USD conversion , several options
 

I have done 2 conversions now and wanted to show some of the options for those concidering this. I was looking to find any frontends that were an easy swap but most require machining , some worse than others ,
the better one where from 2001 thru 2003 RM125, which are Showa 47mm twin chambers,(more valving and spring options),
http://imagizer.imageshack.us/v2/640...745/QZcwA6.jpg
These are 2004 RMZ450 KYB 48mm,
http://imagizer.imageshack.us/v2/640...904/gM2jpq.jpg
another is the 2oo0 to 2003 YZ125, the stem on all need to be re-turned on the top ,or as I did just make new stems.(I didn't take many pics unfortunately)

I started with milling the top clap front flat just to have a good mount surface, didn't absolutly have to,also drilled and tapped 6mm x 1.00 holes in an even pattern which I am doing on all my conversions.
http://imagizer.imageshack.us/v2/640...633/p3Y8XE.jpg

The mounting was fairly easy once I made the stem shorter on this one (RM125) it used the OEM lower bearing but need a conversion bearing from All Balls Racing for the top because the RM had a bigger top bearing and I didn't want to turn the hollow shaft down small enough to fit the stock bearing.
http://imagizer.imageshack.us/v2/640...904/k73KNn.jpg
For the guages I bent an 1/8" aluminum plate with the hole pattern I had drilled on the top clamp. I marked out the shape for the ignition switch and some areas for cables.
http://imagizer.imageshack.us/v2/640...673/XzFvHs.jpg

Here's how it ended up from above,
http://imagizer.imageshack.us/v2/640...746/gT1qGO.jpg

Originally I wanted to only run the factory guages for looks mostly , but that turned into a no go with offset(or lack of one) and the speedo drive being on the brake side, no waay it would work even making brackets to move the caliper over it ended up with the tire off center in the forks, so I searched around and saw my '83XL600 speedo is on the other side soooo,
I made an axle for 17mm, ,
http://imagizer.imageshack.us/v2/640...538/rp5KzG.jpg

Using the XL(early model XR's also)hub and drive with cable, got me my original way of driving the speedometer.
http://imagizer.imageshack.us/v2/640...905/2vwQTM.jpg

http://imagizer.imageshack.us/v2/640...673/dtQaCE.jpg

The finished setup,
http://imagizer.imageshack.us/v2/640...742/crBZIP.jpg

http://imagizer.imageshack.us/v2/640...538/gc9XeF.jpg

The other bike using a YZ125 frontend was made similar up top only I went with a Vapor for the speedometer and used a 2004 RMZ450 front wheel after making some special spacers and an axle for the big bearings they use.
http://imagizer.imageshack.us/v2/640...538/SMPMre.jpg

The Honda XL/XR brake disc bolts right on the Suzuki wheels, ending up with quite a mix of parts, few hours of investigating things , some of the same parts are cheaper from different models .
http://imagizer.imageshack.us/v2/640...910/NhnnQc.jpg

http://imagizer.imageshack.us/v2/640...537/FLUPm1.jpg

http://imagizer.imageshack.us/v2/640...540/YysxLs.jpg

A sneak peak and the next one , This one I was able to use the stock stem and stock bearings, easiest to do, just a bushing in the top clamp for the smaller stem then the '04 RMZ450 they came off ,
http://imagizer.imageshack.us/v2/640...673/Xf385A.jpg

http://imagizer.imageshack.us/v2/640...674/6yvuGE.jpg

and some of the work to get the inverted forks to ride great . No a person won't be greatly impressed with the usd's unless some valving is done, They are a vast improvement but definately need to be tuned, maybe a bigger guy and loaded down they would work better. Most of them are rather stiff for pavement.

This is the working part of the Showa twin chambers, The base valve -left, mid valve right, lots of tuning options
http://imagizer.imageshack.us/v2/640...908/odRQ5c.jpg

http://imagizer.imageshack.us/v2/640...913/Xmgg3v.jpg

and the inards of KYB open chambers,
http://imagizer.imageshack.us/v2/640...661/1FwjZ6.jpg

the valve shim stack laid out , I took several out in key areas to soften up low speed hits.
http://imagizer.imageshack.us/v2/640...538/SlvIfk.jpg

Some differences between 2 KYB shocks, one from the YZ, the other from an RM250, both "look" the same from the outside, but they're not.
http://imagizer.imageshack.us/v2/640...536/wDnheU.jpg

The stops are one issue I didn't take care of yet. I have some tabs I wanted to weld to the sides of the head, but until I'm ready to powder coat the frames I've put them off. The bars do stop before smacking the tanks as they are but can pinch wires and is too sharp.Bigger tank will hit, I'll have it sorted out on the white(and blue) one before finalizing it.

The speedo is off a bike with the same size front tire so luckily between the 2 brands the gearing came out the same as the original. Still shows 4mph fast , not gps confirmed but police radar station and riding next to people I know at a predetermined speed, close enough.

I wished I had taken a few more pics of the stems and such, once I get going it is finished before remembering the camera if I have one available at the time.

A friend of mine just gave me his wr 450 white power front forks and I wanna do the same... your post is very helpful and I will try it too...

https://imageshack.us/i/jvdsc02971bj
https://imageshack.us/i/5pdsc02969mj
https://imageshack.us/i/ngdsc02965pj

The bleeders should be at the top ^ , I put speed bleeders on mine, I hit them most mornings ,air comes out more than I would have thought

Thanks Bacardi!