Rotating mass weight reductions
- Thread starter wfieldin
- Start date
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how do you like the pro gears in the khaos ?
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The rotating mass reduction has been a hot trend for a while. I have an Indy Dan long rod motor with his clutching and the heavy clutch cover actually added weight from stock by quite a bit. I took it off for a couple rides and put on a light weight cover. I couldn’t believe how much the motor vibrated and how rough it felt with the lightweight cover. I didn’t notice any difference in performance in fact I think the heavy cover performance is better the motor is so much smoother throughout the RPM range
I would personally not chase weight in the primary side of things for hte vibration issues mentioned above.
That being said, a twin trax helix for secondary is like 4oz lighter then the stock single. brake rotor etc that stuff all adds up. I wouldnt drop my life savings into it, but it definately adds up to a snappier sled thats for sure!
That being said, a twin trax helix for secondary is like 4oz lighter then the stock single. brake rotor etc that stuff all adds up. I wouldnt drop my life savings into it, but it definately adds up to a snappier sled thats for sure!
the heavy cover eliminates clutching inconsistencies and premature wear.
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maybe thats because you threw the balance off by changing the clutch cover !
from the factory the clutch is balanced as a unit .. if you start changing parts out you will need to re-balance it
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I see how that is possible but trust me it wasn’t a balance issue. The heavy coverI replaced it with wasn’t balanced either and I have a fully balanced clutch assembly on an 800 with a lightweight cover and it’s not any smoother also the maker of the lightweight cover said I shouldn’t need to re balance after installing the cover.
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Torsional vibration increases when the crank mass is reduced, .....hard on clutches, and much harder to get belt grip.
Really like the gear down, have ran this on all my Axys sleds prior too.
Thought I would hear more positive information on this.....May just send my clutches to Patrick’s for balancing
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Don't want to argue with your comment however it is not correct. The stock cover has balance holes drilled in it. If you remove it you have affected the balance. This is why our Happy Face cover has balancing holes pre-drilled in the face so weight can be added to balance the clutch. Look at the ZRP site. They recommend re-balancing when adding their cover also. The biggest advantage to an open design cover is the heat reduction factor by allowing air to pass through it and transfer the heat away from the clutch. http://www.cascadecp.net/Polaris-Clutch-Cover.html
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Ok let me start from the beginning. I agree that clutches should be balanced. I started with a completely balanced clutch assembly from Indy specialty. The bolts backed out that hold the replaceable center bushing on. I called Indy Specialty and they wanted me to send my clutch in for warranty replacement Of the cover and re balance but I was leaving on a trip so I had them send me a new cover and we could balance later. The cover didn’t make it in time so I threw on the ZRP cover I already had. I didn’t notice any performance gain but did notice the motor was much rougher. When I got back I put the unbalanced Indy specialty cover on and it was much smoother. My 800 actually has your happy face cover that is fully balanced and it’s not as smooth as the 850 with the unbalanced heavy cover. I understand ideally everything needs to be balanced but I still don’t think that was the issue in my case. I also made a big climb while on the trip and my clutches got smoking hot I have never seen them that hot with the heavy cover.
Sent my primary to Indy for a balance and cover, I had wanted the heavy cover but Dan did not have any at the time, so had the windowed cover instead. Sled is so silky smooth and very mild clutch heat, nothing else Ive ever had even comes close. Belt life is a non issue!
I’ve had the Patrick’s on my 2020 axys 850 for 1,600 miles now. This is taking weight out of the primary by shaving material off the clutch and adding a carbon cover and ti cover bolts. The secondary is about a pound lighter as well. There is absolutely more bottom snap and improved throttle response.
I replaced the weight bushings at 1,200 miles. They were shot and hitting the tower. That’s about the same longevity I get on stock primaries for the axys before needing maintenance. I clean the clutches regularly and blow them out after every ride. I do notice some vibration. I’ve never tried the heavier indi dan style, but would really like to ride them side to side!
Is it worth the $800 I paid? Probably not, but chasing weight reduction and bottom snap has been a priority for me.
I replaced the weight bushings at 1,200 miles. They were shot and hitting the tower. That’s about the same longevity I get on stock primaries for the axys before needing maintenance. I clean the clutches regularly and blow them out after every ride. I do notice some vibration. I’ve never tried the heavier indi dan style, but would really like to ride them side to side!
Is it worth the $800 I paid? Probably not, but chasing weight reduction and bottom snap has been a priority for me.
I am surprised so many talk about loosing weight via the clutch cover but no one talks about light clutch ramp weights. I run 67.8 gram weights in my clutch with a lighter primary spring while others run 72 or more grams in the same machine at same altitude. Light ramp weights are key to reducing rotating mass, clutch life and quicker back-shifting.
The Polaris motors have been on a weight reduction for years. They have the new Pork Chop crank they developed for better throttle response. the first ones of the pork Chop cranks had issues, as we balanced some of the cranks for Polaris to make them work, and last for testing. The new wave is light weight flywheels too! We have been balancing and lightening clutches since 2012. Our business gets busier every year. There is a benefit from balancing, we have seen that. Most stock clutches, Primaries are around 1.5 to 3.5 OZ out of balance, that equates to 30-60 pounds out of balance at 9000 RPM. The secondaries can very so much, some 1.5 to 6.5 oz out of balance!!! I have seen some secondaries act over 100 labs out of balance at 9000 RMP. Will adding weight help or make a difference? it seems that every manufacture is trying to reduce spun weight. We believe our carbon fiber cover reduces harmonics as well, being it is a soft material, this helps crank, bearing life. I am not trying to up sell, just giving information, what we do is not for everyone.
What do you think of the SLP head? How did it compare to stock?
Not able to give you a before and after comparison, I put the head on when the sled was new before it hit the snow. I've had no issues with DET or anything although the sled is a bear to pull over if it has been sitting out in the sub zero cold overnight, don't know if that is compression related or not.
Just had the latest ECU flash installed this morning since it did flood out a couple times when cold starting, plugs always looked on the rich side, hope it cures that.
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