Forks

[Motorrad]

Just got a reply from Destry abbott about what they ran on their 500's

"I'm 99% sure we changed ours to 23mm off-set."

So this means Im golden... Shweeeet. Always good news when your told you screwed up in the right direction

Cant wait to pick up my forks and shock from Precision concepts tomarrow....

(was going to go racetech, till I found out they wanted $1600 for the custom rear shock I was planning on having them make)

bringing this one back from the dead.

Im not happy with the way the bike handles.

front end is washy.   and rear will just kick out when bombing a corner (perhapse this is the desert IT rebar tire)... not predictably.

Ive been faking this by running tubliss, with about 5psi in front tire, and 5 psi in rear.   pump the front up any more than that and its a bitch to ride.

I believe its all in the offset of the tripples is where my problem is.   suspension gurus? (ahem alward25)


MY 1991 kx500
Trail:           4.57"
Head Angle:  27 Deg
Travel:         12.20"
Triple offest   22mm


06 KX450
Trail            4.6" (probly same)
Head Angle   27 Deg
Travel:        12.4"
Triple Offset  24.5mm


Now looking for a 20mm or 22mm set of aftermarket clamps.

http://www.kxriders.com/forums/index.php/topic,14872.msg117025/topicseen.html#new

[MRDART]

Well the kx450-08 also has a tendency to wash out the front end, I know a lot of guys bought aftermarket trippleclamps with 22 mm or sometimes even 21 mm
 From what I can remember the kx500 (stock) doesn't have the same tendencies, so less offset would be preferable... Mind you I can only speak from mx experience, no trail or desert riding for me

[alward25]

What is your rear shock high speed comp set at?  Too stiff can cause that too.  Front settings?

[Motorrad]

What is your rear shock high speed comp set at?  Too stiff can cause that too.  Front settings?

ugh. Ill find out.   all suspension was done by precision concepts local chaper for high speed desert set to me.

when I got it, I turned the damping up 2 clicks on the front.   rear felt good.


side note. anyone ever run differant offset clamps on their K5?   stretch I know...

[Danger4u2]

Back in 2006 thru 2009 when I was on my parts/bike buying spree I picked up
a fork set and offset Emig clamps.  I put them in the container and have never messed
with them.  I hope someday if/when I retire I will put them to use.
The p.o. said they make the K5 handle like a CR500.
My plan was to use them on my fat tire sand KX500, another project I haven't
gotten to.  I have all the parts, bike, just lost interest.  I have many projects like that.
I've been clearing out projects that I will never get to.  Like the CR500 AFC bike.
I bought it in 2007.  I rode the bike the day I bought it, brought it home, drained the
gas tank and it sat for 8 years.  A friend started bugging me about the bikes I have sitting one day.
He wants to make a Super Moto so I sold him the Honda for what I paid for it.
He told a friend of mine, "Every time I touch that bike I get hurt on it".
I say "Welcome to the half liter 2 stroke world".
If you would like, I can dig out the Emig clamps and see if they have any i.d. numbers
or what the offset might be.

For those NOT in the know....A quick guide to motorcycle rake, trail and offset.
http://www.autoevolution.com/news/a-quick-guide-to-motorcycle-rake-trail-and-offset-part-1-83482.html

[LukeG]

Just in case any one wants to know, I have sent my 1990 250 triples to RSW racing to have a set of 13mm offset triples made. Knowing that they are the same for similar years 500s they could an option. My 250 is being built as a motard so I need reduced offset triples.

[Motorrad]

Back in 2006 thru 2009 when I was on my parts/bike buying spree I picked up
a fork set and offset Emig clamps.  I put them in the container and have never messed
with them.  I hope someday if/when I retire I will put them to use.
The p.o. said they make the K5 handle like a CR500.
My plan was to use them on my fat tire sand KX500, another project I haven't
gotten to.  I have all the parts, bike, just lost interest.  I have many projects like that.
I've been clearing out projects that I will never get to.  Like the CR500 AFC bike.
I bought it in 2007.  I rode the bike the day I bought it, brought it home, drained the
gas tank and it sat for 8 years.  A friend started bugging me about the bikes I have sitting one day.
He wants to make a Super Moto so I sold him the Honda for what I paid for it.
He told a friend of mine, "Every time I touch that bike I get hurt on it".
I say "Welcome to the half liter 2 stroke world".
If you would like, I can dig out the Emig clamps and see if they have any i.d. numbers
or what the offset might be.

For those NOT in the know....A quick guide to motorcycle rake, trail and offset.
http://www.autoevolution.com/news/a-quick-guide-to-motorcycle-rake-trail-and-offset-part-1-83482.html

If its not too much trouble.   Im curious what they put on the K5.   if going 20mm like I think would work is too radical.

[edgar_kx3]

I was looking at a set of 2011 forks and triples for my 500. I think them are still 23mm offset though. When I get it all going I will tell you how that works.

[edgar_kx3]

also didn't you say your 450 forks where longer? by how much? I just measured my 2013 kx450 forks and there roughly 943mm from the top of the upper tube to the center of the axle( I am not including the top cap) and my 500 was like 945ish. there within a couple mm of each other anyways. just curious..

[Motorrad]

Just thought of something.   Since my fork diameter change...  Assuming all else was the same... Change my tail numbers.  Since in theory the axle has to be further away from fork center.     Hmm. Drunken midnight bench racing..  I'll measure if that's a factor in the AM...

[Motorrad]

Just thought of something.   Since my fork diameter change...  Assuming all else was the same... Change my tail numbers.  Since in theory the axle has to be further away from fork center.     Hmm. Drunken midnight bench racing..  I'll measure if that's a factor in the AM...

Yes. this changes things also.

center of fork for the blue legs I have is roughly 28mm
center of fork to the axle center of kx450 is roughly 33mm.

just right there I gained +5mm in offset.

crap.

no wonder its handling like it is.

anyone have a good trail calculator?

[DoldGuy]

Just for testing purposes....trailing axle (-5mm) versus leading axle.

[Motorrad]

Just thought of something.   Since my fork diameter change...  Assuming all else was the same... Change my tail numbers.  Since in theory the axle has to be further away from fork center.     Hmm. Drunken midnight bench racing..  I'll measure if that's a factor in the AM...

Yes. this changes things also.

center of fork for the blue legs I have is roughly 28mm
center of fork to the axle center of kx450 is roughly 33mm.

just right there I gained +5mm in offset.

crap.

no wonder its handling like it is.

anyone have a good trail calculator?

RE-measured this.    not as much differance as when I quickly eyeballed it durring lunch.   

[Motorrad]

https://www.rbracing-rsr.com/rakeandtrail.html



MY 1991 kx500
Trail:           4.57"
Head Angle:  27 Deg
Travel:         12.20"
Triple offest   22mm
Axle offset (work backwards) = 21.7mm
Total offset (working backwards)= 43.7mm


06 KX450
Trail            4.6" (probly same)
Head Angle   27 Deg
Travel:        12.4"
Triple Offset  24.5mm
Total offset to achieve trail (working backwards)= 43mm
Axle offset (working backwards) = 20.6mm


Other.
Dunlop 80/100=  27.72” (704.088mm)
Dunlop 90/100= 27.99” (710.946mm)

[Motorrad]

so.  based on all those numbers.   both bikes came with same sized front tire from factory.  same head angle, only differance is .8mm in trail.   but the tripple clamp offset of the two goes the wrong way to achieve this. so the larger 450 forks would have to have less axle offset to make up for these changes.   20.6mm working backwards to be exact........

Hmm.   Need to go measure this tonight to confirm.