The 40-45mm sag measurement of the monoshock

[Metallicat]

I'm having a difficult time measuring the recommended 40-45mm of spring sag on my sled. I don't have someone else available to measure the spring compression when I'm sitting on the sled (not going to ask my wift to do it) so I've tried laying across the seat and measuring it myself hanging upside down over the running boards - not the best way I'm sure. It would seem that an easier way to measure sag would be from the upper cross shaft of the rear arm to the bumper stop. Has anyone ever measured their correctly adjusted sag to see how it corresponds to rear arm compression? I measure about 8" with the sled unloaded between the cross shaft and the bump stop. When I'm on the sled I have about 2" of sit-in measured the same way.

Thanks!
Mike

 

[yox185]

How about sitting on the sled and measuring the bumper height. Then get off the sled and have your wife and someone else push down on the bumper to get the same height while you measure the spring.

 

[Shootinstick]

If your shock is like the one on my '07 Attak, there is a yellow rubber bumper on the shock shaft inside the spring. While off the sled, slide it all the way down to the shock body. Then sit on the sled. It will slide the bumper back up the shock shaft the amount of sit-in with your weight on it. When you get back off the sled the bumper will stay in place and you can measure from the bumper to the shock body to see how much it moved. If you need to correct the amount readjust your spring preload and try again.

 

[tomanytoyz]

If your shock is like the one on my '07 Attak, there is a yellow rubber bumper on the shock shaft inside the spring. While off the sled, slide it all the way down to the shock body. Then sit on the sled. It will slide the bumper back up the shock shaft the amount of sit-in with your weight on it. When you get back off the sled the bumper will stay in place and you can measure from the bumper to the shock body to see how much it moved. If you need to correct the amount readjust your spring preload and try again.

It totally works.i also fill the sled up with FUEL(60+lbs in center of sled)we all ride with FUEL than NO FUEL.like sitting on sled with gear or no gear..

 

[CaptCaper]

someone here posted to put a wire tie on the shock shaft at the shock and then sit. Then measure between the tie and shock body. Same as using the bumper but with a wire tie.

 

[Metallicat]

Wow, those are some good ideas! Going to try the bumper trick first. Never would have thought of that.

 

[apltx08]

Use a tie wrap/zip tie on shocks rod...as mentioned I'd have a FULL tank of gas and have your riding gear on, I also include my 22lbs weight that I use to set my track tension to make up for snow/ice build-up.

 

[Metallicat]

I just now tried the stopper method (moving the stopper all the way up the shock shaft and them measuring the difference between loaded and unloaded position). I get about 40mm of sag with the spring set at the lowest preload. This is with a full tank, and with me bouncing a bit on the seat, but I'm measuring without riding gear and saddle bags on the back so it should be within spec even with additional weight added. I weight 180 with street clothes btw.

 

[apltx08]

You should be fine...if you still bottom out I'd get a re-valve done, its amazing the difference a good calibration makes, just make sure your rebuilder gets all of your riding style, all extra weight you carry...if you ride with saddle bags...another thing we tend to over look is the ICE/SNOW build-up on long cold day runs, I bet we can have as much as 40-50 lbs easily on the rear part of tunnel.

 

[Metallicat]

You should be fine...if you still bottom out I'd get a re-valve done, its amazing the difference a good calibration makes, just make sure your rebuilder gets all of your riding style, all extra weight you carry...if you ride with saddle bags...another thing we tend to over look is the ICE/SNOW build-up on long cold day runs, I bet we can have as much as 40-50 lbs easily on the rear part of tunnel.

I just had my rear shock revalved and put 200 miles on it last weekend, and it is exactly as you described, an amazing difference in ride quality with little to no bottoming, and I can now run the RA in the softest position for the best ride like you said in another thread. Could never do that with the stock valving. I had my spring set on position 4 last weekend but thought it was too much preload. You're right about the snow and ice in the tunnel. That is a lot of weight right there. I lost my spanner wrench last week too, but found that my set of channel locks actually grip the spring adjustment collar better so I'll just be using those instead of the crappy stamped aluminum Yamaha wrench which seemed to always slip and strip.

 

[apltx08]

Now all we need is SNOW!!! Its been FREEZING rain here all day and more tommorow!

Anyways enjoy your new set-up