Forks

[Nauga Mok]

Does anyone know if we can switch out the fork tubes on FLHs to the tubes the Soft Tail uses. According to the JP catalog, the ST tubes are 2" longer than the FLH's. I know I've read there are "fork extenders", but I got a REAL bad taste from extenders back in the '60's. Granted, back then they were using anything from 4" to 12" "slugs" as we called them then & there was a real problem with breakage. I realize 1 3/4" is a LONG way from 12" & MAY be safe, but I'd rather change the tube to the right length. If this works, it'd eliminate buying sliders too like with the swap to triglide forks. I don't think a 1/4" extra length would cause any problems -- should be better than 1 3/4" too short. <br />
<br />
NM

 

[ultraboy]

I've seen this done successfully before, but I can't remember if there was anything special about it, other than fork stop do-nuts, or lack thereof. If you use TG trees, the stops are built in, so the do-nuts are not required. Check for positive stop contact, fork lock function, and lock to lock travel and clearance. Remember that a trike 'fall away' will be about twice as stiff as a two-wheeler. Aftermarket FL ST type 41 mm softail tubes are cheap and plentiful and available in just about any length. Sounds like a plan.

UB

 

[Nauga Mok]

The only concern I have with the longer tubes is spring length. Might have to put a 2" spacer on top of the springs to keep that length right. Seems I read when adjusting the fork "fall away" on trikes we want 1 swing instead of 3. I checked that on the bike when I put on the painted inner faring. With all the weight (radio, outer faring, running lights etc) off, I was getting 4 swings & thinking "OH CRAP!" When everything was all back together, it had the reccomended 3. I assume this will also be something to watch for at the tighter setting? Thanks fo rthe pointers!<br />
<br />
NM

 

[ultraboy]

NM, I'd go for longer springs. I would also tighten up the fall away a bit as well. I've been setting them a 1 swing or a little less with nothing on the trike front end.

UB

 

[Baz]

NM, I'd go for longer springs. I would also tighten up the fall away a bit as well. I've been setting them a 1 swing or a little less with nothing on the trike front end.

UB

I'm busting to know what is this fall away you talk about ?? Please. Baz

 

[Gorilla]

When I did my Liberty Side Car trees they stated 1 swing. I've had no issues at that setting.

 

[Nauga Mok]

Baz, "fall away" is checked by jacking the front end up so the front tire is off the ground. Turn the front fork all the way to a stop -- either side works. Rrelease the fork & let it swing straight by it's own weight. Count the number of swings it makes to one side & back. My ultra calls for 3 swings, so starting with the fork all the way to the left, it would swing righ, left, right & stop. On trikes, starting all the way left, it should only swing once to the right & stop &not make a swing back to the left. As snug as this setting is, the fork can swing past straight, stop & hold at that stopping point even though it isn't straight. This is where I want it set once I get the trike conversion done. Basicaly, it's adjusting the "preload" on the fork bearings so there isn't any slop in the front end and add a bit of resistance to the turning effort to control front end wobble. Anyway, that's the way I understand the process.

If I'm wrong, I'm sure Wiz or UB will set us straight. <br />
<br />
NM

 

[Nauga Mok]

Longer springs -- like ST springs? Either way would work, but now that I think about it a bit, the longer spring would be preferable. 1 swing with bare fork, Ok. From stop to approximately straight or a bit past straight? The realy cute part of this is I lowered the front end 1" at the start of the summer, so now I have to switch back to stock length 'till I can get longer tubes. Good thing I didn't throw away stock dampers & springs, huh?<br />
<br />
NM

 

[Baz]

<div class="bbcode_container">
<div class="bbcode_quote">
<div class="quote_container">
<div class="bbcode_quote_container"></div>

<div class="bbcode_postedby">
<img src="images/misc/quote_icon.png" alt="Quote" /> Originally Posted by <strong>Nauga Mok</strong>
<a href="showthread.php?p=22513#post22513" rel="nofollow"><img class="inlineimg" src="images/buttons/viewpost-right.png" alt="View Post" /></a>
</div>
<div class="message">Baz, "fall away" is checked by jacking the front end up so the front tire is off the ground. Turn the front fork all the way to a stop -- either side works. Rrelease the fork & let it swing straight by it's own weight. Count the number of swings it makes to one side & back. My ultra calls for 3 swings, so starting with the fork all the way to the left, it would swing righ, left, right & stop. On trikes, starting all the way left, it should only swing once to the right & stop &not make a swing back to the left. As snug as this setting is, the fork can swing past straight, stop & hold at that stopping point even though it isn't straight. This is where I want it set once I get the trike conversion done. Basicaly, it's adjusting the "preload" on the fork bearings so there isn't any slop in the front end and add a bit of resistance to the turning effort to control front end wobble. Anyway, that's the way I understand the process.

If I'm wrong, I'm sure Wiz or UB will set us straight. <br />
<br />
NM</div>

</div>
</div>
</div>Thank you. A good explanation I think.?? <img src="images/smilies/confused.gif" border="0" alt="" title="huh??" class="inlineimg" /> Baz

 

[Nauga Mok]

You think?? Did I loose you somewhere? I TRY to keep my explinations in simple terms, but sometimes I forget & get too technical -- occupational hazard. I did teach apprentices a LOT of years & that helped me in simplifying the terms. I must be at least close 'cuz Wiz or UB hasn't corrected me.<br />
<br />
NM

 

[Gorilla]

If you can not picture it, there is a picture of the swing pattern in the HD service manual.

 

[Baz]

No no a good explanation, just seems to me to be a very unscientific of carrying out a simple set by torque process, but hey what do I know.:no:

 

[Gorilla]

Because of how the tension nut is designed you can not put a torque wrench on it. You have to adjust the tension with a tool that has a hook in it and fits under the nut that holds the triple trees together. That's just the way it is designed.

 

[Baz]

Hmmmmm! don't seem to have any problems setting the preload on any of our machines. hence the question.

 

[Greydog]

When I picked up my Trike I asked my builder if I was going to need a steering damper. He told me not really as he had tightened up the steering for that very purpose. At the time I really didn't understand exactly what he did or how he did it....now I do....Thanx!!!!

 

[Nauga Mok]

Baz, it's like setting the preload on differential pinyon bearings where it calls for so many pounds resistance measured with a spring scale & string wrapped around pinyon housing -- no torque spec, just so many pounds of turning resistance. <snicker> Once saw a guy try to adjust this with the housing clamped in the vice instead of the pinyon shaft. Could NOT figure out why he had TOO much resistance -- EVEN WITH THE SHAFT REMOVED!! That got him the nickname of --- umm -- hmmm -- Probably shouldn't put that here!! Needless to say, the whole shop got a big laugh at his expence.

From what I'm seeing in the Harley service manual, we can't get a wrench on the adjustment "nut", but have to use a steel rod shoved onto a hole to turn it. Evidently a spring loaded catch in there. The top nut we can see when we first tear into it is a "jam nut" with a locking tab. THIS nut needs to be torqued to 60-80 lb ft after adjustment is made, but the actual preload adjustment is done with a rod 16" long -- 5/32" dia with a slight bend in it for FLTRs & 1/4" dia straight rod for all other Touring class. Book calls for "drill rod" -- I'll probably use a stick of 1/4" 7018 with the flux cleaned off. I might have a better explanation after all my parts get here & I get my hands dirty.

NM

 

[SantiagoChopper]

Does anyone know if we can switch out the fork tubes on FLHs to the tubes the Soft Tail uses. According to the JP catalog, the ST tubes are 2" longer than the FLH's. I know I've read there are "fork extenders", but I got a REAL bad taste from extenders back in the '60's. Granted, back then they were using anything from 4" to 12" "slugs" as we called them then & there was a real problem with breakage. I realize 1 3/4" is a LONG way from 12" & MAY be safe, but I'd rather change the tube to the right length. If this works, it'd eliminate buying sliders too like with the swap to triglide forks. I don't think a 1/4" extra length would cause any problems -- should be better than 1 3/4" too short.

NM

The tube of the FLH is 29" long, and softail is 31" with the same diameter. so you will have an extra 2" to work with. I suggest you apply a 6 - 7 degree triple tree with this as well. You will receive better control, and trail.

 

[Nauga Mok]

I finally got the 2" longer Soft Tail fork tubes installed on my Ultra Roadsmith. Makes quite a difference in steering. By my crude calculations, it reduced the trail another 3/4", but then too, I was 1" under stock, so in actuality I raised it 3". Other benefits are; it got the front up to where I can get a jack under the frame & adjust the headlight right. For the springs, I added 2" spacers since I wasn't sure the Soft Tail springs are the same spring rate as the Ultra. I noticed in the parts catalogs that Progressive uses spacers on several of their spring kits. Since suspension is their business, spacers must be OK. I already had the high performance valving installed. One thing that I'd do different next time is install 1" longer cans or spacer the stock cans down at least 1/2". When my front end is off the ground, the tops of the sliders are visible, but not when it's on the ground with the weight on it. Turned out costing about $150 for the tubes + new seals, oil, slider bushings & etc. I now have about 3,000 miles on the new tubes & they're working fine. Front end now looks like it was extended a LOT more than it was. Makes those stock length chrome sliders look like they're 10' long.

NM

 

[Gorilla]

Good job NM