'95 gsxr front end on an '80 1000g refit questions

[Guest]

I've been gone for a short while working and researching and wound up at this current point. I've got a '95 suzuki gsxr front end that I'd like to graft onto my '80 gs1000g for better performance- to loose the air forks, add suspension adjustablilty and improve the front braking, all in one shot.
Btw- Yes, this one bike will be a restomod as my 850g will be stock except for the salty monk brake upgrade and new fork springs on that one. I had to figure that to improve the forks and brakes, together, the idea of a whole front end swap would be easier this time around.

The '95 1100w front end is sans calipers and wheel/rotors, but has TTs with stem, clips ons and axle. Fork seals are leaking a little so new seals and dust covers are in order...and I will change the fork oil too while it's apart. Had a little over 18k on it when pulled.

The oem '80 GS bike specs, if I found them as correct;
Rake- 28 degrees
Trail-4.4"
fork length- 762mm
rotor diameter- 320mm

The '95 gsxr1100w specs;
Rake- 24.8 degrees
Trail- 3.9"
fork length- 765mm {+ 3mm from above}
rotor diameter- 310mm

TT offset appears to be the same. With these new forks the height should be in the same ball park as the oem '80 forks - and I can move the new forks up to change rake/trail to be a tad more aggressive{but not wild}. The '95 year fork as well as the even longer '93 gsxr1100 {at 775mm long} won't require dropped or custom triples to regain height since most gsxr forks come in at roughly 730mm{ish, varies on year/model}.

So, I'm wondering about brake options....what rotors and calipers would you folks suggest with the factory '80 mag rim?{eventually I want a steel spoke rim there}...I could hunt down the oem '95 6 pot calipers and rotors and try a retrofit to the oem '80 rim or try something else for brake/caliper...options are open here so long as alignment is spot on.

-I figure the oem '95 gsxr clip ons might go in favor of a pair of bolt in 7/8" handle bar clamps on the top triple tree.
-I also figure on a set of adjustable travel stops for the triple tree so as not to hit the tank on either full swing.
-New headlight mount will be needed and a way to remount the gauges....will also need to figure out if I can use the '80 oem speedo drive or retrofit it some how to the '95 axle. That was an unfortunate after thought on my part, but I thought certain early year gsxr axles took the '80ish speedo drives...just not sure if mine qualifies or can be made to?

Anyone happen to use the '95 1100w front end on their GS?
Any input as to what you did or would redo about it?
Thanks for reading.

[80GS850GBob]

An add on...if I had read my own notes before I posted {sigh}...
- '93 - '95 GSXR front ends have the "same" steering stops as the GS's...some up to '98 {pending model - but they didn't say what models, ugh}
- Honda 954 TTs work with GSXR forks {52mm}and aid in the shorter length forks offered by most of the models. The Honda 954 TTs offer an 1" drop...and from my searching the '02 on models have both TT clamps with a drop...'00-'01 only have a top TT clamp drop.
-Most GSXR forks are 2" shorter than GS forks {length/ center axle bolt to top of fork} so a drop triple tree {TT} will help to regain lost length and put rake and trail back where you'd want it. Also, don't forget "offset"...the distance from center steering bolt to center of forks...wider and/or narrower offset distances can affect your rake and trail. Dropping your height {via forks slid up} can affect your rake and trail. Low trail numbers make for an unstable bike.
"Typical" sport bike rake and trail is roughly 23 degrees rake and 90-95mm trail with a short offset {models will vary somewhat}. Stiff rake and low trail cycles will come from the factory with steering dampers for a reason!
My '80 GS has 28 degrees rake and 4.4" {112mm} trail.....compared to the average sport bike of 23 and 92.5...our GSs are laid back a tad. A little change can make a noticeable difference. When modding street bikes, please check your set up to make sure your in a safe/usable range...racers can run smaller numbers.
- last tidbit I forgot and one of the reasons I wanted what I got aside for just the length....'92-'95 GSXR speedos run the same speedo gearing as a GS.
Just make sure your speedo cable reaches the wheel drive and has some slack.
Later model GSXR front ends will not have that capability and render you looking to electronic pulse or GPS speedos.

I'll probably look for a set of correct GSXR 6 pot calipers and GSXR rotors to use for this...we'll see if they mate up to the GS wheel easily{unless someone knows already}.

As an additional thought for anyone looking to attempt a newer front end, there's a site that has a chart that shows what spacers for the newer vertical bolt calipers and what spacers are needed for what other rotors....any interest in that and I can forward that...but at the moment I see little interest in what I'm doing let alone that.

My thread here isn't to offend the purists...but with frequent talk of GS folks adding adjustable damping cartridges, upgraded spring rates and upgraded front brakes...well....I'm just tossing this up as an alternative direction to the same thing - but with easier preload, damping and better brakes. Follow your own path.

[80GS850GBob]

Man plans...god laughs.
My original intent was to grab gsxr 6 pot calipers {still in the works} and the same gsxr rotors for these forks while using a GS front wheel - but.....I decided last night to check out the bolt hole spacing and found out the gsxr rotors are 5 "bolt" - GS rims are "6 bolt" {I really want GS rims}.
So, now I'm researching rotors that are 6 bolt and 310mm diameter {I'll sort out offset later}.
On a plus note, I found out it's fairly straight forward to rebush USD forks if all the videos I saw were correct - at least that should be easy.
It's a good thing I like puzzles....stay tuned for more laughs/progress.....

[kingofvenus]

Get some four pots instead, six pots are not any better and do not have as good of feel. Harder to bleed too.

[ChrisM]

1980 GS1100L with 2002 Z600E triples, 2007 Ninja 650R forks, wheel, and brakes. Just for ideas.IMG-0272.jpg

[80GS850GBob]

Get some four pots instead, six pots are not any better and do not have as good of feel. Harder to bleed too.

Still on the rotors stage but I had thought of that as well.
Thanks for the valued input.

[80GS850GBob]

1980 GS1100L with 2002 Z600E triples, 2007 Ninja 650R forks, wheel, and brakes. Just for ideas.[ATTACH=CONFIG]52543[/ATTACH]

I saw that one..nice blue.

[80GS850GBob]

Ok...back to the rotors.
So, it seems Busa rotors are 6 bolts and come in at 320mm round like the GS stuff......now to figure out bolt pattern spacing and center hole size.

edit- also figuring on Busa calipers to match with the rotors...on the gixxer forks.

[isleoman]

You can run Bandit wheels and rotors as well

[80GS850GBob]

Alright...these just arrived an hour ago. Now I can make/take real measurements.
USD forks 001.jpg

[kochic]

I have-had (I just switched to 1986 gsxr fork and wheels today) a 1994 gsxr forks on my gs1000.I used 1991 triple tree with homemade riser.You can see pictures in my albums on my profile.
The steering stopper is in the middle on the 1991 bottom triple tree.You just need to weld two new stopper on the frame.
Dont loose the axle nut on the left side.
Marc

[80GS850GBob]

I have-had (I just switched to 1986 gsxr fork and wheels today) a 1994 gsxr forks on my gs1000.I used 1991 triple tree with homemade riser.You can see pictures in my albums on my profile.
The steering stopper is in the middle on the 1991 bottom triple tree.You just need to weld two new stopper on the frame.
Dont loose the axle nut on the left side.
Marc

Curious - Why the switch in forks?
Also, you can buy new stops that bolt in...they're slotted so you'd have some fudgablilty. Cognito comes to mind right off the bat, but there might be other places too.
I looked up the allballs steering head parts I need for the swap....#99-3518-5 {top} and #99-3519-5 {bottom}.
Now I need to look up a seal/bushing kit for my forks and grab some fresh oil.
Might not be a bad idea to learn how to adjust these forks too...lol...{preload, damping and compression settings}. I haven't had any real fork adjustablility since 20yrs ago with my FJ1100...time to relearn.

[80GS850GBob]

Kochic, I just checked out your two profile galleries.....Nice build and I swear I've seen that bike elsewhere.

I love the bar risers...that's exactly what I want to do to keep regular bars. A kit?...or what alloy are they made from?
Also, love your rear set brackets....same thing I planned on using for my tarrozi pieces {G models aren't on the list of plate mounts so I'll have to make a plate/bracket - I have everything else I need} Same alloy as the bar risers?

[kochic]

Thank you,
The riser are just 1''x2'' flat stock, rear set plate are 3/8''.
Why I made the 1986 swap? Tires are new, I always liked the look of these on old GS bike and I was not able to sell the kit.
This is a try, since i already had GSXR rolling gear everything was bolt on, so why not?
I will upload new pics in album this week.
Right now the bike spec are: 1986 gsxr fork, wheels, brake, gs1100e swingarm, V&H street magahone, GK cylinder, head and bs34 carbs and a stock single headlight.
Marc