Well the reason why I thinking that there is something wrong with the front end is that from what I see, using the nighttrain front end has likely decreased trail some. If you look at the parts list for 2000 softails, the frame and swingarm are the same but the trees and forks are different. The FXSTC is 64.5" and the FXSTB is 66.9".. You mentioned that the nighttrain (FXSTB) forks are 2 inches longer than the your FXSTC.. Well the FXSTB wheelbase is 2.4 inches more and tubes only increase between the 2. It can't all be forks. After all they don't point straight out. HD added rake to the trees and some offset to get that extra wheel base. If you were to simple swap the 2 front ends including the wheel you might have been OK but,, You installed the forks on heavier bike that likely caused the front end to squish down a little more. You use a 16 inch tire that is 2 inches smaller in diameter plus added a bunch of mass with the fat boy wheel.

It's possible that the changes you make may not have caused the bike to wobble right off. Something else may be a little looser like swingarm bearings or wheel bearings, fork or whatever to bring out the wobble but I'd agree with you mechanic saying it it likely the front end being the root cause.

 

I may have caused some confusion with my sig line. I put FLSTCustom... because after the modifications, it's really not a pure FLSTC anymore but it did start out life as a Softail Heritage Classic, not a Softail Custom. There may be some variations in the data you pulled up to show me.

According to the info you shared and I wasn't considering, it's not just the length of the forks but the additional weight and more angle loss from the reduced tire size. That was one of the reasons I had originally thought that the progressive springs might be a little stiffer and help with what feels like a "soft" front end.

I had been hoping that maybe, just changing the rear shocks back from 1" drop to OEM might resolve the rake issue... but that likely wouldn't work as it wouldn't resolve all the issues that came on with the new front end. Might help though?

Damn. I'm in no position to afford another front end and I've really come to like mine... but I have to think, 1 guy pointing out a problem is an opinion. A couple, unrelated guys pointing out the same issue is a consensus and something I really need to consider.


Damn! Quite a loss for all the time and effort over the years to get this thing setup the way I wanted it... but this problem is really sucking the joy out of my riding.

Thanks for the valuable input. Sounds like I really do need to consider swapping out the front end, again.

 

One thing that I've learned is that what you think will fix a wobble and what really fixes can be 2 different things. If you like the way the bike is and are willing to mess with it, trying heavier springs should help. I would also go to heavier fork oil in the front. The springs will give more rake by lifting the front end. Both springs and heavier oil will get rid of some of the floatiness of the front end.

Raising the rear in theory, would decrease rake and trail in the front end and might make it less stable but,,, I've seen going from a progressive lowering shock to Works taller shock actually make the bike feel more stable. I really don't know if it was the change in chassis geometry or the fact that the damping on the works were much better.

I would try spring / oil first in the front and see what it does then try the back.. Hopefully you can find a set of rear shocks that are cheap or can be returned if they don't help.

 

I do have have a set of Works kickin around the garage.

 

yea... I've been figuring that one out myself. damn frustrating problem but good to know it's not just my own ignorance.

yea... it would be a damn shame to change everything I've done to it to get it setting where I'm most comfortable. the biggest reason I keep trying to hang on to this front end is that my *** is still sitting comfortably in my Corbin Gunfighter & Lady seat but I'm dragging my footboards a lot less when cornering... or at least, I was before I started getting nervous about the wobble coming on at 70 mph in the corners.

I was also re-thinking the whole setup and it occurred to me... the forks may be 2" longer/taller but the drop from a 21" tire to a 16" should minimize the overall rake gain. 21" - 16" = 5" / 2 = approx. 2.5" Or am I just totally off here?

I think I'll have to try the progressive shocks and heavier oil, as suggested and cross my fingers. If nothing else... if I have to go back to a closer to OEM front end... at least the new shocks will help re-sell the set I have now.



appreciate the though tommyglide but I'll have a few things to try first.

 

You math is way off, geometrically... Also what is getting you trouble are the fork trees.. Longer tubes should have helped but the trees likely add rake to the fork tubes. Adding rake to the fork tubes without adding it to the frame, takes away the trail.. Too little trail is you issue.

https://www.rbracing-rsr.com/rakeandtrail.html

 

I will admit... I've always had a mind for artwork and literature and struggled with math. I took an AAS in Auto-Body a million years ago but painting and body repair came much easier to me than re-aligning a frame. I appreciate the correction and the info MH. I'll read on through that link.

If I'm reading your recommendation right, it's entirely possible that a different set of triple trees with a closer too stock rake could resolve the issue, without a need to redesign my front end? Assuming that rake correction brought the tire in closer to the frame, it would also lift the front end... more inline with what I've been thinking all along, not realizing the difference in the rake of the triple tree itself?

I know... sorry man. Just trying to make sure I'm visualizing this correctly.

 

Well, I would class different trees as a redesign..

When selecting trees, you need to look at 2 things.. Rake and offset from stem.. Both rake and offset effect trail.. Rake is more important tho. I don't have any measurement for nighttrain or heritage forks so I'd not sure what is needed to correct it but removing any tree rake and decreasing offset will increase trail.. And as you say decreasing rake in the trees will lift the front end of the bike. This will also increase neck rake which is a good thing.

One thing to note is that doing so will also slow steering, make parking lot steering harder and require more force to turn at high speeds.

 

You have to approach this systematically, it's a process of elimination compounded by the fact you have swapped in pieces not made for your model bike. If it were my bike, first thing I would do is work through all the common components for spec. I'd start at the swing arm bushings, as Harley's are notorious for speed wobble when those are worn, then check the neck bushings for tightness and I'd also replace the tires. If you go through all the common fault areas and they are good, then it may be a component you put on the bike. The only way to determine that is to swap it back out with a stock unit that is made for the bike. It's not going to be quick and easy....

 

well... I'm a complete moron. I'm quite embarrassed... but being a long time forum user, I feel the compulsion to finish this thread up in-case someone searches for similar problems and finds it.

I'm not exactly sure how but I do have a suspicion of why. I've been chasing this issue around the bike since I got back from Sturgis '15. I took it to a friend who did a lot of things to it and never got a receipt to remind me what was done and what wasn't and/or why, I made some changes and chased it again... but somewhere along the line, it got fixed and I don't know where. I think it probably would have been tightening the forks at the neck. So the question is... why, if that fixed it... didn't I feel the benefits immediately?

Bottom line. I checked the tire pressure today after repairing my air compressor. I had both the front and rear Dunflop E3's set at 32 lbs. pressure. My eyesight has been going to **** lately so I got a magnifying glass out and read the tread. 42 lbs cold recommended. I damn near slapped myself in the head.

Aired up to 42 and took it out for a spin with my Pops chasing on his Chopper. Took it up to 105 in the straights... smooth and straight. Took a fairly mellow corner at 90-ish and she stuck like an arrow.


For some stupid reason... I've had 32 lbs. pressure stuck in my head. I'm not even sure where it came from but it's obviously wrong. I can only assume at some point, I did this to myself, prior to the neck adjustment and didn't realize it was fixed. I didn't even focus on the tire pressure as an issue. Been running around this problem so long now, I missed to forest for the trees.


As all good trouble shooters know... when all else fails, get back to the basics and when in doubt, check it out. Thanks for the education fellas. Great info and learning experience for me... both here and on the road. You can bet your *** I won't forget that 42 is good and 32 is not. Not after this.