Doing a 121 to 136 stretch, what a pain in the #*$&@

[evil eagle]

I wanted to do a stech of my apex mono to a 144 or 136. I understood the geometry is completely wrong for the 144 and not as bad for the 136. But I can say the 136 is almost undriveable with just adding rail extensions. To have proper track tension amd not skip over the drivers on whole shot. Then the track is too tight for driving and the track it's self is the suspention and becomes very rough.
So I bought the tunnel brackets for a attak and added the wheels more to the rear to bring the geometry in line.
All the venders of these entension kits don't mention a word of how this messes up suspention, and makes me quite pissed of how much extra money and time to make it right.

 

[07apexcan]

I swapped out the skid for a 136 and added all tunnel brackets to make my sled an attack
Lots of work but thought I would make it like Yamaha factory

 

[MrSled]

Been talked about many times... you cant just take a 121 and extend it... maybe to a 128 but that's it without the cross shaft and 136 brackets to make the geometry work.

But the new 128 mono skid you can extend to 136 without a problem.

 

[evil eagle]

Been talked about many times... you cant just take a 121 and extend it... maybe to a 128 but that's it without the cross shaft and 136 brackets to make the geometry work.

But the new 128 mono skid you can extend to 136 without a problem.

I understand now what not to do. All of the vendors of these kits don't mention nothing about the side effects of stretching them.

 

[MrSled]

Been talked about many times... you cant just take a 121 and extend it... maybe to a 128 but that's it without the cross shaft and 136 brackets to make the geometry work.

But the new 128 mono skid you can extend to 136 without a problem.

I understand now what not to do. All of the vendors of these kits don't mention nothing about the side effects of stretching them.

That tell me they just sell the parts and have not done the work.

 

[gsxr]

I did an Apex 121 went to 144 Tracks Usa was awesome !

 

[journeyman]

I have a couple friends that did the kit from tracks USA and they have never mentioned any issues. So to do it right what is all needed to go from 121 to a 136 on the 2007 Apex GT?

Is going to a 128 a better option?

 

[Jona$]

i made my gt 121-136 relocating to 144" its awsome, and moves up on snow alot better.

 

[gsxr]

121 - 128 IS NOT WORTH THE TIME , GO AT LEAST 136

 

[gsxr]

TRACKS USA KIT WAS AWESOME , NICE RAIL EXTENTIONS , GOOD FIT !! PRICING WAS GOOD !

 

[journeyman]

I guess what I am asking is .....is the geometry of the factory 136 skid different than the 121 geometry? Will a take out 136 mono bolt right into a Apex that was 121? If I do a rail extension from tracksusa on a 2007 Apex GT what pitfalls will I run into? Would a person be better off to find a 136 mono skid out of an Attak GT to do this upgrade and just sell the 121 skid?

 

[Turtle]

We consistently try our best to inform our customers of the track tension issues present with the monoshock and proctive suspensions. Much of it can be alleviated by running extrovert drivers and a loose track. Most tend to opt for the extrovert drivers since it's an easy thing to do which doing the track change.

I'm sorry for your experience, but we have always tried to inform our customers of this situation.

 

[journeyman]

Correct me if I am wrong, do the extrovert drivers scrub some top speed?

 

[evil eagle]

This is what I learned doing this stretch. I could have used the extroverts and run the track with about 4 or more inches of sag. Any tighter the track will get very tight, so tight it won't ever bottom out. That is wrong, and very hard on the track and shafts and bearings.
I did an experiment with a small jack. I placed the small foor jack on the rear sissor arm and jacked up on the track to place the track in place where an attck has the smaller rear fixed wheels. To do so I had to loosen the track 11 full turns. So to run extroverts I'm sure I would have to loosen the track about 8 to where it is suppose to be to keep it from binding on it's travel.
I fixed it by getting the ltx or attack tunnel brackets, It was a few hours of drilling and re riveting the brackets . But to add to the excitement I had to get the 2010 apex only or 2010 and newer vector ltx rear wheel stub mounts. The one piece axle from 2006 -2009 solid axle won't clear the 121 apex rear arm. In 2010 the 136 apex wnet back to the strait rear arm for what ever reason and used the stubby shafts for the wheels.
I would recomend for anyone that is wanting to go 121 to 136 to buy the brackets and the stubby shafts and wheels. Mine does look a little odd with 4 wheels on top like it does.In time I will take the larger wheels off of the skid and fab some brackets for the little plastci shoes right next to the shock mount.

 

[journeyman]

As I mentioned earlier.....wouldn't it not be better just to find a Attak/LTX 136" mono skid?