KX Conversion Finished!

Questions and comments about converting to beefier forks..
Post Reply
User avatar
m0rie
Supporting Member I
Supporting Member I
Posts: 2220
Joined: 10:25 pm Nov 29 2004
Country:
Location: Crescent City, CA

KX Conversion Finished!

Post by m0rie »

Well I finished the KX front fork conversion last night. Everything went together pretty easily. Phil's custom axle was perfect! Didn't get to take it for much of a test run last night but it felt substantially better just running around the yard hitting stuff. :rolleyes: I could feel the rear end not doing its part so the next project after getting the forks sorted out will be servicing the shock and respringing it to my weight.

CC and Ski! You guys have to help me get them dialed in this weekend and let me know what you think of them.

Looked like somebody had been into the base valves as well. The threads at the top of the compression assembly were filed. After I get some ride time on the forks i'll pull the base valves and post up what the valving is for anybody that is curious.

Ended up going with 5w Fork Oil set 110mm from the top of the forks. I'll try and get some pictures posted up tonight.
1989 KDX 200
2007 TTR-50E
User avatar
m0rie
Supporting Member I
Supporting Member I
Posts: 2220
Joined: 10:25 pm Nov 29 2004
Country:
Location: Crescent City, CA

Post by m0rie »

For those that have finished their conversion did it seem like your bike wanted to stand up and wheelie after the conversion?
1989 KDX 200
2007 TTR-50E
Green Hornet
Supporting Member II
Supporting Member II
Posts: 1455
Joined: 06:54 pm Aug 08 2005
Country:
Location: Orange County-New York
Contact:

Post by Green Hornet »

HUH, HUH. I still have the scabs on my assssss to prove it :rolleyes:
"Growing Old is Mandatory, Growing Up is Optional"
2008 KLX450R
2008 DRZ400SM
2005 KDX 220R
1985 KDX 200A3
2005 KLX 125L (SONS)
2003 KTM 50SX Pro Jr
B Senior # 254/0092

http://sponsorhouse.loopd.com/Members/R ... fault.aspx
Thanks to my 2008 Sponsers:
Dunlop, SteelMX, Amsoil, Simpson, Pro Works Racing, Pro Moto Billet, SLAP Energy,Boyesen, Rhino Stands, SixSixOne/SunLine Moto for your support.
John W Read Jr
User avatar
skipro3
Gold Member
Gold Member
Posts: 4329
Joined: 11:58 pm Nov 04 2004
Country:
Location: BANNED FOR LIFE!!
Contact:

Post by skipro3 »

Asweome m0rie!!!

What year forks were they again?
Jerry

I'd rather be a smartass like carvr, than a dumbass like.... well, you fill in the blank!
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

If your bike wants to loop that bad, I'd wonder about the heighth of the fork in the clamps.

How far up are they? ..and how big (thick) a spacer under the top clamp?

To answer your question, no. My bike didn't do that. But, I measured the level of the bike before I started to ensure getting the frontend back 'down' to where it started.

What's your stack look like? Is the piston OEM?

I don't recall if you took the cartridge apart..or if you said one way t'other. Still have a midvalve setup or a check plate?

What about the 'ol bladder thing? Got those?

Good to hear! You made it in time for THIS weekend!!

If you're interested in more than a rebuild...House of Horsepower (Richard Wilson, Eugene OR) does a good job on revalving the KDX shock.

Got bleeders on them? A lot less wear-and-tear on the seals for the brazillion miles to/from ski's this weekend!! We can just loosen the screws once everything is cranked down.

Great!!! You're in for a treat!!

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
User avatar
m0rie
Supporting Member I
Supporting Member I
Posts: 2220
Joined: 10:25 pm Nov 29 2004
Country:
Location: Crescent City, CA

Post by m0rie »

Ski - 1996 KX125 w/0.38kg springs, 5w@110mm.

CC - I'll do some measuring this evening and post back. I'm not sure that it really pulls up that much easier, my testing last night only consisted of 5 minutes in the dark, by no means a complete test. But it seemed like it came up a little quicker. I was thinking that was due to the unsprung weight difference, more than a fork height issue. I figured we could play with it a bit this weekend.

I didn't take apart the stack, just noted that the threads were unstaked so I figured somebody had done something to them. I pretty much just pulled everything down enough to change the seals and that was it. After I get some ride time on them and I have an idea what I do and don't like about them i'll take the carts apart and look at the valving.

No bladder! At least there was none by the time I got to them.

No bleeders, they are on the list (along with a fork prophylactic) after the trip.

I'm going to start with just a rebuild since i'm sure its never been done. Fresh oil and wear parts should go a long way towards making the rear end work a whole lot better. I'm on the borderline for my shock spring as well, figure i'll up to a 4.8kg while I'm into it. After thats all done and i've got some riding in i'll see about sending it out for a revalve if it needs it.
1989 KDX 200
2007 TTR-50E
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

There's a lot to be said for keeping up with shock maintenance. It generally surprises me to hear the, 'I've had my bike for six years and the shock is fine!' sort of statement.


A general statement for others reading:
If you ride much at all, the shock needs to be serviced at least once a year. That said based on the riding I do..and the huge difference in shock performance I notice after an annual rebuild.

Re: unsprung

I've not weighed the separate parts, but I'd question whether the aluminum outers are heavier than the steel inners. The lighter parts may be the unsprung parts on a conventional fork.

Whatever it is...is. Knowing one way or the other about the unsprung part wouldn't make the USDs any less a better 'spender!

'96s are..what size? 46mm?

You don't have a tank clearance problem?

Curious how you put the push rod nut back on. How 'squished' was the o-ring? I didn't measure the 18.5mm part as noted on the Jenks write-up, but used what I figured to be a 'correct' amount of squeeze to the o-ring. I've read other assembly instructions that had the o-ring squeezed too tight to suit me. Can't tell you what imo is, but it's not tightened to bulging and it's not loose neither.

It's 'just right'.

What preload did you end up with?

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
User avatar
m0rie
Supporting Member I
Supporting Member I
Posts: 2220
Joined: 10:25 pm Nov 29 2004
Country:
Location: Crescent City, CA

Post by m0rie »

>|<>QBB<
canyncarvr wrote: '96s are..what size? 46mm?

You don't have a tank clearance problem?

Curious how you put the push rod nut back on. How 'squished' was the o-ring? I didn't measure the 18.5mm part as noted on the Jenks write-up, but used what I figured to be a 'correct' amount of squeeze to the o-ring. I've read other assembly instructions that had the o-ring squeezed too tight to suit me. Can't tell you what imo is, but it's not tightened to bulging and it's not loose neither.

It's 'just right'.

What preload did you end up with?
I'm guilty of the not servicing the shock ever but thats a habit i'm looking to change.

The 96 forks were 46mm.

No tank clearance issues that I can tell. But I think i'm rubbing my radiator cap a little bit on full lock to that side. Might have to space it out a smidge to fix that.

I didn't actually take the push rod assembly apart. When I took apart the 94's though I couldn't get the pushrod nut to tighten down to 18.5mm without pooching out. Can't recall what the preload on the springs was, something along the lines of 6mm. When I take it all down i'll measure everything up again.
1989 KDX 200
2007 TTR-50E
User avatar
Ryan
Supporting Member II
Supporting Member II
Posts: 1047
Joined: 01:30 pm Sep 25 2005
Country:

Post by Ryan »

you all probably know this already, but cleaning and filling the shock seemed 10x's easier to me than the forks. No special tools are needed at all and it took me all and all about 90 minutes to do everything. I took the whole thing apart and cleaned it, refilled with oil and reassembled. It is really cheap to do. Cost me about $27.00. $15 for nitro and 12 for a liter of oil which i still have about 3/4 left.
2001 kdx220

1987 honda xl250
User avatar
m0rie
Supporting Member I
Supporting Member I
Posts: 2220
Joined: 10:25 pm Nov 29 2004
Country:
Location: Crescent City, CA

Post by m0rie »

Yeah I looked over the destructions in the manual and it looked pretty straight forward. I'm going to tear it apart in the next couple of weeks and replace the bladder, etc if they are worn. A local shop can charge the nitrogen and I should be good to go.
1989 KDX 200
2007 TTR-50E
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

When I get rich and famous, I'm going to buy a nitrogen setup so I can effectively do the job myself.

Still, there are advantages to trusting your tuner.

I just got a call from HoH (mentioned above). He said, 'I noticed you're only two clicks in on compression. Want me to soften HSC a little?'

I HAD noticed the HSC was off (I think some of that may have to do with more 'speed' in the HSC due to riding faster with the KX forks. Don't learn me about bike speed and HSC..I know the difference. One does effect the other). I've merely adjusted the clicker without checking its position. I noticed the '2-in' part when I wrote down the settings before I sent the shock up.)

Anyway I get a valving adjustment as part of the deal just because he's worked on the thing several times before.

Good deal.

Oh...don't change your shock spring until you get your shock serviced! With 'real' oil in it, you may find the spring you have is fine. Oil-wise, the shock tends to soften over time...if it's not pushed TOO far.

That's not taking into account that it may stiffen over time if it gets so far out of hand as to turn into goo.

Shops I've talked to around here won't charge a shock they haven't put together. It may come apart under pressure!

I've watched Wilson service my shock before. I guarantee you he has MUCH more in the way of proper servicing equipment than I wll ever have...like a really nice agitene tank!!

He uses an oil blend of his own recipe, too. That stuff can get spendy!!


My fork preload is around 6-8mm I recall. Not quite as easy to change that in a USD setup. Still, the effects of too much preload are not present in my KX forks. I doubt I'll mess with it.

Having used a custom axle...did you keep an odo with your KX forks? I don't recall if you even HAD one to start with...........

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
User avatar
m0rie
Supporting Member I
Supporting Member I
Posts: 2220
Joined: 10:25 pm Nov 29 2004
Country:
Location: Crescent City, CA

Post by m0rie »

I kept the wheel spacer on the caliper side and the odo drive on the other side. My actual odo was gone when I got the bike. Adding a odo back on is one of those projects that I want to tackle one of these days. Most likely go the aftermarket route than mess with the stock odo setup.
Last edited by m0rie on 06:55 pm May 15 2006, edited 1 time in total.
1989 KDX 200
2007 TTR-50E
User avatar
Ryan
Supporting Member II
Supporting Member II
Posts: 1047
Joined: 01:30 pm Sep 25 2005
Country:

Post by Ryan »

ya go with trailtech comps. Im gonna get me one of those when im rich and famos.
2001 kdx220

1987 honda xl250
User avatar
m0rie
Supporting Member I
Supporting Member I
Posts: 2220
Joined: 10:25 pm Nov 29 2004
Country:
Location: Crescent City, CA

Post by m0rie »

I checked and in addition to rubbing the radiator cap it looks like i'm barely touching the tank on either side at full lock. I'm not sure what i'll do about it yet, maybe do a little spacer deal on the steering stop.

Forks are 1/2" out of the top clamp.
1989 KDX 200
2007 TTR-50E
User avatar
skipro3
Gold Member
Gold Member
Posts: 4329
Joined: 11:58 pm Nov 04 2004
Country:
Location: BANNED FOR LIFE!!
Contact:

Post by skipro3 »

That's the same forks I have on my KDX: 1996 KX125. I have them set up with gold valves and a shim stack set for hard trail/enduro riding. What it is? I don't know!!! Race Tech Eric set it up for me. Race Tech springs too. We can compare them this weekend when they are mounted to the bike shoes in the trailer. That makes it easy to see which has a softer feel to them. You'll see.
Jerry

I'd rather be a smartass like carvr, than a dumbass like.... well, you fill in the blank!
Post Reply