KDXRIDER.NET

I have a 1989 and a 1990 kdx200. I would like to be able to install 1- 1/8" bars. Is this possible. I know some KX's have the bolt-on bar clamps with rubber mounts but I dont know if they would fit.

Sadly, the stock triple clamps only hold 7/8" bars. Went through this when I had my '90 and ended up just sticking with the smaller bars.

That said, you can get adapters that bolt on to convert to the larger bar but be aware that they do raise the bars to some degree. Here's a couple of adapters that would work...

https://www.rockymountainatvmc.com/part ... lamp-kit-p
https://www.amazon.com/Black-Universal- ... 4UU8TM4LLP

Check the offset, but you may be able to use a 1986 - 1988 KDX200 upper clamp and the cone spacer that those bikes require under it. Also, mid 80's KX may be useable.

Be aware that any adapter is going to not only raise it, but put it back in your lap also, as it will move the bars rearward to your normal hand position.

Yeah, I'm not too crazy about adding adapters/bar risers for that reason. I find the bars are already too close too me. Would be nice to find a top triple clamp that fits which has bolt in place bar mounts instead of the standard cast ones.

I think the older ones you can spin them around backwards to move them a few mm forward.

The 1989 - 1992 models that use the right side up conventional forks with damper rods can be upgraded to the 1995-2006 triple clamps upper and lower, in which you get rubber mounted handlebar risers that are mounted vertically to the triples or perpendicular rather, so they don't sweep back the way the E-Series do.
Getting the entire forks off of a 1995-2006 would be the best plan of action here because the forks on the 89-92 are old antiquated fixed orifice damper rod forks.
Better yet is to use those 95-06 triple clamps + Showa 43mm conventional forks from a Honda XR400R (.40kg or .41kg springs stock) or '96-'98 Suzuki DR350 43mm forks (.39kg springs stock), with Race Tech Gold Valves. Those forks will bolt directly into 95-06 KDX triples which will bolt directly onto the E-Series.

You'll need the brake caliper off the donor or H-series KDX, & for the 43mm Showa XR400R & DR350/DR350SE forks, you'll need the axle, spacers, and front wheel from the donors, as it's a big upgrade from the flexy KDX 15mm axle up to 17mm diameter.
I believe the E-Series vs H-Series steering stops are the same, but some modding may be necessary potentially. Visually compare them.

Any of those will benefit from a revalving job, which is made significantly easier/better results usually by purchasing a srt of Race Tech Gold Valves for the fork model. The 350 & KDX use the same, the XR400 uses a slightly different variation.
H-Series 95-06 KDX springs are 0.345kg/mm and are for a very lightweight rider, 115-145lbs.
96-98 DR350/350SE use 0.39kg/mm springs stock, which are suitable for a 150-185lb woods rider.
XR400R use a 0.40 or 0.41kg/mm spring if still stock, which is suitable for a 155-195lb woods rider.