July 4th, 2016, 05:23 PM | #1 |
CCS Amateur #501
Name: Dave
Location: Iowa
Join Date: Jun 2015 Motorcycle(s): '09 250 SE 'Booger' Posts: 406
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Preferred steering behavior?
Now that i've discovered the black freaking magic of trail adjustments, Im curious how other track riders prefer their steering to behave. Do you like to hold a little bar pressure one way or the other mid corner, or do you prefed the bike to hold its lean angle without steering input from you? Do your ninjette stand up in turns when you apply gentle braking?
Right now (after raising front end & taking out 1 click of shock preload), mine is doesnt require bar input mid turn when im centered on the seat but tends to drop into the turn a little when I hang off of the seat a bit. Im thinking id prefer for it to be neutral when im hanging off. Mine does not tend to stand up under braking at all, which I love, as all the bikes I had in my younger days (ex500 and a couple gsxr's) would stand up under braking, which sorta stunk in hindsight knowing that its not normal. |
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July 4th, 2016, 06:56 PM | #2 |
ninjette.org dude
Name: 1 guess :-)
Location: SF Bay Area
Join Date: Jun 2008 Motorcycle(s): '13 Ninja 300 (white, the fastest color!), '13 R1200RT, '14 CRF250L, '12 TT-R125LE Posts: Too much.
Blog Entries: 7
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The more neutral, the better. I like it when the pressure applied to the bars linearly affects the roll of the bike linearly. Hate the feeling of a bike falling into turns, and hate the feeling of having to apply a ton a of bar input to hold a bike down in turns. Suspension in good shape can help make this work better, but I've found front tire wear to be a large component of this as well.
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July 4th, 2016, 08:13 PM | #3 |
ninjette.org member
Name: David
Location: Arizona
Join Date: Mar 2016 Motorcycle(s): 2015 Ninja 300 X 2 Posts: 24
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The magic trail number seems to be about 102mm... for me anyway.
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July 5th, 2016, 12:56 PM | #4 |
CCS Amateur #501
Name: Dave
Location: Iowa
Join Date: Jun 2015 Motorcycle(s): '09 250 SE 'Booger' Posts: 406
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How the heck do you measure that? I could tape a stick to the fork leg, measure the distance between where the stick intersects the ground and the tire contact patch, then adjust for triple clamp offset, and assume fork legs are parallel to the steering stem... Or take it to a chassis guy?
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July 5th, 2016, 01:09 PM | #5 |
Track Clown
Name: Chris
Location: Kingman, AZ
Join Date: May 2012 Motorcycle(s): '08 250R, 21 MV F3 800, Kawasaki 400 build Posts: A lot.
MOTM - Sep '15
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there is a very experienced racer, teacher, coach and book writer that said something about steering requires only 1 input at entry and any additional inputs mid corner is a mistake from the initial input.
this is off my memory, and not exact. |
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July 5th, 2016, 01:41 PM | #6 | |
ninjette.org member
Name: David
Location: Arizona
Join Date: Mar 2016 Motorcycle(s): 2015 Ninja 300 X 2 Posts: 24
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Quote:
To measure, it is a formula from things easy to measure... if you know the offset, if you know the steering head angle, and if you know the tire radius, then you have the trail. There are variations with actual trail and effective trail, and I use actual trail which is a more complex formula. Keep in mind that it's a dynamic number that moves around as the tires/forks/frame/attitude move around, and 102 is a great target... maybe a little more like 103 or 104 if the bike setup moves around more than usual (16.5" tires move more than 17" tires... setup for Laguna Seca may move around more than the setup for Daytona, etc) |
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July 5th, 2016, 04:43 PM | #7 |
CCS Amateur #501
Name: Dave
Location: Iowa
Join Date: Jun 2015 Motorcycle(s): '09 250 SE 'Booger' Posts: 406
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Ahh yep that makes it easier. I could pick up steering head angle off of the fork leg, the leg should be parallel to steering stem. The rest is piece of cake.
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July 5th, 2016, 05:01 PM | #8 |
CCS Amateur #501
Name: Dave
Location: Iowa
Join Date: Jun 2015 Motorcycle(s): '09 250 SE 'Booger' Posts: 406
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Thanks. Sounds like the consensus is neutral steering is best on the track. That was my guess. Now my big problem: now that mine steers nicely, ill be upset if I dont drop 5s/lap at my next track day! 2 weeks to go!
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July 5th, 2016, 05:07 PM | #9 |
The Corner Whisperer
Name: Chris (aka Reactor)
Location: Northern KY
Join Date: May 2011 Motorcycle(s): 2010 250 (track), 1992 250, 2006 R6 (street/track), 2008 R6 (track) Posts: Too much.
MOTY 2015, MOTM - Nov '12, Nov '13
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I will be different... I prefer mine to oversteer just a tad.
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Goal: Shake A Million Hands | Look through the corners | Track Day Prep | Closest track? | The Mid-Ohio School |
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July 7th, 2016, 05:42 PM | #10 |
CCS Amateur #501
Name: Dave
Location: Iowa
Join Date: Jun 2015 Motorcycle(s): '09 250 SE 'Booger' Posts: 406
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My trail worked out to be ~101mm (with pretty imprecise angle measurement). I think 102-103 would be about perfect for me too, but ill leave it as is for now until I have a xhance to try it on the track with track pressures and leathers etc.
Fyi - the stock '09 triple clamp offset measured 50mm. Theres an online trail calculator at RB Racing. |
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July 16th, 2016, 07:56 PM | #11 |
CCS Amateur #501
Name: Dave
Location: Iowa
Join Date: Jun 2015 Motorcycle(s): '09 250 SE 'Booger' Posts: 406
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Whoohooo! I dropped 6 seconds, got both knees down, and felt heaps more comfortable. I still need more trail though, the more I hung off the side themore it would fall into the turn. Ill go down to #2 on the shock and see how that goes, I dont have any more room to drop the forks, and my front sag is ~26 mm so i dont want to preload the front any more.
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2 out of 2 members found this post helpful. |
July 26th, 2020, 07:24 AM | #12 |
CCS Amateur #501
Name: Dave
Location: Iowa
Join Date: Jun 2015 Motorcycle(s): '09 250 SE 'Booger' Posts: 406
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Fast forward a few years: Im a 6' 230 lb dude barrel chested wide shoulder build. On my 09 250 with 110/140 tires, I had to raise the front and lower the back so much to get neutral sterrring behavior that Id drag the lower fairing and had peg clearance issues and not enough room for my boots when leaned over. If I didnt raise the front and lower the rear excessively, the bike would always fall into the turn too much which I cant deal with all that well.
I did a bit of analysis and it turns out the best way to address major trail issues is thru adjusting fork offset. I ordered a few sets of triple clamps off of other small bikes I thought might be adaptable but nothing worked out. There was a set of adjustable triples on ebay but I didnt want to spend $500 on a $1000 bike. What I ended up doing, and worked out really well for me, was to reduce the fork offset (increasing trail) by shifting JUST THE UPPER triple clamp forward by 2mm. I did this by elongating the center hole of the upper triple 2mm rearward using a hole saw on a drill press. Warning, yes this reduces the strength of the upper triple so do this at your own risk and keep an eye on this. Yes there are many ways to screw up elongating the hole so you may want to buy a spare used upper triple. After you elongate the hole, you will need to shim the forward part of the hole to keep the clamp from shifting forward / aft under use. When you reinstall the upper triple, be sure to loosen the lower triple clamps first, then install the upper with the shims so everything is in its new position, straighten everthing and then tighten it all down. It takes a bit of elbow grease but not difficult. |
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