Geometry Difference 129 vs 137

[ROCKERDAN]

If its a drag race just out on a lake or lg field,the 129 may be a tad quicker out of the hole,but the 137 has shown it has longer legs on top,even in the spring copy of American snowmobiler real world stats,it was 137,s that were running quick and fast,the slug of a sw ltx-le gets out quick at 0-30 in 1.46and runs 660 ft at 7.62 but other real world vids of seeing the 137,s run top end of 120 gps mph all stock seems more likely on the 137 they appear to have a slightly better angle of attack.

I have seen just as many 129s running big stop speeds, so I dont see a clear difference there....so i will always take the lighter track with less stud weight on the gun, when all else is equal.

Ill take the agile 129 always for my area...regardless.

 

[ViperBill]

Can't comment on the sw but on the viper which is the Same chassis there is no difference other than rail length. We have a 129 and 137. I installed m20s in both and mounting locations were identical skids side by side were the same except for rail length. Sw may be different.

 

[Bt04f250]

Can't comment on the sw but on the viper which is the Same chassis there is no difference other than rail length. We have a 129 and 137. I installed m20s in both and mounting locations were identical skids side by side were the same except for rail length. Sw may be different.

What is a m20s?

 

[**sj**]

look at the two pics provided and specifically the two upper wheels/mounts location....this is the difference in the transfer I feel.

 

[snowbeast]

I have seen just as many 129s running big stop speeds, so I dont see a clear difference there....so i will always take the lighter track with less stud weight on the gun, when all else is equal.

Ill take the agile 129 always for my area...regardless.

I hope next winter coming,i don't regret my decision to go 137,i am not a wheelie nut,so I am not all broke up about its ability to lift the skis to the moon,but it needs to stick the front end during hard cornering,this is a must.

 

[cannondale27]

The link for rear shock is on the front arm on 129 and is a separate mount on 137. Guys on skids even a 1/8in difference geometry wise is a big deal.

 

[snowbeast]

The link for rear shock is on the front arm on 129 and is a separate mount on 137. Guys on skids even a 1/8in difference geometry wise is a big deal.

Yes it is steve,1" can be huge,just that fact you talk about here,is huge.

 

[LouTurbo]

Would a 129" extended to a 137 transfer better, or be more detrimental ?
I know of some that extended 121" to 130" + but don't know/recall how well they transferred.

 

[snowbeast]

Would a 129" extended to a 137 transfer better, or be more detrimental ?
I know of some that extended 121" to 130" + but don't know/recall how well they transferred.

No,a 121 or 129 will transfer much better,just given the shorter track length. Take a longer swing arm on a 4-wheeler or bike,and they do that so it wont wheelie as high,because of reders riding two up,on a shortie,it will pull up on a big bank to the point of tipping over.

 

[stevewithOCD]

Well i know 1 thing, i have to buy a bigger trailer (mo' money) due to that 1 lug on the ground...

 

[stevewithOCD]

Wish i went with a 129

 

[cannondale27]

Wish i went with a 129

Even my 129" the flap gets caught in the cover of a 10ft Clamshell. Seems all the sleds are longer nowadays.

 

[SideHogger]

Just a thought, is it possible to mount the front arm in a different hole than what they come from factory? What would that change? There are , I believe, 4 holes there.

 

[ROCKERDAN]

Id say the rear arm would need relocating(scissors) to make it transfer more, but who knows for sure.

 

[Doc Harley]

Well i know 1 thing, i have to buy a bigger trailer (mo' money) due to that 1 lug on the ground...

I had to buy a new trailer as well. It was a bittersweet day. Loved the clamshell. Not one issue. Well.....Except the 137"
As far as speed difference. My 137" will easily run with the best of them.