesse Stephenson /

those robo swingarms were notorious for being flimsy and poorly made, I owned one once and just gave it away because it was weird and I didn't feel like fixing it. I prefer the magnum style swingarm honestly. But it would benefit from a clevis connection too.

Re: Polyurethane Puch Swingarm Bushing

I think now that I squared it up it's pretty stout. The thin section that goes between the tire and frame is just a single thickness of 1/4" ish mild steel and it's got no inherent rigidity. That's part of the reason I tweaked the axle clamping ears to square them so I could get a better clamp in the joint.

100% if you just bolted it right out of the box on your bike it would be a nightmare. Magnum swingarm is way way better. I have one on my race bike, but I couldn't find one when I was seeing up the maxi.

Re: Polyurethane Puch Swingarm Bushing

Jesse Stephenson /

right, like cool that it has box channel but like it doesn't go to the flange so it's just window dressing, it's why the mlm looks the same and I wont' bother to try one. It's an inherently bad design, oh wait, that is a good time to talk about force diagrams!

Re: Polyurethane Puch Swingarm Bushing

EH 📣FCC of the QCB /
9D1A9CE3-67A9-4BD5-9760-DC26F3C876D6.png

just payed attention to radial force, it better with fluid dynamics, mainly with added ball bearing

Re: Polyurethane Puch Swingarm Bushing

Jesse Stephenson /

So I'm glad I started this thread, because now I know what my metric of comparison is: does this work better than 25 rolls of electrical tape? As long as it's better than that I have succeeded. But honestly to know......I have to put 25 rolls of electrical tape on a swingarm.

Re: Polyurethane Puch Swingarm Bushing

> EH 📣FCC of the QCB wrote:

> -------------------------------------------------------

> > > I'm running a modified chrome robot

> >

> > What's that?

>

> https://www.treatland.tv/puch-robot-wide-swingarm-chrome-p/puch-robot-chrome-swingarm.htm

>

> The old robot swingarm from treats.

Huh, I had no idea that thing existed. Shame it's not great.

Re: Polyurethane Puch Swingarm Bushing

Blake Totally a real doctor /

Yeah they're old school trash but have merits if you beef them up.

Working on some better shit but these bushings look like they could be an a+ upgrade. I personally love a factory look with improvements. The MLM looks like welded leaf springs..

IMG-20220203-WA0004.jpg

Re: Polyurethane Puch Swingarm Bushing

Yea funny enough I just swapped to an MLM swingarm and expected to feel super beefy but still has some weirdness to it.

I bet it's the rubber bushing.

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account