Viper_Jim
New member
I'm in the process of converting my 04 shorty Viper to a 144" x 2" Mtn Viper....I've gotten some advice from a few knowledgable fellas already.....I'm just looking for some input from anyone out there who has done the same thing. Right now everything is stock in terms of gearing/lutching
thanks
thanks
Viper_Jim
New member
I've noticed taht a lot of guys are running with a 20 top and a 40 bottom gear......and I believe hat the stock Mtn. Viper is 21 top and 40 bottom which would mean a larger chain for me....by the way....I will be purchasing 8 tooth drivers
151Viper
New member
I have a 121 viper extended to a 151 and I have been running the 20-40 setup with my stock chain and it has worked well. At sea level elevation I can run my stock gearing at no problem with the 8 tooth drivers. The drivers gear it down quite a bit. At 8-10,000' I run the 20-40 setup. I have tried a few oddball things with the clutching at elevation but I was never happy so I purchased a clutch kit from Tom Hartman this year and hopefully it works the way it should. A sea level elevation my stock clutching has worked fine for me. I think the drivers make up for the extra resistance from the longer track.
mountain_mod_viper
New member
Viper Jim. I don't know how big of a hurry you are in, but I'm trying to decide whther to part out or fix up a 2003 mtn viper. If I part it out, I'd have alot of stuff that you might want for your project. pm me if you might be interested
Viper_Jim
New member
Pm'ed
ViperXC
New member
Got a question for those that have been converting shorty Vipers. Have you guys been changing out the skis to the wide mt version ones? Or do the wider skis not matter since it has the trail suspension geometry? Meaning the approach angle of the track and the trenching issue. With flotation skis will it cause it to trench worse? Thanks for your input. xc
MtnMax600
New member
Get the wider skis, you will be happy you did. Otherwise you will be plowing more snow in the front which could very will cause more stucks.
yam_apex91469
New member
running 42/21 in my SRX 151" with 8T no-slips. Also running wider USI skis
Viper_Jim
New member
so far I've seen either 20-40 or 21-42....still not sure...
I'm going to run 23/42 with 8's in my 144"x2" 600srx this winter. Works out to about a 2.06 ratio by my math. I've had good luck setting up my longer track sleds at around a 2.0 ratio for general riding. Works in the flatlands here at home and in the hills of Wyoming and Montana without having to swap gears.
151Viper
New member
Viper_Jim said:
These are the exact same. right?
20/40=2
21/42=2
You might get by with different chans for each though.
Tom Hartman recommended that I run a 20/42 setup this year out west.
Viper_Jim
New member
I'm unsure if it is the same set-up or not....I'm leaning toward the 20/40 setup because I can still use my stock 60 link chain then....I believe the stock mtn Vipers come with a 61 link chain....I stand corrected though
20/40 with 8's is going to put you in the 2.26 range for a gear ratio.
Viper_Jim
New member
Ryan B said:
Is this a good thing or a bad thing?? What ratio should I be looking for>?
That's up to you. It all works together - clutching, gearing, track length. For a trail sled 2.25 is going to be pretty steep. For deep snow hill climber it might be about right. It's all in what your using the machine for and how you want it to work.
Viper_Jim
New member
Ryan B said:
Although I'm doing all of this to use my sled in the mountans....I'll still be using it on the trails from time to time as well....what are te effects of a ratio such as 2.25 on the trails?
The deeper the gearing the less top speed you'll have. (That's the short version there are lots of theories and ways to accomplish things) Like I said earlier I like to set my dual usage sleds at around a 2.0 ratio. This way I don't have to swap gears depending on whre I'm riding. At that ratio my sled will pull a 144 or 136 track nicely, have lots of corner to corner grunt, but still run a respectable (85-95mph) top speed. That's my take on things. Like I said there are so many different opinions on this and alot of it is personal choice.
Here's a quick gear chart that might help. I ran 21/39 with 8t and a 144 x2 and was mostly happy. Mostly off-trail but not any huge climbs like outwest.....4000 ft. max. Low enough to keep the track speed up in the fluff but tall enough to be respectalbe on the trail (80-85mph or so).
http://www.mountainperformance.com/yamaha_gear_chain.htm
http://www.mountainperformance.com/yamaha_gear_chain.htm
Viper_Jim
New member
The 2.0 ratio makes a lot of sense to me...I do a lot of powder riding..I'm guessing a 2.0 can be achieved by combonations such as 21/39 as nben mentioned
LoneViper
New member
We ride mostly powder and I feel you need to be at least 20/40. It just helps keep the clutchs cooler and easier on belts, especially in some tight stuff and close trees.