2 STROKE WORLD .net

The 2-Stroke Garage => General Chatter => Topic started by: Eric P on February 21, 2019, 02:28:03 PM

Title: RD350 Ninja 250 Suspension Swap
Post by: Eric P on February 21, 2019, 02:28:03 PM
Did anyone manage to save any of the technical info regarding the Ninja 250 swap? I guess that's one of the threads that didn't get archived.

I'm about 3/4 of the way through a swap on my RD250 and seem to have lost the spacer drawings when I moved my shop. I still need to make the steering neck spacer. At the moment, I just have a piece of pipe in there so I can roll the bike around.

I don't need ALL of this info since most of it is already done on my bike, but for the sake of continuity, I want to document the following info:
- How much to cut off the swing arm
- Drawings for rear lower shock spacers to fit the stock kickstand bracket
- Drawing for rear upper shock mount bracket
- Drawing for steering neck spacer
- Lower shock mount bolt size
- Upper shock mount bolt size
- Steering stem bearing size

Here is the RD250 that I've nicknamed Project Tetanus:
(https://i.postimg.cc/FKvJWV3Y/Full-Size-Render-7.jpg)

(https://i.postimg.cc/k49FSdfh/Full-Size-Render-6.jpg)

This bike will be disassembled, cleaned up, de-tabbed, and painted once everything is welded and in place.

Anyway, I was able to come up with a little bit of the above requested info, but I want to confirm it's correct as this is mostly from memory:
- Cut approximately .25" off each side of ninja swing arm pivot tube (measure frame to verify, make sure sprockets line up, tap bearings in and tape them off first!)
- Upper bracket started life as a 1.5" x 2.5" x .120" wall x 12" long piece of rectangular tube stock and a 12" long piece of 1" x .120" wall round DOM tubing. I think I needed about 6" of the rectangular stock and about 8" of the DOM tubing
- Lower shock mount bolt size: m12 x 140mm
- Upper shock mount bolt size: m12 x 45mm
- Steering stem bearings 30mm x 48mm x 12mm (upper AND lower?)

I may have the drawings saved on my old desktop, but I haven't had time to sift through all of my old files yet. If somebody has them, please post them. Also, feel free to correct me if any of the above info is incorrect.

I'm also interested in seeing what people have come up with for rear sets and which aftermarket pipes will fit around the bottom shock mount. I seem to remember a lot of people reusing the ninja rear sets, but mine were in pretty bad shape.

Edit: I'd also like to hear what people are using for sprockets as the Ninja and RD use different chain sizes.
Title: Re: RD350 Ninja 250 Suspension Swap
Post by: m in sc on February 21, 2019, 02:39:52 PM
Murray P has all that info, not sure what his username on here is this go around
Title: Re: RD350 Ninja 250 Suspension Swap
Post by: Clem on February 24, 2019, 05:09:39 PM
I did a similar swap using the 2008-2013 parts from the newer gen EX250. I didn't trust the center stand mounts for the suspension system so I cut them off and made new brackets so I did not need any spacers. I used as GSXR600R rear shock and knuckle with a lighter Racetech spring. Up front I installed the RT emulators and new oil and it handles pretty well. Good luck with the build and let me know if I can help.
Title: Re: RD350 Ninja 250 Suspension Swap
Post by: SoCal250 on February 24, 2019, 05:20:30 PM
Clem, love your bike! :clap: Would you mind posting something in the Show Off section with more photos and details of the parts & mods?
Title: Re: RD350 Ninja 250 Suspension Swap
Post by: Clem on February 24, 2019, 10:49:23 PM
Sure, I just need to get some photos in one place and re size them to fit on the site. I need to do the same with the Daytona now that it's finished.
Title: Re: RD350 Ninja 250 Suspension Swap
Post by: RustyRD on September 07, 2019, 10:25:35 PM
Hello
Did you find the drawing for the spacer? I saved. This drawing somewhere..