Ideal Gearshifter Geometry

[redbirds_imp]

Thanks Greg for the info and diagram. Going to put my bike on the lift and check.

[Greg_imp]

Was that done in SolidWorks?

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[Red Mist_imp]

Greg, trying to understand this, but would the optimal geometry be the same for everyone? No matter the size of their shoe, be it gym shoe, work boot or touring boot? If this 3.86" is ideal, what is that in relation to the factory setting? ( length of rod)

I too felt mine was too low, and rather than mess with the rod, moved mine one tooth on the spindle which at first I thought might put my lever too high ( and still feel it might be a tad high) but I'm enjoying the extra room on my foot peg.

Hi Ferret. The point of my post is that there is an ideal geometry for the shifter mechanism, which is when the linkage connections form 90° angles, but that of all the controls, the shifter has the most adjustability to accommodate individual differences.

So, knowing the ideal, along with knowing how the two adjustments affect it, allows you to make informed decisions about how to set it up to work best for you.

My opinion is that simply moving the arm one spline - the easy mod, which raises the shifter foot peg 1.25" - is not the best way to raise the shifter foot peg because it takes both linkage angles away from the 90° ideal. Better to leave the shifter arm with the dots aligned and shorten the linkage. Chances are good that a smaller rise distance - done by shortening the linkage - will satisfy most riders, and doing this will at least keep the linkage/shifter arm angle at 90°.

People who have moved the shifter arm one spline may find that instead using linkage adjustment to raise the foot peg will result in an easier, quieter shift. More "snick" and less "clunk", though my opinion on that is not scientific.

Like I said in the original post, I don't have good information about how this mechanism is set up from the factory since I adjusted my own before measuring my own stock set up. Even if I had, that would be a sample of one and not very reliable. I have considered going over to my local dealer, who has a couple of 2014's on the floor and measuring them. Anyone who hasn't changed their factory setup could help shed some light on this.

Yes, that's the best way to adjust the shift lever, not to move it over a spline. In some kind of extreme case a spline offset might be needed but at that point, better to go with a different set of controls, such as might be needed to accommodate a very large foot or boot.

[DAC]

Very useful post, Greg. My gear lever feels fine but the brake lever might need some fiddling. This post at least makes me think a little more about the geometry - a challenge since i haven't considered that particular subject much since high school!

[CBXBob_imp]

I ADJUSTED THE ROD. Did not re-index the splines. There is a large range of adjustment just using the rod.

[Cormanus]

Useful post, Greg, and great diagrams. Thanks.

[the Ferret]

BTW I went back and forth moving my gear shifter 1 splines worth. The first was too low for me, the second a smidge (Australian for small amount I've learned) too high. With the bike on the center stand, measuring from ground to center of shifter with it on marked dots it was 12". Moved 1 spline, it was 13" or 1 inch higher. So I realigned the dots on the spline/shifter and loosed the lock nuts on each end of the shift rod. The one on the left towards the front of the bike is the one that's reverse thread, so loosening that one is like tightening any regular nut. Anyhow, with both nuts loose, a couple turns on the rod raised the shifter until the measurement from ground to center of shifter was 12 1/2 inches, halfway between the too high measurement and the too low measurement. I locked both nuts down (again remembering the one on the left, towards the front of the engine is backwards). A short 20 mile test ride confirmed this is a very good spot for me and I intend to leave it this way.

Thanks for all the info Greg and by suggestion CBXbob.

[Greg_imp]

I'm glad people are finding the post useful!

Part of putting it together was labeling the names of all the parts down there, but I did miss "Toe Peg" somehow, calling it Foot Peg, which is confusing.

[Cormanus]

Nice usage of 'smidge' Ferret.

[shdwghst457_imp]

Smidge is Australian? Blimey, I knew I was adopted!

Was that done in SolidWorks?

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Ah. SolidWorks is amazing; you could reproduced a working 3D model of the mechanism, test it's limits and whatnot. It would even give you a bill of materials!