03 busa rear shock on 99 kat 750

[Sleeper_cell]

So I orderd a 03 busa shock the other day and it came in the mail
Yesterday.
Liked the stock shock on my kat but wanted to change it up
A lil.
Well as u know the busa rear shock is not a direct bolt on
So a lil grinding n cutting is needed.

The battery box has to get cut a inch or two
To fit the busa shock and cut the tabs off the battery box to slidr
Ur battery back.
U also need to use the stock t arm? (bolts up to shock, links, n fram)
U will have to grind down the t arm a lil so u get the
Clearance to fit the busa shock.
Now that the busa shock is bolted on
It will lift ur kat a lot
So loweing links is recomended.
I love the way the busa shock feels
Smooth and lots of adjustment can b done.

I will post pix asap

[Tmod]

This is strictly my opinion, Don't do this mod if you are thinking it is a good idea.

(1) Regardless the spring is still not correct unless you are 130lbs

(2) The valving is not correct for a kat

(3) It raises it so high that it really screws up the geometry

(4) With very little suspension compression the chain will ride on the plastic block on the swingarm and wear it out.

(5) If the OP is referring to the t-arm as the lever (Don't ever grind a lever, Do you really want a suspension failure when heading down the road doing 80+?)

(6) You have all this adjustment but do you know what to do with it? I have seen more suspension setups screwed up by riders that really don't know what the suspension is actually supposed to do.

(7) Not only did you have to mod to get the shock in there now you need to get lowering links which is another failure waiting to happen, The Hayabusa shock has alot more shock travel than a kat shock and now you used links to lower it, You did nothing to reduce the travel of the shock but you did bring the tire closer to the fender, What happens when you have 5" of clearance between the tire and the fender but have 6.5" of suspension travel? Damn right you tire is driven into the fender and it will want to stop. Imagine hitting a bump at 80 MPH and it compresses the rear enough to drive the tire into the fender, Stops the rear from rotating and you never expected it.

That is all the reasons I can thing of at the moment, If you feel that it is a great mod then by all means post and I will be more than happy to discuss the advantages of this mod.

I did not post this to crap on the OP's thread, I just don't want to see mis-informed riders getting hurt.

Tmod

[datdoood]

Thank you TMOD I have also just purchased a 07 Hayabusa rear shock and I am going to put it right back on ebay!! thank you for the info!

[datdoood]

hey Tmod I have a question I am 175lbs 5'10" I have both a r6 shock and a hayabusa shock. I am wanting to put a hayabusa swingarm on my 91 kat. I could not get the r6 to work right with the swing arm?? I seen the guy with the hayabusa arm and his thread said he used the hayabusa shock. Will I still have the same problems that the stock sa would have? I am just trying to get some ideas of what my options could be?

[ManQu]

BTW this thread is 18 months old.....

[maniac1886]

I have a 97 kat 600. I did the busa shock swap. i love it. It feels so much better on the Expressway. With the kat shock, I popped off my seat a smidge with every other bump. i live in Michigan, our roads suck. So.. I drive the eway for 50 60 miles to and from work every day weather permitting and it gets old bouncing all over the place. especially with my laptop in my backpack bouncing off me the whole time.. I put the busa shock on there and it feels like im floating!! I've had it to 130 on the eway and it takes bumps at high speed well!! I was concerned of getting popped off my seat by a bad bump or hitting a bump at high speed mid turn and getting air with the kat shock. Busa shock keeps you on the seat and the bike on the ground! You do have to grind the lever a little bit but not very much at all. Im no "expert" but the grinding i did, looked more like heavy scrathces than grinding.

**Things to understand with the busa upgrade***

You do have to cut the front of the fender off, to get the battery box back far enough. I took the metal hose clamps and ran them around the the frame and through the mounting holes of the battery box and clamped it down a couple inches back.

It throws your chain adjustment off. Adjusting your chain requires two people. One person to sit on the bike as to compress the swing arm and another guy to adjust the chain while under pressure. 1.25 inches while on kickstand WILL NOT WORK YOU WILL OVER TIGHTEN YOUR CHAIN My chain is at about 3.5 inches on the kickstand. (im 200 lbs, my girl is 150 lbs. I had to adjust the chain tension while we both sat on it.)

ITS HIGH. if you arent tall, dont put a busa shock on there... sure you can put links in but that has already been explained why thats a bad idea above. Im 6 foot tall, longish legs. Most my friends cant touch the ground on my bike. But its comfy to me,

The geometry changes greatly. I have my front handlebars lowered about 1 -1.25 inches. This takes some getting used to, puts ALOT of weight on your arms, especially 2 up. You will find that you will not be getting as low in your turns because your center of gravity is higher. It takes a while to acclamate, especially if you are a beginner and dont really understand the physics of the bike staying up.

The back tire does not come off the ground on the center stand. when i put it up on the stand, the bike only goes up about an inch and is still nowhere near going off the ground. Makes things a lil tricky when removing the front or rear wheel from the bike. more so the front. I used a cherry picker and scooped it up by the trees to pull my front tire.


These are all the downsides I have came across from experience. On here its easy to make it sound like a bad idea, but its just a setup that has a very specific set of people who would benefit from it. Being 6 ft tall, and not a small fella, the shock is great for me and my girl to go out riding. WAYYY better than that crappy kat shock.

[Million$]

I did the shock swop as well with no problemz.

[muddyjeepr]

I did the shock swop as well with no problemz.

Did you do it on a pre or post Kat?

[Million$]

Pre

[scottynoface]

I did the shock swop as well with no problemz.

Your bike is lowered and stretched, you wouldnt notice a problem with the handling because its already so bad.

[Kreylyn]

Just a general observation...

It's quite common for someone to post...

"I did it, works fine!"

... and nothing else. No details, no info, no description.

Then you find out they are talking about a massively modified bike, not the same bike, or... that they simply don't have enough information or skill or quite frankly... intelligence to know there is a problem.



There is a reason that companies that make vehicles do months and months of testing, track driving, and verification of how their designs work. Even the best drawn up plans by the experts sometimes do not work like expected in the real world.

I'd suggest that the suspension "expert" is probably the best person to listen to in this scenario... And while Tmod is trying to be gentle in his response about how it's probably not the best choice with out modifications to the shock to use one off a Busa... don't let that make you think any less of his information provided.

Just my $.02....

Krey

[Million$]

Not lowered. Just stretched.

[GSXFJim]

All that work and you could have just had T build a b12 shock and spent the rest of the time riding.
I'm 6-2 and i have a gsxr1100 unit on my '91, raised it up just enough.

[MEngineer]

Not lowered. Just stretched.

The longer arm helps to provide a greater force against the spring. Which helps bring the height down. Now everything else, that's a different story.

[Million$]

Just checking back here... any bad issues with the bus a shock swap on the post 98?