Broke my forks

U

uts

Member

Jan 8, 2004

305

0

• Sep 2, 2010

• #1

Hi I have a 93 CR500, and the other day while riding motocross I managed to snap the top clean off the piston rod inside the forks on both sides. I think maybe one side already had a problem as the rebound clicker just kept turning the day before (I found this adjuster in the bottom of the fork after dismantle), but other than that I don't know why the other side broke.
I was landing pretty hard but not bottoming out. Any ideas what could have happened? I got a pair of CR125 forks from the same year to replace them but I just wanna know what to look for when I pull them apart to inspect them before I wack them in th 500.

UTS

 

U

uts

Member

Jan 8, 2004

305

0

• Sep 2, 2010

• Thread starter
• #2

Another thing. I checked the parts listing for the 500 and 125 of 1993. All fork part numbers are the same except the springs. Anyone know of any differences I am missing?

 

U

uts

Member

Jan 8, 2004

305

0

• Sep 2, 2010

• Thread starter
• #3

Just noticed that the damper part number is different. Are these forks gonna be any good on my 500 or is it time to try stuff that motor into the 125??

 

S

SS109

Member

Jul 27, 2009

310

1

• Sep 3, 2010

• #4

Why not get yourself some more modern forks on your CR?

 

E

eagles22793

Member

May 25, 2008

146

0

• Sep 3, 2010

• #5

I would look at getting newer forks that are a little more heavy duty then the ones you got now. for a bike that has that much power as the 500 there is a chance this might happen again and you might get a better feel for the newer forks

 

U

uts

Member

Jan 8, 2004

305

0

• Sep 4, 2010

• Thread starter
• #6

:bang: If I could afford a new set of forks I am pretty sure I would have bought some by now

 

whenfoxforks-ruled

Old MX Racer

~SPONSOR~

Oct 19, 2006

8,129

2

Merrillville,Indiana

• Sep 4, 2010

• #7

The valving and springrates are different, and would need to be stiffer and revalved. What is the diameter of the fork slider tube? I may have a pair? Vintage Bob

 

U

uts

Member

Jan 8, 2004

305

0

• Sep 4, 2010

• Thread starter
• #8

Hey Vintage Bob,

They are 43mm forks. I was planning on putting the springs from the 500 forks in them. What does revalving mean??

UTS

 

whenfoxforks-ruled

Old MX Racer

~SPONSOR~

Oct 19, 2006

8,129

2

Merrillville,Indiana

• Sep 5, 2010

• #9

There are holes in the piston and there are what looks like washers with holes in them. The stacks and piston are likely different because of the weight and power differences, the 500 is set up stiffer and slower than the 125. The washers with holes in them are now valves, not washers? 1 spring rate or 2 difference is generally not a big deal, if you are really fast/crazy, or more than a couple of spring rates, then I would send it to MX Tech to get set up properly. If you can set it up exactly the same, why not? The forks I have may well be the same, but they would have to come apart to verify, and I do not know what a 500 valve looks like or shim stack, compared to a 125. That stuff is somewhere between voodoo and rocket science! They even have non bottoming technology now! And when was the last time your suspension was serviced?

 

U

uts

Member

Jan 8, 2004

305

0

• Sep 6, 2010

• Thread starter
• #10

Thanks Vintage Bob,

I am getting them fixed at the suspension pro near me ( I am in Aus). He said he can use a lot of the parts from the 125 forks (broken piston rods) and will revalve for me. I couldn't see any of the valves etc in the manual because it shows the damper assembly as a complete unit. I appreciate your time. I should be back out on the track by the weekend, and will be more vigilent with suspension servicing now.

UTS

 

whenfoxforks-ruled

Old MX Racer

~SPONSOR~

Oct 19, 2006

8,129

2

Merrillville,Indiana

• Sep 6, 2010

• #11

MX Tech needs a southern hemisphere shop outpost? Best of luck, neglected suspension can get pricey to fix! As bad or more than the engine.