Front disc bolt pattern?

[Tumbleweed]

I recently got some forks off ebay for my '91 kx 500 (my current tubes are smashed and dented). The auction said they were from a '90 kx 500, I looked up all the parts on buykawasaki.com and everything matched.

When they arrived I noticed they were from a newer bike, (the bottom tubes were twisted in the picture so I didn't notice they had the 3 bolt holes for the newer style fork protectors.

They do bolt onto my triple clamps but now the caliper is mounted much higher. so a larger disc is needed. Anyone know if I can just buy the newer large disc and bolt it on? or would I have to change the hub too? 

[MadKaw]

not sure on this one. I've changed front discs from several bikes and they were all interchangable. from a 01 KX250, 99 KX250, 89KX250 and 93 kx500 were all the same size disc. its possible he had that done for the bigger disc upgrade from Braking or Galfer.

[Tumbleweed]

sounds promising, thanks!

[demographic]

When I was getting the supermoto setup for mine I found that the discs were the same four hole patern for 90 on but the caliper relocation brackets that were avaliable only fitted 92(ish) and later bikes.

I assume that means that the brake calipers changed.
You might have to get the newer brake caliper to match the forks?

Just as a matter of interest what colour are the forks? my 90 ones are anodised gold, the 91-93 ones were anodised blue then after that they went a nasty shade of purple for a while then silver.

You can also work out the years by the slider fork diameters 90= 41mm, 91-93 id 43mm and then I don't know when it changes again but it goes through 45mm as well maybe another size also.

[Tumbleweed]

When I was getting the supermoto setup for mine I found that the discs were the same four hole patern for 90 on but the caliper relocation brackets that were avaliable only fitted 92(ish) and later bikes.

I assume that means that the brake calipers changed.
You might have to get the newer brake caliper to match the forks?

Just as a matter of interest what colour are the forks? my 90 ones are anodised gold, the 91-93 ones were anodised blue then after that they went a nasty shade of purple for a while then silver.

You can also work out the years by the slider fork diameters 90= 41mm, 91-93 id 43mm and then I don't know when it changes again but it goes through 45mm as well maybe another size also.

The forks look a little silver but may have a slight gold tinge, my current forks are blue. I don't have a camera at the moment but I found a picture on the web that shows the differences I'm talking about.



My current fork guards and I think the '90 fork guards are flat and don't have a mount for the fork guards that curve around the side, and the caliper bolts up closer to the fork leg. The forks I got have a longer top mount (I think these models came with the floating brake, with a larger disc) I am getting a caliper from a '96 model off ebay, and I'm crossing my fingers that it will work. If that goes as planned  ... The disc will be the last piece of the puzzle.

[demographic]

I know what you mean about the 90 ones having the flat guard and the later ones wrap around.

Do you have a vernier caliper to measure the diameter of the slider? That will give you some idea of the year that the forks were produced for.

[Tumbleweed]

I know what you mean about the 90 ones having the flat guard and the later ones wrap around.

Do you have a vernier caliper to measure the diameter of the slider? That will give you some idea of the year that the forks were produced for.

I don't have a caliper, but I have one of those soft tape measures. I'll measure it in inches and try converting that to mm.

[demographic]

If you use one of those soft tapes I assume that you will get the circumferance, you need to know the diameter if the tube so you know what year its off.
You need to devide the circumferance by Pi
By the way, I am pleased that it fits the triple clamps cos that means that I can use newer forks in my 90, that makes getting spares simpler for me.

As your 91 bike will have the 43mm forks the newer forks should be (as far as I remember and I have not checked) either 45mm or 48mm.

Don't forget that you should always check this info out as my knowledge gets kind of hazy at about 1990 cos thats what year my bike is.

Regards Scott.

[cyclepsych0]

Hi there,
 I'm hoping to help you out in atleast identifying the year of your forks.....
  Off the top of my head, I would guess you have forks from a '94-'96. '94 was the first year they had the wrap around protectors and they were still 43mm like your stock '91 blue forks up to '96. (This would explain why they fit in your '91 triples.)

  '94 was the 1st year they stopped the blue anodizing and went back to a goldish color, and '95/'96 are basically the same fork as '94.

  '97 is when they made the jump to 46mm. (Which I believe would NOT fit your clamps due to an increased size in outside diameter of the upper tubes.)

 Nick

[cyclepsych0]

   After some quick research, I found that EBC brakes lists the same part # for front rotors for all 500's from '89 - '04. This would indicate they are all the same physical size rotor in these years.
   While I was at it, I checked the part # for their oversize rotor kit and found the # is the same for 500's from '94 - '04. ('93 and earlier kits aren't offered). To me, this says the adapter bracket included for the caliper is the same for these years. Which means the calipers' bolt pattern is also the same from '94 - '04, but it's different for '89 - '93 or else this kit would work on those years as well.
  I'm almost positive the '96 caliper you're getting will fix your issue as long as the brake line mounting/routing hasn't changed. (Fingers crossed).
  Let us know how it goes!!

Nick

[Tumbleweed]

woo! I'm getting excited! I'm still waiting on the caliper to get delivered. I'm feeling good about this. I got the forks for $50.00 cause no one else bid on them. I guess if they knew they were from a newer model more people would have bid.

[Tumbleweed]

alright, no caliper yet, but I took some pictures in case anyone was interested.

the forks do look more silver than gold, I will use those triple clamps cause they are in better condition than the ones on the bike currently here is a picture:



Here is a picture of one of the tubes bolted on to my current clamps:



and here is a lame attempt to measure the forks with a ghetto homemade caliper. The yardstick is marked cm, when I converted it to mm it turned up at 45mm. most likely not a true measurement, but I tried.

[demographic]

I have just had a look at my catalogue and the seal sizes listed for KX500s are as follows...

83-87, 43x55x10.5 (right way up forks)

88, 43x55x9.5/10 (right way up forks)

89, 45x58x10.5/11 (right way up forks)

90, 41x53x8/9.5 (upside down forks)

91-96, 43x55x9.5/10 (upside down forks)

97-03*, 46x58x9.5/10 (upside down forks).

So, the 83-87 bikes ran 43 mm right way up forks.
88 bikes ran 43mm right way up forks with different seals.
89 ran 46mm right way up forks.
90 bikes had 41mm upside down forks.
91-93 bikes had 43mm forks.
97-03* bikes had 46mm forks.

*I would guess that the 04 bikes also use the same size forks as the 03 but don't know for a fact.

[BDI]

I don't know If this Is any help to you but on my digital caliper one inch converts over to 25.4 mm. My digital caliper Is probably the single most used tool In my garage next to the bottle opener bolted on side of my bench. I would be lost with out It every one should have one even If It is just a cheep plastic one from harbor freight digital Is sweet becaus you can convert inches to mm. My wife even uses my caliper for girl type stuff.

[don46]

  Must be a European thing, don't ever remember seeing a KX with purple forks, there were some purple fork boots about 96 for the bikes that had right side ups and purple fork guards for those with upside downs.