marcusgunby

LIFETIME SPONSOR
Jan 9, 2000
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Im really impressed with your help and knowledge-i have learned alot on your few posts.Could you fill us in on your background? :cool:
 

terry hay

Member
Nov 8, 2003
200
0
Marcus
I'm an Aussie who is about to lose a lot of money on the world cup rugby if the Kiwis stay true to form. I have been involved (specifically) in the suspension industry for the past 8 years. We currently run a company called "Shock Treatment" on the outskirts of Sydney. We are fortunate to be situated on a 120 acre property that comprises our workshop MX, SX Enduro and natural terrain bike tracks. If we wish to try something new we simply fit it up, ride out the door and go testing. We have had a great deal of success in the offroad market and for the past few years have also been involved with road bikes. This year our bikes won three of the four major roadrace titles in this country. Because of our facilities we get to work beside most of the factory teams. Last year I was asked to run the Kawasaki Roadrace team which didn't work out that well. It seems ZX9s just can't compete with R1s and GSXR1000s. We have worked with Chad Reed, Andrew Macfarlane and many others. The road racing has opened my eyes to many problems that exist in the dirt world but have been perhaps too subtle to question. I love talking about bikes, especially with like minded people. We currently import RaceTech components into the country and are an accredited WP centre. We have come up with many innovations and cures for motorcycle suspension on a local level and we are about to release a new product called "Reactive Suspension" on the world market. If you are keen to try it let me know and I'll send you the necessary equipment free of charge. I like your style.
 

podia

Member
Aug 31, 2000
187
0
hey Terry, i have read about the Reactive stuff from the australia dirt bike magazine. it is interesting and i was thinking to get my own (top out )spring into my fork now and have a go at it.
By the way, i have been to the RT seminar in 2000 and i'm very near from ya, i'm from Singapore.

a nice surprise to see ya :)

cheers
 

terry hay

Member
Nov 8, 2003
200
0
Podia
You won't be disappointed. Reactive suspension makes braking bumps a thing of the past and increases front wheel grip. If you wait till December when I get back from the States we will have a new version coming out that should exceed the previous units performance. Andrew from team Mezzo is trying to get Glenn Allerton (who works for me) to race the final round at Sepang in December. Apparently he's keen to run a suspension workshop over there as well. Perhaps it will work out and we can demonstrate the benefits of reactive while we're there. Good to hear from you.
 

podia

Member
Aug 31, 2000
187
0
Yup, Andrew Morrice from Team Mezzo,

they have been using Bitubo shock on their R1 and R6 previously
but they have some complaint with it though.

For me, I'm a motocross guy, so i'm more focus in dirt bike stuff
Anyway, drop me a PM if ya guys are coming up north

I'll be glad to meet ya guys who I can talk shop about suspension,
when come to suspension/revalve stuff, there are not really anyone
in singapore I can discuss or talk to. It will be nice to find guru like ya
to shed some light for us riders over here.

cheers!
 

KiwiBird

LIFETIME SPONSOR
Jan 30, 2000
2,386
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Hi Terry, I think we did the RT seminars together, back in 97? - I was the Kiwi on crutches with the broken leg.

You are correct - we (Kiwis) are going to kick your arse in the World Cup - still, you Aussies aren't a bad bunch.

Anyway, welcome to DRN, I look forward to hearing your opinions on suspension and about your reactive suspension products.
 

bclapham

LIFETIME SPONSOR
Nov 5, 2001
4,340
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Wellcome to the board Terry, its great to have another expert to throw ideas around with and learn from. :worship: Be aware that it sometimes it can get a bit "heated" in here but dont ever take anything personally!:) so we have about 6 posts and weve got two pommies, an auzzi, a kiwi and a bloke in singapore- the internet really is a good thing! I just hope we see either of you lot in the final!

I expect you are going to be busy during your trip to the US but if you need any contacts etc both myself and Kiwi are in SoCal and we know all the good riding spots- Kiwi is a desert warrior and i know most of the good mx tracks, but the ride out of your back door doesnt quite work well here.

cheers mate! :thumb:
 

terry hay

Member
Nov 8, 2003
200
0
K1 W1 & bclapham
I'll be in LA from the 19th - 27th of this month. I'd love to hook up with you guys if your keen. I don't know if I'll have much time for riding as we will doing a fair bit of testing and I have to meet with the guys from Eibach, BRP, RaceTech and a mate of mine from Graves Yamaha. As you no doubt read we are testing and reveiwing a new suspension mod with Larry Rosseller. If you are keen to come along let me know and I'll keep you posted on the dates. And Kiwi, I know if the Wallabys go down to the All Blacks this weekend I can at least count on your heart felt sympathy. Yeah right!
 

terry hay

Member
Nov 8, 2003
200
0
Jeremy
Basically we are using a Rebound valve/ check valve mod coupled with springs in opposition to the main spring in order to stabilise the front end of the motorcycle. Because one spring is reacting to the other we called it Reactive Suspension. We first developed the concept through road racing as this greatly assisted in holding a tighter line on the exit of turns. As an added bonus we also achieved improved corner entry, front end grip and the change of direction was awesome. Because roughly 65% of our business is dirt related it didn't take long before the obvious question was asked. All the benefits related to the street bikes were also evident on the dirt with an added advantage - braking bumps. It seems like they're suddenly half the size. Because energy is now being stored in the main spring the bike doesn't develop the same amount of momentum upon impacts reducing the amount of travel being utilized. This in turn means there is less spring force pushing the front of the bike back up. The seesaw effect you normally get from your front end is now stabilised and you find you can attack the bumps more aggressively and brake deeper into the turn. I remembered the guys at FMF were trying something similar with "Contractive Suspension" back in 96. But it clearly never got off the ground. They were using a form of mechanical restriction to stop the bike from entering the area above the sag line. I tried to call Don Emler to discuss our findings and see if he was interested in the further development and marketing of the idea but he never called me back. I believe FMF have got out of the suspension game.
Now, I would like you to try something if you would. Take one of the latest KTM straight rate springs. Lets say an 8kg unit from a 125SX. Using an angle grinder cut 15mm off each end coil. Spread the coil to allow the grinder access to the underside of the coil and taper it back appr 40-50mm. grind enough away so you have a gap between the first and second coil on each end. Adjust the gaps so that one is slightly larger than the other. Appr 4mm and 6mm. I assume you have a spring tester. Measure the points of compression where the first coil touches the second. Tune the gaps so that the first one contacts at around 35mm and the second one between 45 and 50mm. Plot the spring force curve then go test. This will suit a 65-70kg rider and works really well. I in turn wiil happily test one of your needles and am quite prepared to develop a taste for humble pie.
Regards
Terry Hay
 

jmics19067

LIFETIME SPONSOR
Jan 22, 2002
2,097
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Hi Terry,

1st let me apologize if my post in the other thread seemed cold and caustic.I was only trying to portray what I believe is fact.

2nd I am glad to meet you ,if only in a discussion, it is always a pleasure to try to learn and understand.

welcome to the board and I hope for people like me that you have the patience to help us understand.
 

Jeremy Wilkey

Owner, MX-Tech
Jan 28, 2000
1,453
0
Terry,
I've tried 7.6 to 9.5 springs before (The PDS #7) The distinct knee points of your version are a bit diferent in feel and a pain in the butt to make... I'll let some manufactuer do that for me next time... I think a PDS 7 is a little stiff for your rider weight but all in all Fair Dinkum on the exercise.. I quite enjoyed it really and I'm more than a little impressed with how you came up with that, aperently you have some neat software up your selve or you brut forced your way through the math.. Most impressive.. Now that being the case you had better be sending me an address to send that pie to, (Aluminium verison..) Mr. Hayes I belive you have some testing cut out for youself as well.. I learned some creative spring stuff from you, I think I can show you a thing or two about PDS technolgy...


BR,
Jer
 

terry hay

Member
Nov 8, 2003
200
0
Jeremy
Can we start again?
I re- read what you had to say in your article and also disected my retort. I can certainly understand how my comments would have raised your hackles. I have worded my comments in an ambiguous manner and I understand the veiwpoint you have adopted. My intention (all bull**** aside) was to ask if perhaps more value could be found elsewhere, easier. You can choose to accept this and go on or you can brand me a knuckle dragging luddite forever. Perhaps that humble pie could be served with a side dish of humility and we'll both eat like kings
 

Jeremy Wilkey

Owner, MX-Tech
Jan 28, 2000
1,453
0
Terry,
Of course we can.. Its all good, and thanks for taking the time to relook at things.. I get a little worked up on this stuff, I know, but I'd be willing to bet that over a few of AU's finest we could debate away rather famously.

BR,
Jer

I lay in bed last night tinking about that spring.. that was really weird and cool.. I can't make up my wind wether I think its rubsih practicaly, or if its so cool I want to exsperiment further with it...
 

terry hay

Member
Nov 8, 2003
200
0
Jeremy
Take the time to try it. Sometimes it just too easy to dismiss an idea than to have a go. After all, you weren't going to use that straight rate for anything else. I'm surprised coming from the land of "needs stiffer springs" that you would say the spring rate and weight I suggested is wrong. Pleased in fact. I have found in the past that tuners in the States all too often tend to recommend stiffer rates than I would normally choose. I figured if I recommended a rider weight of 70-75 kg you would have said "that's way too soft a spring!".
Terry
 

Jeremy Wilkey

Owner, MX-Tech
Jan 28, 2000
1,453
0
Originally posted by terry hay
Jeremy
Take the time to try it. Sometimes it just too easy to dismiss an idea than to have a go. After all, you weren't going to use that straight rate for anything else.

I was playing with it further, and I will give it a go.. I don't think its remotely practical, yet it is a cool way to make your own progressive.. As you've demonstrated by changing all the ramps and crossover points, I've done some net stuff with it already.. I really dig it for testing new combos.. I'm just working a way to make reliable predictions of what is going to change by how much I do or don't remove..

As for the spring stuff, man I can't agree more.. These guys in the US a friking nuts.. I think they generally just us the springs because they cut damping rates to create "plush" and then use springs to make up the difference.. Its a joke..


BR,
Jer
 

KiwiBird

LIFETIME SPONSOR
Jan 30, 2000
2,386
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Terry, sorry I won't be available to meet you when you're in LA - I'm off riding for 9 days in the desert during that time.

Rob at RG3 was the one doing all the development on the contractive suspension at FMF (he's a Kiwi too ) I met him when he first came to the US. He MIGHT share some info with you although he tends to play it close to the chest.
 

Okiewan

Admin
Dec 31, 1969
29,555
2,237
Texas
Kiwi...
Sorry man, gotta do it. It's "close to the vest" lol. :p
 

tonynz

Member
Jan 14, 2001
11
0
Just looking though these posts.
Even though I live in NZ
I have had Terry do suspension work on my last 2 KTM's
01 520 SX
03 525 (540) sx
He does a great job and suits my riding style.
When I get my next bike I will being sending the shock and forks to him a again.
 

PMK

Member
Feb 20, 2002
33
0
Didn't Charlie Curnutt work with the reactive suspension also? Somehow I thought he was instrumental in some of the basic theory.

This will be interesting to follow as the only reactive suspension I ever enjoyed was when racing on road model cars. All my other setups (on MTB's) almost felt to hooked up and at times almost vague or dead in the bumps. Being this hooked up also made clearing trail obstacles either by prejumping or bunnyhop became more difficult. Never realy tried it on a motorcycle, other than the negative spring setup in the 03 KTM. I'm open minded to it though as it will tend to follow the ground.

PK
 

HONDA65

~SPONSOR~
Mar 4, 2000
145
0
Terry and Jeremy,
I just wanted to chime in on the last portion of this discussion regarding spring rates. 1st, I'm just a small time tuner who is constantly trying to learn new things to make suspension better. And though I understand things pretty well, I'm not qualified to "discuss" the more technical aspect of things, so i just sit back, read and learn. And if something strikes my attention, I'll go out and try it myself to see if it works or not. And the one thing that I keep coming up with is that, as both of you stated, most suspension companies are always recommending spring rates that I feel are to stiff. But being a small potato in the field, I sometimes feel hesitant in going against the grain. So thank you for letting me know I'm not out of my mind.

Terry, where can I learn more about your reactive suspension product? I would like to try it if possible. If its something that can be purchased, I'd like to. And as I write this, I realize that what your were doing may be construde as spamming so you can PM me if you like. I don't want to get anyone (including myself) in trouble. I respect the rules.

Jeremy, since I'm posting here, and you ARE authorized to discuss things for sale, do you sell a greater variaty of valving shims then whats offered on your website? I buy shims from you now, but i need some that aren't listed. I am planning on calling on Monday anyway, but I'd thought I'd ask now since I'm in a typing mood.

Thanks
 

terry hay

Member
Nov 8, 2003
200
0
Honda65
I guess it's hard to talk about the positive aspects of a product without sounding like you are promoting it. I have just arrived home from the States after testing with Dirt Rider magazine. The guys were really impressed and are committing to a 3 or 4 page article in their February issue. We tested at Glen Helen and Piru with a variety of riders. Some of whom were involved in the testing of the FMF "Contractive Suspension". A big "thumbs up" from everyone concerned was very welcome. At this stage it looks like it will be distributed through Race Tech in LA. I have tried to answer peoples problems without mentioning products but when the solution lies in a replacement part, What do you do?
Regards
Terry
 

HONDA65

~SPONSOR~
Mar 4, 2000
145
0
Terry,
Thanks for the response. I own a Race Tech Center, so I guess I'll talk to them. But if you have any more info to share you can send me a PM.
Thanks
 
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