Pro-Twin discussion

[wayne]

in reply to robert,
well karl won every race and i think sam was beaten fair and squarely by mr jones at ruapuna, compare apples with apples..........i believe they both deserved there wins, and everyone had fun........

[Robert Taylor]

in reply to robert,
well karl won every race and i think sam was beaten fair and squarely by mr jones at ruapuna, compare apples with apples..........i believe they both deserved there wins, and everyone had fun........

Yes indeed, no argument. And the point I was trying to make is the improvement in lap times was not all about the riders.

[svr]

Yes indeed, no argument. And the point I was trying to make is the improvement in lap times was not all about the riders.

It's a valid point. For a `control class' there is now quite a bit of additional cost and development involved in producing a competitive bike.

[Robert Taylor]

It's a valid point. For a `control class' there is now quite a bit of additional cost and development involved in producing a competitive bike.

All perfectly within the letter of the rules and isnt it human nature to make things as best as possible within the rules?

[GSVR]

All perfectly within the letter of the rules and isnt it human nature to make things as best as possible within the rules?

The letter of the rules is an interesting concept Robert. Having looked closely at many ProTwin bikes I find almost universally all have had their emission control canisters and pipework removed which if you read the rules is definately not allowed!

Funny how some stuff that is spotted that is technically legal is pursued and other stuff is just overlooked. Possibly it has something to do with the knowlege of the people doing the checks or who is instructing them.

[svracer12]

please go into this more. i need some more horsepower.

[GSVR]

please go into this more. i need some more horsepower.

Well if your in ProTwin there is no worry as everyones got the same HP.

My thoughts on why Sam is so fast is he gets on the gas sooner and harder out of corners and brakes later and less into corners than his fellow competitors.

He's also reasonably light and has for want of a better word "balls".

[Robert Taylor]

The letter of the rules is an interesting concept Robert. Having looked closely at many ProTwin bikes I find almost universally all have had their emission control canisters and pipework removed which if you read the rules is definately not allowed!

Funny how some stuff that is spotted that is technically legal is pursued and other stuff is just overlooked. Possibly it has something to do with the knowlege of the people doing the checks or who is instructing them.

Fair enough points. I should have clarified my particular interest, suspension. I have little interest in engines other than having to ''accomodate'' some abrupt power delivery curves that can tie suspension in knots.

[Robert Taylor]

Well if your in ProTwin there is no worry as everyones got the same HP.

My thoughts on why Sam is so fast is he gets on the gas sooner and harder out of corners and brakes later and less into corners than his fellow competitors.

He's also reasonably light and has for want of a better word "balls".

Theres a very simple mod we do to the emulators that allows later braking and better ride height control. Note also that the first two placegetters in both Formula 3 and Pro-Twins ( all SV650 mounted unless the green meanies had their way ) all use Ohlins TTX36. Notwithstanding harping on like a broken record about the damping control virtues of these twin tube shocks there is another sizable advantage in their construction that can be accomodated within a ''normal'' Ohlins shock and was doubtless in Karl Morgans WP shock last year...The TOP OUT SPRING. The advantage of a top out spring is that it offsets / counteracts the effect of spring preload at the top of shock stroke / re-extension action. The shock is more supple at the top of its stroke which gives more sidegrip but also during that last part of re-extension it doesnt top out as violently and can also allow a ''softer'' low speed rebound calibration delivering further traction. The effect is you can go in later on the brakes and this is what every rider has told us.
In our box of tuning goodies we have 6 different top out springs alone for TTX36 and we often strip shocks to test just those as a combination.
If anyone remembers Ronnie Dewys from years past he was a very effective peddler of an Aprilia RSV1000. The standard oem Ohlins shock supplied for those didnt have a top out spring so we installed one. Instantly his laptimes dropped and the comment was ''I can brake later''
At Phillip Island Superbike tests last year I removed the top out springs out of Chris Walkers and Katsu Fujiwaras WSS Kwaka 600s as a test ( TTX36 equipped ) and recalibrated the rebound so that the top of stroke re-extension character was like a Penske character ( a company that doesnt use top out springs ) The riders after two sessions asked for the springs to be refitted as their lap times deteriorated and the data traces supported why. ( The Kawasakis were slow all year due to horsepower deficit )
Fast forward to this year. Peter Tanner is a very fast Aprilia RSV1000 rider who was using the oem ''non top out spring'' Ohlins. We recently custom made a TTX36 for that bike and instantly he was faster and mirrored Ronnies comments.
Winning races is also about an ongoing technological battle and that is one reason ''technophobes'' are attracted to a sport such as motorcycle racing. It should not be sanitised too much as it is about much much more than about the riders.

[Ivan]

Interesting read there.
So does the Ohlins I run use the top out spring?

Im going to try and make my Pro twin suspension as good as I can get it with inside the rules.

[Robert Taylor]

Interesting read there.
So does the Ohlins I run use the top out spring?

Im going to try and make my Pro twin suspension as good as I can get it with inside the rules.

Its an option on that type of shock and it can be fitted. Usually though it does also involve fitting a longer shaft to accomodate the extra length that the spring and its holder mechanism takes up. That also has to be consistent with ensuring there is still adequate internal clearance at shock full closed position. I do trade good shafts so it may be a viable option when the shock is due for rebuild.

[wayne]

Pro Twin is still slow to get going regettably. It really has the potential to revitalise the both the club and national scene with predominantly young, developing riders. We all all want that....don't we?
I have huge respect for Robert taylor, but I hope his comments don't discourage riders into thinking you need very expensive suspension parts and Robert on "speed dial" to get a look in. It's worth tempering this by reminding readers that the Ruapuna round was won, two race wins and including the GP by Patrick Jones. This bike owes him less than 5 grand. It started as a $2000 wreck in Auckland (anyone could have bought it). No new parts, all straightened with a bit of ingenuity. A $400 "nobody" shock off trademe, the emulators, dampers, spacers and springs all home made. Even the fork oil was home made, a brew of ATF and 20/50 engine oil from the Warehouse.
By all means get the best, but remember what the class is really for, getting young riders out there. The low spec bikes of Carl Morgan and Patrick this year show it still "can be done".

The main risk to Pro Twin is cheating. SVR is right, looking at a lot of bikes there is obvious "no compliances" all over them. Different brakes, subframes
not to mention the apparent horsepower differences. It was noticeable, no way can it explained away by "better drive / lighter rider" This year is over, I just hope next year there is tighter tech control to prevent these suspicions
false or not, ruining the freindships, respect and support you hope to see between the riders.

[svr]

Even the fork oil was home made, a brew of ATF and 20/50 engine oil from the Warehouse.

Cool - I used 30wt engine oil last year!

The main risk to Pro Twin is cheating. SVR is right, looking at a lot of bikes there is obvious "no compliances" all over them. Different brakes, subframes
not to mention the apparent horsepower differences. It was noticeable, no way can it explained away by "better drive / lighter rider" This year is over, I just hope next year there is tighter tech control to prevent these suspicions
false or not, ruining the freindships, respect and support you hope to see between the riders.

I didn't say that at all.
However, it does seem that there is bugger-all speed difference between highly developed F3 sv's (with `on the gas', lightweight riders) and some PT SVs!

[johnsv650]

are you saying a bike which cost less than 5k won a national gp title, so racing at the top is possible on a smallish budget.
and before that he raced a streetstock which seem very cheap to purchase also, and his sv would be competitive for how many years...??????
seems a cheaper way to go than those expensive gp 125 bikes

[johnsv650]

i have noticed more (sorry guys) older mature riders going to club days and having alot of fun and some going quick also, others having alot of fun racing in there own group.........
good to see the older wiser guys helping the young x streetstock riders also.