FXDX Winter Suspension Project
 

Just got a start after work today. The plan is to upgrade suspension at both ends, and add some front braking (and of course more "making stuff pretty." Powder coating, instrumentation cleanup, finally do something about the cereal bowls that act as turn signals, etc.).

After a few years of reading the forum, I knew I would be calling Howard Messner at Motorcycle Metal when I was ready to start suspension, and I finally made that call last week. The plan is to go with Ohlins piggyback shocks in the back, and some upgraded internal components in the fork. If you aren't familiar with the FXDX fork, from 2000 on it's a Showa cartridge design, not a conventional damper rod system. There is basically nothing in common inside. I knew I could change springs and fluid, but I didn't know there was anything else I could do with this fork. Howard informed me that Ohlins makes a kit that includes rebound and compression pistons, with pre-assembled shim stacks which get installed inside the cartridge assembly. So that's the plan up front... Ohlins piston kit and springs, overall fork refresh, and a lighter weight oil.

I've honestly been nervous about getting into the forks. I've always had a vague notion that suspension was filled with some sort of black magic stuff that only people with wizard hats fully understand. I was initially thinking that I may send the forks to Howard and let him do it, but talking with him instilled some (some) confidence. I already knew he's a bonafide HD suspension expert (maybe with a wizard hat), but I learned something else talking with him: He's extremely patient. I told him I needed all of this in really simple, basic terms. I've adjusted sag and played with external settings, but that's it when it comes to suspension. We've had two lengthy calls, and he's really broken everything down for me well.

So tonight I started disassembly.

Before taking anything apart, I took lots of detailed pictures and measurements... Hopefully I didn't miss anything I'll need later.

https://cimg2.ibsrv.net/gimg/www.hdf...a1dc79faa5.jpg

With the wheel off, I cracked the 8mm bolts at the bottom of the forks, but didn't remove them. These secure the cartridge in the lowers. with my fork brace still in place, the lowers couldn't rotate. I thought this may be easier than futzing with them later. Then I dropped each tube down between the trees and re-tightened the lower clamps. This allowed room to crack the fork caps with the tube held tight. Maybe unnecessary, but I thought it would make disassembly easier when I'm ready.

https://cimg4.ibsrv.net/gimg/www.hdf...3768a2f4fb.jpg

Next, I took apart the trees/steering neck, as I'm planning on replacing the bearings and races while things are apart. Looking at what I found, this was a good plan.

https://cimg8.ibsrv.net/gimg/www.hdf...58f577450b.jpg
https://cimg6.ibsrv.net/gimg/www.hdf...127c93c8d2.jpg
https://cimg9.ibsrv.net/gimg/www.hdf...0636de1f47.jpg
https://cimg0.ibsrv.net/gimg/www.hdf...1ccccb1805.jpg

The gauges came fully apart tonight too, as I'm going to do something with them... Either replace with something entirely different, or a clean-up and LED upgrade. Not sure yet.

https://cimg3.ibsrv.net/gimg/www.hdf...8d0b0eda7c.jpg

It kind of looks like a mess, but all the loose bits are properly supported with pieces of wire, there's no kinking or stress on the brake lines, and the bars and other finished surfaces are wrapped in bubble wrap.

https://cimg5.ibsrv.net/gimg/www.hdf...e683e53b5f.jpg

Two and a half hours later, everything from the front of the bike was organized and bagged on my bench. Now I need to take stock of what needs to be included in round one of ordering, and make some powder coating decisions...

https://cimg0.ibsrv.net/gimg/www.hdf...1df2404e28.jpg

This should be a good thread ... Good info on those Ohlins Kit ... I knew Race Tech offered a compression valve for those cartridges.

Continue on :)

https://cimg3.ibsrv.net/gimg/www.hdf...c89d2e0cf5.gif

A little late for you now but maybe it could help out others in the future. When we remove forks from bikes we measure from the bottom triple clamp to the axle center not whats sticking above the top clamp. The reason for this is everything is built to a certain tolerance. You could get slightly longer or shorter pieces especially in springs. So after you change out all the internals your forks could be slightly different lengths then what they were before even different lengths from each other. I'm not talking inches here but possibly a few mm. If you have the number from the clamp to the axle you can return the forks to that same number and not affect the ride height and the handling as far as geometry of the bike. What sticks above the clamp, sticks about the clamp and has no affect on the bike.

Makes sense... I may have that measurement written down somewhere. I'm not positive, but I may have recorded that last time I measured/set sag. I'll look for it...

I wouldn't sweat it too much after the fact if you dont have the measurement. It's just one of those small details people that aren't familiar with this type of work miss. I can recall doing the same thing many moons ago before I started working at my friends shop. I'm hopeful to get my front end done this winter as well. The plan is cartridges by GP suspension and finish off the dual disc conversion.

Question on powder coating the upper and lower trees... This would never have crossed my mind, except I had a minor issue with a shift lever last year. After powder coating the shift lever, it no longer tightened properly around the shaft. I had to make a sort of shim to tighten it fully. It seemed like the coating didn't allow the aluminum to move enough for a secure fit.

Should I be concerned about any similar outcome with the pinch areas on the triple clamps? My guess is that it was only an issue because it was a smaller, more delicate part. I know I've seen plenty of coated trees, but sometimes I just worry about stuff...

Yup, my PC shop does a great job masking everything... No concern there. My concern is whether the coating will reduce the needed flexibility of the pinch points. That's what seemed to happen with my shift lever. It seemed the amount of force that would have been required to "close the pinch" and achieve a tight seal would've stripped the threads out of the lever before it was tight... I'm probably being unnecessarily paranoid, but it isn't a problem I want to encounter in the trees...

Next question (I'll have a million): Anyone have thoughts between OEM fork components vs. this kit from James Gaskets (or any other one out there)?

https://www.jpcycles.com/product/220...al-rebuild-kit

Not wondering about pricing differences, just quality/functionality. I've found in general that some specific gaskets are best from the MoCo, whereas others are better from Cometic or James. Having never done forks, I have no idea what the brand-of-choice is for this...

Thanks!