Installing Racetech 3750 springs on a 1992 KDX200

Questions and comments about converting to beefier forks..
Post Reply
SCARYMOOSE69
Member
Posts: 7
Joined: 04:17 pm Feb 26 2022
Country: United States

Installing Racetech 3750 springs on a 1992 KDX200

Post by SCARYMOOSE69 »

Hey guys,

Just picked up my racetech 3750k springs for my 92 kdx200. Im looking to use the long spring plus the 2 little springs to acheive the coveted .40 spring rate for my skinny ass.

What order when installing do the little springs go (or does it matter), where do the washers go (between little springs or spacers), and what fork oil height level do you use (OEM spec or altered)?

This is what im thinking for the install, let me know if i have it right if youve installed the 3750k kit. Im listing items as i put them in the tube

1. Long .46 spring
2. racetech Washer
3. Little spring #1
4. ractech washer
5. little spring #2
6. OEM spring cap/washer thingy
7. custom spacer cut for 5mm or so preload

Racetechs instructions also mention putting washers on both sides of the spacer, but i think the oem steel spacer rides between the cap and the OEM spring cap washer thing. It looks like the OEM shock diagram confirms this.

Thanks! Stoked to get my rear linkage rebuild too and hit the trails again
User avatar
KDXGarage
KDXRider.net
KDXRider.net
Posts: 14047
Joined: 06:45 am Nov 01 2004
Country: United States of America
Location: AL, USA
Contact:

Re: Installing Racetech 3750 springs on a 1992 KDX200

Post by KDXGarage »

What is the middle rate option?

You sound correct on installation. Did they not come with instructions?

If you want to really know and spend time, start at the lowest level, then add it to help bottoming.

What is your weight in full riding gear, skill level, terrain, etc.?

Oil weight is going to have an effect on rebound rate. Since you have gone stiffer, don't hesitate to start off with ten. EDIT ADD-ON: meaning don't try the 7.5 deal.
Thank you for participating on kdxrider.net. :bravo:
To post pictures from a device: viewtopic.php?f=88&t=24128
SCARYMOOSE69
Member
Posts: 7
Joined: 04:17 pm Feb 26 2022
Country: United States

Re: Installing Racetech 3750 springs on a 1992 KDX200

Post by SCARYMOOSE69 »

So im prob 180 with gear, i ride mainly tight woods in the NW but do some desert riding.

I'd say im intermediate, ill hit jumps off whoops and thats really why i want to get the front end stiffer, i bottom way to easy and its dangerous.

I'll stick with 10wt but what should i do with the oil level, keep it the same as the OEM spec?
User avatar
KDXGarage
KDXRider.net
KDXRider.net
Posts: 14047
Joined: 06:45 am Nov 01 2004
Country: United States of America
Location: AL, USA
Contact:

Re: Installing Racetech 3750 springs on a 1992 KDX200

Post by KDXGarage »

You DEFINITELY need to gather all your riding gear and hold it or wear it and step on a scale.

I am thinking you should try the 0.43 option at some point. Also, you may want to get a 4.8 rate spring for the shock.

You are going from 0.30 to 0.40, so that is a 33% increase in fork spring stiffness. It is indeed going to spring back a good bit quicker. That is why I suggest not to try 5 r 7.5, as in damper rod forks, the viscosity plays a noticeable role in rebound.

I would start at the lowest OEM oil level, then go from there. It is easier to add an inch of oil than to remove an inch of oil. If it is bottoming out too much, then adding oil within spec will help bottoming.
Thank you for participating on kdxrider.net. :bravo:
To post pictures from a device: viewtopic.php?f=88&t=24128
SCARYMOOSE69
Member
Posts: 7
Joined: 04:17 pm Feb 26 2022
Country: United States

Re: Installing Racetech 3750 springs on a 1992 KDX200

Post by SCARYMOOSE69 »

For what its worth i called racetech and they confirmed what i listed above except for adding a washer on top of the PVC spacer. I did it last week and rode out in the woods here and the setup kicked ass, no more goofy bottoming on small obstacles.

.40 felt pretty good, im used to soft forks on my old 80's XL's so it felt at home, i stiffen them up later potentially.
User avatar
KDXGarage
KDXRider.net
KDXRider.net
Posts: 14047
Joined: 06:45 am Nov 01 2004
Country: United States of America
Location: AL, USA
Contact:

Re: Installing Racetech 3750 springs on a 1992 KDX200

Post by KDXGarage »

Cool. It won't cost anymore to give the 0.43 a try in the future. Enjoy the "not 0.30" springs and ride!
Thank you for participating on kdxrider.net. :bravo:
To post pictures from a device: viewtopic.php?f=88&t=24128
Post Reply