VW Coilovers for Leading Link Forks

[Fowler]

I have not posted on this side for a long time Im usually on the Non-VW side now. But im working on my VW Trike now. So here I am

Anyway... I want to build new front forks for my VW trike. I want to build a leading link setup and was thinking of using VW coilover

Does anyone know the average spring weight of something like these?
Anyone ever try this with these

 

[Fowler]

or something like this

 

[Fowler]

I think I will need to make another fender
This is what I made out of fiberglass years ago. Still holding up


Thinking of 3D printing this. The inside will have a structure (Gyroid infill) that works well when filled with epoxy

 

[Gorilla]

Nice Trike

 

[Fowler]

On my other trike I used 2x2x3/16 square tubing for the leading link forks
Im thinking for this one I will use 1 1/2x1 1/2x1/4

This link has some examples of Leading links
https://bettertrikes.yolasite.com/monster-leading-link.php

 

[Sidecarbill]

I would guess they would be way to stiff. My trike has forks off an old flh. I ended up with forks springs from a Honda 80 dirt bike just to get them to go up and down. I can't imagine there's much weight on that front tire, of course I don't know what it's built out of. If it's built from half inch boiler plate then all bets are off.

 

[Fowler]

I think I need to weigh the front end. Its been years since I built it.
Im going to steel the bathroom scale and rest the front tire on it.
I know i have done this before but dont remember the results

 

[irondad01]

Hi Bob, on mine I used rear shocks off a Honda 250 rebel. They are not real high quality shocks but they work great. When I redid my trike in 2019 I changed the leverage on the forks but the shocks still were fine. My front weight is a little heavy but I can lift it fairly easy. I would think any shock up to about a middle weight bike would be good. Big bikes might be too stiff.

 

[Fowler]

Thanks
I plan to try to weigh the front end today when the Ol'Lady goes to the store and I can steal the bathroom scale

Then once I decide on the metal I need go pick it up during the week.
And decide on the shocks I need and order them

One problem is I don't have a lot of room. My shop/garage is also my workout area. So I cant leave the trike down for to long.

The other side of my shop is taken up by another Trike I am building
88 Blazer Trike

 

[Fowler]

Put the front wheel on the scale. The scale maxes out at 300. It weighed 298lbs. (round up to 300)
I have about 1/2 a take of gas and have about a 12 gallon tank. So 6 gallons would be 36lbs (round up to 50)

Total weight on the front wheel without me on it is about 350lbs. I'm going to call it 400lbs

Now to find a set of shocks that will handle that correctly.

I have a big set that are 220lbs each but I dont like how big they are. From eye to eye they are about 14 1/2 inches



I could get these but know the dementions


Not sure what Shocks to use yet
What do you all think about using 1 1/2 X 1 1/2 X1/4 square steel tubing for the legs?

 

[Fowler]

OK change of plans (kind of) I was pulling everything off the forks and started thinking 2" legs would not look bad like I originally thought and with the 2" legs I can use the shocks I already have. I can get spring for those shocks in different weights

 

[irondad01]

I agree, 2" legs would look good. VW trikes tend to have a lot of bulk in the rear so heavier forks help balance the look.
I hope you got the tire track off the scale before you put it back.

 

[Fowler]

I agree, 2" legs would look good. VW trikes tend to have a lot of bulk in the rear so heavier forks help balance the look.
I hope you got the tire track off the scale before you put it back.

She will never know

 

[Fowler]

I ordered all the steel. Had to order 24' of the 2x2 so I will have a lot extra. They don't sell just 8'
Also I got 48"X20"X1/2 plate. Again had to order extra
I can always use extra steel
I will pick it up in a few days when the ice on the roads is cleared up.

 

[Fowler]

Got the old forks off

cut a 8' 2x2 in half and slotted the ends
I inserted a 1/2" flat bar on each side of each leg

drilled hols for welding through


welder the seams also




New 3D print for the yard

 

[Fowler]

Still have some cleanup to do

 

[Fowler]

Tomorrow I will try to get my rake and Trail.
When I built the trike years ago I had no idea about rake and Trail. It did ride strait though
I have had it on the road for 15 years and about 70K miles. Iv been run off the road a number of times . When I first built it I used to like to pop wheelies a lot. Its been through a lot and I cant get it as level as I would like. I will just have to work with what I have.

 

[Sidecarbill]

I was run off the road, more than once a matter of fact. It used to happen on highways a lot. It wasn't intentional, but the result was the same. They'd pull along side to see what it was. So they'd be in the fast lane gawkin. No problem right, wrong. People have a tendency to steer in the direction they're looking, bad news you're gonna be on shoulder of the road, if it has one. Of course this is 40 years ago so a trike was kinda unique. Got to the point where if someone pulled up to look, I'd cut the throttle so they sorta had to pass. Crazy times back then for sure.

 

[Sidecarbill]

Wow just scared myself when I realized that was actually 50 years ago.

 

[irondad01]

Hi Bob, On my front end on the swing arm I used oil-light bronze bushings I got from McMaster-Carr. You can get bronze thrust washer to take care of the side loads. I used a shoulder bolt for the pivot. After about 18 years of use there is no noticeable wear. I've seen others who used no bushing with metal on metal with no problems. I would think you would need to keep grease in it. Just some suggestions, with your background on building trikes I'm sure you have a handle on it.

 

[Fowler]

Hi Bob, On my front end on the swing arm I used oil-light bronze bushings I got from McMaster-Carr. You can get bronze thrust washer to take care of the side loads. I used a shoulder bolt for the pivot. After about 18 years of use there is no noticeable wear. I've seen others who used no bushing with metal on metal with no problems. I would think you would need to keep grease in it. Just some suggestions, with your background on building trikes I'm sure you have a handle on it.

Yep I did this on the last forks I made. Unfortunately that tike is still up on stands so I have not had a chance to test it on the road yet

 

[Fowler]

Today my goal is to get the rake and trail, measure the wheel axle, figure out the size for the 2 plates on the tree and cut the plates.
I may need to buy a new 1" hole saw, my old one is missing teeth.

 

[Fowler]

It has a 49.5 degree rake

plate ready to cut

2 plates

my hole saw made it through both plates (I spilled cutting oil everywhere)

cut the slots for the legs
I lost one of the neck spacers I will have to find or make one. Need new seals also.

 

[Fowler]

I drove around town trying to find every thing, found almost everything. A few thing I had to order so I am waiting on them to continue
I did not order the spacer I lost yet. the cheapest I can find it online is about $25 so I want to try to find the one I lost first

 

[Fowler]

So while I am waiting for the stuff I ordered to come in I have been doing some research. Looking back at my last fork build, I went with a 2" trail. I will try to do the same on this one.

The rockers (wrap around) I was planning to make out of the 1/2" A36 plate I have extra of.
Found this online

A "1/2 inch A36 plate" would be a thicker and stronger plate compared to a "1/2 inch A32 plate" because A36 steel has a higher yield strength than A32 steel, meaning it can withstand more stress before deforming; both plates would be the same thickness (1/2 inch), but the A36 would be considered a better choice for applications requiring greater structural integrity.

Key points about A36 and A32 steel:

• A36:
  This is a widely used mild carbon steel with a higher yield strength, making it suitable for most structural applications like building beams, columns, and bridge components.
• A32:
  This is a lower-grade steel with a lower yield strength, typically used in applications where high strength isn't as critical.
  

 

[Fowler]

Out looking at the trike again. Measured the Neck height and Rake again.
Rake 47.5
Neck Height 40" (measured at the top of the neck centered
Wheel 21" 14" to center
Not sure how to figure offset into the equation.
I believe I can adjust offset at the neck, this would change the Trail.
I would love to put a little offset at the neck to clear up some space there
I have plenty of steel to make a new bottom plate
Any suggestions?

 

[Fowler]

need to research more

 

[irondad01]

Hi Bob, If you turn your bottom plate around it looks like you would gain 2" of offset. You would have to drill another hole for your stem bolt. That would move your axle ahead some reducing trail. Because of the rake angle I don't think it would move it the full 2". If you have room on the floor you could make a full size drawing in chalk. Make a 90* to represent the ground and neck height. Put in the rake of the neck, where that hits the ground is the point you use to measure trail. Always use where the fork pivots to get that point on the ground. Draw a second line parallel to the rake line moving it out 2". On that one find your axle height. From the axle drop a line down to the ground line to show where the tire will contact the ground. Measure the distance between those two points. If it's for example 6" that means you would need 4" rockers to move the axle forward to get 2" of trail.
Hope that made sense and wasn't too confusing.

 

[LarryA]

I can't contribute anything mathwise, Thinking I copied a harley type offset 1 or 2"?? to get neck to fork tube clearance, then just did a mockup to get the trail... but trail changes can be made by changing rocker length.

 

[irondad01]

That's one of the nice things about leading link forks, rocker length can be changed to get the trail you want. The old BMW earles front ends had, I think, two pivot points on the rocker. The rear one shortened trail for sidecar use and the front one lengthened trail for solo riding without a sidecar.