Ok, I admit it. For as much experience I have had on motos I’m a dense blob when it comes to adjustments and feel. I just ride the bike. If it turns in easily, great! If it doesn’t or does too much – I just adapt how I ride and move on. The great Porsche racing driver Hans Stuck was the same way – he frustrated his engineers who wanted feedback to make the car better and he was just one of those drivers that just drove the wheels off of anything he was given.
I was watching a video of someone I subscribe to the other day and he was talking about setting up his rear sag. I know what sag is and how it changes the geometry of the bike and yadda, yadda, yadda…
But it got me to thinking…
One of the big reasons I had not set the sag on my 690 is because it’s a little too involved. Just to get to the shock and the preload adjusters you need to remove the
- Seat
- Top Rack
- Rear Fender
- Side plastics
- ECU
- Battery
- Fuel Line
Once you have removed all of that, only then you can remove the lower tank mount and tilt the gas tank/subframe up and out of the way. Remember, this is just to get to the shock!
If you are doing this all properly, it’s then make a small adjustment, then put everything back on the bike. Next, get dressed as if you are riding, load up the packs with all your gear and then check the measurement again.
Chances are you might be a little off and so it’s off with the gear, off with the luggage, remove all of the parts again, tilt the tank, make adjustments, rinse, lather, repeat. Or just ride the bike – as I have done most all my life.
BUT…
When I last swapped tires, I noticed as I had the bike up on a stand that I had a little vertical play in the swing arm. I sourced the play down to the lower shock pivot heim joint bearing and so since I had to pull everything out anyways, I thought I would at least check.
So before I started disassembling the bike to replace the bearing I set the bike up on level ground, I bounced the bike up and down a few times and let the bike find it’s level. I then chose a point to measure on my top rack and then the center of the rear axle.
It was 29.625 inches.
Next I piled everything I would normally be carrying on a trip (including me and with the help of the wife we repeated the bounce, bounce measure a few times.
It came out to 26.375 inches.
This gives me a sag of 3.25 Inches. I converted this to metric and that came out to 82.55 mm.
I then looked up the rear travel of a 2014 KTM 690 Enduro R and found it was 9.8 inches. Most online resources I found suggest that roughly 1/3 of your overall travel should be used by sag. Or putting that the other way, your sag should be equal to 1/3 of your overall travel.
Here’s something nobody mentions… If you have a lowering link on your bike (like the Kouba Link that came on mine) that reduces the overall travel of the bike. I removed mine and so I am running the stock set up again. Just something for others to be aware of.
Math suggests that 9.8 inches is equal to 249 mm and a third of that would be 83 mm! What was my current sag again? With everything loaded and me on the bike? 82.55 mm!
I cannot believe how close I came to the perfect rear sag set up without measuring, without trying, without knowing! Wow!
DISCLAIMER:
Yes, I know you don’t have to remove everything and tilt the tank up to get to the shock. You could just reach in there with a long screwdriver and pound the adjustment rings to where you need – but we’re more civilized than that aren’t we? (https://aufroad.com/who-the-fork-does-this-to-a-shock/)
He's an avid hockey fan, rides a mountain bike, sometimes rides a road bike, has a few motorcycles (he had a really fast one, had a big cool orange one, rode a really slow one, and is currently building a perfect "BDR Weapon"). If that isn't enough, he makes cheese and sourdough bread, loves strong beer and good red wine, and poorly plays the Mandolin.
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