Ordered mine today
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pDrive CLUTCH... DISCUSSION... TUNING, CLICKERS, FLYWEIGHTS... PHOTOS AND VIDEOS.
- Thread starter mountainhorse
- Start date
What is the weight in grams of the 967 weight (417224225)?
Including an unloaded bolt and clicker assembly? (ie weight ready to install on axle pin)
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Including an unloaded bolt and clicker assembly? (ie weight ready to install on axle pin)
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Seems to be heavy weight and spring combo on the primary to me.
So, on a 967 weight with standard pin... you have to figure about 74 grams for the weight (the eccentric is part of the pin assembly and not a factor IMO).
With that kind of weight, and the lower RPM of this engine and the super stiff primary spring.... seems to me that the primary will have a lot of "authority" over the secondary...and backshifting will be difficult for the secondary to pull off well....
With the possibility of Putting a lot of frictional load on the belt and generating a lot of heat.
IMO, a bit lighter weight and lighter spring in the primary would go a long way... you can still keep the Engagement etc balanced and lower the energy from the stock heavy/heavy spring/weight combo in the pDrive.... and give the secondary more of a fighting chance to keep clamping forces on the belt up.
Funny thing with all of this clutching talk... I've not really read a systematic breakdown of the INTERACTION of all parts involved.
Where can I find the helix angles of the stock 417127532 ... and force of the stock 417127039 secondary spring?
Joey, have any input on this??
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So, on a 967 weight with standard pin... you have to figure about 74 grams for the weight (the eccentric is part of the pin assembly and not a factor IMO).
With that kind of weight, and the lower RPM of this engine and the super stiff primary spring.... seems to me that the primary will have a lot of "authority" over the secondary...and backshifting will be difficult for the secondary to pull off well....
With the possibility of Putting a lot of frictional load on the belt and generating a lot of heat.
IMO, a bit lighter weight and lighter spring in the primary would go a long way... you can still keep the Engagement etc balanced and lower the energy from the stock heavy/heavy spring/weight combo in the pDrive.... and give the secondary more of a fighting chance to keep clamping forces on the belt up.
Funny thing with all of this clutching talk... I've not really read a systematic breakdown of the INTERACTION of all parts involved.
Where can I find the helix angles of the stock 417127532 ... and force of the stock 417127039 secondary spring?
Joey, have any input on this??
.
.
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P
In a way the primary spring helps backshift a bit by pushing against the clutch weight.
To Balance stuff out the most reasonable way is to drop primary spring pressure and increase secondary spring rate and + ad weight not just on the pin.
I use a 150-300 spring in the primary dropped engagement to 3300 RPM shift out in deep snow 7900 ish with 1.1 grams on the stock 38 mm Pin clicker 4 at 4500 feet. So far back shift is OK , but have a heavier secondary spring sitting here to play with once I get the ZRP weights if needed.
This clutch holds RPM over a fairly large range of temp and altitude or else the motor maintains good power over a fairly large range of conditions. Maybe both.
I know where this messed up clutching is coming from. The demo last year fell on its face real bad not back shifting at 7 -8 thousand feet altitude. In long pulls my XM would eat it halve ways up the pull. Something had to be done this is what we ended up with. It sure revs
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The pdrive weight does change its curve essentially as you change the clicker position. Although the axle is fixed the cam essentially gives it 5 different axle locations so the statement of it not changing the profile is incorrect. Your one diagram even shows the profile changing as the clicker changes ( essentially giving you 5 different profiles in one weight. The bolt in the center of the pdrive weight( changed for weight corrections) is the fixed pivot with the tip and the base both moving up and down ( like a seesaw) as the clicker is adjusted.To me... the term "Ramp" is an outdated carryover from the TRA that does not have any application to the pDrive Clutch in the 850's, IMO.... and confuses things more for the end user to understand in discussions.
Cam, flyweight, or just 'weight' IS a better description of the part.
You would actually have to change the weight to one with a different curve of the face of the weight, that contacts the roller, to do the same thing as a clicker adjustment of the TRA.
The TRA clicker actually changes the Ramp inclination.... whereas the clicker on a pDrive, the weight still pivots on the same axle location regardless of the clicker position; the pDrive weight will never change in terms of inclination, only starting point of 'throw' and will, IMO, only change engagement RPM as it can't change the max travel of the clutch or any aspect of the shift-curve.
The clicker on the pDrive only changes the "tip in" position of the weight and not the profile nor inclination of the curve in relation to the roller travel axis.
Correct me, with better info, if I'm wrong here....
As such, changing the clicker setting can only change how much of the weight is in the "centripidal stream" acting on the weight... which only changes engagement RPM. I know this is contrary to the manual... but I believe that the philosophy there too is a carryover from previous manuals.
In fact, I cannot see anywhere in the design where the clickers on the new pDrive clutch will have any similarity to the clickers on the TRA... and cannot see where they will adjust anything but 'tip-in' RPM...
As an owner of both TRA's and P85-Polaris clutches I've taken the time to understand them both...and, from the beginning of this very thread have evolved my understanding of the pDrive.
The mentality of P85/Cat tuning applies much more to this clutch than the mentality of tuning TRA's.
AS ALWAYS... I am sincerely open to any thoughtful description/info to the contrary... I love to learn about this stuff.
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The reason it takes much more weight correction in a pdrive to correct final shift rpm is the location of the weight in relation to the tip of the ramp. If the weight was closer to the tip (like a TRA adjustable pin) one gram would make a 150 rpm difference. The Pdrive weight is far enough away from the tip I've had people call that added 4 grams to stock clutching and were still over 7900 rpm
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Thanks for that...
Interesting.
I thought that the eccentric acted on the levers, not the weight.... but I can see that I was wrong. :face-icon-small-blu
Is the hole for the eccentric in the weight actually not a hole, but an elongated-hole?
Anyone have some good photos of the stock flyweight and all the parts, disassembled?
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The hole in the molded cam ( axle hole ) is offset with the hole in the ramp ( or weight) elongated so when the molded can is spun to the different clicker positions it changes the axle location.
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S
Reading all these post makes my head hurt.Hope that Joe comes out with a fix.
P
What threw me of is on Page 131 of the race manual they have a graph that shows the amount of weight change by adjusting the Clickers.
In Reality the weight does not move back and forth to change weight ahead of the pivot. Looking at the Drawing it just changes angle of incident on the weight arm and it asked to add or subtract weight on the pivot bolt in conjunction with Clicker adjustments to take full advantage of the Clicker feature. :face-icon-small-dis
Them doo engineers sure know how to confuse us:face-icon-small-hap
In Reality the weight does not move back and forth to change weight ahead of the pivot. Looking at the Drawing it just changes angle of incident on the weight arm and it asked to add or subtract weight on the pivot bolt in conjunction with Clicker adjustments to take full advantage of the Clicker feature. :face-icon-small-dis
Them doo engineers sure know how to confuse us:face-icon-small-hap
N
So turning the factory clickers down to say 2 increases or decreases primary clamping force??
Learning here , thankyou
Learning here , thankyou
SHR has the only "in sled" adjustable weights, motor mount shim both fix the stock mountain and trail set ups...
call for details...
weight kit includes TOOLS to access on the trail...
-BJ
call for details...
weight kit includes TOOLS to access on the trail...
-BJ
C
To me... the term "Ramp" is an outdated carryover from the TRA that does not have any application to the pDrive Clutch in the 850's, IMO.... and confuses things more for the end user to understand in discussions.
Cam, flyweight, or just 'weight' IS a better description of the part.
You would actually have to change the weight to one with a different curve of the face of the weight, that contacts the roller, to do the same thing as a clicker adjustment of the TRA.
The TRA clicker actually changes the Ramp inclination.... whereas the clicker on a pDrive, the weight still pivots on the same axle location regardless of the clicker position; the pDrive weight will never change in terms of inclination, only starting point of 'throw' and will, IMO, only change engagement RPM as it can't change the max travel of the clutch or any aspect of the shift-curve.
The clicker on the pDrive only changes the "tip in" position of the weight and not the profile nor inclination of the curve in relation to the roller travel axis.
Correct me, with better info, if I'm wrong here....
As such, changing the clicker setting can only change how much of the weight is in the "centripidal stream" acting on the weight... which only changes engagement RPM. I know this is contrary to the manual... but I believe that the philosophy there too is a carryover from previous manuals.
In fact, I cannot see anywhere in the design where the clickers on the new pDrive clutch will have any similarity to the clickers on the TRA... and cannot see where they will adjust anything but 'tip-in' RPM...
As an owner of both TRA's and P85-Polaris clutches I've taken the time to understand them both...and, from the beginning of this very thread have evolved my understanding of the pDrive.
The mentality of P85/Cat tuning applies much more to this clutch than the mentality of tuning TRA's.
AS ALWAYS... I am sincerely open to any thoughtful description/info to the contrary... I love to learn about this stuff.
.
In my testing, Changing of the clickers does not affect the engagement rpm. Changing weight to the flyweight may affect it like in the past. Also changing the clickers does change the rpm like the tra, defiantly not the same amount as the as the tra but they do work. What was found tho going down in clickers was the same as going up in the tra. The sled got buzzy, and didnt pull as hard.
What was noticed tho that the amount "flash"rpm was worse on the lower clickers on the pDrive. Thats why the max function on the gauge should not be used for tuning.
I think these new adjustable flyweight is going to be the ticket. Forget about the clickers, leave it on 3 and add or subtract the weight as needed.
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P
85 gram weight 6 Grams in the heel and 2 grams in the middle good from 3 to 8000 feet.
this is true but clicking down 1 will show less RPM at shift out (roughly 6 grams heavier) clicking up 1 will feel better but will over rev at shift (roughly 6 grams lighter)...
the 967/951 weight is ok on click 2 and 3...
the 968 weight ok on click 3 and 4...BJ
---The Cat Team primary clutch 16 and newer is pretty rugged..
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