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Discussion Starter · #1 ·
Ihave a05 gade 800 with 11/4 track and the sled is box stock. I
t had the stock 23/43 gears so I went to 21/43 and it did not feel to pull nearly as hard as stock gears did. It would seem to have lots in the first few feet but fall off quickly after about 20mph, unlike the stock gears that seem to love that 20 to60mph range. Is it possible the clutches could not shift up fast enought? This was played with on medium hard pack.
 

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hmmm...make sure you HAVE the 21 tooth...I just dropped two teeth on my sled and man, it wants to yank your arms off...Also, check your peak rpm...
 

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Discussion Starter · #3 ·
I am sure I have a 21 gear and the rpms look the same 7900-8000 on tach. It felt realy weak in the fields(cross country).
 

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longtrack said:
I am sure I have a 21 gear and the rpms look the same 7900-8000 on tach. It felt realy weak in the fields(cross country).
[snapback]268072[/snapback]​
hows your belt and its deflection look?
 

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Discussion Starter · #5 ·
I have already switched back to stock gears and it feels to hook much better. I did this all in the same day, so conditions should not have had a lot of affect on tests. It really felt to have poor accel. after about 40mph, just rev. quicker but not accel. as quick.
 

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DELINDELL said:
put more weight on the arms.
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If you drop teeth on the top gear, you will have to remove weight from the arms as your peak rpm's will be lower. With a smaller top gear, there will be less load coming from the ground and this will cause your secondary to want to shift up alot earlier than usual. therefore, your primary will also shift up earlier resulting in your drop in Peak RPM.
 

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if you gear down on top you are going to have to add weight to pins because sled will over rev causing you to lose peek hp.
 

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Think of it this way...by reducing your gear ratio you give your sled's motor more of a mechanical advantage.

Now add some weight to the tips of your TRA arms on your drive clutch to get full benefit of that advantage. The motor can now handle more weight being thrown at it due to the increased mechanical advantage it now possesses.

Then you will really have to hang on!!

Jerry C.
 

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Also, you have to consider to the traction....With the drop in teeth, the track wants to spin EVER more faster, therefore, the need to drop a hole or two out of the limiter or soften your rear cams isn't out of the question either...
 

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You guys are thinking backwards...

You have to REMOVE weight. Dropping a top tooth will cause to to UNDER-REV.

Remember....the secondary will see LESS load from the track...which means it will allow the primary to UPSHIFT FASTER. The primary will achive full shift at a LOWER RPM.

What do you do to increase rpm?? --- Remove weight from primary (or turn clickers up)
 

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Jason Blier said:
which means it will allow the primary to UPSHIFT FASTER. The primary will achive full shift at a LOWER RPM.
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So if the primary is upshifting faster won't it over rev then?
 

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FlipMode said:
Jason Blier said:
which means it will allow the primary to UPSHIFT FASTER. The primary will achive full shift at a LOWER RPM.
[snapback]268631[/snapback]​
So if the primary is upshifting faster won't it over rev then?
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No....it will under rev. A primary clutch acts like a governor.

Here is a quote from RK TeK:

OK,

WITHOUT.. getting into major specifics....

The secondary is LOAD sensing... When you gear down you DECREASE the LOAD on the clutch, as seen from the track. Like shifting your motorcycle down.. you do this to get the power back to the tire and this is done by lessening the load on the engine.

So since the secondary is load sensing and you decrease the load on it via lower gearing.. your secondary will want to (and will) shift up faster because of the lessened load... faster upshift, usually results in lower rpms

Kelsey
I have reduced my drive ratio similar to dropping 3 teeth on the top gear. My peak RPM's are now 7300 RPM. I had to go up on the clikcers and still need to remove weight to slow the clutch from shifting out too early.

Make sense????
 

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I played with gearing many times and I have to say that Jason is right.
Lower gearing = lower rpm.

Pierre
 

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Are you telling us that you are only 7300 rpms at wot? Because if you are you better have friend with a tow rope. You are not even making peak hp at 7300rpm you should be at 7850 + or - 100. You are lugging that engine and could very well burn it down.
 

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WILD-THING said:
I played with gearing many times and I have to say that Jason is right.
Lower gearing = lower rpm.

Pierre
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It is hard to picture...but the drivetrain in a sled does not work like the drivetrain in a car or motorcycle. The primary clutch is actually an RPM governor. The faster it shifts out....the lower the shift RPM will be. Heavy weights create more force at a given RPM. More force will cause the clutch to shift out MORE at a given RPM. Less load on the secondary (lower gearing) will cause the secondary to allow the primary to upshift (secondary will UPSHIFT when the load from the engine is higher than the load from the ground). The faster upshift will result in lower Peak RPM. You will need lighter weights to lessen the force at any given RPM. The reduction in weight will make the secondary "see" less load from the engine and keep the primary from sh&%ing out. this will cause peak RPM's to increase.

Clear as mud?
 

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Laker said:
Are you telling us that you are only 7300 rpms at wot? Because if you are you better have friend with a tow rope. You are not even making peak hp at 7300rpm you should be at 7850 + or - 100. You are lugging that engine and could very well burn it down.
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You are exactly right. The first run after my gearing change, I was peaking at 7300. I had to go up on the clickers and I still have to remove weight. I am at about 7800 RPM currently.

On a side note...if you are pulling drags and such...you can choose to clutch for the meaty part of the torque curve (about 7500 RPM) and this will allow you to pull a pretty good load (Sleigh, drag, etc) and not spin the crap out of the trails and softer snow.
 
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