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Posted by: dual-sporter
aluminum axles scare me as an engineer. the only way to really get similar strength would be to increase overall diameter of it... as in compltely different swingarm, bearing carrier & much larger bearings & seals to match... then to make it lighter they would be able to hollow it out.
the big problem on all axles is fatigue... which all components of aluminum are severely prone to, even in non-stressed applications. every time an axle makes a rotation the surface goes from tensile stress(bottom) to compressive stress(top) in a cyclical manner.... which causes fatigue. also, when the quad hits any bump, jump, etc, it causes a significant stress riser, specifically near the center, just outside of the bearing carrier... when & if you see an axle break it will be at this location every time, almost guaranteed... this is also why most axles taper at the ends.
i ride dunes and i'm currently running a durablue X-33, which is made of a high tensile steel, but it is also hollow to reduce weight(about 12 lbs). it can handle everything i will throw at it(lots of whoops & small jumps), but i'm not jumping 80' doubles... and it's not made for it either. i don't like the fact that the warranty is limited or the pin-drive hubs, so i may sell it to get a lonestar. mechanically speaking the design of the x-33 could be improved, and weight even reduced more, but i would want them to pay me for the engineering work.
7075 t-6 aluminum is the strongest alloy available in aluminum, but it too is still prone to fatigue, in a big way. tensile strength of this alloy matches a mild mormalized steel, but is nothing compared to a titanium or high strength micro-alloyed steel(i.e 4130 or 4340)that's heat treated properly. titanium's problem is the fact that it is very brittle(won't deflect much at all before it breaks), not to mention a real pain to work with(machining, welding, etc.) and it is more dense than aluminum.
conclusion: an aluminum axle would be great for a dedicated dragger, on reasonably smooth surfaces, reducing unsprung weight and rotating mass greatly.
the decision is still up to you, but i'd stay away from it
Posted by: Zorro
Aluminium is soft. For such a stressed part, I don't get what advantage you get...to match steel resistance, it's gonna be HUGE (and almost as heavy). Maybe titanium is good, but for an axle, I'd stay traditional and get a steel composite one...like the X33 or similar...just my 2cents, I might be wrong.
Posted by: LT80
It may sound weird, but the aluminum axels are very strong. Jimmy Elza (GNC PRO rider) has used them for years now, and if he can't break em, you cant't! The bad part about the alum. axels are the price,,but if you need the lighter weight of a alum. axel,, go for it! good luck
Posted by: LT80
aluminum axels were made legal for this years GNC racing,quads only, not bikes
Posted by: LT80
well dang,,LSR is the only maker of an aluminum axel that i know of. that dont mean there isn't others out there. curious,why did LSR say no dunes on one?
Posted by: crhye250r
I run an LSR Axcaliber in my R. I race MX. I have never had one single problem with it. (Although it is bent) Its not enough that it matters. The next axle i get will be a RPM Dominator though.
Posted by: Fasterthangas
I'm looking at purchasing an aluminum axle for my hill racer. It's made out of 7075 T-6 aircraft. Glamis has some bad whoops. Any comments?
Posted by: Fasterthangas
I don't dune. I just race up the hill. Thanks for your replies. I'm hoping to here from someone who has actually run an aluminum axle.
Posted by: Fasterthangas
You've got to be kidding. Not even I would use aluminum for GNCC. I know all AMA events have outlawed aluminum axles and TT racing is about to phase them out. I just figured that I wasn't riding as hard as these racers being that I'm a hill shooter. It's just the whoops that I'm worried about. Thanks for the info.
Posted by: Fasterthangas
Any idea who makes his axle? I know Lonestar makes aluminum axles, but they warned me against runing one at the dunes. Theres are extra thick too. Maybe I'll call Nac's and see what's up with the aluminum axles.
Posted by: Fasterthangas
Rad Manufacturing makes them too. There's are definately week. I talked to Nac's today and the aluminum axles are used for TT only. Lonestar said their axle would break through the whoops at the bottom of Oldsmobile.
Some guys can get away with it with their super light drag chassis. My bike is still at 340lbs.
Posted by: Fasterthangas
Thanks for the excellent reply. Lonestar's aluminum axles are thicker and use a larger bearing and carrier. The one I was considering was stock thickness. My biggest fear was time. It may not break instantly, but over time it most likely will.
Posted by: IceMan11
I would agree with Zorro. For just about anything except drag racing, aluminium would be way too soft (even aircraft grade aluminium.)
