Shock Valving 101 and the 07 Apex RTX vs REV-XP MXZ X

[yamadoo]

Thanks Rex you are the "king", I appreciate the time and will continue to play with the rebound.

Interestingly I have felt that springy rear, were she dances all over and kicks you in the but when you go through bumps. I "blew" the shock when up north and rode for several long trips with the back end just dancing til I got it back to the dealor for an eval, he said the shock was not functioning at all, ? why, and eventually a new shock under YES.

I will keep decreasing the rebound (goal of decrease compression) until either compression to soft or back end dances and kicks

How often to rebuild, 3-4K, if so a specific rebuild after next year.
Thanks

Yamadoo

 

[ReX]

How often to rebuild, 3-4K, if so a specific rebuild after next year.

You'll hear lots of different answers on this.

Some say 3-4k, most say around 5k for a trail ridden Yamaha. Really it depends on the size of the shock, if it has a reservoir (more oil), how it is valved, how hard you ride as well as how many miles it has on it.

I usually keep riding until I notice the shock fading a little too much and then freshen it up (new oil). My stock 07 RTX started to really fade at around 450 miles, but then it didn't get much worse until the center shock completely failed at around 2700 miles. When I pulled the center shock apart, the oil was very black, very stinky and well mixed with nitrogen. I also broke both limiter straps since they were handling most of the rebound.

Since the rebuild and revalve, I now have about 5000 miles on the center shock and it still feels quite good. I can feel it fading just a hint on really rough trails, but it is still not too bad yet. The center shock on the RTX is probably the hardest worked out of all of them, especially when you consider how much smaller it is than the others and how much weight the front of the track supports. I will rebuild it (and slightly tweak the valving) in the summer.

My Floats now have over 8000 miles on them since new and have never been rebuilt. They are still working well, but it probably would be a good idea to change the oil in the summer.

The rear shock has been apart many times while I've been dialed it in, but it is probably good for well over 5000 miles between rebuilds with my riding style.

 

[yamadoo]

Thanks again yamadoo

 

[Kevin Garceau]

This is great....

Its august now and Im just starting to get my mind wrapped around sledding again.

I sold the race car, and just about to pull the sleds outta the trailer and into the garage. I have a few things to do maintenance wise, and this is definatly one of them.

I hope I can get the shocks to Carver in a few weeks, and have them ready to go long before the snow flies.

Rex - I owe you a cold one some time, dont know how, when or where....but definatly appreciate all of this.

 

[welterracer]

Just had my front shocks GYTRs rebuilt..

Guy who did it, said the fluid was fried.. at 7000 miles..

 

[bottlerocket]

Just had my front shocks GYTRs rebuilt..

Guy who did it, said the fluid was fried.. at 7000 miles..

I can't beleive it was fried after only 7000 miles ~ lol.. I feel bad going 2000 miles.

 

[welterracer]

I could tell they were getting a little soft..

they still had a good charge..

 

[bottlerocket]

I rebuilt shocks years ago and some came in with 500 miles looked worse then some with 2500 miles. They are way better now then 10-12 years ago with the Fox and Works of the time.

 

[JIM]

So does anyone have a good valve stack for the gytr in the front of an apex mountain they would like to share?? Or know where to get some help from someone who has experience with them.

Jim

 

[downlow]

I see..

I just purchased an Apex Gt after suffering the SRX no-action skid's, and wasnt very happy/impressed. Thought I had the world by the #*$&@ but by the time the ride was over it wasnt a smile I was wearing. The thing booted me,bottomed out and dam near embarrassed me with a near miss dump...errr.....Glad to hear a fix is available. After reading this post I also have a better understanding of shocks....thx...

 

[Sledsquatch]

Should I just take my M-10 Master out of my old Vmax and install it in my 07 Apex RTX that I just bought? This has me a little worried. I love my M-10 and was hoping for a comparable ride/performance in the newer skid. My M-10 is only one season old.

 

[thegrizzly1]

Great posts REX! Thanks for all the info. I don't really have the time to think about this right now, and nowhere near the expertise as you, so I'll ask you.

I have a brand new suspension I pulled out of my 07 RTX when I exchanged it for a 144" ZX-2. It has been sitting on a shelf ever since. I am looking at a combination of rail extension and setback to put this skid in a different machine. (RX-1) With the setback as well as leverage differences of longer rails, would I generally want less damping or more damping? I am assuming the machine weights are about the same.

Also, I am closer to 290 lbs ride dressed. Are you willing to make an educated guess where I would need to start?

Thanks.

 

[Chasx7]

Wow,

Nice Rex. I went throught this on my Viper. I found a guy who really did a lot of work on his setup and sent him my shocks. I was astounded at the difference with the proper valving. The No-Action actually worked very well after his changes. He basically said the same thing you did in reference to the Yamaha valving. Unfortunatley he closed his shop down due to some health problems. Anyways great work!!!

 

[ReX]

It has been close to 2 years since I started this thread and I was wondering if Yamaha has started to use multi-stage valve stacks yet?

You can put together a good multi-stage valve stack for less money that it costs for the crappy single stage stacks they were using so cost isn't a reason to keep using single stage stacks. Yamaha could save a couple of bucks per sled while providing customers with much improved high performance ride.

Are they still the only manufacturer using single stage valve stacks on their performance sleds?

 

[smacho]

It is hard to believe they would ignore such an obvious consumer request... Perhaps Yamaha has an employee that thinks the "single-stage" is in some way "good" instead of a manufactured defect that customers must fix.