too much camber?

[jmoney45]

I just installed my new a arms but since this is the first time I have done this I'm not sure I have the camber right. I mostly ride motocross type trails and regular trails. It still seems like it's a little too much. What do ya think? Hope the pic is clear as it's real sunny here (finally).

[MX26]

Looks about right to me. Nice setup

you want like 2 degrees camber

[QuadTrix6]

How does it ride ?

[Sparks425Ex]

You want to have less camber because of the tires you are running. Round profile tires need 0 degrees camber where flat profile tires need more camber.

[jmoney45]

Actually I'll have my Kenda Klaw MX tires front and rear but I haven't put them on yet. I'm still waiting for my new exhaust and my new PEP fronts. I probably won't be able to get any good seat time in until I get my shocks. I was just curious about the angle and if it was too much. Anyone else?

[Jnine]

Use 4 to 5 degrees of camber for everything. Thats what the pros use. if you try to go to 0 degrees the front end will get twitchy and will tend to dart around in the rough stuff.

JA

[stocktires]

Originally posted by Jnine
Use 4 to 5 degrees of camber for everything. Thats what the pros use. if you try to go to 0 degrees the front end will get twitchy and will tend to dart around in the rough stuff.

JA

John, How much toe-in do the pro's run also? Isn't it 1* or 2*?
Is there anything else I need to know about setting up my front end for mx?

[racerx573]

I think it's 4* also.

[EX 80]

yeah 4-5 degrees. take a square to the outside of your tire, measure at the top should be roughly 1 1/2 inch gap. thats how i do mine.

[Glamis400ex]

I only run in the sand, but when I did mine, I put like 5/8th inch camber at the top of the tire. I used a carpenters framing square. I didnt know how to get that into degrees. As for toe in, I put about1/4 inch or so. Mine runs real nice and solid with those measurements.

Duncan has very usefull info on their site.

Glamis

[OutlawEX]

Originally posted by Sparks425Ex
You want to have less camber because of the tires you are running. Round profile tires need 0 degrees camber where flat profile tires need more camber.

JNINE how much toe in for MX?

[Jnine]

Hello Guys:

I don't know what the person who was posting 1*, or 2* means. I'll calculate the camber for you.

Heres how to do it. Use the carpenters square flat on the floor just like the other person wisely suggested.

The hard part is deciding where to measure on the tire, so I'll give you several locations up from the floor, and hopefully you can get something that is relatively flat to the plane of the edge of the tire and/or rim.

What you need is the little angle between the rim/edge of the tire and a line straight up & down. It would be even easier to measure if you could put something flat against the edge of the tire/rim, and then slide the edge of the square up against it to form the little point at the bottom.

Anyway, for the tables below, measure up from the bottom of the square, which is the little point at the bottom of the tire/rim plane, and then over. Just make sure you are measuring to a consistant point on that wheel/rim plane I have given you several measurements because I didn't know what tire size everyone has, and I rounded off to make it a little easier.

For a 4 degree Angle:
UP 12" - Over 13/16"
UP 14" - Over just under 1"
UP 16" - Over just under 1.25"
UP 18" - Over just over 1.25"

For a 5 degree Angle:
Up 12" - Over 1-1/16"
UP 14" - Over just under 1.25"
UP 16" - Over just over 1.375"
UP 18" - Over 1-9/16"

Hope that helps. Also as far as toe in, I use about 1/4", however at Cannondale some testing was done with zero toe in, and the test guys actually liked it much better. You might want to try that. Even Tim Farr liked it, and he's as good as they come.

OH.. Learn your geometry & Law of Sines. It has a purpose. You can use it to measure camber!

Talk to you later!

[jmoney45]

Everyone, thanx for the replies. John, thanks for the tips on how to actually measure it. I am going to do just that.

[boogiechile]

you can buy a little angle finder at sears with a magnetic base for cheap. cut a peice of flat steel or square tubing to fit across your rim from edge to edge and then just stick the magnetic base to the steel. hold it against your rim and read the angle.

oh yea, I like 2 or 3 degrees negative camber and 1/8 inch toe in.
taht works best for me but try different settings till you find what you like.

[Jnine]

Good Tip on the angle finder! I was thinking the angle finder was a good idea also, and that would be the best way. Go to Sears and get one, and that will make it even easier, and you know they will be even.

[boogiechile]

The angle finder can also be used to set the caster if you have caster adjustable a arms. I just hold a straight edge against the spindle mounts for the ball joints on alum spindles or the side of the ball joints on steel spindles that are skinnier than the joints, set the angle finder on the straight edge and adjust the caster.

;)

[boogiechile]

Exactly what I was talking about 2-Rs. Great pic.

no prob ...
we also attempting to build front end alignment fixture/tool of sorts, for ease of setting up the machines
similar to pics we have seen in manual & editorials ..but w/our twist on it ;)
I'm sure there will be some trial & error involved w/this

[boogiechile]

post some pics of the finished product when you get there.

I use the angle finder at home but I work at a college that has an auto program and i am going to use the electronic alignment machine there on my quad. it will actually work if i set the quad on the floor instead of the rack and put all four heads on the wheels.

and when u give recomendations on all these measurments there taken with the rider on right? so u want 4 degrees witht the rider on or off? Thanks

[boogiechile]

yes, with rider on is best. I don't run 4 or more degrees negative camber like many do though. I prefer 2 to 3 degrees negative with rounded tires.

[Jnine]

I agree with you on the 2 or 3 degree setup for rounded tires. The 4 to 5 degree setup is more of a motocross thing and for smaller tires with a flatter profile.

[d-14 rider 27]

is caster measured from the ground, or the frame? if its from the frame, i got 0 degrees caster, my ball joints will touch with the spindles off, but if it from the ground, im runnin the opposite angle to the rake of my frame, oh, and i run about 3 degrees neg. camber for mx with grooved radials, i dont like the big camber like some people, too much, and your gonna bust your spindle.

[boogiechile]

Caster is measured against a line perpendicular to the ground. Sitting on level ground and looking at the quad from the side (not the front) if a line drawn between ball joint centers is perpendicular (straight up at 90 degrees from the ground) then the caster is zero. If you adjust the joints to where the line leans back at the top that is positive caster (leaning forward at top is neg ). About 4 degrees positive caster is a good starting point for mx. You can measure it with an angle finder like 2-R's posted a pic of. If you have a 400 then put a straight edge across the frt of the spindle on each boss where the ball joints go through and with the tires pointing straight ahead measure the angle.

Do not go by how close you joints line up with the spindle off. Say you had a 250r, it has about 15 degrees or so frame rake. If the ball joints met perfectly without the spindle on then that would be about 15 degrees positive caster. Might be good for drag racing but not much else.

Very good expaination boogie,..;)
caster adjustmenst seem to be the most time consuming (least for me)thus the reason for a fixture
..camber is not so bad ...now

[d-14 rider 27]

I bet im runnin some crazy camber then, cuz mine are perpendicular with the frame, how much rake does a 400 have? im runnin my herrmann long travels with the rear heim all the way in, and the fron one is out 8 turns, thats where its perp. with the frame. excellent explaination too. thanks

[d-14 rider 27]

oops, caster, not camber

[boogiechile]

rider 27

A 400 does not have nearly as much rake as the 250r. Not sure exactly what it is. I have never measured it. Get you an angle finder from Sears. They have a cheap plastic one with a mag base that works just fine. Then check your caster, it is probably a little too positive. I build my arms to where there is 4 degrees caster with 3 or 4 threads showing on each heim. That way when they are the same you have the most often desired 4 degrees but you have plenty of adjustment each way. I would think Herman and most other a arm manufacturers would be doing the same thing around whatever they feel is the optimum caster angle. People need to ask these questions when they buy arms and stuff. I beleive that there are people making arms that don't know these answers themselves. When you see that its throw up the red flag time. I would guess that Hermans is a sharp outfit so your arms will most likely give you the correct caster when the heims are close to the same frt and rear.

[sylvan56473]

Great Thread!! Very informative. I do have a question myself to throw in also. I have an 88 250R with Leager's +2 a-arms (not castor adjustable). When I stand above the front tire and look straight down, the bottom ball joint is farther forward than the top. By almost 1". I heard you taking about this on a 250R and was wondering if this is what you were talking about? thanks.

[boogiechile]

Yea, when you look straight down like that if the bottom joint is further forward that is positive caster.

[Jnine]

This is quite possibly the most accurate statement ever made on EXriders.

"I beleive that there are people making arms that don't know these answers themselves. When you see that its throw up the red flag time."

That goes for stems, swingarms, frames, shocks, and every other part some companies are trying to pawn off on every one of us. Watch what you buy guys!

Anyway, you are right that the rake angle of the 400EX is appx. 6 degrees less than the 250R. No point in me giving any of the half wit companies any more help, then again they would probably screw it up anyway!

[d-14 rider 27]

ooh somebody's $hit dont stink :rolleyes: :p

"2-R's Rider" I am getting my a arms in soon from houser and i will have to be adjusting the camber on them. What exactly is this thing u are using and its to adjust the camber right? How does it work? Thanks

magnetic angle finder ....re read the thread this will help