Making Swingarm Longer

[idahoaj1]

here's a thought from my truck building days... when mounting nay kind of shock, the closer to vertical it is, the better it will function. so, when making longer swingarms, move the shock mount in close and you will get good travel, and the shock will dampen like a longer shock mounted rearward. Also, it may necessitate a stiffer coil spring or stiffer setting to be comfortable with the increased leverage. When jumping, Suspension travel is pretty important to ride comfort.

Any comments?

 

[crusty4365]

uhhhhhhhhhhhhhh!? ahahah please enlighten me on this concept i do not understand and id love to understand what your trying to teach us

 

[suprex]

be careful...

changing the geometry of your quad's suspension could be caustic. the closer you move your mount in, the more stress it will put on your axle and carrier and the swingarm itself.

when you extend your swingarm it is recommended to KEEP THE SAME MOUNTING DISTANCE.

i am not an expert, but the experts say the same.

 

[flyers42091]

I made an extended swing arm over the summer with a friend of mine. We cut 3 inches from each side off one swing arm and cut another one in half. Put the 3 inch pieces in where you just cut and weld them in good. we moved the shock mount up about 5 inches cause he wanted his shock more vertical, but it caused to much pressure on the swing arm and made it start to crack. So we put it back a couple inches to the spot it should have been and it worked fine.

 

[idahoaj1]

there is the weak link of doing that. When doing that, it changes the focal point of the stress on the rear suspension to a point that is further rearward than what the shock mount is, and you get a leverage action. If the swingarm is constructed well enough to withstand the additional stress, it will work fine. Unfortunately the mild steel or aluminum that most are made of can't withstand the forces. If I was building one, I would likely use Chromemoly or DOM Tubing.

 

[blaster_schmaus]

i am thinking about doing this, but to re-enforce the swingarm you can just weld a piece of rectangular stock on the insides of the swingarm. this would give you a lot of strength, just like the I-beams in a house. just make sure to not pick anything too heavy though. just a thought.

 

[idahoaj1]

problem with doing that is the unsprung weight you are adding... that causes suspension reaction problems in itself that could take a whole nother thread to talk about... Your best bet is to use quality materials in the first place, then you don't have to worry about it.