xr650l USD forks settings for compression and rebound?

Hi. First of all ,Thanks for all the info in this forum.

I just finished installing 08 crf450r forks on my bike. Where should I start as far as setting the rebound and compression rates.

I'm 180lb. Ride on the street and forest roads.

Also What about the rear shock settings. Where do you guys have yours set for your riding and weight?

If the 08 forks are un-modded, you'll probably want the compression clickers fully open. They may still be a bit harsh. For rebound, use the factory recommendation for the original bike, or maybe a click or two further open. It may be around 8 to 10 clicks out from closed.

For the shock, you'll probably want the compression nearly closed.

The reality of USD fork conversions is that the suspension becomes unbalanced. The forks are now correctly sprung and valved (or maybe a bit too stiffly valved), while the shock remains soft and wallowy. I can recommend valving stacks for the 08 forks.

What would I expect as far as modifying the shim stack. Where do I get the parts?

Yes. It does feel soft in the back. I plan to rebuild it and do what I can ,gold valve I hear, if it will help.

Well today was the second day riding since the USD conversion. I don't remember if I went fast enough yesterday. But today after changing my suspension settings to the above recomended anything above 65 (trail tech/ more accurate )i get head shake. Any turbulent gusts make things very uncomfortable . I have rsw clamps with rebuilt 08 crf450 forks. I have the forks(a conservative) 1 cm above the oe install height ,as recommended by various USD posts, because of the added length of the fork.

What gives?

Bike was stable as a rock as far as I know past 80... I'm sad my efforts have turned in to a sour experience so far.

I'm stuck riding slow on the side streets til I can figure something out.

Is a stabilizer the only answer and how effective is it?

1458886683156.jpg

I too had the same problem. what helped me was to lower the forks down to the grove for the stock ride height. the forks got shorter the newer they are, they also moved the axle in a little the newer they are. so by running them up in the triples its got a pretty steep angle. mine feels a lot more stable at speeds around 70 now, doesn't feel like a chopper and in the woods turns great. I also had the steering stem nut a little loose, no play in it but if you looked at wrong the bars they would freely swing from one side to the other and bounce off the stop a little. a little snug up helped and they still fall to the side with a finger flick.

with that said I have a Scotts steering damper Im installing tomorrow morning!

ive got rsw triples and an 05 450r forks with d606 tires. ill let you know how the dampener feels, eBay score for 250 shipped. new style, in great shape.

Edited by lax30

From your picture, the forks are fairly high in the triple clamps. Try lowering them 1/4". And double check the tightness of the steering stem bearings.

I had my USD forks shortened about an inch and used Emig clamps.

 

I was told if the forks weren't shortened to run the up in the clamps an inch.

 

I opened up the compression all the way on mine and is seems to help  Rebound is at about 8.

 

It seems to work pretty well in the woods now.

Changing any setting front or rear could cause what you describe. Start with the one end or the other and make small changes and see if it helps. Making changes to the front and rear at the same time will make you crazy.

I used a 2003 crf540r  fork.  I upgraded with race tech valves front and rear.  They have really good info on the site about doing the upgrade.  Videos about disassembly and reassembly etc.  They have replacement parts and tools for both.  recommended valve stacks, and clicker settings.  Which have proved to work well for me.   I also upgraded my spring rates to .52mm/kg in the front and 12mm/kg in the rear.  I wanted to get good performance with the added weight of the bike and luggage.  While you are in the forks its pretty easy to add spacers to shorten them to the length of the stock forks so you can match the geometry of the stock ride. 


 


Here is a link to my build for my suspension... and the rest of the bike if you want to put up with it.


http://www.thumpertalk.com/topic/1113715-yaxrlb/page-5


 


Mark


Thanks dudes for the suggestions. This morning I went out lowered my tubes to oe height, locked bottom bolts, pried up my top clamp and put more load on the stem nut, Then after I lowered down the top clamp started to torque the top nut (side bolts loose!) And counter intuitively this also affected the steering "drag" .What's the torque spec for this? I thought the top nut was simply sandwiching the clamp between the two nuts...

Any hoo ,went for a put this morning and she's rock solid again. Turns fine.

As noted in another post, Raising the forks in the tubes or shortening the length of the forks with internal spacers may not be nessary based upon your components/years...

Steering bearing adjuster nut is .7 ft-lb

Steering stem nut is 85 ft-lb

Glad you got it riding good again!

Edited by lax30

Hafty is right on.  Spring rate is the very first thing you want to do besides ride height.  I put USDs on my 600 and after much experimentation I ended up with .51kg springs front, 11.5kg rear, with both ends revalved, fork tubes down 22mm.

Just a fork change and nothing more is not a good deal.  After matching springs and setting sags, maybe a revalve, the effect will be quite good.

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