Gear down 09 XP

[bluefinger]

Thinking about gearing down my 09 800 XP with a 154
I weigh about 200 lbs with all my gear
I ride 9000 - 12000 ft elevation and almost never on trails
Should i start with a 20 tooth or go all the way to 19 first?

thanks

 

[bigrig73]

is it completely stock?

 

[bluefinger]

MBRP can is the only mod so far.

 

[Original Tetonice]

Gearing down slows trackspeed.

OT

 

[Wyoming T/A]

stock i would go 19--we have 2 -2008 154s with the 09 clutching and they have 19s and run great

 

[bigrig73]

i would do a dynamo joe clutch kit. they really work and i think you would be happier.

 

[winter brew]

Thinking about gearing down my 09 800 XP with a 154
I weigh about 200 lbs with all my gear
I ride 9000 - 12000 ft elevation and almost never on trails
Should i start with a 20 tooth or go all the way to 19 first?

thanks

What are you seeing that makes you want to gear down?

 

[xp174]

No it doesn't

Gearing Your sled down does not change your track speed. It changes where your belt runs on the primary vs the secondary at full throttle under load. Your xp does not have enough power to turn the track at 75mph. What gearing down will do is save Your belts. A 19 tooth top gear will run 1oo" F. hotter than a21 tooth top gear. I recomend a 21-49 combo. Oh idealy you want the belt to run the same diameter under full load on both primary and secondary so take a black felt marker with You and check it under full load. [Up a steep hill in fresh powder] PS I've never taken the heat gun to a 20 tooth upper because I don't have one.

 

[Dynamo^Joe]

Gearing down you'll observe track speed "staying power"

Example...
Running across a fresh 2' snow meadow, full throttle.
Pulling off 38 mph track speed with a 21, if you have the capacity to turn the sled 90 deg carving hard onto it's side, you may observe the track speed diminish by up to 8 mph.
Maintain full throttle, then top track speed recovers at a certain time.

The sudden load increase under full throttle reduces track speed.
Go down to a 20 turn with same maneuver beside old track, then lose 6 mph. Top track speed recovers quicker than the 21
Go down to a 19, turn with same maneuver beside old track, then lose 5 mph. Top track speed recovers quicker than the 20

Gearing lower reveals "staying power" for whatever track speed you can achieve for the load the sled sees.

 

[Original Tetonice]

Thats funny my XP on the flats will hit 84 mph. And the short track XP's will hit low 90's. Drop to lower gearing and your trackspeed slows under the same conditions.

By the way if have yet to see a 19, 20 or 21 top gear reduce clutch heat under load while climbing hills in powder.

OT

 

[xp174]

Buy a heat gun.

Everyones sled could be different . Check Your own and You'll Know. I'ts easy to pop the the top rubber out and give it a shot. I assumed You were not discussing going down a lake on ice . No one I know rides like that so I assumed You were capable of doing the math to see Your reduction in top speed going down a lake.

 

[Dynamo^Joe]

*Gearing down reveals track speed "staying power"

It's a clutching principle just like;
*flyweight determines...
*ramp angle determines...
*spring force determines...

Calibration is observed under full throttle. Make changes according to full throttle rpms.

If you lost too much track mph under full throttle with "X" gear; Then reduce gear ratio by whatever means necessary to achieve that lower gear.

 

[2009skidoo800rxp]

I have an 09 800 154 with Roosterbuilt clutching and I'm pulling 48 mph clutch speed going uphill in 2+ feet of pow. Also with all my riding gear I weigh 230 easy. I first installed Winterbrews kit and used my stock 21 gear but after about 5 rides I geared down to a 19. I love it compared to the 21 gear and I still hit 94 mph track speed on the lakes.

 

[snowdan]

I have settled on 19t gear and I have tried all three. Most of my riding is at Cooke City [8 to 10k ft]. 19 seems more responsive while boondocking and in deep powder. If all your interested in is the hero snow highmark or top end on a lake then maybe 20t, maybe? Elevation eats horsepower,vertical eats horsepower, powder eats horsepower, you decide.

 

[Original Tetonice]

Gearing down you'll observe track speed "staying power"

Example...
Running across a fresh 2' snow meadow, full throttle.
Pulling off 38 mph track speed with a 21, if you have the capacity to turn the sled 90 deg carving hard onto it's side, you may observe the track speed diminish by up to 8 mph.
Maintain full throttle, then top track speed recovers at a certain time.

The sudden load increase under full throttle reduces track speed.
Go down to a 20 turn with same maneuver beside old track, then lose 6 mph. Top track speed recovers quicker than the 21
Go down to a 19, turn with same maneuver beside old track, then lose 5 mph. Top track speed recovers quicker than the 20

Gearing lower reveals "staying power" for whatever track speed you can achieve for the load the sled sees.

Joe, nobody turns there sled 90 degrees and carves there sled at 38 mph.....And everytime you do lay your sled over your always going to loose trackspeed regardless of which gear you use.

If your going to test gearing you have to test on long flat trails where the TRA has the ability to acheive "overdrive"..... When operating the TRA in deep powder acheiving "overdrive" is not going to be possible.

Furthermore "staying power" depends on the effectivness of the "belt". As the clutch heats up under load the "belt" can and will loose it's effectiveness due to "heat" aka "heat soak" which is a common problem with the TRA.

Clutching/Gearing is only as good as the effectiveness of the belt.......*flyweights, *ramp angle, *spring force means nothing if your using a weak belt.

Many snowmobilers tend to beat the belt to death which is a no no when you want peak clutch performance.


OT

 

[800 XXX]

19 is the ticket!!! Staying/Consistent power in all conditions.... Head to Head 19 gearing works best unless you want to race on flat land all day at top speed...

 

[PJ-Hunter]

What would gearing down do too climbing in the steep and deep. I was watching my tach and noticed that whenever the load changed, such as softer,deeper snow or a steeper grade change I would drop to 7900 then it would move back up to 8100-8200 quickly. So I am assuming that my clutches are shifting normally. Would like to spin the track faster though.

 

[Sasksummit]

I just had mine out in the mountains for the first time last weekend.
I never ran the 21 tooth went straight to a 20 and was happy with the way it worked.

 

[MURDOCK]

Gearing Your sled down does not change your track speed. It changes where your belt runs on the primary vs the secondary at full throttle under load. Your xp does not have enough power to turn the track at 75mph. What gearing down will do is save Your belts. A 19 tooth top gear will run 1oo" F. hotter than a21 tooth top gear. I recomend a 21-49 combo. Oh idealy you want the belt to run the same diameter under full load on both primary and secondary so take a black felt marker with You and check it under full load. [Up a steep hill in fresh powder] PS I've never taken the heat gun to a 20 tooth upper because I don't have one.

You are saying you only want to use 50% of your variable transmision (clutch face) This has got to be one of the stupidest statements i've heard. In any car or truck with a direct drive tranny there is much to be gained with lower diff gears and an overdrive tranny. Its self explanitory. The more "gears" you have the easier it is to stay in the power band. How has nobody else jumped on this.

 

[800 XXX]

PJ, I had a tough time pulling rpms with stock gearing. I went to the 19 and it just seemed to work better in the steep/deep. Power was right there all the time, I did a few other changes that could have played in this too but I feel on my xp the 19 is working best for me...