Extended fork tubes

[fredintoon]

I put a special front end on a standard, useing the the standard triple trees, it raked it out some. not sure how much, short shocks on the rear, i am thinking about putting 4" over tubes on it, this thing rides ruff because of the short shocks but it handels just fine, the rake did not hurt it as much as the short shocks, 11 inch schocks. - - -

Hi Bob,
that's fine as long as you understand that you will be changing the bike's steering characteristics by doing it.
And watch your terms, eh?
Swapping Special legs into your Standard's 'trees did NOT change the frame rake.
It's still at the 29.5º it left the factory at. The only way to increase it is by cutting and welding.
The rake can be decreased by the ol' TC trick of driving the bike into something but I wouldn't recommend it.
What you did with the fork swap was to decrease the trail which lightened up the steering.
Going to longer fork tubes will tilt the frame backwards and thus increase the effective frame rake without changing the neck angle.
This will increase the trail to kinda reverse the decrease you got with the fork swap.

[bikerphil]

I've tried the Special tubes in the Standard lower legs before. After slipping them in on the bench, I noticed that they were binding up pretty good, so I scrapped the idea. It may be possible to remove the lower slider bushings from the Special's fork tube (Standard's tube design doesn't have any) and run it that way, I didn't try it though. There is a member on here, can't remember who, that has done this mod, but I don't know the details.

[Eveready1100]

Me???

Might be me you're talking about. In desperation to get my bike mobile again after local Yamaha dealer repeatedly stuffed up my fork seal order, I fitted the Standard fork sliders onto Special tubes and ended up with 100mm overstock forks. I minimised the length issues by making up some bar risers to get them back out of the way and slid the tubes 100mm up through the triple clamps though if the chopped look is your bag, this is an instant fix.
Didn't have any issues with binding though all the matching internals from the standard sliders had to be used as the damper rods have different bolt sizes to the Specials. You must also use the Standard's speedo drive and cable as they have different lugs to mate with the sliders.
So basically, if you want to do the swap, everything from the dust seals down must be swapped over including the guard.

If you look closely, you can just see the fork tubes raised way up through the triple clamps.



I do have some other pics somewhere but that's all I can find at the moment.

Here's a link to the original story - http://www.xs11.com/forum/showthread.php?t=20283

[Deathdeelr]

So if I wanted to go 6" over on the fork tube length, to keep the bike stable I'd have to extend the frame down tubes and angle the head tube out to keep the bottom frame tubes level with the ground. I'm dragging my feet on rebuilding the forks until I decide what to do. What I'm actually talking about is making a chopper from a fairing'ed Standard.

In addition, with the extended fork tubes, I'd have to make a spring spacer the same length of the extension (6" over on the tubes uses a 6" internal spring spacer). Yes?

ALSO, while I'm thinking out loud, if I change the angle of the head tube a few degrees is it possible I may run into interference with the gauges/top clamp and the fuel tank? I'm thinking no more than 7 degrees over stock.

I put 5 degree trees on my Warrior when I had it and had no interference problems but I had T-bar's on it with the stock gauge panel (which is tiny in comparison to the Standard). BTW, the trees took a lot away from the maneuverability as opposed to an all out chop.

[Eveready1100]

Just a further comment on my experience with the fork slider swap. Between fitting the frankenforks and making up the risers to shift the handlebars out of the way of the tubes, I did use my bike for a number of trips to work (about 30 klms) sans speedo. I was just careful. The forks had lifted the front of the bike some and when on the sidestand, it was on quite an angle, which in my case, caused some moments with parking etc. mainly cos I'm a shorta*se at 5'8" compared to most of the rest of the XSowners who seem to be all 6" plus, which to them probably wouldn't have an issue with it.
On the road, the bike tracked just fine and still felt about the same when being flicked into the twisties to which I have a particular liking.
In Deathdealr's case, I wouldn't go chopping the steering stem about before just giving it a try as is before the surgery. It does have a nice raked look with the frankenforks on it and depending on the bars chosen, should look agreeably chopped. To add to the image, I'd try to score a 16" rear wheel off a special which would lower the rear some plus give it that fat rear look that also goes with the look. I found that XV1100 virago shocks bolt straight on and are about 3/4" shorter that stock XS units.

[Deathdeelr]

This is why it's so nice to have a lift in my shed. I can mount the bike and use some ratchet straps to lock it down to see what a drop might look like, how it effects the clearances for dragging pipes, etc. Once it gets so bitterly cold that I wont ride I'll start this project and start taking some measurements before I start cutting.

[crazy steve]

So if I wanted to go 6" over on the fork tube length, to keep the bike stable I'd have to extend the frame down tubes and angle the head tube out to keep the bottom frame tubes level with the ground...

There's multiple ways to set up extended fork tubes, and they all have their pluses and minuses. It has more to do with how you want the bike to look but there are handling consequences with each choice.

Simply installing longer tubes with no frame/tree mods won't change steering except the bike will now be top-heavy. Some people install raked trees to help bring the front down (semi-popular because no frame mods are needed) but with a stock neck rake this can reduce trail to a dangerously low amount and seriously effect high-speed stability. Nearly all of the major retailers don't sell raked trees because of this. NOT recommended unless you have a death-wish...

Just raking the stock neck with no other frame mods is the next-easiest method, but now the trail number gets rather large and possible interference between the trees/bars and the tank show up. Big downside to this is low-speed steering gets very slow and heavy and your turning circle is now about the same as your average motor home. To get the bike back down to level with 6"-over tubes, you'll need a bunch of rake; somewhere around 15-20 degrees over the stock 29. This the one legitimate use for raked trees; they can reduce trail back to a reasonable number and improve steering effort.

Extending the down tubes and frame backbone (effectively raising the neck) is probably the best method, but this will change the 'look' of the bike and is a bunch of work. This is some serious frame mods, so first-class welding/fab skills are called for.

I've done this (although not on an XS), so I'm very aware of the pitfalls. Here's a pic of my chopper...

http://www.sportster.org/members/cra...zysteve-5483-1

While it has the 'the look', this bike steers heavily and slowly and isn't much fun at slow speeds. While it's stable at higher speeds, manuverability is terrible. These are only 4"-over tubes by the way and it took an additional 20 degrees of rake to bring the bike level. This is not my 'daily' rider; I have a stocked-framed bike I ride mostly. This is for shows or short hops only...

[Deathdeelr]

So now I'm thinking less on the forks to keep the angles down. The consensus seems to be that the "frankenfork" mod gets you a few more inches on the fork without spending a million bucks. That being said and if I understand correctly, when I set this up I'm shooting for as small an increase in trail as I can manage no matter what the angle is to get the bike back to level. This will keep the bike somewhat manageable (forget parking lots...) at low speeds without being top heavy. Do I have that right?

BTW, the bike is not so much daily but definitely weekly driver. I do long rides and am rarely on her for less than 45min to an hour between stops. My commute is over 60miles each way and I'm about 70 miles from my STAR chapter's home base in Brooklyn so even though I don't want to lose the maneuverability, it's stability at 70MPH I'm after more.