Apex GT bottoming

[Reaper]

Is Tim A.K.A. Reaper coming back from the darkside? Timster...give me a call sometime!!!

Hey Mikey, done any riding yet this year ?

 

[Alatalo]

If you can not avoid frequent bottoming out, even when using the maximum amount of compression damping, you should consider getting a stiffer spring.
The american Apex GT is delivered with a 48 N/mm (274 lbs/inch) spring.
Yamahas stiffer option is a 54 N/mm (308 lbs/inch) spring (Ohlins part number 696-11).
If the bottoming out problem is bad you should consider getting the shock absorber spec from the scandinavian RX-1 GT (Apex is still called RX-1 in scandinavia).
This one is delivered with much stiffer valving and a 70 N/mm (400 lbs/inch) spring (Ohlins part number 696-19).

 

[wolfie]

So get the stiffer spring and revalve the shock if it's so bad. The rest of the sled makes up for it. I have a REV too btw, and overall, I'll take the Apex anyday of the week.

How do you know, have you ridden your GT yet ? Your sig says GT coming soon ?

Rode my buddies, mine should be in this week. I also ran that same suspension all last year on my RX1. I agree it's too soft,but it's fixable. Then again, my 03 REV 600 X was too soft as well.

 

[actionjack]

Interesting that I found that I preferred to ride my GT at the stiffest setting on the guage. After my first 40 miles I adjusted the control rod for a bit more transfer and found that the sled took high speed dips a little harshly (no moguls around yet really). I only weigh 165 but I am def gonna have to stiffen the rear somehow. My dealer adjusted the sit-in per the manual the night I picked up the sled so should I be dialing compression or rebound stiffer or softer or some combination of each? I also think I want to lessen the preload up front to minimize inside ski lift.

 

[Reaper]

If you can not avoid frequent bottoming out, even when using the maximum amount of compression damping, you should consider getting a stiffer spring.
The american Apex GT is delivered with a 48 N/mm (274 lbs/inch) spring.
Yamahas stiffer option is a 54 N/mm (308 lbs/inch) spring (Ohlins part number 696-11).
If the bottoming out problem is bad you should consider getting the shock absorber spec from the scandinavian RX-1 GT (Apex is still called RX-1 in scandinavia).
This one is delivered with much stiffer valving and a 70 N/mm (400 lbs/inch) spring (Ohlins part number 696-19).

Now thats the kind of info I like, Thx Alatalo !

 

[MrSled]

MightyWarrior, I just wanted to clarify that your post is not correct. The spring on the GT is the correct spring for the target that Yamaha was starting the sled at. Also make the rebound harder, you wont believe the difference guys...

 

[Reaper]

MightyWarrior, I just wanted to clarify that your post is not correct. The spring on the GT is the correct spring for the target that Yamaha was starting the sled at. Also make the rebound harder, you wont believe the difference guys...

Can not get my head around how making the rebound harder will decrease bottoming, can you elaborate, Thx.

Also, anyone know what that yellow thing that looks like a beehive is doing on the shock shaft of the Ohlins. It is about 3" long and I can only assume it is to reduce bottoming.

 

[MrSled]

That is a bumper that will help reduce bottoming...

The only reason I say making the rebound slower helps is that I was told from a source that the rebound adjustment interanlly will affect the compression....trust me, I couldnt understand it until I tried it.

 

[Alatalo]

The rebound adjuster DOES affect the compression damping, though not very much.
The rebound adjuster is an adjustable bleed (a needle/jet combination that sits inside the main valve at the end of the piston shaft) that bleeds oil flow off from the main valve instead of letting it pass through the main valve. The more oil flow that is bleeded off from the main valve, the less damping is produced (more open rebound adjuster = less rebound damping).
This bleed works in both directions and therefore the rebound adjuster affects both compression damping and rebound damping.
Since the main rebound valve is quite a lot stronger than the main compression valve, the rebound damping is adjusted quite a lot more than the compression damping.

The yellow thing on the piston shaft is normally referred to as a bump rubber. It adds spring rate to the end of the stroke to avoid bottoming out (kind of like a progressive spring but more extreme).

 

[MrSled]

Alatalo.....Thank You for making that clear. You have some great knowledge and I am very happy you are part of Totallyamaha.

Tom

 

[rx1ton]

for what its worth my gt5 is stiffer than my friends rxx with them both at max on spring and rebound

 

[rx1ton]

sorry bout the 5 i cant type

 

[vice108]

Also make the rebound harder, you wont believe the difference guys...

Tom - are you saying that if I turn the tunnel knob on my RTX towards stiffer that it will increase resistance to bottoming? I haven't ridden mine yet - but I dont fully grasp what the tunnel knob adjustment does for me. Is it essentially soft for a plushy ride and stiffer for a sporty ride?

 

[vice108]

Have yet to bottom my RTX, Im 225 lbs, I love this thing.. My rev is HISTORY!

How do you have your mono set up? How about your floats?

 

[welterracer]

Has anyone tried the larger spring???

I am interested but dont want another rough riding viper! I am only bottoming on the very harsh pot holes and speed bumps!