KLR front end conversion to XR650R Forks Project

I love my KLR but after my last adventure ride to Abitibi Canyon,
http://www.advrider.com/forums/showthread.php?t=601183
I found the spindley 37 mm forks to be just too flimsy to allow some of the more aggressive manuvers needed on these trips, the front end also lacked the stiffness needed when the bike is fully loaded.
I did try heavier oil and Progressive springs but bottom line the forks just don't cut it. Without having compression and rebound dampening the forks leave little hope of much else than what they offer from stock.
I decided to start to look into what front ends would work for a relatively inexpensive conversion, (as all of us KLR owners are supposed to be cheap).
I did some research into USD forks from various models but found the conversions to be expensive due to the plastic guards, brake lines and cables required to get the conversion completed. Most people selling these types of front ends don't have the plastics or the cables for sale with the forks and if you have ever priced out replacement plastics for USD forks you know what I mean.

I decided to minimize the cost I would look for a conventional fork that had a decent diameter as well as compression and rebound dampening.

I am always looking on the FM for parts and came across an inmate that had done an USD conversion on his 2004 Honda XR650R. He was selling the forks, triple clamps, front wheel and calipers along with the speedo and speedo cable.
The Honda specs show these forks are:
46mm leading-axle Kayaba cartridge fork with compression- and rebound-damping adjustability; 11.2-inch travel

I contacted the seller and got him to send me some dimensions ie:
1 - center to center of fork tubes
2 - distance from center of axle to top of fork tube
3 - distance from top of upper triple clamp to bottom of lower triple clamp
4 - diameter of triple clamp stem where it is pressed into the lower triple clamp
5 - fork tube diameter, (just to be sure).

All the center to center fork tubes were very close, the forks were 2'' longer from the center of the axle to the top of fork tube, the distance from the top and bottom triple clamp was less than the KLR's and the diameter of the stem bottom was quite a bit larger than the KLR's.

This may all seem to indicate that the forks won't work but after some discussions with a machinist buddy of mine I decided it would work very nicely.
The longer fork tubes could be remedied by raising the tubes in the triple clamps, just as many people do when they install lowering links on the rear of the KLR's.
Since I am not a machinist, I called my buddy Jeff, AKA "kickerguy" who is a toolmaker and asked him if it would be possible for a machine shop to make up steel bushings to adapt the KLR's stem to the XR's triple clamps and if so does he know of a machine shop that would take on a small project like this without charging me an arm and a leg.
Jeff told me no problem getting such bushings made and whatever front end I go with he could help me out.
The distance between top and bottom triple clamps could be addressed by using a stock KLR steering stem, with the dimension of the XR lower triple clamp stem larger than the KLR's a machined bushing could easily be made to allow me to press the stock KLR stem into the XR lower triple clamp.
The fork tube diameter was 46 mm, SWEET
Because I was using the XR's wheel, no conversion would be necessary with the stock KLR wheel, and the speedo cable and brake line would have to be addressed as the project proceeded.

I decided to purchase the front end for $450.00 US dollars and because I live in Canada I got hosed for shipping but that's another story.

Here is photo of the bike before I started the conversion,


KLR 2010 (4)

The forks and wheel arrived a short time later,




Everything required out of the box,




The front caliper from the XR is a twin piston as opposed to the KLR's single piston, the owner had installed a larger, floating front disc on the wheel and the anodized bracket was needed to bring the caliper out further. This was an added bonus and is not necessary for the success of the project. Below is a photo of the caliper and front wheel with the disc on it.







Here is the stock KLR caliper mounted to the stock KLR forks, humm, looks like the brake line may be a close fit.


XR650R project (21) by intotheabis, on Flickr

Here you can see the difference in diameter of the lower stems of the XR and the KLR's
The KLR is the top one.



You can see how the front fender mounting bolts are very close only offset further back on the KLR, you can also see the difference in diameter of the 37 mm KLR tube as opposed to the 46 mm XR tube.



The unpainted triple clamp photos are of the XR's clamps where the black triple clamp is the KLR's.
I bought a KLR triple clamp from Ebay so that I could do all of the machining with out having the bike out of commision too long. You can get them for $20.00 $40.00 on Ebay.






KLR lower clamp




I set up a jig to press out the stems, the stem goes out the bottom of the triple clamp and takes the lower bearing off at the same time. I had a press but local bike shops will do this for you for a small fee or maybe for free if you buy the new bearings from them.

Here is the XR's stem out of the lower,




Here are the 2 steering stems with the XR on the left and the KLR on the right.








I didn't know it at the time but the upper opening on the XR's triple is larger than the KLR's so I needed a bushing machined to accomodate the KLR stem.





Here is the bushing installed on the KLR's stem, the bushing is actually a little too short and needs to be as long as the upper XR triple clamp is thick.





You can see how much larger the XR's lower triple clamp stem hole is, this gives the machinist lots of room to make a steel bushing to accomodate the smaller KLR stem.




I had the machinist install the steel bushing, bearing and lower clamp assembly so I cannot show you the steel bushing. I will include drawings with this report complete with dimensions so you can go to a machine shop and have them made up for you, it cost me $100.00 for both bushings.

Found a better shot;



Here is the drawing for the lower stem bushing



Lower stem bushing by intotheabis, on Flickr


And the upper stem bushing


Upper stem bushing by intotheabis, on Flickr

Once I got my front end off of the bike and removed the stock triple clamp I had a chance to see how the lower XR triple clamp fit up to the KLR's steering head.

Note. The reason you have to use the KLR stem is that with this method you do not need to modify the KLR steering head which would be a HUGE job!

I discovered that the rear side of the lower triple clamp needed to be machined to allow the turning radius required. I matched it up to the original KLR lower clamp to see how much material I would need to remove.




You can see buy the following photos that a fair amount of material would need to be removed but not enough to reduce the strenght of the clamp. If I had known I would have done the machining BEFORE installing the bearing but no big deal.




I just covered up the bearing and went to work with my dremel tool.











I kept matching it up to the KLR lower and trying it out in the KLR steering head until it looked like it would turn without hitting the gas tank.









Locating it on the steering head and the positive stops;










My helper is tired and said it is time to call it a night so who am I to argue!




To be continued.................

This should have been filmed in IMAX.

Great work! You are going to like that XR front end, but do pick up some stiffer springs - the stockers are a bit soft for me (160lbs) on a XR650R (~280lbs I think) and will probably be very soft for a KLR. If you want still less flex you can always fit a superbrace.

Looks like another item just got added to my todo list.
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Nice!

Forgot to mention, the guy who I bought the forks from had just installed springs for a 220 lb rider and a set of gold valves, he put one 500 mile ride on the forks before selling them to me. I changed the fork oil and the oil came out like new.

Sweet! You got one heck of a deal on the front end too

Ermmmm, you do know it will still be a KLR, right?

So, what are they? I'm always on the lookout for a fork transplant for my DR800 (which has 43mm conv forks)....these look sweet.

How does the suspension travel compare to the stock forks?

Here is the dimensions from my correspondence with the seller.

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I have the clamps and bolts.........the dia of the spindle.....on the bottom clamp is 1.25 inches and the top clamp is 7/8 inches
Hi, I need a couple of more dimensions if you could;

1: The distance from the center of the axle to the top of the fork tube.37inches
2: The center to center of the fork tubes across the top of the triple clamp. 7.5 inches

3: The distance between the two triple clamps from the top of the lower clamp to the bottom of the upper clamp. 6 3/4 inches from the top of the clamp where the fork comes through to the bottom of the upper clamp where the fork enteres....they are not flat accross the clamps


Thanks
Gary
The fork travel is 11.5'' which is much longer than the KLR's stock travel. If the forks were to bottom the front wheel would almost touch the fender. This means you can not install a fork brace later on but the forks are so much more rigid there is no need.

Thanks! XR suspension travel is 284 mm (11.2 inches) according to this http://www.bikez.com/motorcycles/honda_xr_650_r_2004.php

I'm rather curious as to how the XRR forks would compare to the KX upside down forks many people have used for this conversion. Emig Racing sells a conversion kit for the KX forks. The XRR solution might be cheaper.

I may go for a fork upgrade later but I've got a couple other things line before that. I'll keep an eye on this project as I really appreciate all the details.

Nice looking project!

I did a forks swap on my KLR and it is a vast improvement! You'll wish you did it sooner!

Ok, where was I?
Once I had proper clearance on the steering stopper I installed the the new steering stem bearings, upper and lower, (the lower only needed the race installed as the bearing was already installed on the stem). I didn't take any photos of this step as it is a fairly routine install. I did however have the top nut come loose on me during my Abitibi trip so because I had a second nut from my spare KLR stem I decided it couldn't hurt to double up on the nuts.
Next I installed the forks in the triple clamps and started to raise them above the upper clamp in order to lower the front end the 2'' required to get the bike back to its standard hight.




This is when I found out that Honda machines out a section between the upper part of the fork and the lower part of the fork between the area where the triple clamps would normally sit.
(I actually knew about this before this point in the build but thought it would add suspense and enhance reader pleasure if I added it at this point)










This would only allow me to safely raise the forks in the triple clamps 1'' instead of the 2'' I needed to have the bike sitting back level.
I dealt with this by installing a set of 1'' riser links for the rear shock. I have a 32'' inseam and I can still touch the ground although I am on my toes. This gives the bike a much more aggressive look and increases ground clearance as well.
If you are not tall enough to handle the increased hight there is a way to lower the forks by disassembling them and cutting a part of the inside of the fork down. Not sure how to do this but I believe the supermoto guys know how to do this and I am sure there is a link on the web somewhere on how to do this.

Have you priced an Elka shock yet?

Maybe we could arrange a group purchase?

Lornce, I purchased a 7.4kg spring and installed it on the stock KLR shock, works pretty good and only cost me $80.00
The spring is rated for a 220 lb rider Lornce and he does have one that will accomodate a 250 lb rider as well which may work better for when the bike is fully loaded but may be a pretty stiff ride the rest of the time.
I here the Elka's are quite pricy