M-20 in a viper

[ViperBill]

Drove up to eveleth mn on friday and picked up 2 fast m-20 suspensions for 129 and 137 vipers. Installed the 129 yesterday and will do the 137 today. I am very curious to see what they do for top end. Ive always felt the rear suspension has held down top speed as they dont seem to "roll" very easily. Last year on our last trip I hit a wash out and broke my front arm in 3 places and lost all of the front shock oil, We were 150mi from the hotel and i had no choice but to ride it back. Hard to believe but it was the best that sled has ever rode. Rather than putting money in to the stock skid i decided to upgrade. Ive had airwaves in a polaris and a blade and their awesome. I think it does sit a little higher but ill take some measurements when I do the ltx today. They have no front arm spring and the limiter strap runs from the front arm lower mounting to the rear upper cross shaft and has tons of adjustment. Tightening the strap lowers the entire suspension so you can set the ride hight independant of the air spring. Very excited to get some miles.

 

[Redbeard]

Post some pictures! I'm an M20 guy as well! You are the FIRST person I know of to install one on a Viper. I'm curious to see the pics and hear your ride report.

 

[ViperBill]

 

[ViperBill]

Yes I do believe these are the first ones. We just received about 6in of fluffy snow so hard to tell how they work. Rail profile is different and on the hoist the tracks roll fairly easily compaired to the stock suspension. I guess we'll wait for the trails to get in shape.

 

[cannondale27]

It will be faster I bet. Might not be as good at launch though. Haven't had a FAST suspension since M10 in a Formula III so they have changed a lot I am sure.

 

[blueironranger]

They still don't hook up too well, had a lot of fun testing them on different sleds when I worked for FAST back in late 90's. Awesome trail skids though.

 

[Redbeard]

The M20, especially the newer version with one air spring, is a great suspension! The lack of weight transfer at take off is still there, but it's not nearly as bad as the older M10 design.

 

[cannondale27]

Yes they were. Sure was nice never having fear of the rear kicking. I smoked a lot of 5 year newer sleds in the bumps with that setup but hated having to adjust it for conditions all the time. Eventually broke front arm right off when I hit a few big ones on a uphill that I didn't expect and had suspension set real soft. Compromise was setting it stiff and leaving it. Was way to small a sweet spot in that skid without adjusting. Air system and adjusting it I am sure helped broaden the range a lot.

 

[Redbeard]

I can not say enough good about being able to adjust air pressure on the go! It's worth the time and effort to install and your friends will thank you for not stopping at every crossing to make an adjustment.

Experiment with the limiter strap! It rides good in the longest position, but rides even better cinched up one hole from longest!

 

[ViperBill]

We do have the on board compressors. The lack of weight transfer is a plus for me as we ride 95% tight trails and its nice to be able to get on it out of a corner without lifting the skis and losing control. Getting them to transfer is not hard just cut 1/4in off the back of the transfer blocks and you would be suprised at how they will lift the skis. The lack of transfer is built in for control.

 

[ViperBill]

finally got ride in on the new suspensions and WOW they really ride great. Had two concerns one was ski pressure with only one spring. the other was weight transfer. Neither were a problem. There is not a lot of transfer on accl. the rear of the sled actually lifts from a stop but does lift the front end and traction was close to the stock skid. One nice feature is that it controls transfer of weight to the skis on decell. Never really noticed stock but really notice it gone now. Ski pressure is very constant and cornering is flatter.Rode with our normal group 3 vipers 2 switchbacks 600 pro and 800 axys. The 800 always gave me problems but yesterday I was easily able to leave him. When he led it was hard not to run into him in the corners as i could get on the throttle much sooner than he could and still hold my line. Over all VERY happy so far and am told the ride will get better once broken in. Hard to believe!!

 

[ViperBill]

Just wanted to update. Now at about 900mi on the sleds. We did find that in some conditions with c&a rz and shaper bars the steering would get quite heavy so installed the assault air shock on the front arm. With 45psi in the front shock 2in sit in at the front bumper the sled feels about 50 lbs lighter handling is outstanding and ride is incredible. Rode back to back with a 16 ltx and 16 poo switchback in rough trails and there is no comparison far better ride and handling best money ever spent on a sled. Could not be happier.

 

[Redbeard]

...best money ever spent on a sled.

 

[YamaSpark]

Hey ViperBill,
Are you still happy with your M-20? How many miles on it now? Have you had any problems with it?
I had an M-10 in a '95 Cat EXT and then a '98 Cat ZR600, loved the suspension, hated the 2 stroke smoke, so sold it in 2006.
I now own a 2016 Viper stx-dx and thoughts of adding an M-20 to it have keeping me awake at night! Please help talk me in to OR out of spending all of my hard earned dough on an M-20!!
Does anyone else have an M-20 in a YamaCat Viper?

 

[ViperBill]

About 2600mi so far and love it. For trail riding nothing better. Would do it again in a second. No problems although I did fully clip my track as it was hard on slides this seems to have fixed it. No regrets. I do sometimes miss the weight transfer but the improvement in ride quality and handeling is well worth it. Would recommend it to anybody.