* THE "CARL
CLAMP" CLAMPING DOWN ON BENDING AND FLEXING
WOBBLES, WEAVES & SHAKING ISSUES.
UNDERSTANDING WOBBLES, WEAVES,
FISHTAILING AND HANDLING ISSUES
and swing arm
When you really start putting power to the rear wheel the swing arm
and the frame flexes. The solution brace
the swing arm ,brace the frame , stiffen the frame by replacing the
rubber engine mounts and fit radial tyres....standard bias ply tyres
belong on trucks.
Take a look at figure 2.
The generally accepted handling fix concerning the tightening
(or loosening of the steering bearings)
generally works. I
say generally because it solves the standard
wobble that occurs at about 35-45 mph when you accelerate or
slow down in that speed zone.
The weave occurs at
around 115mph either in a bend or on a straight road and is
generally a scary event causing you to slow down for fear of loosing
to stress that it is very important to have your steering head
bearings checked and adjusted. Just as importantly is to ensure that
the big locking nut is properly tightened.
If that nut is loose (even a little) it
can cause sufficient movement that can set off a wobble /weave ...I
speak here out of personal experience.
Fitting a steering damper also works however it adds incremental
stability and also is not a cure all solution and should be seen as
a series of modifications to the entire package.
Done all the mods ?
I think so ,except for the fork brace that is offered for sale by
many Vmax aftermarket vendors. This
device seems a thicker version of the standard device that hangs the
front mudguard over the front wheel. The
idea is that it braces the front fork adding stability....maybe it
does ,I have never tried it.
Take a look at figure 1.
This flexing of the fork occurs in braking, accelerating,
cornering or in combination of both.
It seems as though the flexing occurs on the stanchion in the
area below the triple clamp and above the fork slider.
Modern bikes have much thicker (read less flexible) forks and
it now seems clear why upside down forks do not flex (as much )as
conventional forks since the USD forks are
mounted in the triple clamps on the sliders and not on the
forks seem better suited to high performance motorcycles.
Can we try to stop or minimalise fork
Well short of fitting USD forks
(costly), the other option is not
to ride hard, brake hard or accelerate
hard-something which is near impossible on a Vmax.
I have a design for a possible cure for fork flexing which I
am having machined at this very moment.
When it is completed I will fit it, test
it and submit my results for your consideration.
If I can achieve this the Vmax will handle even better in
corners and high speed stability.
I am optimistic that this will work on the standard Vmax fork in
making it more sturdy and hopefully much less flexible.
Also I have not seen such a device fitted by any Vmaxer
anywhere on any web page and this may be a "Boerepatent" that may
work for me and also for other Vmaxers.
(see follow-up article below)
FOLLOW UP ARTICLES; UNDERSTANDING WOBBLES,
SNAKING, FISHTAILING &
CLAMPING DOWN ON BENDING AND FLEXING FORKS ...THE "CARL CLAMP"
In my previous article
"I am optimistic that this will work on the
standard Vmax fork in making it more sturdy and hopefully much less flexible.Also
I have not seen such a device fitted by any Vmaxer anywhere on any
web page and this may be a "boerepatent" that may work for me and
also for other Vmaxers."
See attached the pictures of the device that
I dreamed up and had machined .
The idea is to strengthen and brace the fork
stanchions themselves, in the section directly below the clamps up
to just above the fork slider when the forks are completely
compressed,thus restricting them from bending and flexing under the
immense forces of acceleration,braking and cornering.
again that all the previous modifications turned the Vmax into a
better handling cruiser than it has any right to do.This is true
insofar that Mr Max weighs at least 100 kg more than a
sportsbike.Yes a sportsbike has aerodynamics ,is superior at speeds
above 150 mph and also in very tight consecutive corners.In the real
world Mr Max (piloted by a competent rider)will however embarrass
many rookie(and intermediate ability) sportbike riders.This
hooligan packs enough muscle in the power cruiser arena to back up
its looks...a heavyweight cruiser that handles like an agile
middleweight on steroids....a power sportcruiser.
What did I set out to achieve with the
-to make the Vmax even more stable at high
-to make the Vmax more stable at tight
cornering , braking and acceleration
-Have I succeeded........the answer is yes
and apart from the clamps functionality it really looks the
therefore introduce to all South African(and overseas Vmaxers) a
modification that has (to my knowledge) never been thought of or
actually done before............................therefore beef up
your fork and clamp down on bending and flexing with a "Carl
have lowered the handlebars on my Max and now have lower flat
straight drag bars which are more conducive to faster cornering and
high speed straightlining.It still looks and sits like a bad ass
power cruiser and can turn from big lazy cruiser into mean hot rod
at the drop of a gear and the twist of the throttle...a real Doctor
Jeckyll and Mr Hyde.
Vmaximus maximus ,long live the power
Original Message -----
Thursday, June 14, 2007 4:42 PM
Clamps and Fin Maxers
Your handling remarks between Hans V's HD and
the Vmax is interesting insofar as the fork goes and the rubber
mounts and I agree.
a HD though the rubber mounts are there to dampen the vibrations.On
a Vmax the engine is counterbalanced(hence hardly any vibration) and
solid metal engine mounts serve to make the engine an internal part
of the frame and stiffen it up(frame brace too). If you ride a Vmax
to the same limit as the HD's maximum performance then the standard
Vmax is ok and should not show signs of handling problems.If memory
serves me the engine performance from a Hog at 1450cc makes about 65
hp at the crank and a lot higher torque figure.Horsepower is what
causes acceleration.The higher you rev the more the horsepower
increases and the torque decreases.
and tractors don't have lots(relatively speaking) of horsepower or
high reving engines. Torque is what trucks and tractors use to pull
heavy weights like ploughs and trailers.A Vmax without Vboost makes
about 85 hp(at 8500 rpm) at the rear wheel(about 100 hp at the crank
and probably more torque than a HD). A Vmax with Vboost makes 145
hp(reving at 8500 rpm) at the crank and about 116 hp at the rear
wheel.....that is approximately two times as much horsepower than a
Hog.The Vboost Vmax makes about 130 Nm at the rear wheel(at
6000rpm).The max has a relatively flat torque curve from 2500-6000
rpm whereafter it starts to drop as the revs increase.
Obviously the HD frame ,fork and swing
arm(and tyres) never has to cope with those types of power
delivery....ever.Power delivery ultimately ends up in the
tyres.Braking and cornering ability also depends on tyres.As I have
said before if the Vmax is ridden like a slow lazy cruiser no mods
at all ever need to be done.The problem is that the engine
overwhelms the entire package of fork,frame,swing arm and tyres when
the throttle is really twisted.The HD never has to face this
problem.Most handling problems are more noticeable when you start
pushing the higher levels of performance.
I am very pleased that your Max now handles
beter for you.If you do ride beyond 4000rpm through the gears then
radial tyres are better in terms of keeping the power
controllable.Also if you live in a area of wide open spaces(with no
hills)the standard Vmax is great.I have also reached a point that
my Max now handles and performs (excuse the pun) to the max and for
me I am pleased at the result.
Regarding the web site I am extremely
pleased.I somehow believed that things would snowball and get even
beter...great news Hans.
As regards the Fins it was very interesting.
What I also noticed from the pics was that
most of them did not have handling mods although one Vmax with many
handling mods and also NOS.
----- Original Message -----
Hans J P Knop
Thursday, June 14, 2007 6:50 AM
Subject: CLAMPS and FIN MAXERS
to me that the weakest point always has been the flimsiness of the
fork. My friend Hans' Harley, a heavy 300 kgs + bike, has thick USD
forks and ordinary, simple, thin, old fashioned Cross Ply tyres. The
engine is rubber mounted.When I had a ride on it recently, it felt
solid, comfortable, with a good roadholding as well.
I am now happy with my Maxes' roadholding and
don't find it necessary to make more improvements.
Original Message -----
John van Nieuwenhuizen
Monday, April 30, 2007 1:47 PM
I trust that you are well, I must
compliment you on maintaining the site. I find myself going back
more often. I keep an eye open for the date last updated.
Hans I have fitted the "Carl clamp"
and can strongly recommend it. One must bear in mind that Carl and I
have the "older" model having the 40 mm front forks with the single
I fitted the clamp this past week end
and took Mr MAX on a trail run. The difference in handling is felt
immediately. I have not done heavy braking so I cannot comment on
the braking at this stage. I would normally encounter a slight
twitch or noodle under acceleration through the V-Boost nearing the
Not so with The 'Carl Clamp" I found
the Brute gentle and very smooth all the way until I ran out of
road. You can use your knowledge and imagination of the VMAX power
and its capabilities to determine the speed involved during this
exercise. I have as you know done most of the frame brace
conversions and can recommend this clamp to all other VMAX owners.
Next on shopping list.Laser Jammer
Till we chat again
PS keep one wheel on the tar.
Saturday, 9 June , 2007.
I have also fitted 2 Carl's Clamps to my Max ,and
I must say, they
you look at the pic of the lateral displacement effects you will
understand that Carl's Clamps should make an inexpensive
alternative to an U.S.D fork, and will be a great improvement to
the fork's performance.
Original Message -----
Hans J P Knop
Sent: Sunday, June 10, 2007 7:22 PM
Subject: Re: VMAXWORLD eNEWSLETTER No 18 (J-T) - CARL'S FORK CLAMPS
i bought a 2002 v-max as you can see on my profile at v- max
world.my previouce bike was a zx600ninja,it was a pretty good
preformar in corners.i drove the v-max just as hard in corners but
never ever experienced the flex u guys are talking about.is my v-max
allready reinforced or is it just something everybody have in their
heads about a v-max?
Wednesday, June 13, 2007
I am pleased that the clamps are doing what they were intented
for.The fork stanchions where definately bending and flexing in all
directions under braking, cornering and acceleration.Thanks for the
kind words from you and John.In my opinion the clamps also look
good on a cosmetic level.
After doing all the possible mods I
had done,I realised that the front fork was a huge problem.John van
Nieuwenhuizen and I debated USD forks however I was not prepared to
spend almost R20 000 on a usd fork from the UK. I sat for many hours
staring at the forks and came up with the idea of the fork clamps.It
was merely a question of understanding the problem and finding a
suitable cost effective solution.It is such a simple device and I
doubt that it can be improved or simplified.I guess it can be
cosmetically changed however the principle remains the same.
When I designed and fitted the clamps
it was simply my intention to improve my bike.If other fellow Maxers
want clamps that is fine.As I said previously it is possible to
commission any machinist to make the clamps.I am just not sure that
they can be made for cheaper than what my machinist charges.The
price is R550 plus R30 for registered mail or R 90 for overnight via
Speed services courier.I will take orders (if anyone is interested)
in the same way that I did yours and John's.
As regards to Marius Swanepoel I am
tempeted to answer:
Welcome to the Vmax world and the
ZX600 Ninja is certainly a very good example of a plastic sport
racing bike and vmax can in all likelyhood never handle better than
any modern technology lightweight machine.The vmax is just too
chubby for that.That does not mean that the Vmax cannot handle
around corners.At the Vmax rally there was a Vmaxer(I cannot
remember his name) who cornered so hard that on both sides both his
foot pegs where worn away.
Please read the technical tips
page,it is loaded with all sorts of mods that according to several
local Vmaxers and also legions of Vmaxers overseas, improve and
enhance the Vmax even more.That said please remember that even in
its most modified form the Vmax is essentially a heavy power cruiser
on 23 year old technology.If you want the fastest top speed bike and
the best track racer, purchase a new plastic racer every two years
because next years bike will be faster.Weight is a big factor and
Vmax will remain heavy,even if you chop as many things off as you
can it will still be 80 kg plus heavier than modern bikes.
No motorcycle jounalist would even
dream of putting a 2000 model of any bike against a 2007 model of
the same bike...the 2007 model is just too technologically advanced
in all regards..the Vmax cannot outbrake a lighter bike into
corners..it cannot outperform a light sportbike around very tight
corners and chicanes...it is not faster than 240 km/h top speed.It
is however a Vmax..a legend ..an icon ...a bad
motherf#@*r .Some of us who ride them, have improved them by
100% in handling without touching the engine.I know what a standard
Vmax rides like(rode it like that for almost 2 years for 25 000
km) and I know what an improved Vmax handles like(I have done the
mods one by one and can feel the difference and have done a further
46 000 km since).Why do I still ride a 23 old bike....because I
can...because it is a Vmax.
I am pleased that you enjoy your Vmax
and that it performs for you as well as your old bike.I also accept
what you say namely that many people dismiss the Vmax as a bad
handling bike and yes it probably does when unfairly compared to the
handling of a modern bike.Ask yourself the question..."how many
people are out there on the road on a 23 year old bike ?".
No one sneers at Mr Max.It might not
be the fastest (anymore)but in 1984 it was and there was nothing
like it.It started the craze for bikes that were exceedingly fast
and the idea of a fast chopper cruiser hotrod is only now catching
on.The Vmax was way ahead of its time.
Vmax is not reinforced if is still standard and I assure you that in
standard form it does flex in the swing arm,frame and
fork.Furthermore the cross ply tyres on standard Vmaxes are truck
tyres and are nowhere near the perfomance to be obtained from radial
tyres .When you are on radial tyres the grip and performance
improves and the flex of all the parts mentioned is more
noticeble.Anyway welcome once again .
Ok Hans regards
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