KaosBanshee44 Posted June 28, 2007 Report Share Posted June 28, 2007 About to get a swingarm anybodys opinions will help. Quote Link to comment Share on other sites More sharing options...
Bansh-eman Posted June 28, 2007 Report Share Posted June 28, 2007 most drag swingers are made from round tube and most dune mx swingers are square you can have a strong swinger from either as long as you get thick walls. Quote Link to comment Share on other sites More sharing options...
lowriderb Posted June 28, 2007 Report Share Posted June 28, 2007 it would also depend on how its made, supports and such that are on the arms.. i havent seen a round tube arm break yet either.. Quote Link to comment Share on other sites More sharing options...
bansheefreak Posted June 28, 2007 Report Share Posted June 28, 2007 "crush tube" is strong and "lighter then square" might not be stronger but its pretty tough.. round tube is ok just needs more braces.. Quote Link to comment Share on other sites More sharing options...
Joshtruction Posted June 28, 2007 Report Share Posted June 28, 2007 Round tube has more torsional stiffness than square tube. Thats why it is used on driveshafts in care. Being that a swinger takes a lot of torsional abuse I'd go round if I could. Quote Link to comment Share on other sites More sharing options...
KaosBanshee44 Posted June 28, 2007 Author Report Share Posted June 28, 2007 Round tube has more torsional stiffness than square tube. Thats why it is used on driveshafts in care. Being that a swinger takes a lot of torsional abuse I'd go round if I could. Somebody else told me the same thing about round tubing. I'm pretty sure i'm gonna go with it even though i think the square tube swingarms look a little better for some reason. Thanks Quote Link to comment Share on other sites More sharing options...
lowriderb Posted June 28, 2007 Report Share Posted June 28, 2007 also make sure that the swing arm is chromoly, its stronger and lighter than steel... Quote Link to comment Share on other sites More sharing options...
crazybluerider Posted June 28, 2007 Report Share Posted June 28, 2007 I built my +3 for my 450 out of round .095 1 5/8" chromoly and it has held up very well. It is 1/2lbs heavier than the stock aluminum swinger. It was 12lbs for the swinger and carrier. I building a plus 4 for my banshee right now out of the same stuff should be a lot lighter than the stock banshee swingarm. Quote Link to comment Share on other sites More sharing options...
SoCalinIt Posted June 29, 2007 Report Share Posted June 29, 2007 it would also depend on how its made, supports and such that are on the arms.. i havent seen a round tube arm break yet either.. BigRed had his +8 break on him! Just an FYI... Quote Link to comment Share on other sites More sharing options...
lowriderb Posted June 29, 2007 Report Share Posted June 29, 2007 BigRed had his +8 break on him! Just an FYI... who built it, what wall thickness was it, what was it built for, was it steel or chromoly (and what style carrier was it for) and what was he doing with it when it did break? aero tubing was not meant for side action, if square tubing gets in a pinch it will fold over, round tubing seems to only bow or bend when hit hard enough with that lateral much force.. then also it would depend on how it was gusseted and or welded as well.. Quote Link to comment Share on other sites More sharing options...
jayzx10r Posted June 30, 2007 Report Share Posted June 30, 2007 I remember when the square tubed "lawn chair" frames came out in the 80s... Everyone HAD to "upgrade" their motorcycles because the "old" bikes had old tech round tubular frames. If the racers were using square/rectangle frame material, it HAD to be better. I pit crewed the USGP in '91 and had a discussion with one of the weldres/fabricators about frame design and his conclusion was that the ONLY reason they used rectangular material is the ease at which a damaged piece can be cut out and replaced!! You don't need to radius and fit square tube like you would the round style. As far as strength, round has superior characteristics in that it resists loads and forces equally where a square/rectangle frame is strongest at parallel/perpendicular loading and weakest at a 45 degree angle to force. In other words, loading forces cause uneven flex when it is received at varying input angles in square tube design versus a linear flex rate equal to the loading force in a round tube design..... Ever look at a Ducati?? :thumbsup: Quote Link to comment Share on other sites More sharing options...
KaosBanshee44 Posted June 30, 2007 Author Report Share Posted June 30, 2007 I remember when the square tubed "lawn chair" frames came out in the 80s... Everyone HAD to "upgrade" their motorcycles because the "old" bikes had old tech round tubular frames. If the racers were using square/rectangle frame material, it HAD to be better.I pit crewed the USGP in '91 and had a discussion with one of the weldres/fabricators about frame design and his conclusion was that the ONLY reason they used rectangular material is the ease at which a damaged piece can be cut out and replaced!! You don't need to radius and fit square tube like you would the round style. As far as strength, round has superior characteristics in that it resists loads and forces equally where a square/rectangle frame is strongest at parallel/perpendicular loading and weakest at a 45 degree angle to force. In other words, loading forces cause uneven flex when it is received at varying input angles in square tube design versus a linear flex rate equal to the loading force in a round tube design..... Ever look at a Ducati?? :thumbsup: See that's what i was thinking, you would think that circular tubing would bend at any direction force is provided where as if you had square tubing it puts out strength equally to anywhere you put force to it. Quote Link to comment Share on other sites More sharing options...
FireHead Posted July 1, 2007 Report Share Posted July 1, 2007 This questions answer really depends on you application and the quality of design and construction of the arm. For most general recreation folks, the rectangular tubing arm probably makes more sense as it would be the easiest to fixture, align, and make good joints where the pivot tube and axle carriers mee the main arm tubes. I have seen a few aero tube arms that I like (I own one of them). I haven't seen any round tube arms that really made me happy, though I am sure they are fin for the most part. :geek: Quote Link to comment Share on other sites More sharing options...
Justintoxicated Posted July 11, 2007 Report Share Posted July 11, 2007 (edited) If you bend any chromoly swingarm that is properly welded, your medical bill is going to be higher than a new arm lol. I have Gary's arm from quicksand Racing and it has held up to some abuse, The chrome is holding up very nice as well. I would go Oval tube maybe on my next try, but the welds are probably your biggest worry. Square tubing is fine too. Most people that go with round tubing do it to save weight (hence thinner materials and less strength than most square tubing arms). My New Swingarm is lighter than stock, and longer too. Edited July 11, 2007 by Justintoxicated Quote Link to comment Share on other sites More sharing options...
BigRed350x Posted July 12, 2007 Report Share Posted July 12, 2007 who built it, what wall thickness was it, what was it built for, was it steel or chromoly (and what style carrier was it for) and what was he doing with it when it did break? aero tubing was not meant for side action, if square tubing gets in a pinch it will fold over, round tubing seems to only bow or bend when hit hard enough with that lateral much force.. then also it would depend on how it was gusseted and or welded as well.. It was a chromoly 3/4" tube swinger. It got about a foot of air and when I landed it caved the hell in hardcore. If you want something tough, go with a locogato swinger. - jared Quote Link to comment Share on other sites More sharing options...
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