Why does my front end feel lighter?

[fiziks]

The preload adjuster was set at the midpoint when I got my '03 ST over Labor Day w/e. I noticed I could back it all the way out and back to the midpoint with no resistance. From the midpoint to all the way in, the resistance was significant. I also noticed that I feel every bump in the road in both my seat and the handlebars. Following the instructions in the preload adjuster oiling article, I cleaned and added oil to the preload adjuster and now I have smooth resistance starting at one click in all the way to max preload. I set it back at halfway and now the rear end rides quite nicely. I can feel that it's planted and the bumps don't jar my spine anymore. It also gave me a feel for just how bad the forks are, so I think I have a rebuild with gold valves coming over the winter. But another thing I noticed is that the front end seems a little lighter under acceleration. It's more noticeable on takeoff, but it feels a little lighter when accelerating at speed as well and I'm not being aggressive. Is there a reason for this or am I just imagining things?

I do know this thing will wheelie and it's easier than I thought, but I don't want to do it every time I leave a stoplight.

 

[Byron]

You could need a little more rear preload. When you accelerate it shift weight to the rear. You can either lean further forward to counter this or add in more preload.

 

[fiziks]

I know weight gets shifted to the rear under acceleration, the thing is, before I change/added oil to the adjuster, I was effectively riding with no preload dialed in, so it would seem to me that the front end should have felt lighter then. Now, I actually do have preload dialed in and yet the front end feels lighter. It seems counter-intuitive.

 

[Jeff F]

shrinkage?

 

[Optimus]

I know weight gets shifted to the rear under acceleration, the thing is, before I change/added oil to the adjuster, I was effectively riding with no preload dialed in, so it would seem to me that the front end should have felt lighter then. Now, I actually do have preload dialed in and yet the front end feels lighter. It seems counter-intuitive.

If I was to hazard a guess, I suspect that before you adjusted your preload allot of the power used to take off from a stop was absorbed in the soft rear suspension. Now that you have a bit of preload more of that power used to get you moving is now transfered forward making you front end feel lighter.

 

[Tankereng]

You're preload adjuster is low on fluid.... a bunch of folks here in CA just had theirs refilled (At various RTE's) by a local member...took about 15 minutes per...

 

[fiziks]

If I was to hazard a guess, I suspect that before you adjusted your preload allot of the power used to take off from a stop was absorbed in the soft rear suspension. Now that you have a bit of preload more of that power used to get you moving is now transfered forward making you front end feel lighter.

Oddly enough, this is exactly what I was thinking as I was riding around last night. I noticed my headlight was aimed lower, even under acceleration than it was before. So I think under acceleration, the front end lifts just a little, but not as much as the rear used to sag before I filled the preload adjuster. Backing off on the preload (now that it is working) seems to have leveled things off.

You're preload adjuster is low on fluid

I filled the preload adjuster, and THEN started noticing the light front end. I double checked it last night, still full.

 

[dduelin]

This a puzzle. Bikes with shaft drive extend their rear suspension when accelerating as the pinion gear tries to climb the ring gear so this runs counter to the idea of the rear end squatting less under power now with more available preload. Placebo effect?

 

[fiziks]

Placebo effect?

i dunno, maybe. One thing I can say for sure. I think I have the rear dialed in now. The front end certainly sticks to the ground quite well, but is still a bit harsh. There is a bit of road down here with some nice bumps as you go around a bend. On the CX500, I can feel the front lift enough to almost lose contact at each bump. On the ST, I can go faster, and I can feel the bumps in the handlebars, but she sticks like glue, none of the uncertainty I feel with the CX.

 

[fiziks]

Mine is tracking quite nicely at six clicks and 1.75 turns on the damping screw. Another thing... now that I think I have the rear setup properly, I am having a very hard time popping a wheelie now. I think I'm good now. I'd still like the front end to be a little less harsh, but I can live with where it is at for now (until I have cash for springs and gold valves )

 

[dduelin]

If you run with a lot of sag and little damping you'll find the ST1300 gets very soft out back at high speeds to the point where the bobbing up and down is essentially uncontrolled. At slower speeds lots of sag and less damping does produce a plush ride though.

 

[dduelin]

I have no doubt you have found your sweet spot but there is no need to reinvent the wheel when it comes to suspension tuning. There are plenty of references on the subject from experts in the field and the spring rate of the stock spring is a known factor.

Igofar wrote: "I found a write up somewhere with a test that was conducted with a stock bike, a police bike and I believe someone elses bike as well.
They tested the preload settings with shield up / down, bags full / empty, all the way up in the triple digits.
The only way they could they cound induce wobble or weave was with the preload cranked past the stock default setting.
Set at default and lower, the bike handled at its best."

I am really interested in reading this, could you share it? Aside from the UK Coroner's report on the Merseyside accident and the RIDE magazine article on the Pan Weave I haven't seen a test or analysis of the ST1300s handling or effects of suspension set up done in a controlled setting.

 

[Gus1300]

...and 1.75 turns on the damping screw.

Where might one find said screw? Just did the preloader overhaul (article), considering the new kit for the forks, but would like to adjust the dampener before going any further on the upgrade train. Thanks.

 

[dduelin]

Where might one find said screw? Just did the preloader overhaul (article), considering the new kit for the forks, but would like to adjust the dampener before going any further on the upgrade train. Thanks.

It is on the right hand side of the rear shock. Access it through the hole in the subframe that supports the RH passenger foot peg. Fully screwed in (apply clockwise light pressure with a flat blade screwdriver, just screw it in until it bottoms out) is full hard or the maximum amout of rebound damping. Then turn it out to the amount you desire.

 

[dduelin]

I think I found it...I just don't know how to cut and paste it into this thread.
I believe it was from: October 2007 Issue of Ride
I saw part of the artical on: http://www.twtex.com/forums/showthread.php?

If it is from the Ride article it is probably cut up contextually and misquoted. I know this because the test mule could be provoked into weaving under different setups and load configurations. The largest factor was speed alone. I could not open the link you provided but I am familiar with the RIDE article. For a while it was available on line in it's entirety but copyright issues removed it.

Try https://www.st-owners.com/forums/showthread.php?28588-RiDE-magazine-(UK)-Pan-Weave-Investigation

 

[fiziks]

Sorry guys, I didn't mean to start an argument. I think everyone has their own idea of how a bike should feel beneath them and so a setup that works for one, might be a little off for another. And a setup that works in some conditions may not be the best for others. I had a chance to unwind the throttle this weekend and I can say that at commuter speeds (50mph and under) and in town, 1.75 turns on the dampening screw gives me a good ride, but at "highway" speeds, it is a touch floaty and I had to dial it back. And while there is still some harshness in the front end at commuter speeds, a lot of that (not all) has disappeared at "highway" speeds. I'm not going to claim that my setup is perfect, but I've got it where it works for me, it is comfortable enough for me, and I can do some serious leaning with confidence. And while I probably will end up with a gold valve mod in the forks and a RT rebuild on the shock at some point in the future, she rides good enough to make it hard to justify the expense right now.