Dogbones - raising rear end

[Pat Conlon]

... so would it be accurate to say that the sport shock I have for sale (86) will fit all years, just gotta change the lower mount?

Not necessarily. I found this out on my '84.

To fit the YZF Thunder Ace swing arm on my '84, I had to convert over to a dogbone style rear linkage and install a '89 relay arm.
I already had a Penske shock I was using on my '84 and wanted to keep it, so I had to change out the lower eye over to a clevis to fit the '89 relay arm.
When I bolted it all together I found out that the shock length is different between the '84 and the '89 FJ's. i.e. the relay arm should hang at about the 8-9 o'clock position but with the longer shock the relay arm hangs at the 7 o'clock position. IOW the relay arm hangs lower with the longer '84 length shock.
I had to use longer dog bones to make it work, but technically with the long '84 Penske used with the '89 relay arm, the relay arm is in the wrong position.

I don't know what length shock the '86 uses, but I do know that my '84's shock (Penske or oem) is longer than the shocks on the 89+ FJ's

Can someone measure the length of the different shocks?  I'll put the info. in the files.     Cheers!  Pat

[TRoy]

thanks for the input Pat, hell who knows.... Traxxion says the length spec on the late model shock is actually longer but with less stroke 

...at any rate I got a really good shock for sale thats probably gonna fit 84-87 FJ's 

peace out!

[TRoy]

on the contrary....  my stock '86 shock, this non-adjustable '86 progressive 420, and an oem clevis mount shock all measure the same... roughly 11 1/2", about 1/8" shorter than the penske I just took off.

I'm not sure what year the clevis shock came off of, Frank gave it to me for misc spare parts projects.

[racerman_27410]

on the contrary....  my stock '86 shock, this non-adjustable '86 progressive 420, and an oem clevis mount shock all measure the same... roughly 11 1/2", about 1/8" shorter than the penske I just took off.

I'm not sure what year the clevis shock came off of, Frank gave it to me for misc spare parts projects.

Troy,

that shock was off a 89 model FJ


KOokaloo!

[Pat Conlon]

Ok that's good to know. The '86 shock is (roughly) the same length as the '89.  Which then means that my '84 shock is longer than the '86 and '89 shocks.

on the contrary....  my stock '86 shock, this non-adjustable '86 progressive 420, and an oem clevis mount shock all measure the same... roughly 11 1/2", about 1/8" shorter than the penske I just took off.

I'm not sure what year the clevis shock came off of, Frank gave it to me for misc spare parts projects.

[Tengu]

Excuse me for resurrecting an old thread but Id like to get some clarifications please

If I shorten the dogbones (either with the adjustable ones or with a single length) will I have to adjust the chain?

Am I better off adjustign the dogbones or getting a new shockie?
Can I achieve the same raising of the ride height through the use of just the adjustable shock or do I need both new shock and dogbones?

Is there anywhere in Australia (or Brisbane) I can get the dogbones or the Penske adjustable shock absorber

Im also a short legged fellow (5'8"ish) and Im a bit concerned about increasing seat height too much!

[billwest]

I went with a Hagon shock ('92 FJ), which is a fraction longer that OEM, and a lot cheaper than a Penske.
I also fitted Soupy's adjustable dogbones.  If I had to do it again, I would fabricate my own dogbones, and drill holes accordingly.


Bill.

[Tengu]

thanks Bill...

do you mean you would "only" do the dogbones?

I have the skill and access to the gear to manufacture my own dogbones... but what material?

[billwest]

It was worth my replacing the OEM shock - it was past its use-by date.
Got it here:
http://www.hagonoz.com.au/HagApps8.htm

Much better handling than the OEM - transformed the bike.

Dogbones - I had them on before the new shock, and it did the trick.  Made cornering so much nicer.
Material -  perhaps a galvanized steel, or even stainless, so that corrosion won't come in to it, and give you a nasty surprise one day.
When you drill them, drill both at once, so everything lines up nicely.

Bill.

[andyb]

If I shorten the dogbones (either with the adjustable ones or with a single length) will I have to adjust the chain?

Yes.  It will be a bit tight.  Back it off, adjust/swap dogbones, then set it as appropriate.

Am I better off adjustign the dogbones or getting a new shockie?

Depends on your budget.  Changing the dogbones is definitely the easy way to play with ride height.  Changing their length does alter the effective shock rate slightly, though right now I'm tired and not willing to figure out by how much  The linkage is a rising rate the farther it's compressed, so a quick thinkthrough says it'll functionally soften the spring a bit on you.

Can I achieve the same raising of the ride height through the use of just the adjustable shock or do I need both new shock and dogbones?

Dogbones will adjust the height without much problem, and unless you're really pushing on a racetrack or the like it won't be hugely different than what you have as far as spring rate (theoretically if it's effectively softer, the damping will be working a bit differently, but it's going to be a mild change for sane street riding).  A shock on the other hand would give you the ability to adjust preload, compression, and rebound to a huge degree compared to the stocker, nevermind likely being in much better shape than your current shock.  Dogbones certainly aren't going to give you a hugely improved ride quality or feedback like a shock would!  If you're really wanting it dialed in exactly for a vintage race class or the like, you'd want adjustability on both fronts, but it'd likely be overkill on the street.

Is there anywhere in Australia (or Brisbane) I can get the dogbones or the Penske adjustable shock absorber?

You can make dogbones from steel bar stock.  1/4 x 1.5" bars, a drill press, some measuring, and some patience is all that's necessary to make them.  Maybe some paint.  You can use aluminum if you'd like, but it may be the difference between riding home and walking if you have a wreck that overstresses them.

My ZX9R is wearing homemade links with two positions in them (two holes at one end) so that I can lower it to race.  My FJ has a set of Soupy links, which were stupidly expensive and are turning to rust slowly, but they're infinitely adjustable to exactly the height I want.  If you go that route, email him before you order and tell him what adjustment range you want, as he usually makes them to only go lower.  Mine go from +1/2" to -2.5" overall height so that I can lower the bike to race and raise it slightly on the street, but I had to specifically ask for them that way.

Im also a short legged fellow (5'8"ish) and Im a bit concerned about increasing seat height too much!

You can cut the foam of the seat down and recover it to keep seat height down a bit.  More importantly, you can narrow the foam slightly, which will make a bigger difference.  It's okay, I'm short too.

Just depends on your budget and your goals.  Swapping dogbones is a really cheap way to make the bike a lot more responsive on turn-in, but a good shock is obviously going to do better things to the way it rides.  At about 100 times the price, it'd better!

[gripit_N_ripit]

You can easily get more ride height (on the later model FJs) by making shorter "dogbones".
These are just 5 or 6mm flat steel with 12mm holes.  Stock is 12.5cm c-to-c.  IIRC 0.5cm shorter center to center on the holes = about an inch of ride height.

Cheers,
Arnie

Arnie, these numbers are spot on... I've been reading up on making dogbones for awhile now and finally fabricated some yesterday evening. I decided to go extreme my c-to-c measurement was 11cm, I figured that i didn't want to make a very little change that was barely noticeable, rather I made a very noticeable change....In fact tooo much!!! the fj feels like a big dirt bike now haha. its fun and looks great but i will have to make some more for a slight adjustment. Thanks  Arnie and all those who helped.

[terryk]

2008 Yamaha Warrior and a 2002 Corvettte, Z51