SPD & knee pain

Especially for light weight issues concerning cyclocross / touring bikes & parts.

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AJS914
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Joined: Tue Jan 28, 2014 6:52 pm

by AJS914

I've been riding my gravel bike with mountain SPD pedals this winter and I've been having knee pain where I've never had it before.

I finally concluded that it doesn't feel like my foot sits flat on the pedal. Because there is only 1/4" of my shoe's sole touching the pedal, it feels like my foot can easily supinate towards the outside while compressing that tiny bit of sole that touches the pedal.

This is not a float or pedal position issue.

I installed a set of Time road pedals today and all my knee pain was gone. My foot feels solid on the platform and can not supinate.

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TonyM
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by TonyM

That‘s one of the advantages of the Time pedals indeed!

As Look invented the clipless pedals in the 80s many bikers, especially for the one riding many km per year, developed pain and injuries in their knees and Time developed their system. I am not sure but I think it was a mechanic of Bernard Hinault that was involved in Time.

Anyway the rotation, size of the platform etc...of the Time pedals is the best IMHO. I ride this system since the 80s and with 10,000 to 15,000 km per year.

by Weenie


AJS914
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by AJS914

I love Time pedals on the road but I'd like an off-road setup for the gravel bike.

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TonyM
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by TonyM

I use the Time ATAC on my MTB

AJS914
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Joined: Tue Jan 28, 2014 6:52 pm

by AJS914

I notice that there are two Atac pedals now. One has a larger body. Is this for more platform surface area?

I could just get these. :-)

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morganb
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by morganb

I actually switched from ATAC to SPD for my mountain and cross bikes due to the excessive float causing me knee pain. It may work for you though.

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TonyM
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by TonyM

Yes I see that they now have 2 versions:

The regular for XC MTB, cyclocross, gravel,...
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and this one for city and sport (as stated by Time):
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I would take the regular!

AJS914
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Joined: Tue Jan 28, 2014 6:52 pm

by AJS914

I also see two other models that have wider bodies.

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AJS914
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Joined: Tue Jan 28, 2014 6:52 pm

by AJS914

Here is what is happening with my SPD cleats and shoes. I wonder if I could have the wrong cleats? Or the issue is my shoes. I never noticed an issue riding my mountain bike with the same shoes but I don't ride the mountain bike that much and maybe the cadence is slower.

Image

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silvalis
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Location: Aus

by silvalis

You could also look at crank brothers pedals. The newer ones come with different height grip plates that fit to the left/right of of the interface which may solve your rolling issue.

AJS914
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by AJS914

BTW, in the illustration I wedged a screwdriver on one side to take the picture but that is what is happening when I put my weight on the pedals.

TheKaiser
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Joined: Thu Sep 05, 2013 3:29 pm

by TheKaiser

AJS914 wrote:
Sat Feb 10, 2018 1:35 am
Here is what is happening with my SPD cleats and shoes. I wonder if I could have the wrong cleats? Or the issue is my shoes. I never noticed an issue riding my mountain bike with the same shoes but I don't ride the mountain bike that much and maybe the cadence is slower.

Image
On your mountain bike, it is also likely that you stand up and move about a lot more, which generally relieves the wear and tear a bit as you aren't doing the same exact motion over and over.

The issue is that with SPD pedals (and most other 2-bolt cleat/pedal designs) there is a very narrow area of the pedal binding mechanism/cleat that interfaces and transmits loads when pushing down on the pedals. This contact point is generally somewhere around 20-25mm wide. This is wonderful for mud clearance, but it also means that if the center of pressure (COP) of your leg's driving force on the downstroke is even slightly to the left/right of that narrow point, then you will get the shoe wobbling either medially or laterally, leading to pronation or supination respectively.

As a secondary support point, Shimano and most other manufacturers have those little platforms on the inner and outer edge of the cleat binding area where they intend the shoe's tread to make contact with the pedal body, thus providing a sort of outrigger support. The thing is, the tolerances on those shoe tread/pedal body interfaces are terrible. It is common for there to be several mm gap between the shoe and the pedal, which again, is great for mud clearance and ease of clipping in, but is terrible for providing a wobble free shoe/pedal interface. On the other hand, there are some companies who have made shoes with excessive tread depth where the cleat pocket is recessed too far, and in these cases it can be difficult or impossible to clip in as your weight is borne by the shoe tread/pedal body before the cleat ever reaches the engagement mechanism. As a sidebar, when you run into that situation of excessive tread depth, you either need to trim the tread down, or shim the cleat out until the heights correspond properly, but that is the inverse of your problem. Even if you get a shoe/pedal interface that is perfect, which is most likely with a matched brand shoe/pedal, it won't stay that way for long, particularly if you walk a lot or even just from wear against the pedal body, because for every mm of tread wear you lose a mm of lateral stability in the shoe/pedal interface.

Juxtapose that whole mess I just described with the simple and stable interface of road shoes and pedals. With road shoes and pedals, the shoe tread plays no role in lateral stability, in fact there isn't any tread at all. With a road pedal, you have a much wider cleat/pedal interface with very tight tolerances. The much wider platform (often around 50mm) of the cleat/pedal interfaces allows your COP to move quite a bit more to either side before it gets beyond the platform and would tend to cause a medial/lateral lean. Even if the COP does get beyond the platform, you may not even notice, because the more precise fit between the cleat and pedal prevents it from wobbling.

So let's look at what your options are:

1. You could try building up your shoe tread with some Shoe Goo or similar hard glue type substance, that will allow you to essentially re-mold the depth of the contact points so that there is a closer fit. This could be worth a try as it's quite inexpensive and doesn't require changing out any of your equipment, however with the minimal pedal bodies you are using it will likely have limited success, as there is so little contact area to work with.

2. You could look at getting other pedals, but don't even think about getting any of those ones where there is a big flat cage surrounding a standard SPD type mechanism including for/aft of the binding mechanism. On cursory inspection of those pedals, it seems like there would be a ton of contact between shoe/pedal, but if you were to actually clip in you would see that due to the curvature of the shoe sole there is nearly none. The only area of the pedal body you need concern yourself with is directly to the left/right of the cleat binding. From your picture, a wider pedal could be good, IF the the tread depth of your shoe allows it to match up. If your shoe tread is too shallow, it will still allow a wobble.

One remedy for that is, as Silvalis mentioned, the Crankbrothers pedals that have little nylon pads of varying thickness, which you can interchange to get the precision of fit you want. You'd probably want to look at the "Candy" model, and in order to get the varying pads included you need to get the Candy 3 as a minimum: https://www.crankbrothers.com/products/candy-3

Another pedal to look at is the Speedplay Syzr. They have mixed reviews for MTB riding, but for gravel their shortcomings seem minimal, and they have 1 big advantage over other 2-bolt cleats, which is that they don't rely on the shoe tread at all. They have a wide cleat, with built in outriggers, that contacts the pedal body in several places, so in that way they are much like a road pedal. This also allows wedging of the cleat for fitting purposes, which I'll touch on in point 4: http://speedplay.com/index.cfm?fuseaction=home.syzr

3. In combination with a pedal with a wider, but non adjustable, support platform like Shimano, Time, etc...you may want to look at shoes where you could tune the tread depth. This would allow you to get the precise fit you want, and then continue to tune it as your tread wears down. The only brand that jumps to mind is SIDI. Their higher end shoes have replaceable tread, and with a little creativity it is possible to place thin shims under the tread as it wears down, to maintain a precise fit to the pedal body. See this pic of the sole for an idea of how that would work: http://www.sidi.com/files/prodotti_cicl ... O-MATT.pdf

4. Last but not least, you may want to consider the possibility that the supination is a symptom of a fit issue. It suggests that your knee is tracking to the outside of the pedal. Without seeing you pedaling it is tough to tell why this is. Depending on the cause, it could be that through some combination of sliding your cleat laterally, wedging in the shoe insole, washers on the pedal spindle to adjust the position of the pedal relative to the bike, etc...you could bring your COP back over the center of the pedal body. If the COP is perfectly centered, then even with the narrow SPD interface you should still have a stable foot.

Well, that's about it. I know it is a long tome, but I like to be thorough, and knee issues are nothing to be trifled with.

AJS914
Posts: 2038
Joined: Tue Jan 28, 2014 6:52 pm

by AJS914

Thanks for the comprehensive reply.

I don't think shoe goo would do it. Putting my weight on the pedal seems to compress the rubber and I don't think shoe goo would really add much to counter that.

Regarding #4 - part of me feels like it could be shoe related as well. Even when I'm pedaling lightly trying not to compress the outside of the shoe, it feels like the shoe/pedal interface is slanted a bit compared to my road setup. On these shoes I cannot slide the cleat laterally but I could try a washer on one side. That, at least would be a cheap experiment. Wedging would be another possibility. Or, try some new shoes.

I've been pondering those Time Enduro pedals mentioned above as I've always ridden Time road pedals and they do have a significantly wider platform.

Image

mattr
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Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

It's why i don't use SPD. I've tried them twice. The first time the pedal failed and ripped a hole in the sole of my shoe (long story, not going into it now).

Second time (about 20 years ago now) i used them for a few hours and started with the knee pain, and could actually feel the uncontrolled rocking causing it.
Back to ATACs. Which i still use now. The SPD type mechanism/pedal surface simply isn't stable enough for me and my knees.
It's also my early warning for new cleats on my ATACs. First thing i do if i get a twinge from either knee is new cleats.

TheKaiser
Posts: 511
Joined: Thu Sep 05, 2013 3:29 pm

by TheKaiser

AJS914 wrote:
Sun Feb 11, 2018 9:06 pm

Regarding #4 - part of me feels like it could be shoe related as well. Even when I'm pedaling lightly trying not to compress the outside of the shoe, it feels like the shoe/pedal interface is slanted a bit compared to my road setup. On these shoes I cannot slide the cleat laterally but I could try a washer on one side. That, at least would be a cheap experiment. Wedging would be another possibility. Or, try some new shoes.

I've been pondering those Time Enduro pedals mentioned above as I've always ridden Time road pedals and they do have a significantly wider platform.

Image
Those Time peds do have a huge platform and a lot of real estate for the shoe to work with. Just remember that if the depth of cleat pocket/tread doesn't match up, it will allow the shoe to rock over up until the tread can bear the load. A combo like the Sidi shoes with those Time pedals could be sweet, as you could tune the shoe to make full use of the pedal.

One other thing to keep in mind is that if the shoe tread-pedal body interface is load bearing, the float will generally not be as free as on a road pedal, due to the greater drag between the rubberized shoe tread and pedal body, vs. the hard plastic cleat and metal body of a road pedal. Speedplay Syzr pedals are the only way around that of the current 2 bolt pedals (and Bebop and Speedplay Frogs as well, but not sure if they are still manufactured).

Regarding wedging on 2-bolt pedals, cleat wedging is seldom effective, because the cleat is too narrow and has too much free play to provide a canting effect, and it is also common for the cleat to come loose if running multiple wedges due to the small surface area and slippery consistency of the wedge itself. I have wedged SPD cleats but applied grip tape to the face of them to prevent the loosening issue. BFS makes SPD wedges here: http://www.bikefit.com/p-3-8-pack-spd-cleat-wedges.aspx

And BFS also makes an actual canted SPD cleat: http://www.bikefit.com/p-6-vv1-cleat-kit.aspx

If you have adequate room, in-shoe wedges might be a better way to go, and can be applied to the heel or the forefoot: http://www.bikefit.com/c-2-in-the-shoe.aspx

When you say it "feels" like the shoe pedal interface is slanted, what kind of shoes are you using?

by Weenie


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