Rotating weight reduction

[Seabass152]

Don't go down the rabbit hole Eric! This thread is dangerous.

One of the other BIG benefits of reduction of rotating mass....is reduction of inertia.

The Gyroscopic effect of all of those parts, rotating in the same direction... will have a noticeable affect on how nimble the sled feels.

If you reduce the weight of rotating parts... especially if that reduction is away from the centerline of rotation (ie, further out from the center line you make your weight reduction)... you will have make the sled more, dare I say, "Flickable"....this is in addition to the responsiveness that you will feel in the sled.

In the new AXYS... you have a lighter crank, a belt drive, a lighter track... more "flickable" eh !

Make the Primary clutch lighter, make the track and drivers lighter... You will notice it for sure!



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[Cinno]

No engineer here but seems an engine producing 100 ft lbs of torque at the drive shaft will spin a 40 lb track a whole lot faster than a 50 lb track.

What are your assumptions? How much is a "whole lot faster" ? Whats the weight of the sled? Whats the gear ratio? From a dead stop or running start? How much traction do you have?

Cinno

 

[LoudHandle]

I find it sad that one poster has his head so far up his own azz that he can not see that he is incorrect. He continues to beat his chest like he is correct, under the guise of math and engineering, but in actuality he is just a misguided soul spouting misinformation. It is also sad that he can not see clear enough thru his rose colored glasses that he is the only one that believes his misinformation. Probably a Democrat too! (Election day Humor)

Anytime you can reduce the rotating weight of a drivetrain, without compromising necessary strength, you will benefit from quicker acceleration and deceleration. It is a fact that it takes less power to spin a lighter object than a heavier one and keep it spinning at given speed.

Here are a couple of rules of thumb to keep in mind when you are making decisions on where to spend your hard earned dollars; you will gain the most from cutting weight from the highest RPM, at the largest diameter, and heaviest objects first (IE: anything connected to the crankshaft, secondary clutch, track, brake disc, shafts).

 

[mountainhorse]

In addition my post above.... on any given engine... there is a point that removing flywheel weight (flywheel, clutch, crank etc) can cause issues...vibration or other 'runability' problems can arise if you remove too much weight.

What that point is... that is the question.

Just something to ponder.



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[Sheetmetalfab]

What about sprung weight vs unsprung weight.

Sent from my iPhone using Tapatalk

 

[nighthawk285]

lol, well that's a whole 'nother discussion on weight transfer and suspension response, it just counts as static weight for the acceleration discussion.....
























But you knew that already

 

[Madtown]

Roughly $4,500 to duplicate that skid. $375 per pound dropped lol.

 

[richracer1]

In addition my post above.... on any given engine... there is a point that removing flywheel weight (flywheel, clutch, crank etc) can cause issues...vibration or other 'runability' problems can arise if you remove too much weight.

What that point is... that is the question.

Just something to ponder.

Yep, and every engine responds differently to crankshaft weight and the reduction of weight. FWIW, I use to race a ZX-7 many years ago. While modding the engine, I had the crank lightened. That engine would rev extremely fast, but I later found out that that specific engine would lose corner exit "grunt" by lightening the crank.

Like already mentioned, the larger the diameter of the rotating items that you can safely reduce the weight of will yield greater returns. I took 8lbs off of rotating weight by going to racing rims on the above ZX-7. That had tremendous effects on how the bike handled and accelerated. Some of the increase in acceleration was due to the rear sprocket being bolted directly to the rim and not having a "cush" drive like the stock rims use. The difference was very noticeable, especially when going through the turns, when I would switch back to the stock rim/tire set up which could be several times in one day due to the racing classes I entered.

Just my real world experience with rotating weight losses.