rear chain drive trailing arms help....

[tannere]

ok so im building a single seat chain drive minibuggy and i have just about every thing worked out but the rear trailng arms

what should i use at the end of them for a bering carier and all vw....?? and just machine a sprocket to mount where the cv would...??


and also at the top side of the trailing arm where should the sprocket be mounted to keep the slack change in the chain throughout the wheel travel


thanks in advance

[capercrew02]

someone can correct me if i am wrong, but from what i know, to minimize chain slack, your trailing arm mount need to be in horizontal alignment as
much as possible with your chain output shaft of your engine. the further forward or behind that point you go, the more drastic the chain tension will change through a given cycle

[tannere]

ok this is about the best i can draw on a computer lol (sorry)

ok well im using a gsxr750 and mounting it behind the seat and behind the motor i have a vw diff sitting in pillow blocks with a sprocket in place of ring gear

next i have sprockets on the cv flanges of vw diff and those will run chains back to behind the motor to a sprocket on the same shaft as the sprocket that will run a chain to the stubaxle

this should explain my idea opinions please


and im having troble with how to do the shaft at the swing arm pivot (the one with 2 sprockets)

also the stubshaft


what and how should i do these two

thanks

[nutz4sand]

Chain drive trailing arms? Are you NUTZ? (I am! :] )

Heres a few ways I have messed with for ideas. I have seen a actual buggy layout built like your diagram sketch Tannre but I am NOT a fan of it. Just don't like it. It seems to work OK for them. I will try to remeber who does it and see if I can find a pic.

I have more pics but these two I made might give you some ideas?

The second pic is a setup I layed out for a lower horse buggy (say under 40 horspower-ish) The shaft in the middle of the suspension point jut makes it eaiser to get to than right in the pivot opoint like Tannres layout. The top link is an easy to adjust chain tension link.

I call it for genrally low power since it has no toe in. I was alwasy told you NEED toe in for fast machines and high pwoer but I just recently met a couple guys with buggies who have some really good power and are fast and the rear tires are straight on. No toe in at all. So I am looking into this.

The first pic is a simple vision of how I was looking to lay MY version chain drivetrailing arms out. You get the power to the front of the arms andthen use small cheap CV's like type 1's (They are cheap and can handle the small angles and and deal with more speed than torque here so this application would be fine with type 1's unless you got MONSTER power and huge tires.

The idea is to have cvs near the center that send power outward and then the outer CV's mount right on top of the trailing arm right above the pivot. It will only move a tiny amount (so type 1's should deal with the movement fine) The front will need to be moveable to take up chain slack/tension. (Or an idler wheel in the middle. I like the front adjustment myself) The rear sprocket would be fixed of course to the rear axle.

I got a few more pictures of this I messed around with and drew up to. I'll diggem out.

[fl250driver]

my brothers rocketa gk 13 is chain driven with trailing arms, it goes to a jackshaft that goes acorss the width of the buggy and then with 2 sprokets on each end of the jackshaft. the sprokets each have a chain that goes down to each hub. ill try to find some pics
http://www.fraleymotors.com/images/345_gk-13-1.jpg
you can see it in that link on the bottom left corner picture
http://store.oohla.com/storefiles/te...1080573352.jpg
http://store.oohla.com/storefiles/te...1080700352.jpg

[tannere]

why would i need toe in on the rear to go fast and have big hp

a drag car has a solid rear and you have no toe \
all non independant street cars dont have any toe because you cant twist a rear end

i know you set toe up front but never herd of the rear

[nutz4sand]

On a straight axle no you cannot have it. But many who make IRS rears say you need some with IRS. I beelive its got something to do with the fact that there is SOME play between all the different joints and pivots.

If you study it some you will find that a lot of people swear Toe in needs to be there.

I used to believe it too but a couple buggies with IRS I have seen (as mentioned above) do not have it and seem to track fine. They do however use a suspension unlike any I have seen before. So its quite stabile. I'll post pics of it.

[nutz4sand]

This is the buggy that has no toe in with IRS and tracks fine at high speeds.

He custom built it to give him wide offset rims to the outside to give him lots of travel witth the Honda motor and tranny. Due to the center CV's are so wide. I could only imagine what you might get with a arm setup like this with the center CVs close together but it would be a lot and low CV ange compared to most.

[nutz4sand]

Wheel Alignment

This article is at the above post. Just over a third of the way down:

Something else to keep in mind about toe is that rear toe is just as important on front toe -- especially if a vehicle has an independent rear suspension or rear toe adjustments. This includes most front-wheel drive cars and minivans as well as some rear-wheel drive cars. Rear toe misalignment can cause toe wear on both the front and rear tires by creating a steering pull to one side. Unlike front toe which is self-centering because of the steering linkage, a difference in rear toe angles side-to-side creates something called a "thrust angle." The result is the same as rear axle misalignment that causes the vehicle to pull or lead to one side.

Wheel Alignment A Short Course

Four-Wheel Alignments
There are two main types of 4-wheel alignments. In each case, the technician will place an instrument on all four wheels. In the first type the rear toe and tracking is checked, but all adjustments are made at the front wheels. This is done on vehicles that do not have adjustments on the rear. The second type is a full 4-wheel alignment where the adjustments are first made to true up the rear alignment, then the front is adjusted. A full 4-wheel alignment will cost more than the other type because there is more work involved.

There are many more links. You can google rear toe in and read all day on it.

One thing about it IS the fact that a front drive car the rear tires ARE just along for the drag. So toe in on them makes them pull out to a truer straight line somewhat (This is being VERY genral about it)

On a rear IRS with tires that ARE driven they are pushing and not being dragged so the suspesnion instead of dragging them will allow the minute play in all the pivots to push the tire forward and inward as it applies force.

If not accounted for many IRS rear ends will be squirrely. Some like the pics above apparently are not so much affected by it.