How to set proper ride height on Apex GT

Lift the sled off the ground, Measure the spring length (spring only), Then set the sled on the ground and sit on it and have someone measure the spring again. You should have 40mm to 45mm of sit in. Caution!! do not preload the spring to less than 262mm or 10.3" when sled is off the ground as it will coil bind and cause dammage. If you are at 262mm and have more than 45mm of sit in you will likley need the optional spring.

Tip, To do this with one person i slid the wiper washer up to the shock body when lifted and then sat on the sled, Lifted it beck up and measured how far the washer was frome the shock body(this is your sit in). If the washer slides back to the shock body you can wipe a thin film of grease on the shock shaft to keep the washer frome moving after you raise it back up.

I weigh 220, have the spring at 10.3" and have 45 to 50mm of sit in so i am thinking i will need the optional spring after i get more miles on it. kviper

Well then most everyone on this site will need it based on your weight.

Is there a measurement for the difference in rear bumper height? That would be a lot easier than going through THIS routine.

Yes MR sled i hear ya. I think they said the stock spring was good for 250Lb's but frome what i am seeing it will not get-r-done.

QC Yamaha say's you can not measure sit in buy the bumper, I am thinking it is because your front suspention setting's would change the amount of sit in if you maintained a bumper height. You could come up with a number for bumper height by using there method and use it for future quick referance though, Incase you would gain a few over a long weekend. LOL kviper

kviper said:

I weigh 220, have the spring at 10.3" and have 45 to 50mm of sit in so i am thinking i will need the optional spring after i get more miles on it. kviper

Click to expand...

In order to get to 10.3" did you have to change the c clip position or is that just with the adjuster turned up all the way to position 7?

The shock body is threaded on the GT's so it is just a mater of screwing it down to what ever you need. The ER and RTX's have the setup you are refering to. I am assuming they are checking the sit in the same way but making the adjustment's with the cam and moving the clip. I think the dealer's should have been to the tec school's by now so they should know your specific setup. I would call your dealer for the detail's. kviper

Because of all the talk about bottoming out on here I discussed this with my dealer yesterday. When I pick up my new GT on Friday I told them I want it setup for me. We got into the manual and there is a chart for setting the preload on the GT. This chart shows a preload setting using the stock sping all the way up to 240 pounds. If you are over 240 the chart switches to a heavier spring. Because of my experience on my 05 and what I have been reading, I am setting mine up for 230 pound rider even though I am probably 225 dressed and ready to ride. I sure hope this works. I will ride it for awhile and then make a decision on the heavier spring.

Correct me if I'm wrong but.......

Once you have your rear suspension all setup perfect for your weight, and then you change the electrical shock adjuster or the RA cable adjuster, does this not then take it out of Yamaha's spec range?

When I adjust the RA to all the way soft, it make a big difference in stiffness.

Chris

Sit in has very little to do with the settings on the RA it will just take longer to sit in if the compression is high.

Also I have some info that if you are find the sled bottoming and you are set at the proper sit in or ride height, decrease rebound on the GT will affect the compression. From what I am hearing is that if you are 180 lbs and have the sled set right you should not bottom.

Spring sag procedure and spec is same for all '05 and '06 monos and is highly recommended. It's simple to do but requires two people because someone gets to lay on the ground and measure spring length while you're sitting on it.

1. Measure the spring length with the unit hanging or tipped on it's side (suspension unloaded).
2. Measure the spring with the rider sitting on it in normal riding position (moving forward and back on the seat will affect sag). The spring length with rider on it should be 40~45mm shorter than the hanging length. Adjust preload to achieve this spec. If max preload will not achieve proper sag, you need a heavier spring.

Several notes / cautions:
- On Ohlins stock spring DO NOT adjust spring length shorter than 262mm hanging length. A couple mm shorter than 262 won't damage it, but don't go any further, if you go shorter and coil bind the spring repeatedly you WILL damage the spring.
- After any preload adjustment you must do both measurements again.
- The procedure and 40~45mm spec works for '05 and '06, KYB and Ohlins, 121" and 136" and optional heavier spring.
- This is an effective noticeable adjustment and actually increases ride comfort even if increased preload is necessary for heavier guy.

This is the way I set my GT tonight and I also added 10 more click of harder rebound from stock for my weight. At 250 lbs my sag is about 3/8 to much with the stock spring set at max as stated above so I will still get a heavier spring. But at these setting I took my GT down some rough crap trail areas near my house that normally toss me off the seat and It ate them up with ease and I coudnt help going back over those areas again and again smiling the entire time....these adjustments can go along way guys...look into this.

make sure you set your spring to max too and yes take it harder...there are 40 clicks total and after going 10 more you still have 10 left.

There are 40 clicks total but the owners manual advises that 10 clicks out is maximum, leaving 30 to play with. There was a day when I'd challenge that but I kinda got tired of having the term "Steve'd" applied to my broken equipment. :wink:

I'll work the clicks, ride the same trails and report back my results.

Perfect...if you add click you can also use less compression..

chrishall said:

Correct me if I'm wrong but.......

Once you have your rear suspension all setup perfect for your weight, and then you change the electrical shock adjuster or the RA cable adjuster, does this not then take it out of Yamaha's spec range?

When I adjust the RA to all the way soft, it make a big difference in stiffness.

Chris

Click to expand...

The spring on a shock is what holds yours and the sleds wieght up. This is why is it important to set the spring preload up to your wieght. As stated above there should be between 40-45mm of sag when seat in a riding postion with gear on.

The RA dial or button on the GT is what controls the valving inside the shock. By turning the dial or pushing the button the GT, what you are doing is making the passage that the oil in the shock passes there small or larger. This controls how fast the shock will compress and rebound. If you do not have the spring preload set correctly for your wieght stiffing the compression will not stop you from bottoming on bigger hits and will decrease the ride.


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