Leaf Spring Springer Fork, have parts, ideas welcome

[Indyjps]

I May be able to build a spaceliner style swinger fork outta this pile.
- Blue fork as the main
- Swing arm as the support
- Aluminum coil spring hangers as the rocker at the bottom of the fork
- Find a trailer leaf spring.

I really like the look of leaf spring springer forks. If anyone has advice on geometry please share.
Does the rocker at the bottom have to be centered? How long for the leaf? What width and thickness of leaf spring has anyone used?

 

[wheelbender6]

We called those "rat trap" forks, because pf the spiraled spring. I wouldn't mind adding a leaf spring to stiffen mine.
-I have seen leaf springs from light cargo trailers used in bicycle forks.

 

[Indyjps]

Yep, leaf spring from a trailer. I found one.

Considered trying to use the suspension bike spring, but really like the leaf spring look

Checking out some motorcycle versions, the fork is the middle pivot, spring and wheel axle are the ends of the pivot arm.

This geometry makes more sense to me instead of the spaceliner where the supports cross over the fork.
Really like the second one, kicks the front wheel location out front.

 

[Indyjps]

Bumping this up, havent spent any time on it, but happened to see this at museum of science and industry in Chicago.

 

[HuffnPuff]

Checking out some motorcycle versions, the fork is the middle pivot, spring and wheel axle are the ends of the pivot arm.
....
This geometry makes more sense to me instead of the spaceliner where the supports cross over the fork.
Really like the second one, kicks the front wheel location out front.

Wouldn’t The spring rate would make a difference on where the pivot is best mounted? Then the two also photos appear to make the spring move in different directions which might affect the spring rate.

 

[sandman]

I following this thread because I found two leaf springs from a
compact tractor seat , to use on some bicycle project ?

 

[Klunkruiser]

Compact tractor seat springs sounds more reasonable than a trailer spring.

I was thinking a piece of an old snow ski would work well.

 

[JaxRhapsody]

I've thought about something like this. Making a springer or hurst style fork.

 

[SSG]

Maybe a single leaf of a golf cart spring? I used a single leaf of a car spring and it was a bit heavy.

 

[GuitarlCarl]

You guys are all over the place! Everything you're picking for your spring salvages are WAY heavier than a bike. Even the motorcycles. Tractor seat springs tho... When you look at the rocker from the two motorcycle examples it shows the differences on where your rockers mount to the axle make on the springs. The leafs are even stacked differently. The rockers are levers and respond accordingly, a heavy spring can support a long rocker. The fork ends are the pivot point. Axle behind the pivot point pulls the spring down when you hit a bump. Axle in front of the pivot pushes the spring up. Beyond my observations, everything I think is theory, having never built one. But I'd go as light as possible and stack leafs to get the required "bounce". I also like the tire out front so my spring would be pushing up (unless my spring arms crossed back behind the forks like rat traps do) Haha, it's all leverage, I've seen long rockers work, but they gotta be thick so there's no horizontal movement. A couple years ago @LukeTheJoker was fabricating a leaf springer with the spring behind the wheel hanging down. I've always thought that was a design worth investigating further.

Carl.

 

[GuitarlCarl]

@Indyjps have you tried flipping your rockers yet? Swap the sides, left for the right and run the spring arms straight down to what is now the leading edges of the rockers.

I know it's not a leaf springer, but it's a look until you build yours.

Carl

 

[sandman]

Now that's the cat's meow GC .