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Tony Foale leverage ratio software

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I am going to rephrase this.

 

We have been measuring leverage ratios for several years.  We use a digital arm to obtain the measurements needed, and enter these measurement in the Tony Foale software.  The software allows you to view and analyze the leverage ratio as well as several other useful forces. 

 

We are looking for someone (or someones) who would be interested in learning to use the software, and figure out a way to document and compare the info for quick and easy analysis.

 

Unfortunately, I am too busy and don't have the time to devote to this project.

 

We will provide leverage ratio files as well as basic info on how the software works.  From there, you'd need to take the initiative and be willing to spend the time needed to fully understand what's going on.  This isn't for the fainthearted.  If interested, shoot me an email or PM.

 

Regards,

Kevin

Edited by kevinstillwell

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Which software?

 

I have a few programs to analyze and give a leverage ratio curve/motion ratio curve if given the link lengths or pivot positions if you have CMM measurements, or at least the correct lengths and a couple of angles as boundary conditions.

 

I think I have access to a couple of models of moto-style linkages that I went through in the past.  What particular info are you looking to gain from it?

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The software is by Tony Foale.  Motorcycle Kinematics.  You enter the CMM measurements (coordinate measuring machine measurements) for the top shock mount, bottom shock mount, swingarm pivot, linkage etc..

 

I would be interested in the type of info your programs have.

 

What are we looking to gain?  Knowledge.

 

You could put this in an Excel sheet.  But it could easily take hundreds of hours to set it up.  Much easier to cut to the chase and spend those hundreds of hours analyzing the info.

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If you're familiar with linkage analysis, it shouldn't take long at all to plot out data in Excel at some reasonable resolution.  That's pretty much the brain of the linkage analysis programs anyway, but just done with super shorthand code and a super fine resolution.

 

Design Of Machinery:  Linkage/4-bar/Cam software is good for dedicated engineering software.

 

There's also a pretty well streamlined bicycle linkage program that applies exactly as you're describing, aptly called "Linkage".  Pretty sure it's freeware  Put in your data points, get a graphical interface of the linkage geometry and how it cycles through the travel.  Get some basic analysis of chain forces/anti-squat, braking forces, and leverage ratio curve/motion ratio curve.  Good for determining small changes from lowering links or comparing two linkages.

 

Again, not sure what specific info you're looking to gain beyond leverage curves and inflection points and maybe chain torque, but that should serve your purposes well and save you some time.

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Resolution is an issue alright, but the first is to get the various formulas ironed out and working properly in the right sequence with each other.  I built a sheet to analyze the effect of connecting rod length on piston speed and calculate actual maximum piston speeds (as opposed to averages, which are really meaningless), and the first version was set up in 10 degrees increments.  Bumping the resolution to one degree increments was just time consuming (very), rather than difficult, once the thing was actually working. 

 

One of these days when I feeling like blowing up my brain, I'll see if I can adapt it to produce a full circle curve that takes bore offset into account :eek:

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I am going to rephrase this.

 

We have been measuring leverage ratios for several years.  We use a digital arm to obtain the measurements needed, and enter these measurement in the Tony Foale software.  The software allows you to view and analyze the leverage ratio as well as several other useful forces. 

 

We are looking for someone (or someones) who would be interested in learning to use the software, and figure out a way to document and compare the info for quick and easy analysis.

 

Unfortunately, I am too busy and don't have the time to devote to this project.

 

We will provide leverage ratio files as well as basic info on how the software works.  From there, you'd need to take the initiative and be willing to spend the time needed to fully understand what's going on.  This isn't for the fainthearted.  If interested, shoot me an email or PM.

 

Regards,

Kevin

Do you have an on board data logging system? If so, mount a pot to the center of the axle and one in the position of the shock and cycle the suspension through its stroke. Most logging software has a motion rate feature which can convert the data within minutes. Takes a while to get the bike prepped with the equipment, but all in all it only takes about an hour to map a bike with all of the assembly work. This method also eliminates the potential of inacurrate measurements by the operator.

Darren

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I built one using both Mathcad and Excel.

It's a simple matter of writing the vector loop equations for the 4 bar linkage, using the starting angle for the input link, and constraining the motion of the tertiary coupler output vector to a maximum distance from the upper shock mount.

The leverage ratio can then be calculated from the instantaneous velocities of the linkage coupler output and wheel.

It can easily be extended to calculate necessary spring rates for various rider weights and to try out different linkage configurations.

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