Has anyone here tried to build their own a-arms? I think I could do it.It would be hard to get the angles right to work properly but I think with some time to figure all the angles I could do it.I would probly make them 2 or 3 inches wider and 2 inches foward.Move the shock mounts so the stock shocks will accomidate for added wheel travel[img]i/expressions/face-icon-small-cool.gif[/img]

 

in regards to changing teh shock mount location to accomadate for increased travel; if aarm builders knew this they would be building a-arms as mentioned. the problem that arrises is leverage, since the arms are longer they have increased leverage and will lower the spring rate of teh shock, causing you to have very soft ride taht would bottom out often. as far as the manufacture of teh a-arm themselves you should get your angles and from that create a jig. once you weld teh arms you will need to place teh arms back in teh jig because they will warb after theyre welded. save yourself the time and frustration and just buy aftermarket ones

 

As for the shocks the position makes no difference at all to the spring rate of the coil.All the possition does is allow a certain amount of travel.Take the coil over shock and stand it straight up or lay it flat on the floor,it is still the same coil.Same coil-same spring rate.Look at the cars that race desert.Example: Two trucks of the same weight in different classes.One class limits at 22 inches of travel,take a 18"coil over shock and run it on a angle to get 22 inches of travel.The other class limits at 32 inches of travel.Take the same coil over shock mount it with a little more angle and get 32 inches of travel.The leverage at dfferent angles as you stated may make them feel a little softer,going from a 60 degree angle to a 50 degree will not make enough difference to matter.It would be like changing the springs with about a 2 or 3 pound difference in spring rate. Your own body weight is not that precise.You may be 3 or 4 pounds heavier this riding trip compaired to the last riding trip you went on


As for the warpage and the jig's.Any good fab shop will make everything with a jig.The whole point of a jig is to get rid of human error or the (thats close enough) saying.The parts are placed into the jig and welded and they stay in the jig until they have cooled.Therefore no warpage.ANY good fab shop will do this.[img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-tongue.gif[/img]

 

I made a set of +3wider+1forward a arms and a +2.75 swing arm for my mojave. I also made a antivibe steering stem and some other stuff. All are made from 4130 cromoly steel. I made jigs for everything using the stock parts and then made the changes to the jigs as needed for the extra length and so on. I can make stock,+2.75, or +4 swing arms with my jig. I can make +2+1 or +3+1 a arms with those jigs. It cost me only one sixth of what aftermarket stuff cost. I had my shocks set up for the new motion ratios(leverage) that are different from stock. It is not really that hard to do. You just need to carefully think out the geometry and make sure you don't get a ball joint bind before your shocks reach the end of travel in each direction. The hardest part is getting the angle on the ball joints right so that most of the extra travel is down and not up. if you add too much additional up travel your frame will bottom before the shock does. You can see pics of the stuff I made at
www.picturetrail.com/mojaveaddict

 

mojaveaddict,

It must me nice to have TALENT. Your quad looks sweet. How does it ride now that it's done?


Smitty

 

thanks Smitty911, I really built it for my son. He helped a lot. I also have a mo and am working on setting mine up now. His handles very good and jumps well too. There is a lot of toe change through the travel but it doesn't really have all that much bump steer. I was pleasantly surprised by that. He has only raced it two times so far and we are still tuning things trying to dial it in to the best we can make it. I made it so that the frt is totally adjustable and we are playing with caster and camber changes, ride height, and stuff like that. Turned out pretty good for my first attempt but i learned a few things that will help on mine.

 

That is some awesome fab work and a good lookin bike to.Where did you buy the ball joints? Also how do those heim joints hold up to mud? I'm sure S.Carollina is the same but we have alot of mud here in Tennessee and would rather use rubber joints just for the cost of replacements.It may be a while but I am gonna try to build some for the raptor.I will build my final set with chromoly but might try a practice set with regular tubing just to get everything right.

 

Some friends of mine and I are planning on doing the same thing. But we thought we would get ahold of some aftermarket a-arms and then just copy them. One of my friends has a buddy that sells after market a-arms and is going to see if he can borrow a set. That way we don't have to worry about the geometry as much. The guy thats going to build them, makes parts for stock cars and used to work for Richard Petty's race crew. He said making the a-arms would be easy he just needs some to copy from. So if you can get some after market ones to copy from,(borrow them from a friend if you can),and that should make things go alot easier.

 

Ratherracedesert, The ball joints that most aftermarket a arms use are simply automotive tie rod ends, unless you get into the real trick long travel stuff. I priced some at the local auto parts store but they were no cheaper than some atv suppliers so I ended up buying them from Houser Racing(John Houser is a great guy) for 20 bucks each. Terry Racing in Alabama is another place you can get the same type for 19. I also bought the top pieces of the steering stem and an antivibe clamp from Houser to make my stem with.

Time will tell about the heim joints, but I think they will hold up well in the mud. We raced in north GA just below Chatanooga at Tunnel Hill in the muddiest mess i ever saw and the heims just wiped the mud away as they worked. You can buy heims made for muddy, dusty conditions. I used them so my front end would be fully adjustable, including caster. They only cost about 10 bucks each so if I have to replace them once a year it will not be that bad. I think they will last a long time though.

Building a test or prototype set is a good idea before you mess up some expensive chromoly tubing. I did not really do that but I did use electrical conduit and bend the tube to the right shape and prefit it to the arms. Then I made the chromoly to match the conduit pieces. You could use conduit to build the arms and then put them on to make sure you had no ball joint bind and the alignment was right and stuff. Then make a jig to fit the conduit a arms. It would be used to build the real thing. I am just too lazy for all of that so I just made the set to start with. I ended up having to change the ball joint angle a little so being lazy cost me.

Or you could do like ptlm3 is talking about if you can get hold of some aftermarket arms you like to copy. If you do this be sure and build a jig fit to the arms. Without a jig you will never have a quality finished product. My problem with copying was that there is nothing to copy from for a mojave.

Good luck if you go for it! Being patient during the work is the main thing.

 

<< As for the shocks the position makes no difference at all to the spring rate of the coil.All the possition does is allow a certain amount of travel.Take the coil over shock and stand it straight up or lay it flat on the floor,it is still the same coil.Same coil-same spring rate.Look at the cars that race desert.Example: Two trucks of the same weight in different classes.One class limits at 22 inches of travel,take a 18&quot;coil over shock and run it on a angle to get 22 inches of travel.The other class limits at 32 inches of travel.Take the same coil over shock mount it with a little more angle and get 32 inches of travel.The leverage at dfferent angles as you stated may make them feel a little softer,going from a 60 degree angle to a 50 degree will not make enough difference to matter.It would be like changing the springs with about a 2 or 3 pound difference in spring rate. Your own body weight is not that precise.You may be 3 or 4 pounds heavier this riding trip compaired to the last riding trip you went on >>




This is VERY VERY VERY wrong. The angle over which a shock and/or spring acts reduces its effective damping or spring rate, whichever the case may be, by a varying amount, depending on the angle. This is not a linear change either. I will see if I can find where I put the numbers so that I don't misquote information, but I can say that this definitely needs to be taken into account. As for actually making the A-arms, yes, it can be done quite easily if you are somewhat knowledgeable in manufacturing and welding. Building a jig is the ONLY way to go. It is the only way to get repeatable results. If you have any specific questions on design or manufacture, feel free to ask. I will try and help as best I can.

John