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Cadillac mountain Enduro
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Discussion Starter · #1 ·
Here we go , made some changes to my RS this year and now it's one slow puppy and it jest don't make sense . Top speed last Friday was 75mph flat out pulling 8000 rpm , now I've have geared down from 26/45 to 24/45 so that I could do a revers from a XR , before the gear down with 26/45 it would hit 111 mph on a really good day and break into 100 at any time , now with the gear down to 24/45 getting 75 took some space and a don't care if I blow this thing up attitude WIDE OPEN TOO LONG ... ........... according to DJ's site it should still be good for over 90 mph ,,, here are some photos

IMG_20160111_120807291.jpg IMG_20160111_120949065.jpg

as you can see it's not going all the way to the top , but close with in a 1/4 of it on the primary .

IMG_20160111_120111381.jpg

and its going all the way to the bottom of the secondary . see the black marker in front of the screw driver tip .

IMG_20160111_144333031.jpg

this is what DJ's graf said it should do if it hits overdrive , IS the RS even have that ? I don't know .

IMG_20160111_144234397.jpg

and this is what it should do at 1 to 1 . 75 is a far cry from 92

Now mind you that I got no sense of smell because of my injury but all of the guys I ride with say they don't smell any belt burning when we stop , the clutches are warmer than what I would want to hold on too for a lanth of time but don't seam hotter than the ones on my buddys sleds ether , belt is like new may have 500 miles on it . any Ideas ?????
 

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Have you made any other changes? Gearing charts are theoretical. With 8 tooth drivers, 24/45 is around 2.05/1 overall.Thats what I use with 10 tooth driver, which nets me around 1.875/1. Your clutches are going to the top, so your in overdrive, which is less efficient, and your rolling resistance and aero drag have become significant. With likely 10-15% loss of power. It's a 600? You have used the mechanical reverse gearset? If you want speed gear it so your in 1-1 at a higher rate of speed, to get the most from the engine when it has the most drag. back to where you were. And isn't a 600rs peak at a higher rpm? My thought on it.
 

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Cadillac mountain Enduro
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Discussion Starter · #3 ·
^^^^^ no it's a 700 top end , the gearing is the only change that I would think that would effect top speed , as far as drag , I can push the sled along on the ice one handed , the track rolls real nice ... and your saying that the RS does have OD that would mean that at full shift as I am getting acording to the marks that the 111 top speed is closer to what I should be seeing , that is even farther away from the 75 that it's holding at ,
 

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Metalhead
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What is your secondary spring end force?

...increase it by 20 lbs.

If you have a xxx/260 then go to a xxx/280 and put more clamp on the belt in the secondary clutch. With the belt going to the bottom of the secondary clutch at a great mph prior to theoretical peaks speed, then you've lost some conversion - the sheaves cannot grab the belt hard enough anymore and secondary "opens up". You achieve the vehicle speed you achieve by virtue of excessive belt slip in the secondary clutch.

Jack up the final force of the secondary spring a bit

joey
 

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Cadillac mountain Enduro
Joined
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3,558 Posts
What is your secondary spring end force?

...increase it by 20 lbs.

If you have a xxx/260 then go to a xxx/280 and put more clamp on the belt in the secondary clutch. With the belt going to the bottom of the secondary clutch at a great mph prior to theoretical peaks speed, then you've lost some conversion - the sheaves cannot grab the belt hard enough anymore and secondary "opens up". You achieve the vehicle speed you achieve by virtue of excessive belt slip in the secondary clutch.

Jack up the final force of the secondary spring a bit

joey
OK now that makes sense maybe the spring is clapped out from being 8 years old with 5000 miles on it too , I am sure you know what the stock spring was for the 08 RS , how do I order one from you ?

edit after some searching I found your phone # and called , vary nice lady to talk too ,vary good customer service you got going , :righton :righton to bad the guy she was talking too is a idiot :headbang LOL'
 

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Cadillac mountain Enduro
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3,558 Posts
Discussion Starter · #8 ·
Davis - I'd say that spring is toast :laugh_old: :laugh_old:
funny thing is last year this thing would fly with the higher gearing , you would think that would have loaded the spring even harder than now ...
 

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Anytime I've seen a sacked secondary spring, its caused slower acceleration because it starts out in a higher gear, as the belt climbs the secondary sheave to fast.A badly sacked one will feel like its almost bogging. Like shifting a vehicle up to soon. Too much spring rate on the secondary won't shift up fast enough. Either way your losing acceleration. Put that spring on a scale. If its good try what Joe said, or swap the gears back and see if its as fast as it was. I think your geared wrong.
 

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Metalhead
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funny thing is last year this thing would fly with the higher gearing , you would think that would have loaded the spring even harder than now ...
sacked primary spring can lost its grip on the belt.

as the vehicle speed increases, the belt goes down in the secondary clutch.

as the secondary clutch opens, the belt goes down, yes?

as the belt goes down in the secondary clutch, the arc area of contact of belt to sheave face is getting smaller.

you are asking the sled to go to a higher vehicle speed and using less area on the belt to perform that job.

when you increase the load on the belt and reduce the area grabbing on the belt, the spring force needs to increase, the helix angle (may) need to change - all to keep sufficient side force on the walls of the belt.

if the final force of the secondary spring is not enough to clamp the belt at high speeds, the secondary can open up and you get your maximum vehicle speed by virtue of excessive belt slip.

The belt is not being clamped hard enough down in the secondary clutch - not converting the engine power to the ground.

...thee end. :madnote:
 

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Cadillac mountain Enduro
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Discussion Starter · #11 ·
^^^^^ makes sense , after I read it ten times and think about what you saying . Took me all day to find out that it was a 180-260 black- light,blue stock spring then did think it was worth you time for me to bother you over a 23 dollar spring , I clicked the order now on a 180-280 orange-black as you recommended. IOU a beer or two or three .... thanks JOE .... .
 

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There is nothing on the face of those primary sheaves to suggest its slipping? I'm not saying they aren't tired, but have you made any other changes other than the gearing? Tired clutch parts would have a harder time getting a machine to your previous speed with steeper gearing. It had to have been pretty close to reach that speed, even on the speedo, with a 700.
 

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Cadillac mountain Enduro
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3,558 Posts
Discussion Starter · #14 ·
Put the new spring in last night , went riding today 86 mph top speed :righton now it pulls from 60 to 80 like it should , now I got to check the clutchs with a marker to see if I can get some more out of it , Thanks again DJ :you-da-man:
 
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