KYB AOS Forks

[bebite]

I managed to get a set of KYB AOS (48mm) forks for cheap last fall. After some investigating I found that a set of triple clamps off a CRF 450R (2009 to 2012) should be a close fit. I got a set off ebay and the clamps fit on my 1990 KDX200 without doing a stem swap. The KDX bottom steering stem bearing can be used and the only thing that I needed to get was a 30mm x 47mm cup and cone bearing for the top. That bearing was a bit smaller so I had to make a small spacer (washer trimmed to size) to fit up top before the top cup was installed. The stops had to be modified but that was it. Fairly straightforward installation.

[Chopperpilot]

Awesome. I just watched a youtube video where they were showing how to valve those just like the SSS versions, because they're essentially the same fork.

[bebite]

I bought these forks sight unseen for $100. I replaced the seals with SKF seals and it looked to me like an aftermarket piston was installed.
Wont know how they perform until the spring but they feel plush.

[Chuck78]

This is great to hear!
I had suspected for a couple years now that the Honda CRF and maybe CR steering stems were the correct height, but only in the last few years have conversion bearing sizes been available to fit the KDX frame and 28 and 30 mm upper steering stem diameters....
Not having to do a stem swap and knurling a heavy steel stem and using retaining compound is a pretty awesome swap possibility. And Honda uses Showa suspension on a whole lot of their bikes as well as KYB. All the Yamaha YZ250 two strokes use the longest version of the Yamaha steering stem, along with some of the 450s. I'm still waiting to see if the medium steering stem fits per chopperpilot once his eBay purchase arrives. Is the one that discovered the YZ250 stems were longer and will fit the KDX. The short Yamaha stems are on the YZ 125 and some of the 250s, and most likely will not fit. Yamaha stuff is all kyb, so now we have good options for KYB and Showa inverted forks to be a direct bolt on. All Balls makes a 3 mm thick spacer that will slide down over the top bearing and bring the stack height up flush to the top of the frame. I would most likely prefer to have one cut out of aluminum versus their heavy steel washer spacer.
Now we just need to document if there are multiple lengths of Honda CRF and CR steering stems, and what applications they are found on.

[Chuck78]

I'm actually surprised that people would do steering stem swaps and get rid of the nice aluminum stems when they could have just used a custom lathe turned spacer to reduce the inside diameter of the bearing, but only if the steering stem was close enough height. The long Yamaha stems and the CRF stems seem to be correct height, which is great news!