Probably because im from NZ and know alot of people on here, genius![]()
Probably because im from NZ and know alot of people on here, genius![]()
What i was getting at is, if Robert was able to use some form of data logging then I am sure the benefit would filter down to ALL and that would be a saving for everyone Re; tyre wear etc, I am not asying it will save bulk but any saving is a good one. It may take a season to filter down but so what!
More promotion is great but who pays for it? Red put his hand in his own pocket for the JBM and he deserves the kudoe there, are we all prepared to do the same thing? I doubt it! Most are moaning about entry fees now! In reality they are very low, back in 1991 I paid 300 pounds to enter a club event in the UK and I had to qualify ofr a start!
I don't mind the fees rising as long as I can see that it will be used appropiately for my chosen sport and not spirited away on junkets ar frivilous parking spots!
As is well known, Robert is a gun with suspension, the trade off is he is hopeless with 'puters!
Here is an interesting submission from RT
ATTN: MNZ ROAD RACE COMMITTEE
3-4a: Privateers Cup Rear Suspension Unit. The following is the only change allowed: Rear Spring
I would like to make comments re the above proposed ruling for 600cc road race
privateer class. I am neither a member of MNZ or any affiliated club. However the
Company I co own with Shayne King (an MNZ member) is the biggest supplier of
whole suspension units and upgrade components to the road racing and motocross
fraternities in New Zealand. Our investment is substantial, not only for reasons of
commerce but also a substantial investment in knowledge and experience. Much of
the knowledge we have passed on for the good of the sport.
As will be well known I am at odds with a number of your CEO’s views and actions
and I would hope that this submission is dealt with in due consideration of the
material presented and free of emotion. I recall a letter the CEO penned for BRM
magazine in which he stated that he had tested a number of the late model 600’s on
Pukekohe track. He thought they worked well with no suspension or tyre issues and
that comments that disagreed with his (ie mine) were “BS”. With all respect to the
CEO, Pukekohe is very much anachronistic to every other track in N.Z. (requiring a
softer overall set up) and his pace is very much off that of our current racers. So he
was hardly reporting from a basis of challenging the limits of the machines he rode
and couldn’t exactly comment on the stability of their performance on our disparity of
circuits that throw up different challenges. ( Teretonga being an extreme example
regards rapid tyre degradation ) To that end I’d pay much more credence to the views
of our top and more experienced (and current) road racers.
ITS ALSO TOTALLY RELEVANT TO POINT OUT THAT MODERN DAY
PRODUCTION MACHINERY IS MUCH MORE SENSITIVE TO SETUP
THAN IN YEARS PAST AND THE CONSEQUENCES OF LESS THAN
PERFECT SETUP ARE MUCH MORE NEGATIVE.
AND ………. IF STOCK SUSPENSION IS THAT GOOD WHY DOES NO
ONE RUN IT IN WORLD SUPER SPORT 600/WORLD SUPER STOCK?
But, it is fair to say that I have no issue with the basic intent of the rules and if it
attracts more competitors then all good! But I do take (technical) issue with only a
spring change being allowable to the stock shock. To that end I make the following
points;
1. SPRING RATES ARE ABOUT POSITION, DAMPING IS ABOUT CONTROLLING RATE OF CHANGE OF POSITION. Sure enough spring rates need changing for varying rider weights, height and skill but this does absolutely nothing about controlling one of the biggest single issues in road racing:- Rear end acceleration squat/chassis pitch control and resultant understeer off corners. This is simply because stock sports bike shock absorbers are internally calibrated for road use, and because of that a decent level of comfort is a pre-requisite. Get them on a race track and you’ll find the rear end squats excessively off especially the tightest low gear corners, somewhat prevalent on our NZ tracks. That manifests itself as understeer and also overstresses the rear tyre too quickly as the rear shock is getting too readily into the rising rate part of the link curve. We see this issue very often just with ordinary every day track day riders and many of the riders come to us requesting a fix after finding out that external adjusters will not do so. As I have been at pains to point out many times external adjusters are not a magic fix all, many people still do not comprehend that fact. They only operate in a small/narrow range.
The simplistic but incorrect approach is to fit a firmer spring to try and control this squat. But then the spring is often too firm to ride the bumps on the track! Or to put it another way; the rider weight will suggest that a certain spring rate is correct to achieve the correct correlation of rider sag and static sag. SO WHAT THE RULING IS IN EFFECT SAYING IS IF YOU ARE HAVING A SQUAT ISSUE OVERSPRING IT! FRANKLY THAT IS A 1970’S SOLUTION WHICH DOESN’T CUT THE MUSTARD NEARLY 40 YEARS ON.
2. As an example a 75kg rider will likely not need to respring his late model GSXR600 or R6 (or in fact any of the current 600’s) because the standard spring satisfies the sag ratio’s but the bike squats too much exiting turns and burns up the rear tyre too quickly. This is a commonly reported problem!
Those who don’t fully understand suspension will say in response “just turn in the clickers” but it is a common misconception that external damping adjusters are a magic fix all and manufacturers publicity machines/magazine testers are guilty of perpetuating that myth.
Closing in the clickers does very little to alter the opening pressure of the shim stacks, because they predominantly only regulate bypass bleed!!! A LOW SHIM STACK OPENING PRESSURE IS THE EXACT REASON ROAD BIKE CALIBRATED SUSPENSION HAS POOR SQUAT CONTROL WHEN USED IN ANGER DURING A TRACK DAY OR DURING A ROAD RACE. Moreover, if you close in the clickers to near or full closed the shock loses its pressure balance and cavitates internally. This is an issue that shock manufacturers such as Showa, Kayaba, WP and Ohlins are abundantly aware of and why all of those companies have race specific settings and train people worldwide to install and optimize such settings.
3. Even high quality aftermarket shocks such as the brand we sell (Ohlins) come
out of the box set up for the road and will squat excessively when used in a road bike with no internal recalibration. Before they are raced we spring and valve them according to rider weight and height statistics, speed, tyre type and brand, power output etc.
OEM ROAD BIKE SHOCKS HAVE LOW SPEED COMPRESSION CONTROL THAT IS WEAK AND POINT OF FACT VERY DECENT IMPROVEMENT CAN BE YEILDED AT LITTLE COST.
4. So back to our 75kg rider example. Instead of a replacement spring at nigh on $300.00 for almost exactly the same cost there are very well proven techniques for revalving the shock piston. Ironically those techniques we have learnt working with the Ohlins product and their large databank of setting information and knowledge. Given the choice between doing the job incorrectly (by overspringing) or doing it correctly (by revalving) I know what I’d choose. I also know what would achieve the best result. THAT ALSO REFLECTS RATHER IMPORTANTLY IN EXTENDING TYRE LIFE.
A heavyweight rider who wants to be competitive will logically require a very substantial increase in spring rates at both ends to achieve correct sag ratio’s. But there is now so much spring force that the stock rebound valving is too weak to control re-extension of that spring! Its hardly a level playing field if it is not permissible to revalve that shock. (and dare I say, forks).
1. Unlike the situation and technology (or lack if it) that prevailed in the 70’s/early 80’s most shocks were sealed for life and non rebuildable. Chassis were relatively flimsy, tyres narrower with much lower grip levels and engines significantly less powerful. Less challenging times and arguably the bikes were more forgiving . But the whole point is the technology of the current bikes has change significantly and 1970’s solutions are now no longer a cure.. Here now in the 21st century sportbike shocks are now serviceable and a whole worldwide industry supports that fact.
2. SO HOW WOULD YOU POLICE IT?
Occassionally a shock will leak so it will need to be pulled apart to fit a new bushing and seal kit. To do so invariably requires grinding/machining/de-peening of the base locking nut to withdraw the seal head to service.
Also, such shocks are bladder type to separate the nitrogen gas from the oil. Such rubber membranes leach nitrogen into the oil, much as a car tyre leaks its air pressure back into the atmosphere, and this happens far more quickly than is commonly realized, given that charge pressure is 10-12 bar. Because of this aeration of oil problem these shocks need servicing frequently to maintain peak performance, much more so than a shock employing a piston seperation system. (and more precise tolerancing and higher spec material choices).
3. No suspension specification cards exist as such for OEM sport bike shocks. They are built as a component by an outside vendor (e.g predominately Showa, Soqi and Kayaba) and supplied to the bike manufacturer. It is not a habit of such vendors to supply their internal valving specs and I suspect that is because there may be a mixture of technical sensitivity and product liability laws in certain countries. Valving specs have in fact never been available from the manufacturers. So the only realistic option would be to strip a brand new suspension unit from every make/model of bike homologated for the series and record the internal settings, piston dimensions, bypass orifice sizes, etc. A labourous task and who’s going to pay for that to be done?
NEEDLESS TO SAY A SIMILAR SITUATION WOULD HAVE TO PREVAIL WITH FRONT FORKS.
It therefore makes a whole load of sense to ALLOW REVALVING OF THE STANDARD OEM SHOCK ABSORBERS. (AND FRONT FORKS FOR EXACTLY THE SAME REASONS) That would totally negate the need of constant technical inspections and the constant inevitability of protests, such as seen in many controlled classes. Not a pretty sight at the best of times as it brings out the worst in people. (just evidence Formula 3 this past year) I can think of at least two internal shock mods that would be highly effective and virtually undetectable except by a very skilled and experienced suspension engineer and access to a suspension dyno. It should also be considered to allow fitting of aftermarket piston kits (e.g Race Tech or from any other manufacturer that sells pistons in the appropriate sizings). There is a huge database of set up info with such kits that anyone can access and that levels the playing field somewhat.
Unless you ban suspension engineers from the class, I don’t see how you can police such a proposed ruling. Even “sealing “ of shocks is less than fool proof, as has been proven in auto racing over and over again. The only other alternative is to transport a portable single phase shock (and fork) dyno to every single meeting, that’s a $30,000 investment plus the need (and cost) of a skilled and knowledgeable operator. That is a step that has had to be taken in the Toyota Racing series.
I respectfully ask that MNZ give full consideration to all that I have said above. I’ve spent 25 years in the suspension industry and right at the sharp end including under contract directly to Ohlins for WSBK testing. Suspension, chassis and tyre interaction is EVERYTHING in 600 and 1000cc class racing and all competitors and technicians at the sharp end acknowledge that. I would also reasonably hope that of all the submissions you receive you give more weight to those from people that have relevant experience (and I mean up to date experience) in such racing classes.
I an available for further comment at anytime.
Yours faithfully
Robert Taylor
Data logging isn't that far out of reach to the average joe. I have a basic 2D logger system that I use to initially setup the fueling on my bike before nationals. It reads throttle position, RPM, front wheel speed, Lambda etc. When you work this out in comparison with a day or 2 on the dyno, and the fact that it is interchangable between bikes it is actually a very good price.
I have tried various solutions, believe me! Having a home track as abrasive as Teretonga can be hell! I have raced 400 - 250GP - 600's - 1000's there. As you go up in the HP the more you NEED tyre/suspension that is compliant. I am being completely honest when I say that regardless of springs, tyre pressures and compounds you need other changes. Granted all of these other things are equally important, but unless you have control inside the shock you will honestly just chase your tail!Thanks for you input Maido but did you do any tests or try other compounds, pressures, springing etc to try and get the standard shock to work?
I take it (just a guess) you attend mainly track days with a bit of racing? I do some coaching for the local club's as well as quite a bit for HRC, usually doing all of the South Island Tracks (I helped at the HRC day in Taupo a year or so back). Now from personal experience, I can tell you factually that even the road riders experience completely different results in their tyres from Ruapuna to Levels to Teratire. The tracks offer very different forces which cannot be completely controlled by springs. Hopefully this shed a bit of light on the situation.
No disrespect, and I don't know how fast you ride, but as I haven't met you at a national meeting I will assume that you aren't at a Nationals pace, which is fine. Until you have actually ridden at the speed that makes a shock really start to matter (around Puke I would say you would need to be doing at least a 1.02 on a 600) then you can't really explain it to someone who hasn't why it is so important.
This isn't a personal attack so don't take it the wrong way please, i am trying to get my point across
As you know, I aim to give my sponsors value for money and try and present my team in a professional manner, thats why I can see the benefit of Shauns letter and ideas. It can only be a good thing for all concerned, me ,you, the riders and the sponsors. It is a pity that so many are short sighted when it comes to promotion! I know that quite a large portion of my yearly budget goes on promotional things.
I'm not sure why you stopped short of suggesting leaving current suspension rules for 600's in place for a privateers cup... as anything less...will infact slow the privateers down...and make them dangerous to faster riders....hell...it will probally make it harder for them to make qualifying cut of times, if ran in the same class as 600SS
Well argued Robert
Heres my submission to MNZ for the superstock 600's
Hi, as has been widely discussed valving changes should be allowed to a superstock 600 class for race bike setup for obvious reasons. No need to re-invent the wheel just copy Aus superstock 600.
Note rule 15.8.0.7
n) Front and rear suspension springs
and internal components, but external appearance must remain unchanged.
Regards Shaun Pattenden
http://www.ma.org.au/AM/Template.cfm...ntFileID=43411
15.8 SUPERSTOCK 600
15.8.0.1 Subject to the required and permitted
alterations set out below, Superstock 600
machines must:
a) Be fitted with ADR compliance
plates for the particular machine,
b) Be eligible for registration in all
States and Territories in which they
compete,
c) Be of a make and model lawfully
sold in Australia,
d) Be as constructed by the
manufacturer,
e) For 2 cylinder engines, have an engine
capacity of no more than 750cc,
f) For 3 cylinder engines, have an engine
capacity of no more than 675cc,
g) For 4 cylinder engines, have an engine
capacity of no more than 600cc,
h) At least 20 production machines of
that make and model must have
been imported into Australia by
the manufacturer or the Australian
distributor representing the
manufacturer.
15.8.0.2 Tyres must be homologated by MA and
must:
a) Be commercially available in
Australia,
b) Be manufactured for road use in all
weather conditions,
c) Be not less than the machine
manufacturer’s recommended
speed and load rating,
d) Be worn no more than to the
minimum tread depth indicators,
e) Not be manufactured for only
competition use,
f) Not have an augmented or modifi ed
tread pattern,
g) Comply with the service description
(load and speed rating) as
permanently moulded on the OEM
tyre side wall,
h) Comply with the relevant requirements
of the nominated standard. e.g.
ETRTO, JATMA & TRA.
15.8.0.3 When, a race or practice has been
declared ‘wet’, the use of a special
tyre commonly known as a wet tyre is
allowed. Homologation of wet tyres is
not required.
15.8.0.4 To be permitted to compete, a machine,
without rider, empty of fuel, but with all
other fl uids at optimum levels, must
weigh no less than:
a) 162kg for 4 cylinder,
b) 162kg for 3 cylinder,
c) 170kg for 2 cylinder.
15.8.0.5 A 1% tolerance at post race control will
be allowed.
15.8.0.6 The following must be removed:
a) Head lamp,
b) Tail lamp,
c) Reflectors,
d) Horn,
e) Traffi c indicators,
f) Mirrors,
g) Centre and side stands.
h) Registration plate / bracket and label
holder.
15.8.0.7 The following may be replaced or
modifi ed:
a) Fairing,
b) Screen,
c) Rear body work,
d) Seat,
e) Mudguards,
f) Tank covers, and
g) Frame side covers,
but replacements must be the same in
shape and appearance as the original.
h) Mounting bracket for fairing, screen
and instruments, but replacements
must be mounted in the original
position on the frame,
i) Passenger footrests,
j) Spark plug type, leads and cap,
k) External gearing and chain, but not
chain pitch,
l) Brake pads, linings and brake hoses,
m) The muffl er and tail connector pipe
at the bolt-on or slip-on fl ange joints
only, the original header pipes
must remain as supplied by the
manufacturer,
n) Front and rear suspension springs
and internal components, but
external appearance must remain
unchanged.
o) Handlebars, but replacements must
be mounted in the original position
on the fork assembly and have
the same profi le and shape as the
original assembly,
p) Footrests and foot controls, but the
replacements must be mounted at
the original mounting points, and
q) Air fi lter element,
r) Engine and gearbox breather tubes
and the radiator bottle overfl ow
must exhaust into the airbox to the
rear of the intakes. The lower airbox
breather tubes must be blocked.
15.8.0.8 The following may be added:
a) Steering damper,
b) Ride height adjuster, providing there
is no modifi cation or alteration to
frame or rear suspension unit.
I agree with you but if I argued that I would be accused by the pygmies that both constantly whinge on this site and inhabit MNZ of having an agenda.
But as youve come to mention it these are the advantages that I can rattle off the top of my head of having quality aftermarket suspension, in random order;
1) Gas piston separation system in a precision honed bore. Prevents constant and rapid areation of the oil through a porous rubber membrane ( bladder ) so the shock doesnt turn into a ''milkshake'', deteriorating its damping response.
2) As knocking out of shock units at the lowest possible price is not number 1 on the agenda there is rather more attention paid to; a) close, precision tolerancing and b) higher quality material choices and closely matched coefficients of heat expansion between key working components to minimise / eliminate fade.
3) Top shaft bushings in many oem shocks run dry, in high quality units such as Penske, WP and Ohlins the bush runs wet, less wear, less friction
4) WP and Ohlins frequently employ internal top out springs in the sportbike and race shocks. There is a choice of these in length but also rate to match the rate of the main spring. The effect is to counterbalance the main spring force at the top reaches of stroke. This allows more agressive main spring preload settings ( where required ) and precludes relatively uncontrolled ''topping out'' There are very plausible benefits in braking performance ( you can go in later under brakes ) Edge grip, pitch control and off corner traction.
5) Companies such as WP, Penske and Ohlins often provide setting banks of alternative internal valving specs for different race tracks and scenarios. It is expected that their relevant distributors in each country will provide high level technical support. ITS NO DIFFERENT IN MX, we have different settings for sand and hardpack surfaces. We won the 3 major junior MX titles at Taupo on the weekend using a mixture of Ohlins, Pro Circuit and Race Tech suspension. Perhaps the CEO wants to ban aftermarket suspension in that sporting code as well? He delighted in telling me that a European rider went very well with stock suspension at the last International there, he forgot that the same rider crashed heavily and didnt come back.
6) Spring options are much more readily available than with oem shocks. Heck we very often exchange them at no charge.
7) Main piston rings are of an expanding type to compensate for main body tube heat expansion, this precludes fade. One of the big issues with oem, especially if you ( often ) have to instal aggressive settings
8) Oil selection in such shocks is usually very ''top shelf'' assisting stability of performance and ultimate service life.
Part 2...
9) Modular construction means that you can usually purchase every individual piece. Try that with a Japanese shock.
10) Convenient quick and easy length adjusters for rapid geometry changes. Very seldom seen on sportbike shocks.
11) Great residual value. Purchase of such shocks is not ''once only dead money'' They are highly sought after second hand and are often transportable from model to model with update changes. Many distributors will trade used for new.
12) In the advanced designs that come from companies such as WP, Penske and Ohlins there are benefits to be realised inride height control, mechanical grip, compliance, tyre life and stability of performance.
13) Better response range from external adjusters, especially in designs that dont rely totally on shaft displacement to create damping.
14) Much easier to recalibrate for trackday / road race use
15) Twin tube recirculating designs have perfect pressure balance. That means the gas pressure can be significantly lowered, that in turn sizably reduces main shaft seal to main shaft friction. The shock is more responsive.
16) Compared especially to short squat single tube shocks there is a huge percentage increase in fluid and nitrogen gas capacity. That significantly aids stability of performance.
17) Such shocks are designed to be quickly and readily serviced, where oem ones really are not.
And doubtless etc etc....
I fear the day technology will surpass our human interaction. The world will have a generation of idiots! ALBERT EINSTEIN
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