ESE's works engine tuner

[bucketracer]

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So that's Chambers FZR-GP100 on the track, now to get TeeZee's FZR and 50 finished and out on the track too.

A bit of suspension work to get things dialed in then we can get back to engine development................

[grantman]

I Agree with Arronduke
Real quick on the stright
When he gets the hang of things it should be evil!

[TZ350]

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A big thumbs up........Speedpro for your sensible suggestions and the parts (hopefully) needed to restore our second FZR's front forks to std spec.

Last Sunday Chambers had a great day on his new FZR-GP100, it ran well but he dropped it after running wide and getting mud on the tires, it crashed well with no damage, like a good bucket should, Chambers was able to pick it up and finish. Latter Jaden took it out for a spin and was most helpful with advice on suspension setup. Chambers wound up the day by punting his 50 around in grand style. Those 50's are so much fun.

Thanks Ray and Damion for the great photos .......

I think Speedpro is right, these FZR chassis are pretty good and I am real keen to get my own FZR-GP125 and RG50 finished for the start of the new season.

[craisin]

I dont know but it look like the frame is twisted on that bike he dropped

[Buckets4Me]

I dont know but it look like the frame is twisted on that bike he dropped

somethings twisted thats for sure

[TZ350]

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Now we have some more springs to play with......

Pic-01 the setup for measuring the spring rate. With a rod inside the spring and the spring held in a tube it is relatively safe.
Pic-02 Chambers takes the initial reading.
Pic-03 And measures the amount the spring has been compressed in mm and the force required in Kg.

We start by pre-loading the spring 10Kg and measuring the length of the press's ram.

Then we load up the spring another 30-40Kg and measure the change in length of the ram in mm.

Kg/mm gives you how many Kg it takes to compress the spring one mm, or spring rate in Kg/mm.

Some of springs we measured and the results we obtained.

Honda RS125 20% Dual Rate spring, 0.62Kg/mm and 0.71Kg/mm
Std FZR250 20% Dual Rate spring, 0.41Kg/mm and 0.71Kg/mm
Std FZR250 single rate spring, 0.61Kg/mm
And the cut down FZR springs that came in one of the bikes, 0.75Kg/mm

With practice we could improve the accuracy of our results but these are sufficient for us to see what ball park we are in.

For comparison, rates found on the net. FZR250 0.70Kg/mm, FZR400 K1 0.5Kg/mm and K2 0.7Kg/mm, FZR1000 0.77Kg/mm.

[TZ350]

About the graphs in pictures 1-2-3

Although the dual rate spring has two distinct spring rates they combine to make a much softer rate and mimics a progressive spring at the start when both springs are compressed together. Its not like the soft one completely collapses and becomes coil bound before the stiffer part starts to compress. The softer spring compresses a lot and the stiffer spring compresses a lesser amount until the softer spring becomes coil bound and the stiffer spring then takes over completely.

Something I copied from the net that explains it better.........

The three spring types are linear (ordinary); dual rate (often called "progressive") and progressive (really!). The ordinary one has a rate of 9N/mm, so to get compressed 120mm it needs 120 x 9N of force, or 1080N. Note that the graph is a straight line, which is why it’s called linear.

Dual rate springs are made by putting a short spring with closely wound coils on top of a longer spring. Initially, when you apply a force it acts on both springs and they both compress. So the total compression is more, for the same force, than either spring alone. That means it has a softer rate. If you don't like formulae, just ignore the next sentence. If you don't mind, the combined rate is K=K1 * K2 / (K1 + K2), where K1 and K2 are the rates of the individual springs.

However, after some compression, the closely wound spring jams solid as all the coils come together (it "coil binds"). So now you only have a single spring, which we’ve already said is stiffer than the combined springs. In the example above, the combined springs have a rate of 7N/mm, while the second spring has a rate of 9N/mm. The first spring coil binds at 40mm: you can see a kink in the graph at that point. Note that the two springs can be made from the same piece of wire: all that matters is that their coils have different spacing.

More can be read here:- http://www.promecha.com.au/springs_advanced.htm

Where K1 and K2 are the rates of the individual springs.

Spring rate for dual rate springs is K=K1 * K2 / (K1 + K2)

Honda RS125 20% Dual Rate spring, 0.62Kg/mm and 0.71Kg/mm

0.62 x 0.71 / (0.62 + 0.71)
0.44 / 1.33
0.33

The effective initial spring rate for this Honda RS125 is 0.33Kg/mm then when the softer spring becomes coil bound the rate changes to 0.71 Kg/mm

And

Std FZR250 20% Dual Rate spring, 0.41Kg/mm and 0.71Kg/mm

0.41 x 0.71 / (0.41 + 0.71)
0.29 / 1.12
0.26

The effective initial spring rate for our FZR’s is 0.26 Kg/mm, then when the softer spring becomes coil bound the rate changes to 0.71 Kg/mm

As a comparison…..

Std FZR250 single rate spring, 0.61Kg/mm

And the cut down FZR springs that came in one of the bikes, 0.75Kg/mm

A possibility would be to use a combination of the cut down spring with the std FZR single rate spring for a combined dual rate similar to the Honda RS125.

Single rate, dual rate or progressive, the jury at Team ESE is still out about what we want to use with our FZR Bucket racers.

[Yow Ling]

Man you really have the knack of taking something we thought was simple and complexicating it, is this what Scientology is all about?

[bucketracer]

Man you really have the knack of taking something we thought was simple and complexicating it, is this what Scientology is all about?

TeeZee should have "Progressivly" found a "Linear" answer to the "Dual Rate" problem of making a sows ear from a silk purse.......

[F5 Dave]

A short conversation with RT & he always espouses linear springs. It makes sense, you will tend to blow through the soft part using heaps of travel (some of course is used in preload so those graphs should start further on than zero in real life). Then to get the same bottoming resistance you need a steeper curve near the end. Excess travel isn't useful on a race bike as it's unsettling.

[TZ350]

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Yea........in spite of the RS125 being dual rate and wanting to restore the FZR forks to their original setup, our thinking has started going in the linear direction mostly for all the reasons you have pointed out. Looks like the guy (ShellRacing) who cut the original springs, was onto it............

[speedpro]

and then there is the damping side to play with. The springs I have are linear, single rate. You guys need to give mine a try. I don't think it's too bad but maybe it could be better.

[TZ350]

The springs I have are linear, single rate. You guys need to give mine a try.

Until recently I had thought that all the FZR250 springs were dual rate and that was the std setup and believed that you were using them like that.

So that was the single rate spring version in #6 when you showed me it the other day. I am greatly encouraged as it looked good, and there is a set of original single rate springs in one of those old forks you lent me to cannibalize for parts as well as the cut down set that came with the bike.

and then there is the damping side to play with.

We have carefully overhauled the fork internals, paying special attention to the rebound foot valve and piston damper rod sealing rings and the centralization of the damper piston in the fork tube. No modifications, just restored to good functional condition. Lots to play with here later like rebound holes, oil viscocity and emulators.

So much, is just fashion with motorcycles that we wanted to take a more critical look at the suspension, after some investigation and as best as we can tell, simple linear springs look the most suitable for our FZR bucket racers.

[mud in ur eyes]

Looks like TZ350 is to polite to mention it but………..

you have posted some "FACTS" on suspension in this thread…..you have fucked up with your calculations, and shortened the springs too much....…should we disregard all your posts on fork geometry?

Well yes, I guess you can..........because………
Motorcycle fork geometry is the collection of the key measurements, lengths and angles that define a particular configuration, primary among these are steering head axis angle, fork offset, and trail.

TZ's posts have been about suspension spring rates and damping not about fork geometry.
If you’re going to debate his work you at first need to understand the subject.
Also one of the FZR's came with cut down springs,
So keeping to the facts without inventing stories is useful too or should we just disregard all of your tuning posts as meaningless hot air.

There is no malice intended.
It's just in the interests of accuracy.
Some people follow this thread in the hope of building a fast bucket, and if some information is deliberatly wrong, it is prudent to mention it.

[gatch]

I think perhaps you may be missing the whole point of the thread ?

Rather than being a "look at me and how smart I am" collection of worthless shit, I think it is intended to be more of a "here is some useful things I have found, that have made my bike go better".

Take advice with grain of salt where preferred..