confused about rear shock switcheroo

[goosefartfan]

ragedigital, a.k.a., Darrin......

I saw your rear shock changeover, especially here: http://www.saltmine.org.uk/fzr/fzr-busa.html

What I want to know is how did it come out? How does it feel? Too stiff for the street?

there's something I am confused about:

(Assumption- OEM spring for both bikes is for a rider who is 150 lbs.)

Hayabusa 1300 = 560 lbs. wet. + 150 lb. rider = 710 lbs.
This is what the engineers want the springs to see.

FZR 600 = 443 lbs. wet + 150 lb. rider = 593 lbs.
This is what the engineers want the springs to see.

My weight with gear = 215 lbs.

So, for the OEM spring on the FZR, the spring is seeing 65 lbs. MORE than it's made for.
For the Busa spring on the FZR, the spring is seeing (593 -710 + 65) = 52 lbs. LESS than what it's made for.

Any comments???

thanks!

[ragedigital]

Mine was more of an experiment than anything. We were looking for anything to replace the stock FZR shock at the time. We now know better.

I would check out the R6 shock. viewtopic.php?f=18&t=9310

[goosefartfan]

I keep reading that the r6 shock's springs are too weak...What am I to do, given that I weigh 65 lbs. more than my assumed "OEM rider" weight?

I'm curious why the Busa shock didn't make the grade????

thanks, as always!

[ragedigital]

There was an unusually high amount of material removed to make the Busa shock work. You're more than welcome to give it a shot though. It certainly stiffened it up.

The fact is that "street" riding doesn't require performance parts that meet the riders needs as much as riding/racing on the track would. If you were racing the FZR, then I would recommend a FOX, PENSKE or OHLINS shock with a proper spring added.

Darrin

[goosefartfan]

The fact is that "street" riding doesn't require performance parts that meet the riders needs as much as riding/racing on the track would. If you were racing the FZR, then I would recommend a FOX, PENSKE or OHLINS shock with a proper spring added.

Darrin

On the other hand, I think it's almost silly not to take advantage of the cheap junkyard parts that can really upgrade the bike. I'm no expert but it seems as though every sport bike sold at your local dealer for the last 15 years has come with adjustable rear and front shocks. I'm not shooting for the track, just trying to bring my FZR up to more recent standards without too much $ or time or scraped knuckles.

aaron

[M in KC]

Carefully, swap the FZR spring onto the R6 shock. Problem solved. Or just have Nate "that kid" hook you up. He has a drop in R6 rear shock setup for the fizz and I think he will even swap springs for you if you ask nicely. Then you get a more modern rear shock with rebound, dampening etc for a 1/10th of what an Ohlins, Fox, or Penske will cost you. Especially if you are not track bound with your FZR.

[Lastmile]

I see the advantage of the busa spring. Even if I put an r6 spring on the fzr shock it's still under strung. I'm 6'2 230lbs without gear. I love the bike but I can't justify spending that much money to put a race shock and then buying a stiffer spring on top of that. I'm going to look at raising the top mount up to help compensate for the height difference. But I have yet to sit down and look at the two.

[goosefartfan]

I see the advantage of the busa spring. Even if I put an r6 spring on the fzr shock it's still under strung. I'm 6'2 230lbs without gear. I love the bike but I can't justify spending that much money to put a race shock and then buying a stiffer spring on top of that. I'm going to look at raising the top mount up to help compensate for the height difference. But I have yet to sit down and look at the two.

How do you plan on raising it?

Will it require welding?

I'd rather keep my project a do-it-yourselfer. For me, that's the reason the Busa shock seems so attractive! If I could grind my way through prison bars, I can sure grind...(never mind!)

[Lastmile]

I see the advantage of the busa spring. Even if I put an r6 spring on the fzr shock it's still under strung. I'm 6'2 230lbs without gear. I love the bike but I can't justify spending that much money to put a race shock and then buying a stiffer spring on top of that. I'm going to look at raising the top mount up to help compensate for the height difference. But I have yet to sit down and look at the two.

How do you plan on raising it?

Will it require welding?

I'd rather keep my project a do-it-yourselfer. For me, that's the reason the Busa shock seems so attractive! If I could grind my way through prison bars, I can sure grind...(never mind!)

My original plan was to grind it down, but you have to take off a lot of material. Moving the mount up would require welding, but if I didn't do it myself the local welder would charge less than $50 I'm sure. The top mount is on a surface the runs diagonally out. Moving the top mount up might throw off the geometry off. It might take more effort than just moving a mount/grinding to do it safely

[goosefartfan]

yup.