KLX250 Sag and Pre-Load, Part 1

As I approach the one year anniversary of the purchase of my 2019 KLX250, and after another bumpy rally (Wild Bear Safari), I finally started working on the suspension. I haven't had any issues with the forks. The rear shock has been a significant weakness, perhaps the only weakness the KLX has in it's design.

The rear shock is an oil dampened, coil-spring, mono-shock with a nitrogen reservoir. The spring rate is reported to be 5.6 kg/mm. Race Tech's spring calculators show a spring for my weight and riding of 8.0 kg/mm, so I'm already in the hole.

However, there's a process that needs to be followed and it starts with the pre-load which I hadn't touched until today because it required me to remove the whole shock.

There are so many sites to take you through the process of measuring sag that I won't go through the why of it all. What I will say is that before you can justify any changes, including clickers for compression and rebound, you need to set the rider sag using the following guidance.

Optimal rider sag 33%* of travel
Optimal static sag 10%* of travel

* Optimal percentages are those that we generally attribute to dirt-bike and motocross suspensions. Other type of motorcycles and riding may be less or more.

Below is a screen shot of my data and calculations. The measurements are from the rear axle to a random point consistently used. The meaningful numbers are the differences that calculate the sag numbers:

In summary, my stock Rider Sag was nearly 60% (optimum being 33%) at the stock pre-load of 107 mm. In short, what that means is that the shock in its stock configuration was giving up 60% of the available travel (9.01 inches) to my own weight plus the static weight of the motorcycle before I even got on the bumpy trails.

Is it any wonder why I was so whipped on the very technical Perry Mountain Tower Run last year?

Onward...

In advance, these actions and calculations are preliminary. They need to be tested, tuned in or abandoned.

To compensate, I adjusted the pre-load to near-max at 120 mm (max is 123 mm). That adjustment brought the Rider Sag percentage down from 57.8% to 38.6%; closer to the optimal sag, but not quite there. Plus, I wound up with an unwanted additional full inch of seat height that I need to look into.

I plan to do some testing next month on the Croom single track, where I can tinker with the compression and rebound. However, I'm probably heading for a new spring with a rate more in line with my needs.

Stay tuned.

I've now completed the purchase of a Cogent Spring with a 7.0 kg/mm spring rate. Installation coming soon...

See KLX250 Sag and Preload, Part 2 for completion of my suspension project.

My $400 Toy Hauler

I have recorded a video of my $400 toy hauler. It is a 1995 Haulmark enclosed utility trailer that I converted into a toy hauler that I use at rallies around the southeast. Enjoy!

Wild Bear Safari

I completed my third Wild Bear Safari this past weekend and, once again, didn't see a single wild bear!

The Wild Bear Safari is a rally hosted by the Apollo Motorcycle Club in Samsula, Florida. The ride was in Seminole Forest and Ocala National Forest. Here are some photos from the ride.

Coming off three rallies on my KLR600 it was nice to be on the KLX250...and I really needed those Michelin AC10s out in Ocala National Forest.

Log into my YouTube Channel and watch My $400 Toy Hauler.

This is my friend Howard Alexander from South Florida.

Here I am (on dry land) trying to figure out my route across that huge/deep water crossing.

Actually, it was hunting season. Generally, we try and avoid the forests during hunting season, but Apollo decided to move forward with this rally. They'll be moving it to April starting in 2020.

Samantha Andrews, one of the leaders on Dixie Dual Sport, can be found riding her XT at most rallies around Florida.

This bike was drowned in the water crossing. These guys got it going and finished the rally.

I'd hate to have to have to lift a big adventure bike out of the sand.

Visit my YouTube Channel for video from the 2019 Wild Bear Safari.

Apollo has reported that the Wild Bear, which was moved from December to November for this year, will be moved to the Spring in 2020 in future years. That's really going to congest the Spring, but it's a good ride that I'll continue to participate in.

2019 Gobbler

The "resurrected" 2019 Gobbler Adventure Ride is not in the books. Resurrected from the standpoint that it hasn't been run by Dixie Dual Sports since 2013.

I rode the 1985 KLR600 on the 115 mile Adventure Track. There was also a track for street bikes. Much of the tracks converged and overlapped which made for some heavy "toy-run-like" traffic, but overall a nice ride.

Benefited mental health issues.

Riders meeting video.

Next stop on the calendar is literally next weekend with the Wild Bear Safari. I'll be using the KLX for that ride. Stay tuned...

NGK Spark Plug Decoder

NGK spark plugs are my brand. I've always had good luck with them whether it be power sports, lawn equipment or automobiles. NGK are one of the OEM brands for my KLR600. However, I erred by using the KL600-A1 (1984) plug on my KL600-B1 (1985) that was a different spec, a result of misinterpreting the Service Manuals.

I was able to determine that the only difference between the right and the wrong plug was that the A1 called for a resistor plug and I determined that using a handy NGK spark plug decoder below.

The decoder is very helpful to understand NGK plugs. I printed a copy and now keep it in my shop.