Front fork conversion

[jesrec1100]

Hi I am new to the site and just wanted to say hi. Also I was wondering if anyone knows if front forks off of a 89 fzr600 would work on my 79 xs11 standard, Or what sport bike froks will.

[CatatonicBug]

Welcome to the site! Is there a reason you want to convert? You can rebuild the stock ones with internal parts, and even find used ones if you need them. What are you trying to accomplish by switching them out?

[bikerphil]

I think Snowdog51 has the FJ front end on his 11. Supposedly handles much better with adjustable damping. It should fit by making a spacer for the stem bearings. I've been thinking of trying this mod someday.

[50gary]

The easy way to check the compatibility of different forks is to check the bearings. If the inner and outer dimensions for both the upper and lower are the same the forks will most likely swap. The other dimensions is the length of the steering stem. For the record the XS11 is 9.25" LOA.
I have a set up that you may be interested in? I took an ebay XS11 triple removed the stem. Then had it spray welded to build up the diameter and precision ground to be pressed into a modern (2001+) R1 lower triple clamp. For the uppper R1 triple clamp I had a machinist bore two holes for handle bar risers so I could bolt on normal bars (Superbike) Then bought new tapered roller bearing (XS11) and viola the modern forks will bolt up. This means a 17" front (1/2 the weight) wheel and good tire choice. Super brakes from the R1. The down side is I haven't figured out how to adapt the cable driven speedo to the R1 forks, modern bikes drive off the trans. Some more machine work will be in order for sure. The FZR600 forks will be longer though the modern sportbike forks are usually only about 28.5" to 29.5" I'd post a picture if I knew how?
Cheers, 50gary

[xschop]

front fork swap

the Busa forks are awesome, but drop the front end by 3-4 iches....I looked at the Road Star Warrior forks and they are almost as long as the stock XS11 forks and are USD and come black anodized from Yamaha......these two forks can handle the XS11's weight without switching springs....

[jesrec1100]

My forks are pretty much shot and i am just wanting the benifits of less weight better brakes and handling.
Thanks for the great info 50gary, I am very interested in that setup you have there. That is awsome.
Also how much did the lowering of the busa forks effect your bike, chop.

[xschop]

the rear swingarm lowered the bike by 2-3 inches, so I have a good compromise. It handles like a dream and the brakes can throw you off the bike with pinky pressure. I had to move the XJ tank back @ 1" to get more turn out of the handle bars. The bike turns quicker and is way more stable at high speeds with the shorter front end. The forks are spread further apart than stock too and alot better tire grab too.....

[50gary]

Jesrec1100, that's the bug-a-boo about short forks, you lose most of the required ground clearance. If you can't lean much the best handling forks aren't much good. The better way would to de-rake the head tube thus making shorter forks act longer by being more vertical. This is major work. The XS11 has nearly Harley like rake. I like the Warrior idea. Your FZR idea is also cost effective they are however damper rod forks not cartridge forks. By the way, R1 or R6 calipers are a direct swap to the stock FZR600 calipers. The FZR wheel (3.00" x 17") is also a better match for the XS11 rear. Standard sportbikes a use 3.5" x 17" front wheel.
Cheers, 50gary

[xschop]

leaning

I can lean far enough to turn this beast quick enough. I have plenty of ground clearance because I have 2-1's on each side mounted high up.....I designed a set of fork extenders ahead of the swap, but found I liked the quick handling of the Busa forks just as they were installed......

[50gary]

Shorter forks decrease the rake angle, puts more weight on the front end, and decreases the front part of the wheelbase. The modern tire will also make a quicker turn in lwith a lower profile. The sportbike triple clamps have much less offset than the stock XS11 this quickens the steering alot. The wider forks spacing will slow the turning a bit but that can be regained by narrower bars at a loss of leverage.
Cheers, 50gary

[jesrec1100]

Hey chop,

How hard was it to put those busa fork on the xs11 frame. I like the sound of quick handling. Also how did you lower the rear? I noticed in past threads that you have donr the R1 mono shock mod, is that what lowered it.

[xschop]

Not Hard

You need to take a 30x48x15 taper bearing to a machine shop and turn off 1mm from the outside diameter of the race to make it a 30x47x15 bearing for the top tree bearing. The Stock XS11's bottom bearing fits the BUSA tree.....the whole front end drops in from there.....even the ignition switch housing swaps right over.....As for rear end. I put on a rear that extended it by 4-5 inches from stock. So the handling is superb......
http://www.xs11.com/forum/showthread...chaindrive+mod

[jesrec1100]

All I can say is WOW. That is a very nice setup you have there. Thanks for that bearing size too. Is there any site I can check out to see more sizes of other bikes to see what I can possibly use.

[oldyam80sg]

XSChop-is that the bike with the ZRX carbs?How is the 1/4 mile times if you are into that sort of thing?Beautiful job on the forks!

[chrisso]

GOOD INFO GUYS!!
Im looking at early Busa front brakes but now may go with the whole front end. How would I go with spoked rims?? Spacers??....Cheers Chrisso