Installed a Race Tech front end kit (with Gold Valve cartridge emulator and fork springs) this afternoon ....

As some of you may be aware, I had previously removed the stock '05 FXDI front end with 39mm fork tubes in narrow glide triple trees (with the unibrow 'headlight visor') and installed a take-off '02 FLSTF (Softail Fat Boy) 41mm front end ... it made the tear down and reassembly a little more time consuming as I had to remove all the fork tins and passing lamp regalia ....

I had gotten the kit a couple of weeks ago and started doing a little research before installing ... for example, the kit instructs the installer to drill 6 holes in the base of the damper rod ... after researching the stock FLSTF damper tubes, I concluded the stock damper tubes have 6 holes in them approximately in accordance with the instructions (I deemed it unnecessary to remove the damper rods to measure the holes ... saved a little time on the install) ....

Also, the kit includes adapter rings for use if the damper rods have 'flat tops' vice cupped top .... I figured once I removed and drained the fork tubes, I'd look down in them with bright light and see if they were flat or cupped (turns out they were cupped ... the instructions note the flat top tubes are very uncommon) ....

On the advice of a Ducati mechanic who does a lot of front end builds and reported having done quite a few HD Race Tech kit installs (offered to do it for $100 labor charge) I used PJ1 Performance Fork Tuner 10 WT fork oil (PJH Brands, Scottsdale, AZ) .... The instructions describe how to use fork oil weight, valve setting, and fork spring preload as the variables to tune your forks ....

I had intended to (and think I actually did) order 1.00kg/mm rate fork springs, but the label on the box indicates 0.95kg/mm rate springs, so not sure if I screwed up my order or if they screwed up packing what I requested; but, I decided it probably wasn't that big of a deal since according to the online calculator on the Race Tech website, I would need just under 0.95 ... I had just wanted to go with a little stiffer spring rate since my initial problem was fork bottoming ....

Another little 'work around' I ended up doing was in measuring fork spring preload spacer ... I didn't have a tape measure (doing the work at the Army base MWR Auto Shop) so I just laid out the stock springs in a clean space and then laid out the Race Tech parts next to it ... then added about 1" or so to the stock length springs for a little extra preload and cut the spacer material (aluminum tube) with a tubing cutter .... I used the first spacer to measure the second spacer ....

The fork oil quantity for my year's FLST forks is 11.5 oz wet and 12.5 oz clean/dry ... I got the tubes pretty empty -- let them drain quite a while, so I used just a shade over 12 oz ....

So, I only have about 5 miles on the ride back from the Army base ... I plan on putting about 100-120 miles on it this evening and will post a follow up ride report later tonight or tomorrow ....

Considering how difficult it was to get the tubes back together (I was near the upper end of the recommended pre-load), I was a little surprised at the give when I first sat on it after finishing work ... but, I figured if it needs further adjustment, I can get to it later ... then when I rode out the front gate, there's a pretty bad stretch of highway ... didn't think much of it until I got about half way down that stretch and thought to myself: 'wow, I usually get beat up pretty bad on this road ...' So far, it doesn't seem like night and day, but it is quite an improvement ... just subtle since it is taking away the harshness I used to experience I suppose ... will post more later ...

R/
'Chop

p.s. I noticed that the Race Tech kit for the newer Dynas with 49mm fork tubes does not have a choice of spring rate ... comes with progressive rate springs that range from 0.60 - 1.10 kg/mm (as I recall, I may be off a bit) ... not sure why they have a different regime for the 49mm forks ....

 

I've used the cartridge emulators and the difference is incredible. Last time I looked they were not available for the 49mm forks. I'm glad they are now.

 

You need to drill the damper tubes to allow the emulator to work properly.
CB

 

FYI I do hope you cleaned up all interior parts before assembly. The inside of your fork tubes are caked with a film of powdered metal from the springs previously rubbing against the inside of the fork tubes. Once I edit my DIY film hosted on my site, I will demonstrate how to properly clean your forks. If you have had your forks apart you hopefully should have examined your bushings for wearing of the Teflon coating against your fork tubes. With looking down the fork tubes indicated to me thast you did not take it apart. It is your bike however.

There are a few other things I would reconsider IMO.

1. Read the instructions again and drill out the seat pipes/damper tubes to the hole size specified. This takes the original damping/rebound out the the circuit. You are using the emulator circuit only.
2. Pre-load spacers: Install the springs, measure the caps than measure from the springs to the top of the fork tubes. Subtract the thickness of the fork cap (threaded part to the "seat") than add 1" to start. Make sure the forks are fully extended and use the washers on both sides of the spring as the spring turns as it compresses/extends. The spring preload spacer length can be tuned/changed which will do the same thing as the adjuster (blue) on top of these fork caps (below).
3. Fork oil level: Again, you should have cleaned the forks out first by disassemble. The fork oil level should be checked/set by a tool like this with the springs out.
4. The level of the oil directly affects the air spring which controls how your forks stop just before bottoming out. Raise the oil level to adjust for more resistance just before the forks "bottom out".
5. Fork oil weight: Controls how the forks move. The Racetech system should not be confused with stock (OEM). The compression is controlled with either opening/closing the valve plate or by using different weights (shown in color) springs (provided). With the changing of *Oil Level, *Oil "Weight"/Viscosity, main spring rate, and emulator adjust by both spring weight & valve plate adjustment the chartists of your suspension can be changed. For the money, this is a very good choice for upgrading your front suspension. It is work to do this changing, if you are prepared than do so.
6. You may wish to reconsider the offer your Ducati mechanic made you. What ever you do, the time I took to make this post was to help you . I do not think whatever you do will effect me so this is only advice to guide you.

 

Isn't that what I said, just a little less detailed.

 

No you did not cover all problems I had noted above. I tried to help him out in his install and cover deficiencies he overlooked. OP you may discard any and all above information as it is your bike.

 

D@mn I hate when I take 20 minutes writing a post and time out and lose it all ....

Howard - thanks for your expert advice ... comports with exactly what the Race Tech instructions say ... I did not anticipate the holes in the damper rod would not be adequate to 'take them out of the equation' ... but, I think I'll have to end up removing them and reaming them out 'to spec' ....

Howard - can you comment specifically on my method of 'swag' (scientific wild-*** guess) for measuring my preload spacer based on stock spring length ... I used the gold valve, washers and new spring in the measurement ...?

My facility places significant time and resource limitations on what I can do, so I tried to take 'short cuts' where I thought it might be possible ...

 

Based on about 50 miles I rode last evening (didn't get as much time in the saddle as I wanted) I think I will need to (i) 'ream out' the damper rod holes, (ii) cut the preload spacer down about 1/2" and (iii) add about an ounce of fork oil per tube ....

Feel of the small stuff, grooves and smaller potholes seemed to be pretty well eliminated ... which I understand is attributable to the gold valve ... if I had opened up the damper rod holes, I think it would improve this feature (by 'removing' the working of the stock damper rod tubes) ....

Still felt the bumps quite a bit ... I think there might have been some improvement ... I'll have to ride a little more to get a better feel ... I think if I remove a little preload that would help this ... to offset this and in particular with regard to my bottoming concern, I think adding a little fork oil would address this issue ....

R/
'Chop

 

Cutting pre-load spacer to get the proper sag:

*with your 0.95 springs in please raise the wheel off the ground and measure between the top of the slider and bottom of the bottom triple tree. Write it down.

* Have your forks still together lower the wheel and have a friend hold the handlebars than sit on the bike with feet up just like you were riding it. NOTE* If you are setting it up for 2 up than have both of you on the bike.

* Have crew person #2 measure from between the top of the slider and bottom of the bottom triple tree. Write it down.

Keep on cutting the spring pre-load spacer until you get 45 mm of total sag on the front forks.

Air Spring:

The higher up the fluid is in the tube the more stopping the compression exerts once near bottom-out occurs. The resistance goes up quite a lot with each 10 mm the fork oil is raised. You do not use thicker oil to adjust bottom out. You use the internals to control the rate of stroke/action (how fast and with how much resistance force) is countering the movement.

 

I've got the Gold valves in my Train front end with -2"springs and tubes.On my bike the ride was vastly improved.It glides over most rough stuff instead of the harsh slamming the stock front end made.It did take taking it apart 3 times to adjust preload and putting all 6 holes in.I'm impressed with the ride seeing my front end sits at-4
" overall.Worth the money to me for the valves.