Do I need +3mm, Standard, or -3mm axle lengths on my Keywins

[63corvairsprint]

I need some help understanding the Q factor and how it applies to my kness. With Standard Ultegra R-600's I was experiencing knee pain on my left side until I adjusted my cleats with more heel in. I normally walk and run a little "duck" footed.

It this due to my axles being too long for my stroke, meaning I need a -3mm (shorter) axle to bring my toes in, so I dont need my heels kicked in so far...

Or does it mean I need a +3mm (longer) axle to allow kness more flair to accomidate my heel in position?

I ordered -3mm Keywin's but they are on backorder, I now have a chance to change the order if needed.

[Valbrona]

And I thought Keywin's were available in six different axle lengths.

[bricky21]

This is kind of a simplified understanding based on my experience and readings, so take it with a grain of salt. Assuming the rest of your bike position is as good as you can get it (and there is no such thing as perfection) if your knee is descending inside of the center of your foot you should go for a narrower spindle and if your knee is descending to the outside of your foot you should opt for a longer spindle. If you are of reasonable functionality then spindle length shouldn't be much of a concern unless your considering maximum cornering clearance or aerodynamics. It doesn't matter for me what length pedals or how wide the crank is, because after about 3 pedal strokes my body naturally adjusts. It's the same phenomenon which allows people to ride both Road and Mountain bikes without any problem.

[BdaGhisallo]

What I would do is measure from the crankarm face to the midpoint of your shoe sole and contact Keywin in NZ with that number and John will advise you.

If you're still nervous you could pick a length and if it doesn't work, buy a set of axles and change them. It's pretty simple to do and the axles should run you about $50 I believe.

Dead center on my +3mm CRMs is 55mm from the crank arm face. So -3mm should put you at 49mm.

[63corvairsprint]

I believe the Keywin CRM's come in +6mm, +3mm, STD, -3mm & -6mm.

I ordered a set located from a US company in order to not have to wait, but it seems there inventory levels were not as advertized and there is a delay getting in the actual product. At the time they said they had a set of -3mm in stock, so I thouguht I would try them and change axles if needed.

I now have the ability to change my order...so instead of just "trying" the -33mm...I thought I woul dask the more experienced rider here on the board.

[63corvairsprint]

I guess that I should add that my knee discomfort was on the outside lower knee and only starting bothering me after about 10+ miles under 80% output or greater.

Moving my cleats to allow my heel position to be more inward alleviated the issue.

Since my main performance riding goal is triathlons, I thought moving my kness and feet inward would alod be more aero as I am already trying to ride with my knees in as much as possible.

So I am still in a quandry as to what axle length I should order...and how it will affect my toe/heel position.

[crohnsy]

I suppose there are no bike fitters "somewhere south of Chicago"

Has anyone bought a suit? Like a real expensive one? $3k or so? (not that this is much in the world of good suits)

If so, I am curious - did you post on forums asking people if the cut was good and whether they should bring sleeve up a bit? Is the waist at the right height? Or did you go to a tailor who knows what the hell they are doing and then enjoy the suit for many a year, fitting you perfectly, moving with you and feeling just great to wear?

Given people spend double or (much) more on the bike than they do on a suit I wondering why the f*ck people wouldn't go to a proper "tailor" to get this stuff sorted rather than posting the cycling equivalent of "does my arse look big in this"? otherwise known as :- "Do I look pro in this position?"

Only to be followed up with "Back, up, down, forward, longer, higher, lower, tilt and drop."

Enjoy your suit.

Rant over.

Carry on.

http://weightweenies.starbike.com/forum/viewtopic.php?f=8&t=98918

[63corvairsprint]

Thanks bricky21, for your response to my question "I need some help understanding the Q factor and how it applies to my knees."

This gives me something to evaluate with my knee position relative to my foot.

For a little additional detail, I was fitted to my previous bike, but over the winter picked up a S-Works Tarmac which I have been feverously swapping parts out on to get it ready for this season. This is the bike that I am putting the Keywins on. I have a professional fitting scheduled for March 16th on this bike. When I assembled the bike I set it with similair measurements from my previous bike and I have already given myself an informal fitting and tweaked the setup a little from time on the trainer. I am generally happy with the current setup but have only logged two long outdoor rides to date. The previous mentioned knee discomfort was on my previous bike and was corrected as stated above. My new bike setup is as close as I could get it to my old and I did not experience any knee discomfort on the new bike setup.

Since I have never riden Keywin's and am attempting to ride more with my kness tight in (for aero reasons) the option of the shorter axle was a consideration and wanted to have them on the bike for the scheduled fitting. After that, it would be easy to get the standard or +3 if reccomended by my fitter.

[clarkson]

Another thought would be that your desire to move your feet inward is a result of your saddle being too high. Since the front of the foot is essentially fixed by the cleat, the heel will drift inward to try and compensate by shortening the distance from hip to pedal.

In my experience (this is anecdotal, not scientific, so take it as you will), medial or lateral knee pain is often caused by that aspect being pushed inward or outward from a neutral position. By that I mean if your knees are forced to arc in toward the top tube, and follow a longer path than they would naturally, medial pain will often result. The counter-intuitive aspect is that moving your cleats laterally will only exacerbate the problem, causing more arcing toward the top tube. Similarly if your knees are bowing outward away from the bike (not necessarily visibly bow-legged, but more than what is 'normal' for you) then lateral pain may result as the lateral knee ligaments are being stretched beyond normal function. Moving the cleats inward would typically cause an increase in that arc, and not relieve the pain.

My first suggestion would be to try lowering the saddle, and see what happens to your heels.

[BdaGhisallo]

I would second this advice. Experiment with your saddle position and see what effect that has. For years I used a lot of wedges under my cleats and, after realizing that my saddle was a little too high, found that I didn't need so many of them! I was effectively reaching for the pedals because I was too high, leading to me thinking I needed lots of wedging. I do still use some, but not as much as previously.