Suzuki GS Twin Digest #41-50



GSTwin-digest           Sunday, July 6 1997           Volume 01 : Number 041




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Date: Fri, 4 Jul 1997 13:14:26 -0800
From: "Michael Moore" 
Subject: GSTwin Archived digests now available

I've just finished dumping the back digests into html documents and
putting them on the web site.  You can find the links on the page that
previously held only the subscription information for the lists. I've
grouped the digests in batches of 10, and in spite of Julian's
pointing me in the direction of some PERL software that would grab the
digests and convert them, I just dumped them into html format with a
 tag, so they aren't terribly pretty.

Now that I'm caught up it shouldn't be too much effort to add each
succeeding batch of 10 digests to the archives.

Cheers,
Michael
Michael Moore
Euro Spares, SF CA
Distributor of Lucas RITA and Powerbase products
Sole North American source of "The Racing Motorcycle: a technical guide for constructors"
http://www.eurospares.com
AFM/AHRMA #364

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Date: Sun, 6 Jul 1997 10:35:12 -0800
From: "Michael Moore" 
Subject: GSTwin Drum brake page

I've started a page on my web site where I'm recording the drum ID and
shoe width for various drum brakes that might find their way onto
vintage road racers.  I've got a good start, but it is certainly not a
complete listing.

If anyone has a drum (mainly fronts, as they are most likely to be
swapped in the effort to get the darn things to stop) that isn't on
the list, I'd be pleased to get a good drum ID measurement along with
a brake shoe friction material width dimensions to add to the list. 
These two measurements let me figure out the brake swept area. I have
noticed that drums of nominally the same ID actually vary a bit, so a
measurement instead of just "it's the 190mm brake" would be best.

Thanks,
Michael
Michael Moore
Euro Spares, SF CA
Distributor of Lucas RITA and Powerbase products
Sole North American source of "The Racing Motorcycle: a technical guide for constructors"
http://www.eurospares.com
AFM/AHRMA #364

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End of GSTwin-digest V1 #41
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GSTwin-digest         Thursday, July 10 1997         Volume 01 : Number 042




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Date: Sun, 6 Jul 1997 18:26:27 -0800
From: "Michael Moore" 
Subject: GSTwin Very many more pictures

My poor scanner is panting, it has been working so hard.

New additions to the graphics page are:

Road race:
Colin Lyster Lyntons, Manxes, G50s and 450 Hondas (with wings!)
The 500cc Phoenix two stroke twin
The 50cc Wooley/Yamaha two stroke single
A 50cc Sachs 
A Mackintosh frame for a turbo Kawasaki road racer
A Difazio hub-steering AJS 7R
Action shots from two different Brands Hatch 500 mile production races
(Ducati and Suzuki 250s, Triumph/BSA 650s, Dunstall 750).  One of the
pictures is a nice shot of Lance Weil. 
A Fahron 125cc two-stroke single 
The Ray Flack 350cc Manx kneeler (solo)
An early Rudi Kurth BMW kneeler 
A MotoBi 250 
Various racing drum brakes (on the drum brake page)

Dirt:
A Wasp MX sidecar
A Cheney Suzuki (the early twin-exhaust port 250 engine)
Some shots of a 175cc Honda twin trials bike
An action shot of Dave Bickers monowheeling

Engines:
An article on a 350cc Desmo single designed by Major John Treen in
1959.

Cheers,
Michael
Michael Moore
Euro Spares, SF CA
Distributor of Lucas RITA and Powerbase products
Sole North American source of "The Racing Motorcycle: a technical guide for constructors"
http://www.eurospares.com
AFM/AHRMA #364

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Date: 7 JUL 97 09:19:56 EDT
From: AGabinet@dechert.com
Subject: GSTwin Hello Andrew-- jetting

This is a response to Andrew Horton's email to me about adjusting the jet 
needle for the GS500.  Andrew -- my manual says there is no adjustment for 
the jet needle on my '90 GS500.  Any clues?  I'm sure K&N must make a kit 
for this bike, but was there a noticeable improvement in midrange power?

------------------------------

Date: Thu, 10 Jul 1997 20:57:39 -0800
From: "Michael Moore" 
Subject: GSTwin New race frames

The new Cycle News has a mention by Alan Cathcart that Tigcraft in 
England has realized that there is a market for 500cc twin frames, 
and has a prototype steel tube frame (like the MuZ Skorpion) under 
development.  The prototype takes an EX500 engine, but the frame will 
take the Suzuki and Euro-Honda 500 twins with minor modifications.  
Tigcraft estimates around stlg4000 for a base-line rolling chassis.  
They also mentioned that Kawasaki has made over 150,000 of the 500 
twins.

I've got a link on my commercial links page to Dana Phelps at One 
British Racing in Florida.  He's been importing Tigcraft singles 
frames and speed parts for the 660cc Yamaha singles, and he'd 
probably be interested in hearing of potential customers for the twin 
frames.

Of course, you could just build your own as Glen and his brother did.

Cheers,
Michael
Michael Moore
Euro Spares, SF CA
Distributor of Lucas RITA and Powerbase products
Sole North American source of "The Racing Motorcycle: a technical guide for constructors"
http://www.eurospares.com
AFM/AHRMA #364

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End of GSTwin-digest V1 #42
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GSTwin-digest         Wednesday, July 16 1997         Volume 01 : Number 043




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Date: Sun, 13 Jul 1997 09:27:07 -0800
From: "Michael Moore" 
Subject: GSTwin Upcoming article and stuff

I got my new copy of "Sport Twin News" published by John Sweeney
(who is on the list) yesterday.  In response to a request for
information on Jody Matsler's GS500 racer John mentions that he will
be doing a feature on the bike in the near future.  I looked around
for the bike at the AFM race at Sears Point two weeks ago but couldn't
spot it.  When I do I'll get some pictures for the web site.

Jody's bike is fast enough to put a novice rider into the top 3 in 500
twins against the EX500 Kawasakis.  Then again, Jody is probably a
pretty fast novice rider too, so we can't give the Suzuki all the
credit.

I'm sure that John will remind us when the article comes out, and
hopefully will put it up on his web site (www.sport-twin.com).  

I'll also mention that John has started the "Sport-Twin Riders 
Association" and if you are interested in finding out more about that
(and his nice newsletter, to which I occasionally contribute articles)
you can go to his web site or drop him an email at:

jas@sport-twin.com

Cheers,
Michael
Michael Moore
Euro Spares, SF CA
Distributor of Lucas RITA and Powerbase products
Sole North American source of "The Racing Motorcycle: a technical guide for constructors"
http://www.eurospares.com
AFM/AHRMA #364

------------------------------

Date: Sun, 13 Jul 1997 09:27:07 -0800
From: "Michael Moore" 
Subject: GSTwin Race Heads

I talked with one GS500 racer at Sears Point two weeks ago, though I
don't recall his name.  He mentioned that he was having great fun
racing his GS, but is also looking forward to bringing his Ducati 916
to the track!

I think he told me that he had actually placed pretty well in 450
Production against the FZR400s, and was planning on trying to get more
power from his GS500.

The way he intends to do this is to cut the center two cylinders from
an air/oil-cooled GSXR1100 head  (though that will mean moving into
the 500 Twins class).  I know that this was been done by a rider in
the Oregon/Washington area (several years ago), though from what I've
heard it was a moderately crude job.  The bike was supposed to have
been pretty fast.

The problem I see with this is a lack of finning on the GSXR head. 
That head is designed to be largely cooled by massive quantites of oil
being circulated through it and then through a heat exchanger.  I
don't know that a GS oil pump will supply the needed quantities of oil
for this to work.

What we need is for some list member in Canada (I hope there is one)
to check and see if the 4 valve/cylinder GS450 head gasket matches up
with a GS450/500 two-valve/cylinder head gaskets.  I'd be very
surprised if it wasn't a bolt on item for the 450, but I've never been
told if the 450 and 500 share the same stud spacing etc.  Since a 450
can be taken out to 500 I'd guess that Suzuki may have kept the same
stud spacing.  

If they can also check on availability and price of the 4 
valve/cylinder heads that would be of interest too!

Perhaps someone can, at least, compare the two 2-valve head gaskets,
just to add to the GS database.

Let me know on this stuff and I'll add it to the GS page - there
hasn't been much coming in to go there.

You racers might drop the list a short report on your activities - let
us know how you are faring on the track.

Cheers,
Michael
Michael Moore
Euro Spares, SF CA
Distributor of Lucas RITA and Powerbase products
Sole North American source of "The Racing Motorcycle: a technical guide for constructors"
http://www.eurospares.com
AFM/AHRMA #364

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Date: 14 Jul 97 08:17:53 EDT
From: AGabinet@dechert.com
Subject: GSTwin Jetting GS Twin

For those interested in less radical approaches than swapping cylinders 
with a GSX 1100, I installed a K&N stage 3 jet kit on my '90 GS500 last 
week.  I have two kids under the age of 8, and I did the job in a single 
evening, with them around, so I can't be too hard!  Simply a matter of 
replacing the stock jet needles and the main jets, and junking the stock 
airbox and breather for the K&N oil soaked filter and constant velocity 
stack.  The difference in the bike is very noticeable -- lots more pull 
lower down in the rpm ranges.  I won't keep up with my buddy's 900CR when 
he pulls out into the straights, but I won't be as far behind, and won't 
need to shift as often in my turns.  This was a fun and very rewarding 
project.  K&N's tech support people are helpful with answering questions 
either on the phone or via internet.  
- -------------
Original Text
From: suzuki-gs-twin(a)list.sirius.com, on 7/13/97 12:28 PM:
I got my new copy of "Sport Twin News" published by John Sweeney
(who is on the list) yesterday.  In response to a request for
information on Jody Matsler's GS500 racer John mentions that he will
be doing a feature on the bike in the near future.  I looked around
for the bike at the AFM race at Sears Point two weeks ago but couldn't
spot it.  When I do I'll get some pictures for the web site.

Jody's bike is fast enough to put a novice rider into the top 3 in 500
twins against the EX500 Kawasakis.  Then again, Jody is probably a
pretty fast novice rider too, so we can't give the Suzuki all the
credit.

I'm sure that John will remind us when the article comes out, and
hopefully will put it up on his web site (www.sport-twin.com).  

I'll also mention that John has started the "Sport-Twin Riders 
Association" and if you are interested in finding out more about that
(and his nice newsletter, to which I occasionally contribute articles)
you can go to his web site or drop him an email at:

jas@sport-twin.com

Cheers,
Michael
Michael Moore
Euro Spares, SF CA
Distributor of Lucas RITA and Powerbase products
Sole North American source of "The Racing Motorcycle: a technical guide for 
constructors"
http://www.eurospares.com
AFM/AHRMA #364

------------------------------

Date: Wed, 16 Jul 1997 21:33:05 -0400 (EDT)
From: MJBoltuc@aol.com
Subject: Re: GSTwin Jetting GS Twin

I found a machine shop that believes in the BARTER system.  I found in an old
warehouse, a 55 gal drum of synthetic cutting oil, that i'm trading for
labor.
the gsxr swingarm is almost on.
I used the stock GS linkage and mated it to the GSXR arm by using adaptor
bushings in the swingarm pivot and spacer bushings where the dogbones attach
to the arm.  The shock used is a 93 GSXR 750 stock unit.  This was done to be
able to go back to the original set up if this didn't work.  The bushings
prevented the frame from being modified.  Next is a new front axle to mate a
3.5 x 17 GSXR front wheel to the Bandit 400 forks, which I need to drop off
on friday.  
It's slow, but fun.   What else is there to do... look for a job

Ken Lehman - (Unemployed Environmental Engineer)

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End of GSTwin-digest V1 #43
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GSTwin-digest          Monday, July 21 1997          Volume 01 : Number 044




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Date: Sun, 20 Jul 1997 01:04:20 -0400 (EDT)
From: Craigroth@aol.com
Subject: GSTwin No Subject

Hello all, my name is Craig, and I am the proud new owner of an '89 GS500E.
This is my very first bike, and I wasn't even planning to bet a bike, but a
woman I work with made it damn near impossible for me to turn this deal down
($500.00, with only 3300 miles!) After looking around a bit a other bikes, I
came to the realization that I like just about everything about this one. 

I am looking for any info on minor performance/handling modifications that
might be done to a stock bike. I'm not looking to race it (who knows, maybe
someday), but I would like it to perform at or near it's peak.

I'm really happy to have stumbled upon this list, and I look forward to
hearing about everyones bike stuff. I've already spent the last hour looking
through the digest archives.

viva las vegas------craig roth

------------------------------

Date: Sun, 20 Jul 1997 17:15:14 -0500
From: kurt 
Subject: Re: GSTwin No Subject

At 01:04 AM 7/20/97 -0400, you wrote:
>Hello all, my name is Craig, and I am the proud new owner of an '89 GS500E.
>This is my very first bike, and I wasn't even planning to bet a bike, but a
>woman I work with made it damn near impossible for me to turn this deal down
>($500.00, with only 3300 miles!) After looking around a bit a other bikes, I
>came to the realization that I like just about everything about this one. 
>
>I am looking for any info on minor performance/handling modifications that
>might be done to a stock bike. I'm not looking to race it (who knows, maybe
>someday), but I would like it to perform at or near it's peak.
>
>I'm really happy to have stumbled upon this list, and I look forward to
>hearing about everyones bike stuff. I've already spent the last hour looking
>through the digest archives.
>
>viva las vegas------craig roth
>





Change the stock fork springs for Progressives  (about $55 including oil if
you do it yourself).  Don't ride on stock Excedra tires, they suck, I've
been running on BT-35's for about 3000 miles and they seem to hold up well.
I also plan on putting a stage one jet kit in mine to correct some carb
problems that seem to be cause by a UNI foam air filter.

Kurt
 knowlwk@mail.auburn.edu

>

------------------------------

Date: 21 Jul 97 10:05:35 EDT
From: AGabinet@dechert.com
Subject: GSTwin performance mods

Hello craig.  Like you, my '90 GS500 E was a steal, and my first bike.  I 
had the same question.  If you have been through the archives, you may have 
seen that Andrew Horton does NOT like the progressive springs.  He is a 
voice in the wilderness on this subject, but his email was fairly 
comprehensive.  If you want it, I can insert it here.  On my bike, I put in 
new forks, but haven't modified them yet.  I removed the stock bars, 
lowered the forks and put on Telefix clip on bars.  This is a nice moderate 
change in riding position and feel.  I also installed a K&N stage 3 jet kit,
 which includes the oil impregnated foam air filter and CV stack along with 
adjustable needles and a variety of jets, depending on whether you are 
modifying your exhaust too.  Do not be too intimidated by the installation 
of a jet kit.  If you have a Clymer manual, removal of the gas tank, airbox 
and carbs is not so hard.  Just be sure to tape over the intake manifolds 
so nothing falls in and be sure not to lose the little black O-rings that 
fit in the edge of the carburetor next to the screw.  This modification 
makes the little puppy bark and snarl like a bigger dog.  I haven't put the 
bike on a dyno to find out how much I gained, but the difference in pull 
from 4500-6500 rpm is noticeable

I also removed the stock headlight and bar mounted fairing and installed a 
Spec II frame mounted fairing.  This makes highway riding more comfortable. 
 It's an ugly job, though, because the instructions suck.

Good luck -- I recommend the Jet Kit as the best performance mod.
- -------------
Original Text
From: suzuki-gs-twin(a)list.sirius.com, on 7/20/97 1:07 AM:
Hello all, my name is Craig, and I am the proud new owner of an '89 GS500E.
This is my very first bike, and I wasn't even planning to bet a bike, but a
woman I work with made it damn near impossible for me to turn this deal 
down
($500.00, with only 3300 miles!) After looking around a bit a other bikes, 
I
came to the realization that I like just about everything about this one. 

I am looking for any info on minor performance/handling modifications that
might be done to a stock bike. I'm not looking to race it (who knows, maybe
someday), but I would like it to perform at or near it's peak.

I'm really happy to have stumbled upon this list, and I look forward to
hearing about everyones bike stuff. I've already spent the last hour 
looking
through the digest archives.

viva las vegas------craig roth

------------------------------

End of GSTwin-digest V1 #44
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GSTwin-digest          Friday, July 25 1997          Volume 01 : Number 045




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Date: Mon, 21 Jul 1997 23:54:30 -0400 (EDT)
From: TatiMB@aol.com
Subject: Re: GSTwin No Subject

Craig, I've snipped out the relevant parts here:

<< Hello all, my name is Craig,... my very first bike... I wasn't even
planning to bet a bike... this deal... ($500.00, with only 3300 miles!)
...looking for info on minor performance/handling modifications that might be
done to a stock bike. I'm not looking to race it (who knows, maybe someday),
but I would like it to perform at or near it's peak.

Craig, the single most effective thing you can do is to improve YOU, not the
bike.  Spend your money on a MSF course... heck, take a few.  You've got a
like-new bike with an effective replacement cost of about $3500 bucks.  Take
more of the money you saved and buy some good (no, the REALLY good stuff)
riding gear, and spend the rest on a few weekend-long riding trips.

If you go with a buddy and swap bikes a few times, you'll realize that you
take the improvements along with you, instead of leaving them bolted to your
bike.

If you know you're a new rider butthink you've got nothing to learn, you're
either an AMAZINGLY gifted natural, or something else.  (I'll let you define
it!)

B.J. Worsham
(I know, it sounds like arrogance, but on this subject I tend to be
(brutally) honest.)

------------------------------

Date: Tue, 22 Jul 1997 07:05:25 -0400 (EDT)
From: Craigroth@aol.com
Subject: Re: GSTwin No Subject

BJ,
	Thanks for the solid advice! When I got my bike, the first thing I did was
got to IronstoneAdventures.com and sign up for a rider safety course.
Everyone I talked to advised me to do the same. In Massachusetts, if you pass
a certified course, then you don't have to take the road test at the DMV,
just present your certificate of completion and you automatically get you M
class license. This is an incentive for a lot of people.
	Unfortunately, the classes were booked for almost two months, and I was
tired of riding at night worrying about getting a ticket for only having a
learners permit, so I went ahead and took the DMV's road test in the
meantime. Boy, was it PATHETIC! The guy was like, "Do a couple of circles and
figure-eights, and don't fall off." I started doing my stuff and I noticed he
was walking away, so I rode up to him, and he signed my permit and said, "See
ya later." I WAS ON MY BIKE FOR 2 MINUTES!  It is pretty scary to think that
some 17 year old kid with his first bike (probably something like a CBR 1100)
can get his license by only doing a couple of circles and figure-eights in a
parking lot!
	Well, I put about 1500 miles on before my class date came around, so I had a
little more experience than a lot of the people in the class, but I pretended
I didn't know anything. I've seen the statistics that 90% of all people
involved in motorcycle accidents are either self-taught or learned from
friends or family. I did not want to a part of that statistic.
	By the way, I passed my road evaluation with no mistakes!

Happy (and Safe) Riding,
- -Craig

Original Text:

>Craig, the single most effective thing you can do is to improve YOU, not the
>bike.  Spend your money on a MSF course... heck, take a few.  You've got a
>like-new bike with an effective replacement cost of about $3500 bucks.  Take
>more of the money you saved and buy some good (no, the REALLY good stuff)
>riding gear, and spend the rest on a few weekend-long riding trips.
>
>If you go with a buddy and swap bikes a few times, you'll realize that you
>take the improvements along with you, instead of leaving them bolted to your
>bike.
>
>If you know you're a new rider butthink you've got nothing to learn, you're
>either an AMAZINGLY gifted natural, or something else.  (I'll let you define
>it!)

------------------------------

Date: Tue, 22 Jul 1997 11:25:58 -0400 (EDT)
From: MJBoltuc@aol.com
Subject: Re: GSTwin No Subject

Just got an extra factory GS500E service manual... burried in friends shop
for a year and I wanted one 6 months ago so I bought a new one, he found it a
week ago and gave it to me, New they are about $55-60 depending on how bad
the dealer wants to bend you over.
$35 inc ship to anywhere from North Carolina
ken still looking for that job and selling off the extra's
(MJBoltuc@aol.com)

------------------------------

Date: Fri, 25 Jul 1997 11:37:28 -0800
From: "Michael Moore" 
Subject: GSTwin Forwarded message about parts for sale

I saw this on the EX500 list, and since there are some GS parts I've 
forwarded it to the GS list.

Cheers,
Michael
*******************

From: "Damian R. Dobosz" 
Subject: Carbs and other stuff for sale(good for lightweight racers :)
Date: Fri, 25 Jul 1997 09:01:01 -0400

In case anyone is interested, I have (4) 33mm Mikuni's,
an entire electrical system for a Katana 600(i'll bet the coils
and fuse box would work on other bikes)and a stock GS500 front end(both
wheels(17"x3.0" and 3.5"), both forks(with fresh progressive springs and
fluid), stock and custom triple clamp, rotor, caliper and stainless
line) for sale.

Email if interested.  See ad in August issue of RoadRacing World.

ddobosz@umd.umich.edu

------------------------------

End of GSTwin-digest V1 #45
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GSTwin-digest          Tuesday, July 29 1997          Volume 01 : Number 048




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Date: Sun, 27 Jul 1997 21:38:37 -0800
From: "Michael Moore" 
Subject: GSTwin Current stats

As of 9:23PM Sunday July 27, the subscriber stats to the lists are:

LW RR - 33
V RR - 97
V Dirt - 54
Suzuki GS Twin - 32
MC Chassis Design - 105

I've noticed that things have been kind of quiet on some of the 
lists.  You know what that means - more posts from me.  You have been 
warned.

What's the deal?  Don't tell me everyone is out riding motorcycles or 
something instead of sitting in front of their computer.

MILESTONES:  I think the Chassis list is the first to break 100
subscribers.  I had actually thought that the two vintage lists
would have had a wider audience appeal.

SPAM: We've been lucky in escaping most of the spam that seems to be
hitting the other lists.  Just a reminder in advance - if you get a
spam that comes to you through the list - DO NOT SEND A 'REMOVE' OR
SIMILAR MESSAGE BACK TO THE LIST!!!!!  Besides, all the 'remove'
message does is give the spammer your email address so they can send
directly to you.  If you must send a "remove" or similar message,
please make sure that you send it to the spammer, and not back to
the list - you'll just have to read it again, and so will everyone
else.  C'mon, we're not talking rocket since here.

THANKS: I'd also like to thank those of you who have been
contributing to the lists - I've enjoyed reading many of the posts,
and have learned something from a number of them as well.  I'm
pretty satisfied with the way things are going on the lists, though
a few more messages from the lurkers wouldn't hurt.  You must have
something to say about the list subjects, or you wouldn't have
subscribed.  

BOUNCED MAIL: A couple people are getting close to being
unsubscribed due to bounced mail.  Of course, they probably won't
get this message.  Remember that I'll cut you some slack for 3 or 4
days, but if things keep bouncing after that I'll unsub you and
you'll have to resubscribe.  If you've gone for a week or so and not
gotten any messages from a list check with me and I'll tell you if
you've been dropped from the list.  If not, I'll invite you to make
a post to the list so everyone will have something to read.

PICTURES:  I've gotten a few neat pictures recently - but the rest of 
you should remember that if you have a photo that you think will fit 
into my graphics page I'll be glad to consider it.  You can send me a 
graphics file or mail me a photo for scanning if you don't have a 
scanner.  Please don't send me a 1MG .tiff file - try to keep them 
below 100K, and most stuff seems to do well at 40-80K.  Also, try to 
view the photo first, and make it big enough to show the details of 
your cool bike.  Better a bigger photo with a bit more compression 
then a tiny photo packed with indecipherable detail.

Cheers,
Michael
Michael Moore
Euro Spares, SF CA
Distributor of Lucas RITA and Powerbase products
Sole North American source of "The Racing Motorcycle: a technical guide for constructors"
http://www.eurospares.com
AFM/AHRMA #364

------------------------------

Date: Tue, 29 Jul 1997 18:33:18 -0800
From: "Michael Moore" 
Subject: GSTwin Teensy fairings

One of the people on the race list wrote in mentioning that he was
thinking of putting RS250 bodywork on his RS125, as the 125 bodywork
seemed too small.  I wrote in and mentioned that if the fairing
doesn't provide full coverage for the rider (no bits hanging out) it
is too small.  Another list member rebutted that and here is my reply.

Since there are one or two racers on this list I thought I'd cross
post the reply:

********************

> I don't think you can say that as a blanket statement.

> the frontal area you have gained top end. From what I've read, what
> the last half of the bike looks like is more important than what the
> front looks like as far as Cd is concerned.
> 
> I would think a fairing just smaller than the rider would be best.

Hello Todd,

You are correct that the back of the bike is most important, and soon
they may actually get some seats that are big enough to do some good.
The current big seats generally seem to be to pointed at the back, as
the sides of the fairing aft of the point of maximum width should not
have an included angle of more than about 10 degrees if there is to be
any hope of keeping the air attached to the bodywork.

As for the bits hanging out in the wind, all the fairings that I
know of that have been really developed in a wind tunnel (HD XR750
long track, Cosworth JPN Norton, Can Am Bonneville record breakers) as
opposed to being developed on some stylist's drawing board have all
made sure that the rider and any small bits are tucked behind the
fairing.  

The boundary layer is very easily disturbed in the area of the 
fairing aft of the maximum width, and those bits hanging outside of
the fairing are just the type of thing that the boundary layer finds
disturbing.  Some of the 50/80cc racers went so far as to replace the
sewn-on lettering on the backs of their leathers with silk-screened
lettering as that resulted in better attachment of the boundary layer.

Don't get caught up in the race to minimize frontal area as you can
easily end up with a worse drag coefficient than a slightly larger
area with a more streamlined shape.  This doesn't mean that you have
to have a Vetter Windjammer on the bike, as having the fairing where
there is nothing to fair in just adds unneeded area.

Pages 177-230 of your copy of John Bradley's "The Racing Motorcycle: a
technical guide for constructors" covers all of this in great detail.
One of the nicest parts in this section is a full page chart
documenting 39 wind tunnel runs during the development of the Can Am
Bonneville recordbreakers, coupled with another page showing various
configurations and a chart with the calculated power requirements for
a given speed for the different streamlining setups.

Cheers,
Michael
Michael Moore
Euro Spares, SF CA
Distributor of Lucas RITA and Powerbase products
Sole North American source of "The Racing Motorcycle: a technical guide for constructors"
http://www.eurospares.com
AFM/AHRMA #364

------------------------------

End of GSTwin-digest V1 #48
***************************
GSTwin-digest          Sunday, August 3 1997          Volume 01 : Number 049




----------------------------------------------------------------------

Date: Fri, 1 Aug 1997 08:55:36 +1000 (EST)
From: d.weiszmann@unsw.edu.au (Dorothy Weiszmann)
Subject: GSTwin Frame beautifying etc

Hi Everybody,

Has anyone got any clues on how to keep rust off the frame on a gs500e? Or
better still what to do to get rid of it now that its there already? 
I suppose suzuki sells some little tin of the same paint for patching but
I'm totally unimpressed with that paint, that's fer sure. Does anybody know
of a car paint colour that matches?

Hmm also if anybody's curious as to what happens when you let your front
brake disc get down to 3.1 mm thick, well your brake pad keeps falling out.
Bummer..

cath

gs500e '89 in bits
r100s '77 in more bits

------------------------------

Date: Thu, 31 Jul 1997 20:48:01 -0400
From: jbb7@psu.edu (Brad Babcock)
Subject: GSTwin a great ride

Hi All, 
        Earlier this week Michael threatened (promised?) more postings from
him if the traffic on this list didn't pick up.  Here's a minor
contribution.  This past Saturday was beautiful here in central
Pennsylvania.  My friend Rick and I decided to go for a ride.  He has a
Honda GL500 Silver Wing.  For a variety of reasons, I decided to ride my
GS450E (not the least of which is it was working better than any of the
others.)  We had a lovely 180 mile ride through the mountains, great
scenery, little traffic, good lunch, etc., etc.  When we got back, he told
me that I was riding much more aggressively on the 450 than I do on any of
my other bikes (750 Royal Enfield Interceptor, GS550M Katana, Yamaha
SRX250.)  I'd attribute this to three factors:  1.  I've ridden my 450
almost 36,000 miles.  2.  I've got Avon tires on it, Road Runner front,
Super Venom rear.  3.  What everyone on this list already knows, that the GS
twins are great bikes.  They have style, longevity and that elusive quality
of balance, with power, size and handling in complementary quantities.  A
friend of mine who has ridden all manner of bikes and owned many of them,
including a Velocette Venom I'd kill for, rides my GS450 by choice when he
comes to visit.  To me, if I needed any independent corroboration, that says
it all.  Stay safe, everyone, and have fun.
Regards,
Brad

------------------------------

Date: Thu, 31 Jul 1997 15:36:53 -1000 (HST)
From: straubis@pixi.com (Straub Tech)
Subject: Re: GSTwin Jetting GS Twin

>For those interested in less radical approaches than swapping cylinders 
>with a GSX 1100, I installed a K&N stage 3 jet kit on my '90 GS500 last 
>week.  I have two kids under the age of 8, and I did the job in a single 
>evening, with them around, so I can't be too hard!  Simply a matter of 
>replacing the stock jet needles and the main jets, and junking the stock 
>airbox and breather for the K&N oil soaked filter and constant velocity 
>stack.  The difference in the bike is very noticeable -- lots more pull 
>lower down in the rpm ranges.

Just a few Questions?
        what was the cost?
        what is the application of the bike?


Robert

------------------------------

Date: Thu, 31 Jul 1997 19:19:47 -0800
From: "Michael Moore" 
Subject: Re: GSTwin a great ride

>         Earlier this week Michael threatened (promised?) more postings from
> him if the traffic on this list didn't pick up.  Here's a minor
> contribution.  This past Saturday was beautiful here in central
 
Hello Brad,

Since my only involvement with the GS twins is my full-race GS450 
engine (for which I need to build a chassis) it is hard for me to 
come up with handy tips etc for this list, unless they are more 
generic in nature.  

Thanks for the post,

Michael
Michael Moore
Euro Spares, SF CA
Distributor of Lucas RITA and Powerbase products
Sole North American source of "The Racing Motorcycle: a technical guide for constructors"
http://www.eurospares.com
AFM/AHRMA #364

------------------------------

Date: Thu, 31 Jul 1997 19:19:47 -0800
From: "Michael Moore" 
Subject: Re: GSTwin Frame beautifying etc

> Has anyone got any clues on how to keep rust off the frame on a gs500e? Or
> better still what to do to get rid of it now that its there already? 
> I suppose suzuki sells some little tin of the same paint for patching but
> I'm totally unimpressed with that paint, that's fer sure. Does anybody know
> of a car paint colour that matches?

Hello Cath,

If you need touch up paint check out your local hobby shop and look 
at all the different colors of paint they sell for use on models.  
Some of them that are for use on the small gas engine airplanes 
should also be pretty resistant to fuel etc.

Be sure to remove all the rust before painting.

Cheers,
Michael
Michael Moore
Euro Spares, SF CA
Distributor of Lucas RITA and Powerbase products
Sole North American source of "The Racing Motorcycle: a technical guide for constructors"
http://www.eurospares.com
AFM/AHRMA #364

------------------------------

Date: Sun, 3 Aug 1997 20:36:48 -0400 (EDT)
From: Craigroth@aol.com
Subject: GSTwin blown fork seals, help

My 89 gs500e has a blown fork seal. I'm thinking about attempting to replace
this myself, but wanted to hear from all you experienced biker types (this is
my first bike). I'm pretty mechanically inclined (I removed, disassembled,
cleaned and replaced the carbs without a manual), but I don't have a hell of
a lot of tools. The clymer manual says I need a vise for the job. I've got a
quote for $100-125 from a mechanic, and I was just wondering if this was one
of those jobs it's just better off having someone else doing? Or is it no big
deal?
?are these things replaced independently (as only the left one is bleeding)
or are they treated as a set?
?what's the deal with the emulators....is this the time to think about
getting them since the forks will be apart anyway? The mechanic said I
shouldn't bother with emulators as I am not racing, but, hey, can't I
pretend?
?also, how dangerous is it to ride a bit more with a wounded left fork?

oh yeah, what is the cost on those stage 3 jet kits?

thanks for any advice 

craig

------------------------------

End of GSTwin-digest V1 #49
***************************
GSTwin-digest          Monday, August 4 1997          Volume 01 : Number 050




----------------------------------------------------------------------

Date: Sun, 3 Aug 1997 18:56:08 -0700 (PDT)
From: Beth 
Subject: Re: GSTwin blown fork seals, help

i'd remove the legs myself and have a mechanic do the rest. well, that's
what i'd do if i were you and in your position. now that I AM A MECHANIC,
i'll do it myself. :) either that or have the guy i'm apprenticed to do it
for me. :) hehehehehe...

remove as much as possible from the labour costs. take the part in you
need done completely prepped for the shop and get a deal. hell, even
supply your own seals if you can find them for cheap. make sense?

oh yeah, good luck! i'm sure it'll turn out fine. you'll have no problem
yanking the front wheel, fender and  then the forks if you went though the
carbs w/o a hassle. it's just parts. parts is parts. :)

- -Beth

         DoD#4508, AMA#542204, NGG resident crash test dummy
*****************************************************************************
             check it out: http://home.cwnet.com/beffie
              http://www.ziplink.net/~holm/ngg/ngg.html

------------------------------

Date: Sun, 3 Aug 1997 21:10:55 +0000
From: dash@cyberhighway.net (dash)
Subject: Re: GSTwin blown fork seals, help

>remove as much as possible from the labour costs. take the part in you
>need done completely prepped for the shop and get a deal. hell, even
>supply your own seals if you can find them for cheap. make sense?

>-Beth

Craig,

By the time you've removed that forkleg from the bike you will have already
done 3/4's of the job, so you might as well do the rest and save yourself
the rest of the money.  I've change my own fork seals and it is a lot
easier than carbs.  Usually it's just a matter of removing a lockring and
maybe a screw at the bottom, then pumping the tube till the seal comes out.

But if you do decide to take it into a shop, DO NOT supply your own parts!
Unless, of course, you can find a mechanic named Beth (I'm just kidding
with you, Beth).

------------------------------

Date: Sun, 3 Aug 1997 20:20:33 -0800
From: "Michael Moore" 
Subject: Re: GSTwin blown fork seals, help

> ?what's the deal with the emulators....is this the time to think about
> getting them since the forks will be apart anyway? The mechanic said I
> shouldn't bother with emulators as I am not racing, but, hey, can't I
> pretend?

Hello Craig,

I don't have any experience with the GS forks, but I can tell you 
that the emulator-equipped forks in the early 90s ZX6 I raced at the 
4 hour last year were really plush (especially compared to the 38mm 
Marzocchi/Ceriani stuff I'm used to).  The big thing is they let you 
dial down the compression damping, which is what makes most 
damper-rod style forks so harsh, especially over the small bumps.

I've put a set of emulators in the 38mm Cerianis on my F750 Laverda 
race bike, and I'm looking forward to trying them at the AHRMA 
national at Sears Point in (gasp!) less than three weeks.

I intend to install Emulators in all of my damper rod forks.

Cheers,
Michael
Michael Moore
Euro Spares, SF CA
Distributor of Lucas RITA and Powerbase products
Sole North American source of "The Racing Motorcycle: a technical guide for constructors"
http://www.eurospares.com
AFM/AHRMA #364

------------------------------

Date: Mon, 4 Aug 1997 00:15:22 -0400 (EDT)
From: Craigroth@aol.com
Subject: GSTwin No Subject

my first impression from the clymer manual was that i had to go through the
entire fork disassembly process in order to replace the seals, but i guess
they can be replaced without tearing the whole thing apart. is this correct?
(if it aint broke, don't fix it, huh?) well, this makes the job a lot less
daunting. thanks!
- -craig

------------------------------

Date: Sun, 3 Aug 1997 23:03:15 +0000
From: dash@cyberhighway.net (dash)
Subject: Re: GSTwin 

>my first impression from the clymer manual was that i had to go through the
>entire fork disassembly process in order to replace the seals, but i guess
>they can be replaced without tearing the whole thing apart. is this correct?
>(if it aint broke, don't fix it, huh?) well, this makes the job a lot less
>daunting. thanks!
>-craig

Well, actually I don't have a GS500, but I have a variety of other GS's
(450/550/750) and I don't completely disassemble the internals to change
the seals.  Just be careful not to nick the tube in the process.

Changing fork seals is a pain, but think "Zen and the Art of Motorcycle
Maintenance" and you can enjoy the MC experience that much more.  If you do
get stuck, the bike shop can handle it and you will have saved yourself
however far you got in labor.  I've torn my 450 down to the nuts then
reassembled it again myself, so I know that it can all be done.

------------------------------

Date: Mon, 4 Aug 1997 00:27:16 -0700 (PDT)
From: Beth 
Subject: Re: GSTwin blown fork seals, help

On Sun, 3 Aug 1997, dash wrote:

> By the time you've removed that forkleg from the bike you will have already
> done 3/4's of the job, so you might as well do the rest and save yourself
> the rest of the money.  I've change my own fork seals and it is a lot
> easier than carbs.  Usually it's just a matter of removing a lockring and
> maybe a screw at the bottom, then pumping the tube till the seal comes out.

depends on the fork leg setup. some are best taken apartt w/ an air
powered impact gun. that screw at the bottom sucks sometimes..especially
on the GS's i've worked on. dunno about your 500E, though. 

> But if you do decide to take it into a shop, DO NOT supply your own parts!
> Unless, of course, you can find a mechanic named Beth (I'm just kidding
> with you, Beth).

guess it depends on the part. for tires, i have to admit that i go used or
new though mailorder. tires from a dealer or a small shop are totally
overpriced. i guess for fork seals, it's not as bad. just don't pay more
than 15 bucks for a set of leakproofs. 

let us know how it went, eh? 

- -Beth

         DoD#4508, AMA#542204, NGG resident crash test dummy
*****************************************************************************
             check it out: http://home.cwnet.com/beffie
              http://www.ziplink.net/~holm/ngg/ngg.html

------------------------------

Date: 4 Aug 97 08:53:01 EDT
From: AGabinet@dechert.com
Subject: GSTwin Jetting GS Twin

Hi Robert -- to answer your questions, the cost of the Stage 3 kit from K 
&N was $123.00, and it took about 90 minutes to do the job.  The 
application of the bike is trying to keep up with friends on faster bikes 
on backcountry roads!   I'm about to make a great leap forward in that 
regard, as I am buying an '84 Yamaha RZ350 Kenny Roberts Signature model  
(a radical two stroke bike) -- it is in parts now, but wait til spring!
- -------------
Original Text
From: suzuki-gs-twin(a)list.sirius.com, on 7/31/97 9:42 PM:
>For those interested in less radical approaches than swapping cylinders 
>with a GSX 1100, I installed a K&N stage 3 jet kit on my '90 GS500 last 
>week.  I have two kids under the age of 8, and I did the job in a single 
>evening, with them around, so I can't be too hard!  Simply a matter of 
>replacing the stock jet needles and the main jets, and junking the stock 
>airbox and breather for the K&N oil soaked filter and constant velocity 
>stack.  The difference in the bike is very noticeable -- lots more pull 
>lower down in the rpm ranges.

Just a few Questions?
        what was the cost?
        what is the application of the bike?


Robert

------------------------------

End of GSTwin-digest V1 #50
***************************



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