Leading Link Front End

[BigPaul]

I have seen several really good diagrams to build a leading link front end. Several I have seen use shocks from smaller bikes or smaller car shocks. While doing some research I saw that for around the same price or maybe a tad more, I could use some adjustable dirt bike shocks.

This would allow for some adjustment for the ride. My question is, would an adjustable set of shocks be worth the extra $40 or $50?

 

[butchvoss]

wish i was smart enough lead you in the right direction. I used a pair of Harley rear air ride shocks. They are ok i guess but plan to go to coil over adjustable spring shocks this winter .. There are some very smart guys here and im sure they will chime in and help you out .. In any case I cant wait to see your build

 

[Fowler]

plan to go to coil over adjustable spring shocks this winter

I have been told VW coil over shocks are a good choice if you have a heavy front end (like mine with the engine up front)

I have not tried them yet. I hope to build a leading link front end by this winter or next summer

 

[BigPaul]

Leading Link

I am using a Corvair drivetrain so the engine will be in the rear. I do plan to make the front end heavy though. I have seen some folks section the front of their frame and fill it with lead slag to counteract the wheelie effect.

 

[LarryA]

Big Paul.......... I just used 750 honda rear shocks...they are supporting about 370# up front. they have 3or 4 steps of adjustment...my thought was maybe if they were too heavy sprung I could go to maybe smaller honda shocks. If you slug your front frame as you were saying, you can adjust it that way also.....sounds good!

 

[BigPaul]

Thanks Larry, Just wanted to have the smoothest ride possible, my old bones can't take that hardtail ride like I used too, need comfort now not speed...lol

 

[stacebg]

by having several hole for the bottom shock mnt an for the link mnt you can change the trail and have adjustment for the shocks

 

[Fowler]

by having several hole for the bottom shock mnt an for the link mnt you can change the trail and have adjustment for the shocks

What do you call that style of forks?

Instead of going straight they bend down.

How do they compare with a set of straight leading link forks?

What does the bend in the legs do?

Is it for better wheel travel???

 

[vwbug72501]

Called an Earls Fork. Used on BMWs 1955 - 1968. Very strong for lateral forces (Trike, Sidecar, etc.)

 

[Fowler]

Called an Earls Fork. Used on BMWs 1955 - 1968. Very strong for lateral forces (Trike, Sidecar, etc.)

Thanks,

That is good to know.

I have tried looking them up but never knew the name

I will have to do some research on them

 

[LarryA]

reply

just guessing here....but I think the bend back just gives you some room so the lower horizontal arm has some length, so it can arc and give longer shock travel. I assume the trail is set by the same factors as straight fork tubes.

 

[irmagoo]

well I will be using adjustable coil over shocks with 4-6 inch travel will buy springs of proper weight rating to support trike front end at total riding weight me and passenger on front end,,, give or take a little- keep in mind that shock-installed angle will change load rating

magoo

 

[butchvoss]

just guessing here....but I think the bend back just gives you some room so the lower horizontal arm has some length, so it can arc and give longer shock travel. I assume the trail is set by the same factors as straight fork tubes.

I have short arms and believe it does not take the bumps as well as long arms. IMO with the arms short more road shock is transmitted . Some times on many bumps close together it feels like its going to knock my hands off the grips...

 

[LarryA]

if

If I were building a front end for a heavy trike.....I would be looking real close at the one on stacebg's post, its strong, plenty of travel and trail is adjustable. Larry

 

[grandpanystrom61]

Not sure if this will get answered, but I have been playing with a new front end for my trike.

Not a big springer fan, but it was what I started building months ago, now not building a true springer design.

I am in favor of the Hyd. shocks up front like the leading link design, but do not like the wrap around design either. I do understand the stabilization that occurs with the wrap around, but I see it as needed when the rocker arm (leading link arm) is to long and more strength is needed to keep all straight.

I have a 48 degree rake on the neck tube with a 2 1/4" offset Triple Trees, Harley 39mm set.

I do not see mounting the lower end of the shock near the axle point a benefit for me, it will just increase how much the shock is laying horizontal, and at some point it this angle effects how well the shock works, remember hyd. tube shocks stop working after 40 to 45 degree angles are met.

Kind a stuck, have had the rockers already cut out, but if I am right I should have room to move more forward towards the axle if truly needed, but I just do not see why I should.

My mind says that I should just lay the shock at the same angle as the main fork tube is, keep the shock mounted parallel to the fork tube.

Again as mentioned before, as you change the angle a shock was designed for, well you lesson the coil spring strength...….still trying to find where I read it and how to figure out how this will effect the design and the shock that is needed.

Looking over it all again chasing that magical shock I discovered that I was looking for a 6" travel in the shock, but I do not need such travel. The lower shock mount hole is 2 5/16 " forward of the RPP, and is 3/4" lower than the RPP line to axle point. This is needed when the rocker is set 90 degrees from the fork tube. When all is set up and you rotate the rocker through it's travel range the lower shock mount hole only moves 2.75" of travel while the axle point moved a total of 6" of travel.

Still searching out the data charts for the shock that meets my front ends needs.

Weighing the front end when the trike is totally together is most ideal for trike owners. I say this because as I added weight to the trike's naked frame I found that at different location this weight is added I got a different ratio of how much of the weight was felt at the front end. I do not think there is a general rule or ratio that should be used on trikes, each seems to be a little different and should be treated individually.

Just my thoughts about it. So how much spring does a coil spring use when mounted at 48 degrees?

 

[stacebg]

to each his own but i would go with the wrap around...no matter how long your rockers are! it must be a tube of some sort round or square...plain bar is a waist of time..

the other thing that can help is a cross brace between your two down tube as far down as you can go and have clearance for the tire.. that would work as well as the wrap around

as far as the angle / height of the shock if you dont weld them on there is plenty of room for adjustment..

 

[TomyJ]

Forked

Different?

 

[grandpanystrom61]

Triple Tree's are 39mm and what I am using along with front tire, the rest is mock up.

I am waiting on the fork bars and rockers to be done at the machine shop, hope this week.

stacebg; I do understand what you are saying, this design is neither a springer nor is it a leading link design, just a bit of both. It could all be a crap design, but to me it should be a more solid set of forks than a springer front end.

I do plan for a crossover brace between the two fork tubes, should be near

15 1/2 " up from the RPP on the fork. It will also serve as a mount for my small original fiber glass fender. If all is correct on paper the fender is near 1/2" up off the tire...…….and once all is getting put together I will confirm if more distance is needed for suspension travel.

I thank everyone for the input and help, and most of all wish everyone safe and Happy Holidays.

 

[neal]

Leading Link

There`s a reason all, (not just some), racing sidecars used a leading link earles type front end. The earles fork turns the wheel on a nearly vertical axis. The Honda ATC trikes caused so many injuries, (& deaths), that they were outlawed. Only in the last year of production did Honda switch to a leading link fork....it was "to little-to late". Also look at the front ends on the side-cross bikes...PS Do Not look at any side cross racing on YouTube, Unless you want to shit your pants...:cxtv:

 

[stacebg]

There`s a reason all, (not just some), racing sidecars used a leading link earles type front end. The earles fork turns the wheel on a nearly vertical axis. The Honda ATC trikes caused so many injuries, (& deaths), that they were outlawed. Only in the last year of production did Honda switch to a leading link fork....it was "to little-to late". Also look at the front ends on the side-cross bikes...PS Do Not look at any side cross racing on YouTube, Unless you want to shit your pants...:cxtv:

not quite sure what the analogy you are trying to make is..

the wheel turns on the same axis (steering stem) no matter if its a leading link, springer or hydraulic...or raked trees for that matter... the main difference being the amount of trail or caster.

meaning the axis stays the same, determined by the neck on the fram, no matter what front end you have hope that made some sense

.. as for the atc, changing the front end would not make much difference in the safety..