Center Stand Touchdown

[mcavotta]

Had a little bit of a scare last night when my center stand touched down on a turn last night with my wife on the back. Does that mean I haven't dialed in enough pre-load (more = tighter, right?)

I'm having trouble determining the best place for my pre-load for a 370lb load. I don't have anyone around to help me with the measurements and all. FWIW, I'm really wishing the bike had the ESA on it as I move a lot between solo and 2-up riding.

Thanks for any advice or input.

[deilenberger]

Start at max - then back off if the ride is too harsh. You also want to increase the rebound damping (screw on the bottom of the shock) as you increase preload. If you don't - you'll have a pogo-stick suspension (over sprung and underdamped..)

Ideally - you want your dynamic sag (the sag with full load you're tuning for) to be 1/3rd the shock travel. The rear on a Roadster is a claimed 140mm travel (somewhat optimistic IMHO based on measurements of shock travel available and lever-ratio of the rear swingarm - 128mm is more like it IMHO..)

So you want 1/3rd of 140mm (or 1/3rd of 128mm if you believe me and not BMW) as your dynamic preload. No way I know of to get this accurately aside from measuring it. Having another person to do the measurement is helpful - although I do it myself by measuring with a tape measure from the inside of the hollow axle (tape measure "hook" there) up to one of the bag mounts.

Dynamic preload is the difference between the no-load on the back wheel (centerstanded) measurement and full load measurement.

Front won't make a lot of difference since your additional weight is centered on the rear suspension.

[mcavotta]

So, max out both pre-load and damping and work back? I will try the measuring thing. I would rather have a harsher ride that's properly damped than a barcalounger on wheels.

Let me know...

THANKS

[deilenberger]

I'd say max out the preload, and definately increase the rebound damping. Dunno if I'd max it out.. work up on it until the bike feels smooth in fast sweepers.

Only problem then is remembering the settings for solo vs 2 up..

[peckhammer]

Only problem then is remembering the settings for solo vs 2 up..

I was wondering if anyone has ever figured out what the ESA settings were for the various selections? IOW, preload at X + rebound at Y = sport setting, and so on. Then you would have a good guide for making quick changes, such as losing your passenger and wanting to adjust the suspension for that.

I'll risk another comment regarding dragging the center stand. Susension may have something to do with it, but riding technique can also have something to do with it. Quick turn-ins with counter-steering require less lean angle. Not using a quick turn-in with counter-steering will require more lean angle to get though the same turn, and may result in touching things down.

[mcavotta]

I'll risk another comment regarding dragging the center stand. Susension may have something to do with it, but riding technique can also have something to do with it. Quick turn-ins with counter-steering require less lean angle. Not using a quick turn-in with counter-steering will require more lean angle to get though the same turn, and may result in touching things down.

When you say quick turn-in, is that simply initiating the turn sooner? Don't mean to be obtuse... Always room to learn.

[peckhammer]

When you say quick turn-in, is that simply initiating the turn sooner? Don't mean to be obtuse... Always room to learn.

There's nothing obtuse about your question. I rode for 20 years thinking I knew quite a bit about riding, and I was suddenly surprised to find out how much I still had to learn.

Please be careful if you choose to experiment with what I have to say. Please feel free to ignore it to.

To initiate a turn, I pick an entry point (visually). I enter the curve at a steady speed, having memorized where I expected to start the turn. I am looking at the exit of that turn, and possibly looking for the entry point of the next turn. When I believe I am over the point I picked (I am not looking at it, I am looking at the exit), I give a hard jab to the right bar for a right hand curve, hard jab to the left bar for a left hand curve. The force I push depends on the speed I am carrying. This is just a fairly aggressive countersteer.

At this point I remain very relaxed, hand barely gripping the bars, and I roll on the throttle (less important with telelever, more important with standard suspension, but still a good practice).

This is what I mean about a quick turn-in. IOW, it's not a gradual leaning sort of thing. It is picking a point and acting on it. This results in less lean angle needed for a given turn, which means that you won't scrape any hard parts.

I learned this technique from Keith Code at the Streets of Willow Springs. It works. I have ridden all over California and Washington and I have never touched a part of the bike down in the past ten years, give or take.

There are many ways to ride. Pick the one that works for you.

[deilenberger]

This is what I mean about a quick turn-in. IOW, it's not a gradual leaning sort of thing. It is picking a point and acting on it. This results in less lean angle needed for a given turn, which means that you won't scrape any hard parts.

I learned this technique from Keith Code at the Streets of Willow Springs. It works. I have ridden all over California and Washington and I have never touched a part of the bike down in the past ten years, give or take.

There are many ways to ride. Pick the one that works for you.

Peck - interesting technique. Sort of the opposite of Reg Pridmore's "smooth" riding techniques.

One question - what does the sudden change do to traction requirements? It would seem to bring the available traction being used way up.. but maybe I'm missing something here..

I do always try for smooth - fluid movements, and given my glacial speeds - wearing out the edges of the tires (or centerstand) isn't a real issue for me..

[peckhammer]

One question - what does the sudden change do to traction requirements? It would seem to bring the available traction being used way up.. but maybe I'm missing something here...

I have never had a front end slide using this technique. As I said above, it is important to be rolling on the throttle throughout the curve. This keeps the suspension from compressing too much. If you use up your suspension travel, you will risk overloading your contact patch (risking loss of traction, as you said) and you will also telegraph the vibes from the road through the bike and your arms to the chassis. This can upset the bike.

I was very curious to see how all this would work with the telelever. I did a round trip from Seattle to Winthrop Washington on Saturday (two-up), passing through some canyons with curves often having cautionary speeds of 35 mph. I was able to enter most of them at 65 to 70, and marveled at the stability that the telelever brings to the equation. It seems to make a bike more forgiving. BTW, I can't see much in the mirrors over 100.

I do always try for smooth - fluid movements, and given my glacial speeds - wearing out the edges of the tires (or centerstand) isn't a real issue for me..

I have also attended Pridmore's class. I came away thinking that there is more than one way to skin a cat. I like Pridmore's techniques too. Smooth is good. However, you can make abrupt changes smoothly, as paradoxical as that might sound.

I think Pridmore's lines that he uses for CLASS are better suited for street riding (compared to Code's lines). Code has you going very deep into corners, which may be hazardous in certain street situations. OTOH, I marvelled at how big the chicane at willow springs seemed to become after using Code's lines.

All that said, if you really want to go fast, it's better to do it at the track. There aren't as many elk out there.