csc1 replacement of torsion leaves

just a bump to see if anyone has pulled apart a csc1's suspension.

They are all that supports the swing-arm from just flopping.

Lonnie

Hack'n - 12/30/2010 12:49 PM

They are all that supports the swing-arm from just flopping.

Lonnie

If they totally fail you can lose the swingarm, wheel tire and all of that . This can really affect one's fun meter rating and create a generally bad day or maybe worse.

here is my concern. since I have had the rig (1 year now and about 5k miles) the suspension has been VERY stiff more like solid. after the last ride this year I was putting the rig up and notice the suspension just swang with no resistance. I could not see (without pulling the wheel off) how the torsion spring were held in there. I'd like to have the parts ready for spring if it is easy to fix, if not I'll just make it solid with a grade 8 bolt.

The spring leaves fit into a square hole in the frame and swingarm.
You can see the ends of them if you get a view from inside the perimeter of the sidecar frame looking out.
Some have made these setups into a rigid hookup as you alluded to. I would never do that if you have the earlier mounts as they did tend to fail with a suspension and without a suspension it is almost guaranteed. A sidecar with no suspension will transfer much mnore direct shock to the mounts and motorcycle. Tread lightly and think things out very well as any sidecar is apt to carry a precious cargo.

I've up graded the old ball and collet to heim joints and clevis. I've had the wheel off many times but there didnt seem to be any obvious way to pull the torsion leaves out. I've heard that vw leaves will replace them. As far as ride, there was never much if any give to the suspension since I had the hack. most of the 'bounce' was in the tire and seat. there are still several months of snow and ice to think about it

Most pilots consider it bad luck to loose a swing arm or wheel on the road.
fix it or redesign it but don't go rigid.

Phelonius

An inexpensive fix that is easily done with anyone with welding ability would be replacing the CSC swingarm with a torsional rubber suspension unit. They come rated (singly) from 250# up.
(I have a new one in stock.)

Lonnie

here is some info for those who might have a csc1
the torsion leaves are basicly held in by a large allen head screw covered by the swing arm. that swing arm has a bronze bushing type bearing, that can get warn or at least gummy. There is very little that keeps all that attached to the torsion leaves (indent drilled into center 2 leaves).
what I did that greatly improved ride and peace of mind was
1. cleaned and re-greased the bushing and leaves
2. attached a small lenght of chain from the cart frame (there was a bolt already there) to one of the cinch bolts on the swing arm. In the unlikely event of torsion leaf failur the swing arm would only travel outward 1/2 inch or so not effecting handling and keeping the wheel where it should be

ratcollector - 5/10/2011 12:11 PM here is some info for those who might have a csc1 the torsion leaves are basicly held in by a large allen head screw covered by the swing arm. that swing arm has a bronze bushing type bearing, that can get warn or at least gummy. There is very little that keeps all that attached to the torsion leaves (indent drilled into center 2 leaves). what I did that greatly improved ride and peace of mind was 1. cleaned and re-greased the bushing and leaves 2. attached a small lenght of chain from the cart frame (there was a bolt already there) to one of the cinch bolts on the swing arm. In the unlikely event of torsion leaf failur the swing arm would only travel outward 1/2 inch or so not effecting handling and keeping the wheel where it should be

Great idea! Much easier than replacing it before it fails.

I was told at one point that you could use the leaves from a early vw beetle torsion axle to replace the factory leaves.
Haven't got there yet. I was led to believe that some grinding of the leaves, at the ends would be necessary.
You would have to be very careful not to get the metal any hotter than 390 degrees while grinding or you will change the heat treat of the spring.
That means go slow, cool with water very often. Best to polish the ends of the leaves first and quench before there is any color change.
Then have the leaves shot peened after they actually fit. That would be the best way, in a perfect world. My world is seldom that perfect.
Do it how you see fit.

I like the chain idea. Even a new spring could conceivably fail. I was thinking a short length of cable, but chain is probably better. It is probably
more fatigue resistant.

These cars were very inexpensive cars, as cars go when they came out. I am not sure great handling was ever a design criteria. They remind me more
of a model T than a Alfa Romero.

The swing arm really needs some sort of travel stops. The need for a upper one is obvious. Having the wheel in contact with the fender would affect handling. In a hard corner it could effect your life expectancy.
Without a lower swing arm stop the torsion spring actually helps the car lift in a right corner. If there was a stop it would could only contribute to the lift until it ran into the bump stop. I think this would help with the handling of an empty or lightly loaded car of this type in right turns.

Myself I am in the planning stages of putting a sway bar on the car. That may negate building a lower stop.
Once I figure the sway bar out, I may convert the car to the torsional rubber suspension Lonie has, providing it does not have more travel.
I am looking for less travel not more in whatever I build. It's looking like I may have to put some suspension in the seat of the car for comfort.
Better handling is a priority for me. I think there is room for improvement.

Btw a smaller tire that weighs less has less inertia. This means that when you hit a bump in a corner the smaller lighter wheel and tire will return to the pavement sooner than a heavier one will. This is never a bad thing. The coefficient of friction of a rubber tire in air is vastly less than it is on pavement.

There is a second benefit you might reap from a smaller wheel and tire.
If ...... it allows you to get the car mounted closer to the ground, that lowers the Center of Gravity of the rig. This will make it less tippy. But only if you can actually get the car closer to the ground.
However If when you lower the car the frame drags on hard left turns, because of car suspension travel you will have introduced another problem.
Let me know if you do it and what the results are. If it doesn't work on yours I won't waste time doing it on mine. LOL

I am not an expert. I am not an engineer, and I am a beginner with sidecars. So don't blindly follow what I say. Check it out yourself.
I'm just passing along my observations that I have made pondering my own FS1.

I'm sure some of these fellows here have forgotten more than I will ever know about sidecars. This is a great group here.

I ride my cart pretty agressivly and have never came close to bottoming the swing arm, but I dont carry much weight in it. my son is about 70lbs and that would be the most in it. a narrower tire on a lighter wheel would be nice. the original mag rim is poorly engineered when it come to the lug nuts and the tire for the rim is EXTREAMLY close to the cart and requires the swing arm to be at the outer most setting. I believe the small trailer tires/rim combos available at menards (any home inprovement place) would fit better. I need to do something by the end of this season, my tire is getting a bit worn and I just noticed (written in large letters) 'proudly manufactured in the democratic republic of germany' so I guess it's a bit old.