Need some clutching/gearing help!!

[mezz250x]

I have an 05 sno pro chassis with a 700efi motor in it, 136x2" challenger track, team industries secondary clutch. This sled is going to Cooke City in a month. I have no idea where to start for clutching this sled for the mountains. Anybody have ideas?? Also, is the stock gearing gonna work for me? Any help is appreciated.

 

[mezz250x]

Really?? Nobody??

 

[Bedhead]

Depends just how dedicated you want to get for riding out west. I'm from the Hutchinson area, and when we setup the Crossfire for a trip we just swap out the track and clutch for the altitude. I'm sure I leave a lot on the table performance wise, but with most riding done here and 1-2 trips out west it's to much work swapping gears. With that said, I am not familiar with the SnoPro gearing. I would check a clutching chart for an M7 for the altitude you will be at, and use that for a base line.

 

[mezz250x]

Does anyone have a clutching chart from an M7? The drive shaft, drivers, and gears are out of the F7 so i most likely will leave that alone. I'm mainly going after the primary clutch. I'm not riding this sled out there a friend of mine is, so i'm not to concerned about it being perfect but i dont wanna give him a turd.

 

[Bedhead]

What elevation?

 

[Bedhead]

Hope the pic worked.

 

[mezz250x]

Does the clutching vary at all from chaincase to diamond drive sleds?

 

[diggerdown]

F7 gearing is going to be way high for off trail up there. I would go pretty light with the weights and a stiff spring for high engagement. Maybe Y/W spring and 65 weights...just guessing. Secondary is pretty important, without going into that you will be bogging down on a pull. Pretty easy to take a few weights and springs along for the primary, it doesn't take long to change them out. Cooke is an easy place to experiment because you ride so close to town to run back and change things and go out again.

 

[av8er]

this is the m series section

maybe u should ask that ??, elsewhere

 

[mezz250x]

maybe u should ask that ??, elsewhere

Its going to be close to an M series set up in the sled. Maybe you should keep your useless comments to yourself

 

[mezz250x]

I've been to Cooke to numerous times, and i'm not riding this sled. It's my MN sled but a friend of mine is coming out this year and he's riding this sled. The setup don't have to be perfect, just good enough.

Reason i had asked about the clutching being different from chaincase to diamond drive is that i found a chart from an 04 700 that shows 61 gram weights for 5-9,000ft and 57.5g for 9,000+

 

[diggerdown]

Was that chart from a M? Remember there is a huge difference in the gearing when you look at 25 to 30 mph difference in top end between a M and F turning the same rpm
Av8er was just saying that a lot of guys in the M section of the forum do not know much about gearing and clutching a trail sled for the hills....what ever happened to Minnesota nice?

 

[boondocker97]

I think it might be tough to figure out what you will need to even be close. The diamond drive secondaries on the M7 clutches run much different helix angles than the F7 and snopros with chain cases and different secondary clutch design. Throw in the fact that the snopro has a team secondary and there isn't one place to look to figure this out. If it was mine, this is what I would do:
1. Find a clutching chart for an F7 and use the primary recommendations for 9000'+. If you can find one for an F7 EXT with the 144 1-1/2" track it might be best.
2. Compare the gear ratio you have to what the F7 runs and see how close they are. If there is a big difference then you have even more work to do.
3. Compare the F7 recommended helix angles. Take the difference between your current elevation and the 9000' recommendation and apply the same change to your Team helix choice.

 

[DYEMAN]

mt set up

y/w is a good spring , 36 deg helix is a good choice , gear ratio approx 2.33 follow m- seri weight chart you will have fun . adjust belt and ride for a couple of days , if snow is deep powder high engagement might be a problem for a first time ride , he/she will not need to pull hole shot a y/w should bring the sled in around late 3 to 4000 rpm top rpm see chart should be 7600 ? 8000? have fun

 

[Thunder101]

What belt !!!
The sno pro gearing would have been good, F7 gearing will be
WAY to high. As said 2.3 ish will work
If your running the 020 belt I would guess 58gr to 60gr, my 03 F7
Came with 63.5gr and 020 belt. Try to find
A 49* helix, the old powder specials had them.

 

[mbcat]

Depending on which primary set up. Set screw or not. Set screw go by04 f7 high elevation non set screw go with 03 f7 hi elevation. Gear slightly lower than short track recommendation.

 

[mezz250x]

It is the 020 belt, set screw weights. Maybe thats why im seeing the difference in the amount of weight to put in it? I had the chaincase apart this fall for a track swap, the top gear was 19, i forget what the bottom gear was. I'd think with a 19 top gear the gearing should be ok. More or less just trying to get a ballpark for weights and a helix angle.

And about the helix...since it's a team secondary would the angle be the same as a cat secondary? An angle is an angle no matter what, but being they are a different clutch does that change things?

Thanks for the help guys!

 

[boondocker97]

I don't believe helix angle is quite the same across all clutches. If the clutch is the same diameter, uses the same helix diameter, and has the same spring force then they can be considered close. I'm not sure how similar the Team and the cat clutches were that year in these regards. That's why I suggested applying the change in recommended angle to your team clutch, not the actual suggested angle. Here's a discussion about helix angles from a little while ago. My thoughts are at the end http://www.snowest.com/forum/showthread.php?t=386582&page=2