High speed stability

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JimGregory
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CT USA
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07 ST1300
If you need to crank the shock preload before getting it to respond, then I would add some fluid to the circuit. I bought mine w/ 1185 miles & rode it 18k miles before I checked the preload. Sure enough, the circuit needed oil. Adjusting the preload to the recommended setting made a positive difference for me.

I loved the way the bike handled before the adjustment...I love it even better now. I might add I do not go triple digits.

I weigh 160, ride w/ full gear & use 42 psi F & R.

Your comments about the VFR are interesting. I put 35k miles on a new 95 VFR. I never had confidence in the suspension. I was so frustrated, I put in RaceTech springs & Gold Valves. Improved my confidence marginally.

I think a lot of our handling preferences are formed by what's comfortable to each one of us.

I hope you enjoy your new ride!!
Well the 98 VFR was a complete redesign. No clue if it was for better or worse. I got it beginning last season with about 3500 miles and sold it the other day with about 8000.
I have to say the suspension was great but I also dont know if it was stock or not. The guy I sold it to had already gone through 2 of my vintage and now has a like new third one. I'm gonna miss that little red devil.
The BIG news is I wound the ST up and wound the windshield down and she handled pretty darn nice. Didnt do anything else. Wound the windshield up and she felt a little flighty.
I guess that's that and am happy to not have to visit those speeds again. Thanks for ALL the food for thought guys. I will sort through all the little things in time.
 
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If you need to crank the shock preload before getting it to respond, then I would add some fluid to the circuit.
Okay I need to ask about this. I have looked in the service manual and have not found anything that describes adding fluid to the circuit on the rear shock. I have seen mention of this in another post but no reference on how to do this.

What am I missing here? please provide a link or a reference in the service manual.
 

970mike

Mike Brown
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I got my 2008 ST1300 in April this year and it is bone stock, factory wind screen, handlebars, suspension, etc. with 14k miles. I moved to this bike from a 1991 ST1100. A couple of things I noticed immediately are windscreen position at high speeds and dirty air from semis. I found that a slight movement down on the windscreen makes a big difference. the next thing I noticed is my body weight on the handlebars. I found that my ST1300 requires a light touch on the bars as soon as I get heavy handed the bike wonders. That is the main reason I took the riser block out that the PO had installed. There was to much leverage on the bars with it in.

As suggested above check the suspension and other mechanical things too.
+1
I just got my 05 ST in April, the tires are new PR4's. While going down the interstate at a spirited pace I got the infamous weave, I tried leaning forward which didn't do anything. Then I lowered the windshield and the weave went away. I'm convinced the windshield in the higher positions is the biggest factor in high speed handling problems.
 
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I have found that there will be a happy medium on the windscreen height. My sweet spot is where I have about a 2" line of sight over the top of the windscreen. I am 5' 10" with the seat in the highest position. That does not mean that I don't change the height but for the majority of riding that is where it is. It would not be uncommon to drop it a bit when there are trucks around. I have had the screen in my sweet spot at 118 mph on the GPS with out any issues at all.

I think when all is said and done is that there are many potential contributing factors to the starting issue of this thread. Start simple and go from there. All bikes and all riders are different what may be a fix for one may not be for another.
 
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Rock Spring, GA
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I am thankful for this thread. It really makes a lot of sense when you think about raising or lowering the wind screen. I think of it like a front end spoiler on a race car, which puts down force on the front end to keep it stable at high speed. I remember one of my first automobiles being a 1970 Dodge Charger with the 383 Magnum engine. I remember getting to an indicated 140mph on the interstate and it felt like it was going to lift off the ground. Cars back then were very high off the ground compared to most any car of today. If you look at a Dodge Challenger today it reminds me of that. Anyway raising our wind screens is like taking away a front end spoiler and in my opinion makes sense why the front end gets lighter feeling. I test drove a BMW K1600GT and a BMW R1200RT a few weeks ago. I liked the K1600 not so much the R1200. The wind screens were bigger as I recall on both of those bikes than on the ST1300 but they also seemed more flimsy in the wind. I expected better from $22,000-$26,000 bikes. I am very pleased with the ST1300 wind screen, it seems big enough and also very sturdy. I have not been over 85/90mph yet that I am aware of but have been at that speed both solo and 2up. It is a very comfortable bike to me at that speed. It is not as heavy on the front end as some bikes I have ridden before but it suits me fine in most all other areas of importance to me. I am contemplating bar risers though as I could be a little happier with a more upright seating position.
 

acedantinne

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The bikes are under spring for all but the lightest of riders in the 145-165 lb range. Preload helps cope but does not really raise ride height enough to quicken steering.
BINGO on that Dave. Wayyyyyy under spring/sprung.
 

dduelin

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BINGO on that Dave. Wayyyyyy under spring/sprung.
Lucky I'm the Japanese ideal at 150 lbs in the shower and the spring rates are good for me. With 16mm of fork preload and a RaceTech rework of the shock I've been happy a long time. From zero to 143 :)
 
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Reisterstown, MD
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Any opinions here about some of the windscreen mounting mods that some forum members like? I'm wondering specifically if tilting the screen backwards (especially at raised positions) would increase the downpressure on the front end at higher speeds.

Any experience-based opinions here?

Jack
 
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JimGregory
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Lucky I'm the Japanese ideal at 150 lbs in the shower and the spring rates are good for me. With 16mm of fork preload and a RaceTech rework of the shock I've been happy a long time. From zero to 143 :)
I dont know why but I really like my dampening and spring rates. Big heavy bike handles our bumps and potholes well for me. I'm 185 lbs. But I am so not looking for trouble either.
I hate my seat and muffler sound though.
 

dduelin

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I'm short and never ride with the screen up more than about 2" to begin with.

I did monkey around with the ST screen mod for a while. I made three sets of spacers from .75" to 1.75" to open the slot behind the screen those additional amounts but in the end went back to stock. For me it was the best combination of protection and noise as a solo rider.

I think the broad, blunt nose of the bike is a contributing factor to the weave...... the true high speed weave that earned the name The Pan Weave. The OP did not refer to the weave and it does not show up until 115 to 130 mph if it going to show at all. The light steering at lower speeds is just a characteristic of the ST1300. If you experience the weave it is almost like the bike is "swimming" back and forth as it oscillates around the longitudinal axis. The front wheel is tracking true but the rest of the bike undulates around the headstock. I think it is vortices shedding of either side of the front of the bike that combine with a lack of stiffness in the frame or swing arm to set up an oscillation.
 
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I made a fork brace in my home machine shop 3 weeks ago.

Rode 800 miles of Colorado mountain roads as a tour guide for the Jackson, MS Harley Owners Group last week.

The brace definitely improved the handling & stability of the front end.
 

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