My front axle weights at 1 lbs 1.6 oz My rear axle weights at 1 lbs 1.0 oz I have heard of Aluminum Alloy 7075 T6 axles... I can have them made at my local machine shop. My only concern is will the aluminum treads hold up the torque specs... To be removed and re torqued time and time again? Luis
I would be a little concerned with the strength of aluminum axles. I know they definately make Ti axles. They are in the neighborhood of $300 a piece for front/rear/swingarm.
I had a real nice Titanium Ducati rear axle in my hands last summer....it was super light...felt like it only weighed about 500 bucks.
why would you want aluminum axles? is to save weight? unless you have gone through the entire bike and have reduced all the weight you can and you stop eating, IMO the weight you save would not justify the safety/service concerns :tut:
I have 7075 aluminum axles on my gsxr750 track only bike. Yes you can use them, yes they hold up fine. Mine are from Durbahn in Germany. He is a well respected builder. I also know of a guy in Canada that made a limited run of 7075 front axles for 916/748 Ducatis. They worked fine. Very light. Mine have held up over 3 seasons so far. I torque them to 1 or 2 less ft/lbs than the manual calls for.
I was going to say: "But, I have heard of them..." Titanium would be fine, if I had a supersport... I only have a dinky SV650... I figure I can have both the axles done to exact OEM specs for $60.00-$80.00 + the cost of the 7075 T6 aluminum... Luis. PS: I am on a Diet too!!!
Aluminum is 1/3 as strong as steel. Titanium is 3/5 as strong as steel. In a frame they can bulk aluminum up to compensate but there isn't enough space with a conventional axle...
Haha, when people ask me, "hey what can I do to the bike to lighten it up for better performance?" I tell them, go buy a treadmill, have you looked at yourself in the mirror lately?
That statement is almost true when comparing the tensile strength of untempered 6061 (18 ksi) to 304 stainless steel (73 ksi). But 7075-T6 has a tensile strength of 83 ksi. All aluminum is not the same stuff.
I don't think the Al axles will fail but I don't really think they're worth it either - have the shop bend and weld you up a subframe out of 3/8" 6061 dowel instead. Will save way more weight and total cost will probably be about the same. Axles don't rotate (and even if they did the MoI would be extremely small) so they're not going to give you big improvements for small weight savings.
Yes that is the guy made mine. You will not have a problem with those axles. There are more factors than just the material that go into the appropriateness of a particular application and material combination.
As the actual difference this will make in a race on someone's lap time is about .00587 seconds, I pretty much laugh. Take a dump. Lose the beer belly. Replace the subframe and fairing stay. Buy mag wheels. Alu axles? I guess if you have no other place to spend your money.....
I agree, makes no difference in performance. Part of the fun for some people is building and owning a trick bike. It's like a collector that owns 100 motorcycles, sometimes 2 or more of a particular model. The point is the collector likes them and can afford them. These axles make no significant difference.
Subframe is on the works too... I guess I was a little disapointed on weigh savings on my Marchesini wheels... Besides, I want to put my buddies machine shop to good use... Luis
For an axle stiffness is important. Stiffness and strength are not the same. A fishing pole can be very strong (hard to break) but not very stiff (easy to bend). The stiffness of steel is 3 times the stiffness of aluminum (all alloys of each have about the same stiffness). Stiffness is important when making an axle. People have tried aluminum axles, a lighter aluminum axle will not be as stiff as a steel axle. This can cause flex. Street bike axles are over built. The trick is knowing what is the minimum stiffness needed for your axle without getting too much flex. If you make an aluminum copy of a steel axle, it will have about 1/3 the stiffness. Question is, is that stiff enough? Any surface damage to an aluminum axle may result in a catastrophic failure.
