|07-02-2013, 01:54 PM||#1|
Joined: Apr 2008
Location: Denver, CO
Front end weirdness
Been trying to figure this out for a while without any progress:
modified 1st gen klr650
- DRZ400 fork, wheel
- straight rate, .62 spring rate and factory recommended oil wt.
- Shinko front tire in VGC, no weird wear patterns
- Modded Cogent rear shock (up 1") to accommodate higher front end
at speeds between approximately 30mph and 48mph the front end feels very "reactive", like it would if the wheel was badly out of balance (which it is not). The fork gets a very low frequency vibe, much like it would if you we're riding over slightly washboard surface. It feels like every 3rd-5th rotation is when it vibes again. Everything smoothes out above 50mph and there's no hopping feeling at all. (Though it is very annoying in town)
What I have tried:
Two different front whls, neither is perfect, they do balance out on a machine
Checked and re-checked steering bearing. It's snug and does not move.
Riding several different surfaces to make sure I'm not just feeling actual bumps or sensitivity in the fork.
Lowered the fork aprox. 1 inch in the clamps.
Various tire pressures
What I have NOT tried:
Double-check pre-load, overall geometry of the bike. (This was pretty much educated guess work)
Any ideas fellas?
"What is to give light, must endure burning."
|07-02-2013, 03:46 PM||#2|
Joined: May 2005
I noticed the same issue on my LC4 Adv but only when using Continental TKCs at full street pressure. Never had the issue on lower pressure or any other tires. So I guess it has something to do with tire's internal spring rate.
If you are thinking outside the box,
its better to know the box first.
|07-02-2013, 03:49 PM||#3|
Red Clay Halo
Joined: Aug 2003
Location: Richmond, Va
A little nonsense now and then is relished by the wisest men.
You can be Han Solo, and I can be another Han Solo...
|07-02-2013, 03:51 PM||#4|
DualSport Crazy !!
Joined: Jan 2012
Location: Redding, CA
You said two different front wheels, with the same tire? I am betting on a defect in the Shinko... Wouldn't be the first time.
"Where ever you are, there you go..."
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