i am thinking about buying, or possibly making an aluminum axel.

the stocker i beleve weighss in at 15lbs. while the aluminum axel weighs in at 4

would this mean that i would be loosing not only 11lbs in weight, but 11 lbs in rotating mass?

wow!! if this is true, wouldnt that be like taking 11lbs off your flywheel? (not that a flywheel weighs that much, but im hoping you get the idea.)

now think about this, the motor would be swinging 11lbs less weight rite? equaling faster accelaration and better all around throttle response

fill me in on what you guys think.

all replies are greatly apprecated

ross

 

I personally don't think this concept fully applies to the rotating mass concept. It is rotating, yes, but not in the same sense as to steal power, as the flywheel. I think the reduced weight would be a very good thing for you, but I don't think it will be equal to that of rotating mass. It might, however, count some as rotating, due to turning a lighter mass....similar to that of how lighter tires work(not really the same concept as a lighter flywheel). Make sure, if you decide to make/buy one, that your power can be held by this lightweight axle(which it should be, if you are only in a strait line, no real power is hooked up to the axle, other than perpendicular power). Sounds like a great idea though, suprised you guys haven't made this mod yet......good luck with everything, and I'm just speculating, I don't really have much of an idea(without looking one over) as to wether my ideas are correct. Again, good luck!!

 

thank ya bradracer for your input.

if anybody else has a comment please free to post. il certianly apprectiate it

thanx

ross

 

i think the aluminum axle if for dags only, will bend over jumps

 

being a drag only bike you should be ok.

I don't however think you will notice much more then weight savings.

since the axle is the center of rotation its not the same as removing weight from the edge of a flywheel or lighter tires. the axle is the rotation point. when going to smaller tires /rims you gain more then just the weight savings. the weight is also closer to the rotation point so its easier to get them spinning.

think of it as a clutch weight, the 10-58 weights take longer to engage then a s58 becuase more of the weight is at the tip of the weight instead of the bottom. this is a crappy analogy but all I could think of.

 

Still though, he will get the benefit in 2 different ways. He will still get an 11 pound weight savings, plus some rotational weight savings. It still does take power to turn a heavier axle, so it will help. When it comes to drag racing in 300ft, about every 35lbs will get you another .1 of a second. On my wife's Honda I replaced even things like the tie rods with aluminum because it lost .5 lbs total. You can buy aluminum bolts to replace those heavy stock ones, a handful of bolts can weigh a couple of pounds. If you keep looking for things you can always find something to shave a little more, and nickels and dimes will add to dollars before long.[img]i/expressions/face-icon-small-happy.gif[/img]

 

I agree it is weight none the less.

why not do some frame mods like your cuz or did you cover those already?

ive wanted to build an aluminuim subframe that bolts on for a while just havn;t had any drive. should be some weight savings there. Also who makes the axle and how much is it?

 

Theres a guy down in kentucky I think. BT Racer gave me his #. He wants like, 450 for the axle plus he cant start on it until june. He told me the type alum. it was made of, and were gona try to beef up some gocart hubs or maybe jr dragster hubs. If it turns out.... (IF) we should have around 200$ in it.

 

I have an aluminum axle on my 400. We only dune with it and have not had any problems. Looks nice when you polish it with Mothers too!

 

i think 99% of your gain will be from the loss of 11 lbs. The rotating mass is not quite the correct term to use. It would be angular momentum. It is the force that keeps the wheel spinning when the it is spun in the air, much like the momentum that keeps you going while slowing down from a flat out run. It includes the mass of the rotating object, the speed at which the mass is rotating and the radius of the center of mass from the rotation centerline (which on a rear axle is probably much less than 1" and would still be the same as the steel axle). The center of mass is so close to the center of roation that any difference is minimal. You also have to take into account that the rear axle is geared down significantly from the engine(maybe, 3:1 to 5:1??). So rpm is much less than a flywheel attached to the engine. Your only real gain would be the actual weight difference of removing 11 from the quad. All that being said, I know quite a few people that would die for a 1% gain.