Suspension Tuning - It's a Process!

[bigjohnsd]

Had a great day today, met Dave Moss <a href='https://feelthetrack.com/'>https://feelthetrack.com/</a><br />

at Thunderhill Raceway for some suspension tuning help. Dave inspected, adjusted, sent me out on a few test rides, changed more stuff, sent me out on another test ride, adjusted some more and my FJR is a much more delightful bike to ride both on the slab and in the Twisties. I heartily recommend Dave. He has a unique skill set and is gifted in getting information from the rider, then applying the correct tweak to the bike. Thanks Dave!

 

[Mudslide Miller]

Or just get an ES! Sorry John, yes, I can be a smart-*** sometimes. Glad you were able to get it dialed in. I'm sure the difference is quite noticeable from stock settings.

 

[Bill Lumberg]

Good stuff. I had serious reservations about mine. I was able to get closer by talking to folks here. But when I visited a forum member who had his bike dialed in by a race shop, and figured out that, even though he was notably lighter than me, they had cranked his "preload" to full on hard, I gave in and cranked mine to full on hard. Much different. I've never had a bike that was so sensitive to having the suspension properly adjusted. My others could be improved by some adjustment, but they handled well and were comfortable regardless (except for the mean streak- which, regardless of setting, approximated a bike that did not come with a suspension). Worth the time and money to get the FJR dialed in.

 

[thompsonian]

I'd love to get mine dialed in a little better. Being a "fluffy" guy I know she has to work a little harder to fling my fat arse around.

 

[Pterodactyl]

So, John, care to share any info on how you are adjusted these days? Out relevant characteristics are somewhat similar.

 

[gregory]

I assume that your still running the stock suspension?

 

[MCRIDER007]

So, John, care to share any info on how you are adjusted these days? Out relevant characteristics are somewhat similar.

My question also. Not much you can do to the shock since there isn't any preload/height adjustment and John didn't have much damping adjustment left on his well used shock, so I would guess that he lowered the height on the forks for some quicker steering and then played with the fork's damping to compensate for the 10 wt. oil John installed after the Ruben run.

 

[RaYzerman19]

The A has progressive fork springs, so those need the preload dialed right in to get rid of a lot of fork dive. Stock damping settings of 12 are about useless, everybody should start at about 7 or 8 clicks out and go from there, probably end up at 6 for a normal rider. Rear shock spring is decent (976 lbs), damping needs to be dialed in (for John) likely to about 5 clicks is my guess.

 

[Punkinhead]

Dave Moss has some youtube videos that do a good job of explaining suspension setup. I've forwarded links to them to several friends over the past couple years.

 

[bigjohnsd]

<blockquote class='ipsBlockquote'data-author="MCRIDER007" data-cid="1339223" data-time="1474648485"><p>
<blockquote class='ipsBlockquote'data-author="Pterodactyl" data-cid="1339208" data-time="1474640736"><p>So, John, care to share any info on how you are adjusted these days? Out relevant characteristics are somewhat similar.</p></blockquote>
<br />
My question also. Not much you can do to the shock since there isn't any preload/height adjustment and John didn't have much damping adjustment left on his well used shock, so I would guess that he lowered the height on the forks for some quicker steering and then played with the fork's damping to compensate for the 10 wt. oil John installed after the Ruben run.</p></blockquote>

I'll check and record the dampening settings when I get home. The front has less preload etc than when I arrived. The rear is still on hard. I don't know what the front and rear dampening settings ended up at. I rode, he twiddle. I rode again. Got to say that it worked well between Thunderhill and Calistoga

and again down CA 1 on Thursday. I'm more confident, it's less tiring and it stays settled in the corners better than it did, especially if there are mid corner bumps.

 

[Fontanaman]

Most excellent John! This one way to do it. In a shout out to the Pacific NW group, you can do it the way I did, hang out with them to get some help with all things FJR.

 

[bigjohnsd]

Dave Moss Grey Ghost Suspension Baseline Settings:

Front:

Preload 1 1/2 lines showing which was 1 1/2 lines softer than when I arrived

10 WT Maxima Green Fork Oil!!!

Compression 12 clicks out

Rebound 5 clicks out

Notes: Over the various runs he had me make he noted that I also liked the bike with six more turns of preload in the front. He wanted me to ride it with the softer front to aide in steering. If i didn't like it he told me to add three turns of preload and add one click of rebound, that would put me in the middle of the range I liked.

Rear:

Stock Shock - 36,000 miles - no maintenance done on it.

Spring on Firm - which he said was "Race hard"

He has the rear at 3 clicks out, I came in with 5 or 6 clicks out and the rear spring on Firm.

During the testing and adjustment, I was fully loaded for touring, Front tire at 39# rear tire at 42#, both Panniers were full and the Top Box was on and had a load in it, mostly light clothing. gloves etc.

While we were talking we discussed the very slight cupping on the front tire. Dave said it was suspension related, not tire pressure related. I meant to ask him if the front adjustment had cured the cupping cause but forgot to. I have asked him and am awaiting an answer. I'll add that to this post with an edit when I receive his answer.

 

[Pterodactyl]

Thank you John.

 

[bigjohnsd]

The cupping is from rebound damping being too fast/ too open. As I closed down the rebound circuit by making the adjuster move closer to the closed position, it stopped the weight transfer back and forth/pogo/rocking that the bike was doing. As the fork oil ages, the cold to hot viscosity variance increases dramatically so regular servicing of the forks is a good idea between 8-10,000 miles. With a big bike like that, tire carcass is also VERY important as tire pressures have to match carcass design (soft tire carcass needs a lot more pressure). Start at 46/44 and bring it down to 38/36 to see how the bike's handling changes based on the tire flexing as you turn in and then go through the corner. Defining tire pressure is as important as getting the bike set up.

 

[escapefjrtist]

Interesting information regarding front cupping John. Thanks for the post.

--G

 

[dcarver]

John, really. Get some good suspension and be done with this mess.

There is only so much you can do with stock, mass production components for bikes that cost less than 40k....

..and I know you have bucks to afford it - I saw you order the "Supreme" at the Mexican restaurant in La Pine!

 

[redneckj]

John, I agree with what you did on your suspension tuning. Tire pressure and tire carcass is important. I am running regular T30 EVO's right now. Great tires. But just like other tires I've run before, I will go through 3 front tires to 2 rear tires. I think that might possibly be due to not running a GT or a A Spec carcass. I am trying out running Nitrogen in my tires also. I just installed it yesterday so I don't have any data yet to see what the pressure difference is between cold pressure and up to temperature pressure. I'll post that after my ride home on Friday. How bout that 10w fork oil?

 

[MCRIDER007]

Regarding tire pressure and tire carcass, motorcycle tires are designed to heat up thru sidewall flex which raises internal temperatures and pressure until the sidewalls no longer flex. The lower the starting pressure, the more the tire has to heat up until the sidewalls no long flex. Lower starting pressures result in higher operating temperatures and more traction....but shorter tire life.

I used to run 36/38 in my ST1100 until a Bridgestone tire representative told me to run 40/42 if I wanted a 20-25 percent longer tire life. He also said I would have 95 percent the traction at the higher starting pressures. There wasn't any way to verify the traction but he was right on regarding the tire life.

I think the 10 percent rule (difference between cold and operating pressures) is a good rule of thumb for sport-touring tires to maximize tire life while still maintaining adequate traction.

 

[bigjohnsd]

The Avon folks also advocate the 10% pressure rise rule for Tire pressure as well. Cold pressure should be set at whatever pressure it takes to achieve a 10% rise in hot pressure. So 38 cold would end up at 42 hot.