better suspension on budget

[300ex mxracer]

anyone got any used/new 400ex shocks and a-arms for sale??? if i put 400ex shocks on my 300ex will i have to change just lower or upper and lower a-arms?? already know gotta get a shock relocator kit. anyone got a used one cause aint really got the $$$ to buy one for $90

[theTman]

Originally posted by 300ex mxracer
if i put 400ex shocks on my 300ex will i have to change just lower or upper and lower a-arms??

gotta change upper/lower

[ajr400ex]

The best bet is to get shocks that are made for the 300. I had a set of works steelers on my 300 that were way better than stock. If you want to use 400ex shocks, you need to use 300ex a-arms and figure out where the shock mount needs to be to get the travel right. It takes some work to get this setup to work correctly. Getting the rear setup to match the front is also a challenge on the 300. 400ex a-arms will fit but this is not a good setup on the 300.

[300ex mxracer]

i dont really have the money to buy aftermarket shocks. anybody got any used ones??.

[87250rxrider]

get some used Works shocks... they don't cost too much, and they make a huge improvement over stock.

[CBF2]

Why do you say the 400 front is not good on the 300?--and do not say bumpsteer, there is no reason for there to any extra bumpsteer with 400 arms over other arms. Get 400 shocks, stock 300 knuckles and a new upper shock mount. It is a huge improvement over stock, mainly in the handling due to the wider arms--I can actually keep my inside rear tire on the ground now.

[honda250xrider]

yes 400ex a-arms do add bumpsteer, get some shocks and some +2 a-arms burgard has a reasonable priced set. you shouldl be happy with the improvement

[CBF2]

I see there is a fight about this bumpsteer thing almost everyday. What I don't see is an explanation, just what people "heard".

Explain what in an aftermarket arm magically makes the bumpsteer go away.

You have no bumpsteer if:

1. Your tie rod pivot on the frame side lies in line with your control arm mounts.

2. You tie rod pivot on the wheel side lies in line with your upper and lower ball joints.

AND

3. The angle of the tie rod passes through the instant center created by the upper and lower control arms.

SO

# 1 and # 2 are met since the steering stem and knuckle are unchanged. The angle of the rod does change BUT it would with ANY lengthed arm, the longer the worse it would get.

Again, someone explain how an aftermarket arm would not change # 3 since it only depends only on the attchment points of the tie rod which is only influenced by the knuckle and steering stem.

I have found the difference in bumsteer is negligable both visualy when compressing the suspension with no springs and when riding. My tie rods never hit the arms anywhere in the travel, reguardless of how much the wheels are turned.

[bwamos]

Most people with stock length a-arms will use a 3:2 Wheel putting the center of the tire 1" outside of the Balljoint centerline giving a little extra witdh and stability.

However once you add +2 or +3 a-arms alot of people switch to 4:1 wheels putting the center of the tire inline with the center of the balljoints thus reducing bumpsteer.

However on the point you gave.. the a-arms moving the same degree pitch will give the same amount of bump steer. However having longer a-arms means that same degree pitch change of the a-arms will move your wheel further in the vertical direction. Thus a 4" movement in the vertical will give less bump steer on a longer a-arm than a shorter one would.

See attatched diagram for a quick example of what I'm talking about.

Note: there is no camber or caster on this setup.. and the attatchment at the frame is shown vertical. However, the concept remains the same either way.

I also agree that the bumpsteer difference between the two is minimal. I think the biggest difference is seen when switching from the 3:2 to the 4:1 wheel offsets. redicing the "leverage" the tire has when you smack a bump.

One thing to note regarding using the 400ex a-arms vs. aftermarked 300ex ones.. is that the 400ex a-arms are designed to work with the geometry of the 400ex frame.. whereas putting it on a 300ex frame is going to jack with your caster and/or camber, also the shock mounting spot on the a-arms may or may not be located in the correct plane possibly putting undue stress on the entire system.

[300exOH]

Do yourself a favor and do a search on the 400ex front end conversion. Its a bad setup. The tie rods ARE at an angle with the conversion which does create bumpsteer. If you don't believe me go out and hit a rock or tree with one front wheel.:eek2: You'll feel the bumpsteer. It's not really noticeable under most riding conditions but if you hit something with one wheel it will show up. Jeff@thequadshop and Bradley300 have made many posts explaining why it doesn't work. Pick up a set of a arms/shocks made for the 300 and you'll be much happier. Even a set of works shocks with stock arms will handle better than the 400ex front end. Good luck

One thing to note regarding using the 400ex a-arms vs. aftermarked 300ex ones.. is that the 400ex a-arms are designed to work with the geometry of the 400ex frame.. whereas putting it on a 300ex frame is going to jack with your caster and/or camber, also the shock mounting spot on the a-arms may or may not be located in the correct plane possibly putting undue stress on the entire system.


EXACTLY. The geometry is all wrong and it creates stress on parts of the machine which causes parts like a-arms and shocks to break,and problems with the frame are common too. The same thing with people puting stock 450 shocks on 400ex's. Buy shocks and a-arms for your specific quad

[CBF2]

Originally posted by aLLoY MX 428
One thing to note regarding using the 400ex a-arms vs. aftermarked 300ex ones.. is that the 400ex a-arms are designed to work with the geometry of the 400ex frame.. whereas putting it on a 300ex frame is going to jack with your caster and/or camber, also the shock mounting spot on the a-arms may or may not be located in the correct plane possibly putting undue stress on the entire system.


EXACTLY. The geometry is all wrong and it creates stress on parts of the machine which causes parts like a-arms and shocks to break,and problems with the frame are common too. The same thing with people puting stock 450 shocks on 400ex's. Buy shocks and a-arms for your specific quad

The geometry is not all wrong, the caster and camber are the same since they are built into the arms and knuckle. Where are are all these frame failures if they are so comon? The shocks mount exactly where they would on a 400 after the new mount.

Of course longer arms add more stress since the distance at which the force is applied is further from the attachment points but again, this goes for ANY lengthened arm.

I am not saying the 400 arms would not add bumpsteer, I am saying it is not as bad as claimed on here by some who have tried and even more by those who just read what they wrote and have not tried it.

Still no one has answered my question WHY WOULD AFTERMARKET ARMS ELIMINATE THE BUMPSTEER? "Because they were designed for the 300 EX" is not an explanation.

[300exOH]

Still no one has answered my question WHY WOULD AFTERMARKET ARMS ELIMINATE THE BUMPSTEER? "Because they were designed for the 300 EX" is not an explanation. [/B][/QUOTE]

This has been explained a million times on here. With the 400ex arms the bumpsteer comes from the tie rods being at a slight angle which gives the wheel extra leverage against the steering. So when you hit a tree or rock it throws the bars back at you. With properly built a arms for the 300 the tie rods are at a better angle to help prevent bumpsteer.:rolleyes:

[TBD]

Originally posted by 300exOH
Still no one has answered my question WHY WOULD AFTERMARKET ARMS ELIMINATE THE BUMPSTEER? "Because they were designed for the 300 EX" is not an explanation.

This has been explained a million times on here. With the 400ex arms the bumpsteer comes from the tie rods being at a slight angle which gives the wheel extra leverage against the steering. So when you hit a tree or rock it throws the bars back at you. With properly built a arms for the 300 the tie rods are at a better angle to help prevent bumpsteer.:rolleyes: [/B][/QUOTE]

First of all Bump steer is not reffering to the fact that you hit a obstacle and you get feed back in your steering. That has nothing to do with it. I'm with CBF2. Explain how a set of arms can get rid of bump steer. I've been building suspension components for about fifteen years now and have yet to design arms that can eliminate bump steer. The only way I know to get rid of bump steer is to change either the location of the tie rod at the stem or at the spindle.

[sampleez]

i was told that it wasn't a good idea because the ball joint angles going into the spindles were way off, and it could snap a ball joint if you landed pretty hard.

so what if put the 400ex spindles on the 300 with the 400 arms? would that help any?

[300exOH]

I'm not a builder myself but my understanding is that the shape of the 250r/400ex a arms causes a misalignment of the tie rods which causes the bumpsteer when installed on a 300ex.

[Out_Sider]

i've rode a 300ex with stock 400ex arms, and my 300ex has +2+1 arms made for my 300ex, and the difference is AMAZING! i couldnt hardly control the quad w/ 400ex arms because its so twitchy, and every small obsticle i encountered on the track made the entire quad pull hard in that direction.. definatly not a setup i would enjoy on my quad

[kyleschonert]

Well, the main reason people do this is b/c they cant afford aftermarket shocks and arms, like me. Im currnetly using stock 250R shocks with my stock a-arms. And i like it alot, its way better than stock. Im trying to get aftermarket a-arms used for cheap and than buy works 400EX shocks, b/c they are more commonly seen on ebay than 300's. Sure, it may hurt it overtime, but that is most likely gonna take a while, unless your racing nationals and such, but i plan on selling it before it gives me hell.

[redrunner]

Originally posted by sampleez
i was told that it wasn't a good idea because the ball joint angles going into the spindles were way off, and it could snap a ball joint if you landed pretty hard.

so what if put the 400ex spindles on the 300 with the 400 arms? would that help any?


just for s&g do a search on the topic. When I did my 300 I talked to the "masters" on this site and was much happier going the right way. I know dollars are an aspect of it but you can get a set of used aftermarket ones pretty cheap if you look. 300exoh and I have both done this conversion.

[kyleschonert]

one guy in the 350cc and under section said that he bought works shocks and +2+1 a-arms for the 300EX and was very pleased. Ive even heard people on here say that if you use 300EX a-arms its ok.