Geometry Difference 129 vs 137

[LouTurbo]

Short of overlaying drawings would anyone have this information?
I dont have a 129 to park beside my 137 to see all the differences.

 

[cannondale27]

That would be a interesting thing. If scale was kept same a pic of each could be overlaid.

 

[lilrez]

I cant find side pics of the SW but here is a close up of the ZR. As you can see the drop brackets are completely different, as are the upper skid wheels, front skid arm, shocks etc etc.

 

[lilrez]

you should be able to click on the pics and go back and forth to visually see the differences.

 

[ROCKERDAN]

Nice comparo clicking back and forth....Those drop brackets look back quite abit further on the 137.....Wonder if this is yet another reason why transfer is better on the 129? Nice work.

 

[**sj**]

easy to see the upper wheel/mount is forward on the shortie....

 

[jaydaniels]

I find it interesting that the 129 has 13 lugs on the ground and 137 has 14. I wouldn't think this would make a huge difference in traction.

 

[**sj**]

its not the lugs on the ground...its the transfer....which I believe is decided by the upper mounting point.....excessive transfer loses traction

 

[jaydaniels]

Sorry not trying to get off topic. I realize we are talking about transfer I was simply pointing out that a 137 doesn't put much more than 2.5 inches of track on the ground than a 129. Just never noticed until I looked at pictures back to back.

 

[Turtle]

Sorry not trying to get off topic. I realize we are talking about transfer I was simply pointing out that a 137 doesn't put much more than 2.5 inches of track on the ground than a 129. Just never noticed until I looked at pictures back to back.

The difference in track lengths in not that dramatic when going from a 129 to a 137. When we used to all run around on 121 sleds, the jump to a 136 was pretty dramatic. It resulted in 7.5" more on the ground. But when going from 129 to 137, the difference is only 4" ... But, the 137 uses a larger rear idler than the 129. So the difference is reduced to about 3.5" on the ground. Now if you take into account that the lug pitch is only 2.86", that leaves you with what you found out ..... Only 1 more lug on the ground over the 129.

 

[ROCKERDAN]

I find it interesting that the 129 has 13 lugs on the ground and 137 has 14. I wouldn't think this would make a huge difference in traction.

If you do the math its one thing,but when side by side its approx 1.5 blocks on ground difference...NOT ALOT. And not nearly as much as many like to think.

 

[ROCKERDAN]

its not the lugs on the ground...its the transfer....which I believe is decided by the upper mounting point.....excessive transfer loses traction

In the case of the 137 vs 129...its been proven many times this yr, the 129 gets up and goes better. In other brands/models the 137 typically hook better and transfer well. Not with SW.

This is the reason the 129 is quicker AND faster.

 

[ROCKERDAN]

Sorry not trying to get off topic. I realize we are talking about transfer I was simply pointing out that a 137 doesn't put much more than 2.5 inches of track on the ground than a 129. Just never noticed until I looked at pictures back to back.

I think its cause the "old" argument of Long track vs short track was always 136 vs 121....and yes, that was significant in traction and smoother ride.

But now its 129 vs 137....and those 'old' arguments barely hold up anymore.

 

[ROCKERDAN]

The difference in track lengths in not that dramatic when going from a 129 to a 137. When we used to all run around on 121 sleds, the jump to a 136 was pretty dramatic. It resulted in 7.5" more on the ground. But when going from 129 to 137, the difference is only 4" ... But, the 137 uses a larger rear idler than the 129. So the difference is reduced to about 3.5" on the ground. Now if you take into account that the lug pitch is only 2.86", that leaves you with what you found out ..... Only 1 more lug on the ground over the 129.

Great post...totally agree

 

[snowbeast]

In the case of the 137 vs 129...its been proven many times this yr, the 129 gets up and goes better. In other brands/models the 137 typically hook better and transfer well. Not with SW.

This is the reason the 129 is quicker AND faster.

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.