 |
 |
|
 |
Forwarded by: "Bob Sims" <rsims@ldl.net
Subject: Hyperpro
suspension
One of the other Bobs was inquiring about suspension options for the GPZ. There was some talk on the Bandit list recently about Hyperpro springs, which are available to replace both the front and rear springs - they are sold as a kit through dealers and are made (I believe) in Holland. I've attached one of the msgs. from the Bandit list. Looks interesting - I visited the web site (see below) and they do make both a front set and rear spring for the GPZ. If I see any more pertinent msgs. come across, I'll forward them.
Bob
attached msg:
Date sent: Fri, 08 Aug 1997
23:59:46 -0600
From:
Tom Gilbertson <munros@cadvision.com
Subject: Re: Hyperpro
suspension availabilty
To:
bandit-talk@mcf.com
Send reply to: bandit-talk@mcf.com
TO: Lloyd Horton:
Hyperpro suspension parts are available from ANY motorcycle dealer.
They are distributed by DYNOJET and "FAST BY FERRACCI" (theDucati boys).
Any full-line dealer who deals with Dynojet (AND THEY ALL DO) can get you the parts.
I strongly recommend that you buy the package deal at 10% off the separate prices. This includes forks springs and new rear coil spring for OEM shock.
The OEM fork springs are MUSH compared the Hyperpro ones. Go with lower setting recommendations as a starting point.
Hyperpro has website: <http://www.hyperpro.com
They originate from Holland and are very sportbike oriented. I warn you,
these springs give the bike real sportbike suspension (read stiffness) and the
difference is like day and night. If you like riding aggressively then these are
what you want with the compromise being the plushness of OEM.
Hope you like them.
TOM GILBERTSON
From:
ebert@newton.apple.com (Bob Ebert)
Subject: Rebuilt
suspension results
Those on the list a while might recall my problems with bottoming out on the rear shock, and the various trials and tribulations I've been through trying to get an aftermarket or a (fast turnaround) rebuild.
I finally chose the rebuild. I was hoping the bike would be ready by last Friday, since it was a great weekend here. (Temperatures in the 80's, even at the beach, and no clouds in a 1000 miles radius.) Alas, the shop got busy with some other work (racers needed some quick turnaround stuff for the Superbike series, I think) so I didn't get it back until yesterday. No matter, I still drove over the hill to Santa Cruz, then down the coast, watched the sunset, and came home. Had a passenger and the bags, and the ride was great.
What was done:
replace the spring with a stiffer one. (I'm 210 lbs.)
anodize the shock body (to vastly improve the life of the oil)
revalve the shock
add an external compression reservoir, from Fox.
It took just under two weeks in total, but most of that time was having the
body anodized. They got the shock off and apart the first day, then had to
ship the body to the anodizer, have it done, and get it shipped back. The
body came back at noon on Friday, and they probably could have had it all
back together on Friday except for the other work. To make up for that
(and the other problems with getting this all put together) they didn't charge
me for the labor to remove and reinstall the shock, and stored the bike there
for me. (Normally they wouldn't keep a bike for 2 weeks...)
I'm happy with the service and the expertise displayed. The final cost was
about $481.91, that's including the 8.25% sales tax.
The breakdown on costs is: $155 to rebuild and revalve the stock shock, plus $18 for a new seal head. $100 to anodize the shock body. $110 for the compression canister and stuff to attach it. $90 for the new spring, which is a 550lb spring. I don't recall what the stock one was, but I think it was around 500lb. I believe the number is the force needed to start compressing it, but I'm not completely sure how springs are measured.
On the 2-up ride, I had the preload set at 4, the rebound at 3, and the compression (new setting, on the external reservoir) at 4 (out of 8.) It turned out to be a great setup. We immediately noticed a huge difference in the ride height--the back end was up where it was meant to be and not sagging. My passenger said she felt taller, and was able to see better. There was no problem with bottoming out, and the middle compression setting was great for the bumps.
This morning I cranked the preload back down to 2 (for just me) and turned the compression up to 7. It felt much more like a sport bike this way--I got a lot better sense of what the road and the rear wheel are doing. I think the compression is a bit high for doing my commute, and I'll probably turn it back down after a while, but it's nice to know I can tweak it for harder rides through the hills.
The compression setting is done by a little knob on the external reservoir,
which is conveniently mounted inside the GiVi rack support on the right hand
side, just forward of the passenger footpeg. There's a good inch and a
half clearence between the reservoir and the wheel, so that's not a
problem, and there's nothing touching the body panels, which I really
appreciate. I'll have to get some pictures put together and up on my
website.
It looks like the reservoir could also be attached to the frame itself, but that would either mean cutting a body panel to make the compression adjustment easily accessible, or having to reach in and around to get at it and maybe not being able to see the marks for the setting without a mirror.
Anyway, the shop is Lindeman's Engineering, 520 McGlincy #3, Campbell, CA,
408-371-6151. This was the first GPz they've done, so they used it as a
project bike to take measurements and notes and put together a parts list, and
now they can easily do other GPz's. They participate in some kind of
dealer exchange program, and they said they'd be willing to share the info
with other shops. So if (when?) your shocks start to go, you might
consider suggesting your shop contact Lindeman's for details on the GPz rear
suspension.
--Bob
From: ebert@newton.apple.com
(Bob Ebert)
Subject: Re: Springs
At 3:26 PM 11/25/97, gpz1100 wrote:
Has anyone on the list upgraded there front, or rear springs. If so
who's did you use.
I upgraded the rear on mine. I had Lindeman Engineering in Campbell rebuild and revalve the stock shock, anodize the body, add an external Fox reservoir, and put on a stiffer spring. The cost was $500, and it took about 10 days. The result is fantastic.
The shock was dead (it had had 16K miles of heavy riders on it) and it's like
being on a new bike now. The stiffer spring (550lb vs around 500lb stock)
is great for me, since I'm 210lbs and requently ride with a passenger and loaded
GiVi bags. At the #2 preload it's fine for me and no
bags.
I liked being able to set the compression via the Fox reservoir. I had to do a short ride over gravel, and I set it way soft and everything was fine. For just me and twisties, the higher settings give it a real sport bike feel, and I leave it in the middle for my regular commutes. The compression adjustment knob is really easy to reach, and I could almost adjust it while riding, though I'd never try that. I have tweaked it when stopped without getting off the bike though.
I managed to keep the upgraded shock when the bike was totalled, and plan to put it on my replacement bike.
--Bob
Date sent: Thu, 13 Nov 1997
From:
jeffrey m lohaus <charloul@pacbell.net
Subject: Re: suspension
mods?
Bob Sims wrote:
Hey Jeff,
Was reading about your performance mods, and was curious about the
suspension mods. I notice you have Race Tech, I assume you have the
Race Tech emulators? How much difference is there over stock?
Bob, hi its Jeff so you want to now about the Race-Tech? Okay well I
have the emulators installed front and rear. Huge difference the bike was
like a new motorcycle, no more soft front forks, they work well. I think
the back was the biggest improvement though the spring is still to
soft. I ride the GPz really hard compared to most people on the list.
I grind parts all the time and the bike never gets upset even with the back end
sliding around. Best money you can spend. There is a place in
Holland or somewhere over that way that makes a set of springs for the GPz front
and rear which I hear are pretty good for 299.95 so maybe you can go that way
too. I plan on buying the set but will probably only use the rear spring
out of it. They only sell it in a kit front and
rear both. Good Luck let me know if you need anything else.
Jeff LOHAUS
1995 GPz1100
The following was posted to the ZX list by Tom O'Hara. Although he was referring to his experiences with a ZX11, they are applicable to the similiar GPZ suspension components.
The rear shock on a -11 is fully rebuildable. The Race Tech kit includes a new piston ring, O-ring expander (fits underneath the piston ring), a large assortment of damping shims, a new piston, and a reservoir and connecting hose. You can buy oil from Race Tech, Bel-Ray, PJ-1, and several other companies. All you need to rebuild the shock are the tools to remove it, a vise to hold it while you disassemble it, and a shop to charge the reservoir with nitrogen.
David is correct in saying that the shock kit, or for that matter, an aftermarket shock, will not transform a -11 into a -9R. The -11 is a big, heavy bike. It is not now, nor will it ever be (at least in its current iteration) a production roadracer (-9R or one of its competitors). I made the suspension changes to stabilize the chassis when my wife rides with me. I got what I wanted. As an extra, the bike is much more stable when I ride alone, although it is slightly stiff as I mentioned in my original posting.
The stock rear spring is 8.5 kg/mm (+/- 0.5 kg/mm) with 19mm of preload. The recommeded Race Tech spring is 7.5 kg/mm with 12mm of preload. That can't be stiffer than stock. I don't know what the original nitrogen pressure is in the stock shock; in the Race Tech kit it is 200 psi. I have the compression shim stack at the minimum, the compression adjustment at the minimum, the rebound shim stack at one less than maximum, the rebound adjustment at #3, and a 9.0 kg/mm spring. I weigh 185 ready-to-ride. The ride is firm, but well-controlled. When my wife joins me, I set the compression adjustment to maximum and all is well. In a Race Tech kit, the spring rate determines the "stiffness". The compression damping is for fine-tuning the response over "rolling" bumps. I mention this because the Works Performance shock uses the spring only to hold the bike off of the bump stops. WP controls the motion in both directions entirely with damping.
I don't know what went wrong in David's installation. Without knowing his weight and the spring rates he chose, any suggestions are idle speculation. I do know that the Race Tech parts are a noticable improvement over stock. On the first ride after the change, my wife commented that the bike felt much more stable and that she was much more comfortable. I changed the valving after that ride to increase the rebound damping and decrease the compression damping because I wasn't happy with the ride and response when riding solo. My wife's comment was that the second iteration was as big an improvement over the first as the first had been over the stock suspension. Believe me, my wife is not mechanically adept. She doen't know, or care, how the changes were effected. All she cares about is that she isn't getting tossed around. We can ride in comfort now, that is something we could not do with the stock suspension.
Regards,
Tom
Date sent: Sat, 10 Oct 1998
23:34:23 -0700
From:
Rod McDonald <rodmcdonald@rocketmail.com
Subject: Re: RACE TECH???
Thanks all for the input. Race Tech recommends 2 turns of preload on the emulators for street and 4 turns for racing - both in their literature and over the phone. They also list an adjustment range of 0 to 7 turns preload. However, due to the fact that the same part which is used for our 590 lb GPZs is the same part number used for some years of the NSR250, YZF600, CBR600, etc., I don't find the blanket factory recommendations too assuring. No big deal though. I'll try 3 turns and adjust if necessary.
Also, the emulators (themselves) have optional spring rates. The emulator preload can be adjusted to tune low speed damping and the emulator spring rate can be changed to adjust high speed damping if needed. Sounds like a good deal.
By the way, you know that part in your owners manual about changing fork oil every 18K miles (30,000 Km)? It's not the crap I always thought it was. I have just shy of 18K and the oil I drained looked really grim - except for those pretty metalic flakes!
Rod
More from Rod...
Got my bike back together Sunday afternoon, just in time to ride to Carl's Jr. for dinner. $300 for the installed emulators seems a little steep if you have to remove & lug 'em the forks yourself. The installation requires normal hand tools plus (Race Tech told me no special tools - hah!) a 10mm hex driven by an impact wrench to remove the damper rod bolts, a 12mm hex/allen wrench to remove the front axle (with adapter for use with a torque wrench would be best but I couldn't locate one), a drill and 5/16"/8mm bit, a torque wrench, a debur/chanfering tool, a tubing cutter, a vice, locktite blue, two pints of fork oil, a metric ruler, some kind of fork oil sucker (I improvised with a small diameter piece of aluminum tubing - about 3/32" ID - and a baby snot suction bulb, and here is the biggy, you must have some way of preventing the damper rods from spinning when you loosen/tighten the damper rod bolts. ("No special tools" - right) Kawasaki list a tool for this in their manual. I improvised one. The top of the damper rod has a very shallow depression that looks like the the inside of a socket. I didn't count the points, but I think there were 18. Anyhow, a 27mm axle nut seemed to fit pretty good. If you took an axle nut and ground the seating portion of it down a little to remove the radius, and then welded it to a steel rod say 3/4" x 18-24" with a second rod welded to form a T handle, it should do the trick. I made the T handle I just described but instead welded a rectangular piece of steel strap 6.5mm x 17mm to it instead of the nut. It worked great. Once you get the damper rods out you drill 6 8mm holes in each damper rod. Then chanfer & debur, reinstall, put in the emulator, spring, washer, shortened preload spacer, and set the cap on top. Measure the distance from the top of the fork tube to the mating bottom surface of the cap. DO NOT SKIP THIS STEP. This way you will know if the emulator gets out of place after you ad the oil and can't see down inside. Remove all the stuff down to, but not including the emulator. Fill with oil, slowly pump to remove air. reinstall spring, etc. and remeasure distance from top of fork tube to mating bottom surface of cap. If it is the same, close it up. I used 120mm of 15 weight Maxima oil. I'm using the stock fork springs. They measured out at the new length spec'd in the factory manual. I bought some new ones from Race Tech (1.0kg/mm, they say stock is .829kg/mm) but they are 2mm smaller in OD than stock and I don't want them flopping around inside, I will probably return them and buy Hyperpro springs. I shortened my preload spacers 6mm. The emulator adds 12mm of preload so I gained 6mm. This brought my sag up to the Race Tech recommended 1 1/4". I used 3 turns of preload on the emulator valve's spring. How do they work? Can't really tell any difference! I haven't been able to tear it up yet but on the street I think the low speed damping has increased very slightly, the high speed feels about the same. I will have a better idea next weekend when I can put some miles on them. As of right now I got a feeling new springs and a shock are going to be needed. Oh yeah, the emulators come with "sizing circlips" for some applications, use 'em. Hope this helps.
Rod
A followup...
Well I finally figured out my suspension problem. You may remember I was trying to diagnose and cure a bad case of head bob and weave during turns. It was particularly bad during throttle transitions. The whole time I thought it was the suspension misbehaving. I tried screwing with the shock rebound damping and put Race Tech emulators in the forks with new 15w oil. Didn't do crap for the problem. I measured my suspension sag and everything was in spec, 1.6" in front, and 1.1" in the rear (with the preload set to #1). I didn't know what to do other than replace the shock. Then I rode a buddies ZX10 and realized it turned like lightning compared to my GPZ. It got me thinking (finally!), I had a handling problem, not a suspension problem, duh. I left the shock damping rebound at #3 and started playing with the shock preload to raise the rear of the bike. I started at #1 which made handling a joke, #2 made the bike turn better, #3 was better still, and #4 was a little too quick. At #3 the sag is .75". Changing shock Preload made no noticeable changes to the suspension action but dramatically changed handling characteristics. The whole time my suspension was fine, I was just riding nose high, tail low which made the bike so stable that it wanted to keep going straight all the time, even when cranked over during turns, hence the head bob and weave.
Works great now. Don't feel I need a new shock afterall.
Rod
From Dave Dempster:
According to Koni's website, the part number for their rear shock is #2615-1013 and was scheduled to be available beginning 7/98.
The U.S. headquarters are located at:
Koni North America
1961 International Way
Hebron, KY
http://www.koni.com {this website seems to
no longer exist}
1-606-586-4100
fax 1-606-334-3340
I have not yet found a price for this shock.
The shock is nitrogen charged with a diaphram separating the gas from the oil.
Can anyone add to this??
Dave Dempster
Date sent: Sat, 6 Feb 1999 14:41:25
-0800
From:
"RA Pierson" <RAPierson@worldnet.att.net
Subject: Koni Shock
I have posted a couple of times for opinions on the Koni shock for our Gpz's. I realize now why there was no response (I might have missed it since I often just do a quick browse of my list in digest form). there was no response because nobody can find one.
I called every local dealer and parts shop in the area and the ones who had a Koni catalog didn't have any listing for the new line of street monoshocks, the 2615 series to be exact. For the Gpz the model number is 2615-1013. Then I started calling the big mail order houses with the same result, nobody knew anything.
Then I called Koni in Kentucky 606-586-4100 and got the name of some Michigan dealers. They gave me some names and Pep Boys. Pep Boys was no help but I called a place, evidently a high performance auto parts house in a small town 80 miles from me, and he had the catalog and took the order.
I will have to wait till it comes to be sure I am getting the right part, but I am confident that it will be. I am also curious about how long delivery will take. I will post a note when it gets here. The interesting thing is the price, about $250, which I think is really cheap. I seem to recall visiting that Koni site last year and reading that the price was $350.
I don't doubt that the Koni will be a quality unit. I felt that the stock one was starting to get limp a 10K miles. The most noticible trait being wallowing in sweepers. A full review of how it works will have to wait till spring but for those of you thinking you need a new shock call Koni and find someone who will sell you one. At this price you can't go wrong.
Bob Pierson
From:
"RA Pierson" <RAPierson@worldnet.att.net
Subject: Koni shock
The Koni rear shock I ordered on Saturday was at my door today. It certainly looks like the correct one, my bike isn't here where I live so a visual comparo isn't possible.
It will be a few weeks, or more, before I install it and test it out. The
only thing I was slightly disappointed at is the spring adjustment is by a
threaded collar which requires a spanner, which wan't included. There are 10
turns in the full adjustment. I imagine even with the spanner it might be a
big pain in the ass to spin the adjuster when it is on the bike but that
too is a minor problem. I will preadjust per their recommendation. There is a
thumb wheel like the stock unit for damping adjustment. It adjusts both
compression and rebound damping.
The price was really great, so far it is free because my card hasn't been billed yet. As I said I ordered it from a car parts distributer in Coloma Mich. The shock came directly from Koni in KY. I think he said $245, the shipping was $5. I had to pay Mich. sales tax. Until I am sure the billing is done correctly I won't vouch entirely for the dealer but there doesn't seem much to worry about.
Motor State Distribution
Lane Automotive Inc
Colma MI
616-463-4113
Bob Pierson
Note from Bob: I know Ohlins makes a shock for the GPZ, but I haven't heard from anyone who's actually used it. A dealer quoted me $950 (!) for one. I found the following info about the Ohlins shock part #s (apparently, they also make a front spring set):
Brand, model: GPZ 1100, (ABS) 95-96
Shock absorber: KA 451
Type: 46HRCS
P/C: 23
Front fork: 8820-01
P/C: 300
Bitubo shocks
GPZ 1100 95-
K0030XZE01
HARPER ENTERPRISES, INC.
32401 STRINGTOWN RD.
64034 GREENWOOD, MO.
TEL. 001-816-6973411
FAX: 001-816-5663413
|
|
|
|