Performance Mods to Suzuki VX800
mike tiberio
bought one used and started looking through my old road test literature.
For those that don't know the VX800 is a standard based on the Intruder
(harley cruiser clone) drivetrain. It has less rake than an intruder,
shorter gearing and a longer swingarm. more on this below.
It seems we can do a number of things to the chassis to get this
beast into more of a Road Racing mode. First it looks like a GS500E
front wheel will bolt right on that would take us from 3"x18 front
rim to a 3"x17" front rim. In the back I was thinking about having
Kosman widen the 3.5"x17" rear hoop into a (Hawk Spec) 4.5"x17" rim.
My Feb. 1990 Cycle puts the bug in my ear about the swing arm and
gearing. Suzuki gave the VX shorter gearing than the Intruder, and
a 2" longer swing arm than the Intruder. A swap of a Intruder swing
arm, drive shaft and rear drive unit would reduce the wheelbase 2"
and give us taller gearing to boot, which may compensate for the
low profile radials I would probably run on the wider rear rim.
My question to net land is: Has anyone modified a VX800 or considered
any of the above mods? Secondly is anyone a suzuki parts expert,
and could you comment on my parts swapping plans? Thirdly are there
a good variety of tires for a 4.5x17 rear rim?
PS: road racing this beast would not be out of the question if all
these mods could be done.
mike tiberio
> mike tiberio (mtib...@bbn.com) wrote:
> : it looks like a GS500E
> : rim to a 3"x17" front rim. In the back I was thinking about having
> : Kosman widen the 3.5"x17" rear hoop into a (Hawk Spec) 4.5"x17" rim.
> : My Feb. 1990 Cycle puts the bug in my ear about the swing arm and
> : gearing. Suzuki gave the VX shorter gearing than the Intruder, and
> : a 2" longer swing arm than the Intruder.
>
> are going to go to that much trouble why not go ahead and put
> a better front end on it ,be aware that the 17 inch front will
> decrease rake and trail figures.
I would keep the current 41mm fork just cause I'm cheap. With 30
degrees of rake and 5 inches of trail, it could stand some
decreasing of both.
>
> As for the rear end ,shitcan the Intruder swingarm idea ,the
> longer swingarm on the VX controls shaft effect much better ,if
> you want different gearing I believe the Intruder gearing i.e.
> ring /pinion etc. will work with the existing shaft etc. and
> I think it's the same gearcase.
> With such mods it could be a great streetbike with appropriate
> suspension mods but racing it would be an exercise in futility and
> a lesson in feeding Grovers to the Monster.
Having raced a Moto Guzzi in Pro Twins for 4 years, I know about
futility (although I did finish ahead of Polen and Picotte when they
DNF'd =8^O), I also did my share of burning bucks.
Decreasing the VX's wheelbase from 61 down to 59 inches would be worth
any bad effects from increased shaft effect. And don't forget shaft effect
can have some good effects on handling. Rear shock extension under
throttle helps keep front ends down (but doesn't prevent wheelies as a
recent thread might imply) and rear end squat under chopped throttle
helps elimnate front end loading preventing (but not eliminating)
front end wash out. I would probably look for an assembled gearcase
just so I could swap them around depending on my mood (or track).
Bryan Hinkle
: It seems we can do a number of things to the chassis to get this
: beast into more of a Road Racing mode. First it looks like a GS500E
^^^^^^^^^^^^^^^^^
Improvement is there for the having but the above is
unrealistic.
front wheel will bolt right on that would take us from 3"x18 front
: rim to a 3"x17" front rim. In the back I was thinking about having
: Kosman widen the 3.5"x17" rear hoop into a (Hawk Spec) 4.5"x17" rim.
: My Feb. 1990 Cycle puts the bug in my ear about the swing arm and
: gearing. Suzuki gave the VX shorter gearing than the Intruder, and
: arm, drive shaft and rear drive unit would reduce the wheelbase 2"
: and give us taller gearing to boot, which may compensate for the
: low profile radials I would probably run on the wider rear rim.
are going to go to that much trouble why not go ahead and put
a better front end on it ,be aware that the 17 inch front will
decrease rake and trail figures.
longer swingarm on the VX controls shaft effect much better ,if
you want different gearing I believe the Intruder gearing i.e.
ring /pinion etc. will work with the existing shaft etc. and
I think it's the same gearcase.
: any of the above mods? Secondly is anyone a suzuki parts expert,
: and could you comment on my parts swapping plans? Thirdly are there
: a good variety of tires for a 4.5x17 rear rim?
: PS: road racing this beast would not be out of the question if all
: these mods could be done.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
With such mods it could be a great streetbike with appropriate
suspension mods but racing it would be an exercise in futility and
a lesson in feeding Grovers to the Monster.
B.
Sean L. Okeeffe
: Decreasing the VX's wheelbase from 61 down to 59 inches would be worth
: any bad effects from increased shaft effect. And don't forget shaft effect
: can have some good effects on handling. Rear shock extension under
: throttle helps keep front ends down (but doesn't prevent wheelies as a
: recent thread might imply) and rear end squat under chopped throttle
: helps elimnate front end loading preventing (but not eliminating)
: front end wash out. I would probably look for an assembled gearcase
: just so I could swap them around depending on my mood (or track).
Shortening a street bike's wheelbase by shortening the swingarm really
seems like a no-no when it comes to handling. On a race bike that is a
marginal one, like the VX800, where high speed handling isn't so hot
anyway, increasing the weight bias to the rear wheel off of the front is
going to make high speed turning very interesting. Jump over to
rec.moto.racing and lay this on a few of the truly experienced in the
formula singles or twins classes.
Sean
James Montebello
: Shortening a street bike's wheelbase by shortening the swingarm really
: seems like a no-no when it comes to handling. On a race bike that is a
: marginal one, like the VX800, where high speed handling isn't so hot
: anyway, increasing the weight bias to the rear wheel off of the front is
: going to make high speed turning very interesting. Jump over to
: rec.moto.racing and lay this on a few of the truly experienced in the
: formula singles or twins classes.
This made me smile, and I'm sure Mike is laughing out loud. For those
who don't know, Mike T. is *very* experienced at racing uncompetitive
twins. He's a National-level AMA racer, who's spent most of his time
on self-tuned Guzzis. While this is certainly a surprising project
for him, I have no doubt he could make a go of it.
As Mike stated, shortening the swingarm isn't necessarily a bad thing.
The VX is actually quite well known for its high-speed stability, thanks
to very lazy steering geometry (31d/5.6in!) and a mile long wheelbase
(61in). Moving the weight bias back will certainly lighten the front
on corner exits a tad, but the shaft-effect will help to nullify that
somewhat. Getting the bike to steer quickly will be a big plus.
--
Chris BeHanna
:>Mike Tiberio writes:
^^^^^^^^^^^^
:>:[...shorten VX800 wheelbase...]
:>[...I think it's a bad idea, here's why...]
:>Jump over to rec.moto.racing and lay this on a few of the truly experienced
^^^^^^^^^^^^^^^^^
:>in the formula singles or twins classes.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Snigger. Harf. Guffaw. Chuckle!
Mike, how many years did you hold the #1 plate in whatever twins or
vintage class that was?
:-)
--
Chris BeHanna DoD# 114 KotSTA Ed Green 1975 CB360T - Baby Bike
beh...@syl.nj.nec.com Fan Club #004 1991 ZX-11 - Zexy
kore wa NEC no iken de gozaimasen. FOLMA #17 1973 RD350A - seized
Why is Lon Horiuchi still breathing? 1987 EX500 - the RaceBike
Only in America can a homeless veteran sleep in a cardboard box while a draft
dodger sleeps in the White House.
mike tiberio
> :>Jump over to rec.moto.racing and lay this on a few of the truly experienced
>
> Mike, how many years did you hold the #1 plate in whatever twins or
> vintage class that was?
To glorify myself...(BTW all on Guzzi shaft drive v twins)
4 Time WERA Super Vintage National Champion (1988, 1990, 1991, 1992)
3rd in class (Pro Twins GP2) AMA Motorcycle Grand Prix of Miami 1990
3 time Top Ten National Series Ranking AMA Pro Twins (1990, 1992, 1992)
list of folks I have beaten in pro twins (of course due to their DNF's)
doug polen feracci 888
pascal picotte feracci 888
andrew stroud britten
over 200 races (pro and amateur) only 5 mechanical DNF's
over 35 wins
100's of trophies.
many regional twins and vintage titles...bla, bla, bla...
and heck if I was humble I'd be perfect...8^)
seriously, the reason I post questions is to learn from others
experience. While I was half tounge in cheek thinking out loud
about racing a hot rodded vx800, the mods to do so are still
interesting intellectual fodder. On the long shot that someone
knew something about Suzukis, and could possibly spare me wasting
many $100's in attempting a parts swap that had some hidden gotcha,
I will asking for help on the net. I have since decided to go for the
real go fast mods, a neon kit, a tank bra and a fender eliminator kit.
Sean L. Okeeffe
: seriously, the reason I post questions is to learn from others
: experience.
Well, enlighten me here because I'm still unconvinced that shortening the
swingarm by a couple of inches on a bike with so much rake will be a plus.
Did you try that on a Guzzi? What kink of steering angle do/did they have?
And did you at the same time change the (rear) ride height radically?
Shortening a swingarm is opposite what I've always heard and have seen
sold in the aftermarket (like RD swingarms), unless you want to do
wheelies more easily.
I will admit that when I owned a Virago (long wheelbase, shaft, lots of
rake) I used to swear that it handled better with my girlfriend on back.
I later read the same thing in an old road test. After switching springs
front and rear and raising the fork tubes in the clamps, my girlfriend
became more of a hindrance. It's okay now, though, I got rid of the bike
and she got rid of me. The bike was prone to sliding the rear. Even
with a very, very worn front tire, there was never any concern with it
washing--although I never braked through turns or that type of thing.
A little off the topic, but I found it puzzling...
I think the reason that more people didn't give their input to the issue
is the title of the thread--VX800's probably don't grab people's interest.
Sean
Billy Brownsberger
[lots of interesting ideas about modifying a VX800...]
Mike, sell the Suzuki, sell all your Guzzis, and buy a Ducati.
Of course, you probably wouldn't like it. I guess it would
be boring to not have to re-engineer the bike before racing
it, to not have to worry about parts-swapping from other models,
to have nothing on your mind other than just riding it. I
guess now that I think about it I can see the allure of taking
something which was never intended to see a racetrack,
alter it to the point of being unrecognizeable, dump truck-
loads of money into it that you'll never see again, and then try
to race it against machines which are obviously superior in
any contest of speed or handling. Yeah, it's all becoming so clear
to me...
This gives me inspiration! I'm gonna buy back my old
Garelli moped from that kid, work on it for a few months, and
take it racing in FIII. Those RS125s aren't that fast, are they :)
But before I get started, I think I'll beat my head against the
wall for a few hours, just to get in the mood...
Mike, hope you took all that in the spirit it's intended. If all
of us had my attitude, we'd just buy whatever bike seems to
be the best for that particular class, and we'd have a bunch of
spec-type classes, which would bore the fans, and ruin our sport.
It's guys like you that keep things interesting for us all, and
for that, I thank you.
Good luck with whatever your next project is!
Billy
MiffMole
Davidson SR100 baja. It'd be pretty tall, but the wheelies would be
mind-boggling.
Miff