My Solo Seat Spring Assemblage

[Minimichael]

Here is only the bottom part of the seat I'm slowly constructing (for the minibike I am similarly slowly constructing). I was wanting a bobber style sprung solo seat and wished to minimize mods to my mini's frame and seat pan. So the motor mount adapter serves as the foundation for springs and also allows me to use existing holes in the frame. I will have to stabilize the seat (likely at the center front) to prevent rolling over sideways, but testing with the seat blank resting on the installed springs already confirms they provide an adequate feeling of suspension.

Certainly no masterpiece, but I felt like celebrating with a post. That anchoring totem inside the cylindrical spring includes a 3/8" bolt, a steel flanged bushing that fits flush inside the spring base, followed by an internal sandwich of skateboard truck bushing, spring washer, and flanged insert nut. The insert nut is from a pipe hanger strap, and notched with a file to provide some sort of grippable surface.

 

[cl350rr]

I think you are going to find that will move all over the place when you put weight on it. Bobber seats are generally a solid hinge at one end with springs on the other, the hinge limits side to side movement.

 

[RiderZ]

Pretty cool, did you machine the platform?

 

[sparkwizard]

Pretty cool, did you machine the platform?

You might be surprised by what that is. It's very creative, actually. Two thumbs up, Mike!

 

[Minimichael]

Thank you for the comments. It's an engine mount plate. I did not machine it. The hinge point will come next, once I figure what and where that will be (no doubt at the front of the seat and likely attached near the crossbar).

It's coming together as a hodge podge of random parts and materials, including motor mount, skateboard parts, a bar stool, and a dish anchor from a boat dock.

And news flash: many of the springs sold on eBay are useless because they're too weak and compress way too easily. You gotta get real motorcycle springs of a gauge just below that of a shock absorber.

 

[RiderZ]

Thank you for the comments. It's an engine mount plate. I did not machine it. The hinge point will come next, once I figure what and where that will be (no doubt at the front of the seat and likely attached near the crossbar).

It's coming together as a hodge podge of random parts and materials, including motor mount, skateboard parts, a bar stool, and a dish anchor from a boat dock.

And news flash: many of the springs sold on eBay are useless because they're too weak and compress way too easily. You gotta get real motorcycle springs of a gauge just below that of a shock absorber.

Was kinda thinking that looks like an engine mount plate.
Resourceful!

 

[Minimichael]

The bar stool had the ergonomic shape I was after, and a good bit of shiny hardware as well. But it's barely half inch plywood so I have been trying different ways to reinforce it.

 

[Minimichael]

For this build, I want the seat to sort of bounce and float above the frame. But to strengthen the butt pan, I first tried making use of the stool metal, together with an old bicycle seat. The design was to fasten and cushion with rubber mounts.

Alas, that wasn't nearly secure enough.

 

[Minimichael]

Next I tried these u-bars pulled from an edger. They were heavy and felt strong, and I thought they'd be great leaf springs. The first test sitting proved otherwise.

 

[Minimichael]

I tried a variety of spring types, held on with handlebar clamps, but the pan under the holes would have to be reinforced...

 

[Minimichael]

To support the plywood seat base, I cut down a boat dock footing dish I had in the shed, as it has a very similar spherical shape to the plywood bottom.

 

[Minimichael]

The engine mount holes fit the seat pan holes in a more or less optimal position along with the boat dock seat base. Taller springs are at the rear, with beefier hair springs at front. Once all this is secure, I hope to mod the dock dish and wood form so I can have easy forward and back adjustment of the finished seat.

 

[Minimichael]

I think you are going to find that will move all over the place when you put weight on it. Bobber seats are generally a solid hinge at one end with springs on the other, the hinge limits side to side movement.

Thanks @cl350rr. Yes, a stiff hinge pivot is needed so riders aren't falling off sideways. I've looked at gate hinges, offset hinges, etc. Even the ones they sell for bobber seats. Still yet to decide how I'll do this.

Anyway, this is all I've been tinkering with lately. I appreciate the feedback though.

I've been enjoying everybody else's builds and posts on here!

 

[RobertC]

Hey @Minimichael ... here's a link to another fellows project, where he made a springer seat ... I think he uses a steel plate attached to the front hinge for stability.

https://www.oldminibikes.com/forum/index.php?threads/frame-jig.177268/#post-1349779

Also kudos on documenting your trial and error development process on your various projects.

Get's folks thinking outside their box !

 

[sparkwizard]

You mentioned skateboard truck parts. Could you utilize a truck as a hinge?
Nice aluminum parts...

 

[JimN]

Hey @Minimichael ... here's a link to another fellows project, where he made a springer seat ... I think he uses a steel plate attached to the front hinge for stability.

https://www.oldminibikes.com/forum/index.php?threads/frame-jig.177268/#post-1349779

Also kudos on documenting your trial and error development process on your various projects.

Get's folks thinking outside their box !

In the interest of full disclosure, there is a litle side to side slop. Not really noticeable when I'm riding.

 

[RiderZ]

I see a brand new Predator photo bombing the picture.

 

[Minimichael]

Thanks @JimN. Love that hog of yours, and that's some nice clean hinge work, and totally out of sight with the cushion. For my bike though, that hinge would have to be 2-3 inches taller. Plus I'm really wanting to keep a clear space in front under the seat (maybe for some switches). For sure, my design needs a stable pivot point, or two, and I'm looking right at those two holes in the front of the bike's seat pan. Might try a four inch u-bolt, or two individual rod ends as posts, to form a post and lintel type of thing... Plus the iron plate is fully shy of those front holes, so then maybe fasten the iron's front corners to those rod ends or u-bolt with a single or two separate straps or rods (with holes or threads for adjustability). But now I'm just getting creative...

 

[Minimichael]

You mentioned skateboard truck parts. Could you utilize a truck as a hinge?
Nice aluminum parts...

Great minds think alike, my friend. Would you believe I ordered them and they never showed up? Fun fact, the extra hard truck bushings did. Anyway, if I come across a board, maybe that, next.

 

[sparkwizard]

I see boards and skates at my local Goodwill /Community thrift store very cheap,