7

Briefly

I don't get it. Why would anyone want to use SPD pedals—such as PD-M520, PD-M8000 (left of the image), PD-M9000, PD-M9100, ...—when SPD pedals with platforms—such as PD-EH500 (right of the image), PD-M9120, ...— are available?

Within the same design line and in one snapshot for comparison (the two models pictured), the latter is even lighter—383g instead of 425g.

(I'm not sure why the two other models that are two-sided yet are built around a larger frame— PD-M8020 and PD-M9020— exist, but that's a topic for another question.)

SPD vs SPD with platform

Rotational Symmetry

We can use rotational symmetry as a guideline while discussing pedal designs. Rotational symmetry is how many times one can rotate a pedal until it "looks the same" before one full revolution is reached.

SGo4

The Crankbrothers pedals have SGo4 (belong to a symmetry group of order 4). If the present orientation of a pedal is not right, you need to spin it by no more than 45° one side or the other, and you'll be ready to engage.

SGo1

The SPD SL, the Look Keo, and the Look Delta pedals belong to SGo1. There is just one position for clipping in, but that's not a disadvantage, because in all three the rear of the pedal is heavier than the front. The position of the pedal can be predicted, and this can be done (crucially) while looking up rather than down.

(In my limited experience, an SGo1 pedal will not always "lean back and be ready for clipping in." That possibly has something to do with the viscosity of the lubricant inside as well as how cold it is. These issues are also a topic for another question.)

SGo2

Like a rectangle, SPD pedals belong to SGo2. As with the Crankbrothers' SGo4 (which resembles a square), we cannot predict their resting position. Since the SGo2 pedals could be at an arbitrary orientation, the rider may need to rotate a pedal by as much as 90° to one side or the other until the pedal is ready for engaging (and the rider would truly like to be able to clip in without looking).

Question

The platform SPD pedals have a built-in weight because the platform side is heavier so they're always ready for clipping in (leaving aside viscocity, ambient temperature, as well as factory quality control). Plus they provide the option to use regular shoes or boots.

So, once more, why would anyone want double-side SPD rather than single-side SPD with a platform on the other side? Aerodynamics?

Future Questions

I am curious about the following two questions. I do not intend to ask them imminently. You are more than welcome to elaborate on either/both of them and ask.

  1. Suppose I buy a pair of SGo1 pedals. Since the rear is heavier than the front, I expect them to lean back to just the right position, but one of the two in the pair I bought doesn't. Should I return the pedals? Should I heat it and try again?
  2. Shimano has two models (PD-M8020, PD-M9020) that have SGo2 symmetry (we can't predict their orientation), yet that have a large frame. Suppose I don't care about the risk of impact (because I'm using SPD to ride on snow/ice and not in forests) and will (hopefully) always be clipped in, what's the purpose of their existence? In particular, does the frame make it easier to clip in without looking?
  3. My clothes, boots, and wheels have reflectors. My bike has front/rear strong lights. Yet the tell-tale sign for motorists that a cyclist is ahead is the characteristic up-down motion of the pedals. Do I really need to be concerned if I use either PD-M8000 or PD-EH500 (neither has reflectors), or does only the PD-T8000 make sense in an urban environment?
22
  • 11
    "always ready"?!? How many of those "always ready" pedals do you have experience using? Nov 23 at 3:08
  • 7
    in technical terrain, you don't want to have to worry finding the correct side.
    – Paul H
    Nov 23 at 6:32
  • 4
    @MaplePanda: Yes Shimano SPD pedals are heavy. But lots of steel and good bearings also means they are basically indestructible and last forever.
    – Michael
    Nov 23 at 7:02
  • 8
    What I meant is that If I’m in mountain biking technical terrain wearing SPD shoes, the last thing I want to feel underneath me would be the platform side.
    – Paul H
    Nov 23 at 16:17
  • 4
    You seem to underestimate the chaos of technical mountain bike terrain
    – Paul H
    Nov 23 at 16:20
10

Hybrid SPD pedals are somehow "weighted": the heaviest item (that defines the rest position of the pedal) is the rear of the mechanism rather than the platform. In "calm situation", you need to approach the pedal by the rear if you wear to clip, and by the front with regular shoes. But in practice, you develop muscle memory, and it's difficult to change your habits depending on the shoes you wear. And in moving conditions, because there's still some resistance in the pedal, it's very difficult to "predict" which side of the pedal will present itself.

With hybrid pedals, if you have cycling shoes with rigid soles, having the platform side instead SPD side is also be very unconvenient. They just slip on the platform side, and are damaged by the spikes. The opposite is true if you use them with soft soles.

As other have said, the advantage of double-sided SPD pedals is that you just don't bother on which side it is and clip in. That is critical when you stop in the middle of technical steep climb. The 90° angle of rotation you mentioned is not a problem in practice. Maybe a bit in the beginning when you don't approach the pedals correctly. But if you approach them from the rear, they align themselves.

To conclude: hybrid pedals are for me an acceptable compromise only if you want to be able to use your bike with regular shoes and you don't do anything technical (because you can't count on muscle memory). For the rest, you're better off with either pure platform pedals, or double-side SPD (or Crank Brother, or any other good brand of pedal).

EDIT: I made the experiment on my trekking bike that now on my trainer. The pedals are hybrid SPD/platform (PD-M324), the experiment was to simulate a start: you start with one pedal up and make one half turn as quick as possible. At the end of the half turn, because of the rotational effects (due to the crank, but also that the pedals themselves are not "neutral"), the other pedal keeps turning, and faster than expected: the weight that is supposed to stabilize the pedal is actually having opposite side effects: centrifugal effect pushes it "outside" the rotation (which means up when the crank is up), and when the crank rotation stops, you have a rotational effect on the pedal itself: the "weight" that is outside the rotation wants to continue straight, but because the pedal is held in place, it creates a rotational effect on the pedal, which can cause them to make one or two additional turns. If you try to clip-in at this moment, it's then in practice impossible to know which side will be on top.

10
  • Great answer, agree in all points. I use hybrid-SPD on my hardtail MTB, which doubles as both gravel/bikepacking and city bike. The hybrid pedals cover all that well enough, but for technical MTB I would always prefer either fully flat or double-sided SPD. Nov 23 at 10:52
  • With running or hiking shoes it's possible to ride on either side of the SPD/platform pedals, but they're not great on the SPD side.
    – Chris H
    Nov 23 at 11:33
  • @ChrisH indeed. I think it mostly depends on the surface you are riding on: on smooth surfaces, staying on the SPD side is ok (although I stay in that situation only when starting), but if the surface becomes rough (offroad or on cobble stones), there's not enough lateral support to my taste on the SPD side with hiking/running shoes.
    – Renaud
    Nov 23 at 11:46
  • @Renaud that's roughly what I found. Now I ride easy trails clipped in if there's no one in front of me, but getting to that point meant adopting SPDs properly rather than messing around with silly compromises - but I'm glad they exist for those that like them
    – Chris H
    Nov 23 at 11:52
  • 1
    @Sam what I meant by seasonality if that the need for a type of pedal is linked to the season (sorry if I used the wrong word, English is my third language). From what you say, it's the case: you can also buy the cheapest double sided SPD pedals (winter is hard on bearings, pointless to take fancy stuff), that you fit on your bike only in winter. If you swap tires for studded tires, you can swap the pedals at the same time. By grip, I meant the grip of the rear tire.
    – Renaud
    Nov 24 at 13:13
12

I had the platform one side pedals on my previous bike and went to the SPD both sides for my new bike. I think it depends on how you use the bike.

I bought the platform one side as my entry to clipless pedals. I am a recreational rider, but I thought there would be times I wanted to ride for transport, would not want to put on bicycling shoes, and would appreciate the platform being available. After 4 1/2 years on that bike I had ridden for transport (we were down a car for some reason) three times. In all three cases I had elected to wear cycling shoes and clip in. One of the features of SPDs is that you can reasonably walk in them enough to go to the hardware store. If I were using the bike routinely for transport I would want to be able to ride in normal clothes and platform pedals would be required.

Although the platform pedals are weighted, I found that it took some time for the pedals to align, so starting from a stop you had to clip in at the proper point in the cycle. I got used to it so it worked most of the time, but sometimes I would have to kick the pedal to get it in the right orientation. With the two sided pedals I just put my foot down and it clips in. I don't think the size of the angular correction is important as long as you always get the side you want without thinking about it.

You should use what works for you, but this is why the two sided ones work for me. I don't count weight to that resolution.

3
  • For your use case of being able to ride (short distances) in normal shoes, M324 or M424 SPDs have the cleat socket on both sides and a cage around them. They're what I got as my first clipless pedals and I currently have them on my hybrid and my MTB, with M520 on the tourer (pure SPD on both faces)
    – Chris H
    Nov 23 at 11:30
  • Interesting... My reasoning for even considering the platform SPD pedals is not commitment—I only ride recreationally. I am wondering if I need to hedge my bets that it might sometimes be so cold that I would need to wear my bulky, but of known insulation, street boots to ride. The question here really is: how good is the insulation in the MW5 and MW7 boots if one is wearing thick wool socks?
    – Sam
    Nov 23 at 16:06
  • 2
    @Sam, there are different kinds of bike gaiters/overshoes (not sure what the best English term is).
    – Carsten S
    Nov 23 at 22:06
7

Finding the right side is not that easy.

With the SPL SL style Look Keo Blade Carbon pedals on my road bike finding the right side is always a hassle and makes starting in traffic very stressful. With double sided mountain bike pedals (Shimano SPD, Look Quartz etc.) you just step onto the pedal and are locked in in basically all circumstances. Kind of makes me miss the double sided Speedplay Zero pedals I had on the road bike.

Platforms are more prone to ground contact. Since the platform is rather wide it tends to strike the ground earlier in tight turns. I’ve found this to be a real problem when (temporarily) riding road bikes with platform pedals.

4
  • I don't understand why Looks are so popular with all the complaints about difficulties clipping in and out and squeaking.
    – ojs
    Nov 23 at 8:22
  • 1
    The platfrom on the spd/platform combo is even more trouble as you get used to the clearance when clipped in and get a "surprise" when cornering hard in flat shoes
    – JoeK
    Nov 23 at 15:28
  • Isn’t “SPD SL Look Keo” an oxymoron? SPD-SL is Shimano, while look is obviously made by look.
    – MaplePanda
    Nov 23 at 20:21
  • Let me change that to SPD SL style.
    – Michael
    Nov 24 at 7:23
3

I can find few reasons

  1. Safety redundancy. If one side gets clogged or broke, one can easily kick-to-rotate to engage in the other slot.
  2. Size. The whole assembly is smaller than SPD/platform one. It allows sharper tilts without touching the ground.

SPD pedals are not meant for casual rides; they are meant for dedicated rides. The SPD/platforms are somewhat crossbread, or cat-dog, mixing both together at some compromises

  1. The pedal size is compromised. It is slightly bulkier increasing risk of hits (Curbs, ground, stones,...).
  2. Weight. For the same-grade materials the bulkier design means extra weight.
  3. Price. For the same weight the bulkier design needs to opt for ligter materials to keep the durability.
  4. Quality. For the same weight and price the lower-grade materials and/or components are used to keep the product within profitable margin.
3
  • 1
    1. Sure, but we're using SPD for mud/snow tolerance in the first place. 2- I don't understand. The platforms are not so large to protrude from under the shoes, even by a child, and so in any case the boots/shoes will be the first to hit the ground on either the toe or the heel side.
    – Sam
    Nov 23 at 15:58
  • 1
    (now addressing the second 1/2/3/4 points). 1. The bulk is anyway concealed (see 2 above). 2. The weight is actually the opposite of what you'd expect. 3. and 4. I don't see how these relate to the question.
    – Sam
    Nov 23 at 16:00
  • @Sam What about under-foot clearance? The hybrid pedals are thicker than the pure SPD pedals.
    – MaplePanda
    Nov 24 at 7:07
3

I tried SPD/platform pedals on a borrowed MTB when I was used to SPDs (both sides) on my hybrid. They were horrible - I clipped in when I didn't want to, and not when I did. The weighting wasn't adequate to be sure where they'd end up in rough terrain.

The whole experience made me quite reluctant to put SPDs on my MTB at all, though I finally got to like them when riding solo, much less in a group where stops can be sudden and unpredictable.

I'd be tempted to ask the opposite question - why do people ride with those nasty compromises when you can choose something better? Choose from:

  • good platform pedals
  • reliable SPDs (both sides, like M520, which are 380g)
  • something like M424 with SPD on both sides and a cage to press against. This is OK for short rides in soft soled shoes or hiking boots. I wouldn't recommend them in smart shoes with rather smooth soles. I used to ride unclipped with my daughter in a child seat on the back, then clip in after she got off. For family holidays when I'd only be riding with her on there, I fitted platforms.

Picking up on your edits, and using your terminology:

  • All my SPDs with SGo2 symmetry rotate naturally to the right position on contact with my foot (no looking down)
  • I've never ridden with CrankBros SGo4 symmetry so can't be sure, but Id expect them to do the same.
  • SGo1 as implemented in pedals has the unique property that it has two stable positions, only one of which is desirable at a given moment.
10
  • To your question for the third point (hybrid vs double-side with platform), but I didn't try something like the M424, I have M8020 on my hybrid bike — dual sided with a smooth platform): hybrid pedals only present a problem when starting, once in position, they behave like proper platform/spd pedals. M424 seem to offer less stable support than a good hybrid pedal when using "regular shoes". It depends then on where you want your compromise. I think that hybrid pedals are rather for advanced cyclists who can deal with the compromise, and a bad choice for an introduction to SPD.
    – Renaud
    Nov 23 at 12:05
  • @Renaud M820 look interesting as an alternative to my M520 (on my tourer) where the cleat is the only contact. I still tend to start moving then clip in and in the wet M520 are a bit slippery for that.
    – Chris H
    Nov 23 at 12:54
  • Re: "The weighting wasn't adequate" Why? Gravity is quite reliable, no matter how rough your terrain. Might it be the case that the dirt/sand on rough terrain makes gravity unable to overcome the friction? Is the lubricant used at the pedal's ball bearings (see my "future questions") so thick that you were unable to depend on the pedal falling with the heavy side down?
    – Sam
    Nov 23 at 15:51
  • @Sam gravity is reliable, but inertia also plays a part and on rough stuff it's easy to bump the pedal. I recall (it was a few years ago) the pedal spinning almost too freely. Worse, if you're trying to get to the flat side, that means bumping the pedal round 180° just as you get to a tricky bit.
    – Chris H
    Nov 23 at 16:10
  • Re: "if you're trying to get to the flat side": yes, but that's the price we pay, no? If we choose SPD-platform pedals rather than ordinary platform pedals that offer no option for clipping in, we accept that finding the platform side will always require getting the platform side to the top.
    – Sam
    Nov 23 at 16:13
1

If you always use SPD shoes, double sided SPDs pick up either side and are a lot easier to use.

I had ones with "rat trap" platform one side, (and added toe clips/straps) and SPD the other, because sometimes I needed to use normal shoes and sometimes SPDs. The left pedal always hung in just the wrong orientation for a quick pickup until I weighted its toeclip with an old (heavier) 50p piece.

Bike shop owner kept laughing at this modification ... until I pointed out it was the cheapest component on the bike!

3
  • This is actually an excellent solution on two counts. If you make the platform side even heavier by adding a classical toeclip, it becomes easier to depend on that size falling down by gravity even if the lube is too thick or you have a bit of dirt/mud/snow between the pedal and the spindle. Your experience suggests that we can really not depend on the heavier side falling down.
    – Sam
    Nov 23 at 15:54
  • @Sam in fact it fell too far, making it difficult to catch the rear of the pedal, flip it toe clip up, and slide a shoe into it. Weighting the nose of the toe clip made it hang about 45 degrees making that easy, for fast takeoffs when the lights changed. (This was on a recumbent) Nov 23 at 19:18
  • A toe clip rotated 180 degrees along pedal axis becomes effectively a scoop. It is left as an exercise why this could be a bad idea. BTW, pedals intended to be used with toe clips have a sharp point at the back that can be used to flip the pedal to correct orientation.
    – ojs
    Nov 24 at 13:35
0

I don't get it either. Double-sided SPD pedals provide a far easier way to attach pedal reflectors, which are required by law in many cases and heavily advisable if not required too. Pedals such as PD-T8000 already have reflectors built in around metal protection. Some earlier models like PD-M324 require external plastic reflectors that are very quickly broken, so the best solution in these cases is adding reflective tape because it's far more durable and if it ever breaks, easier and cheaper to replace because it's wide available in 5 meter long rolls and a pedal requires only 2 centimeters.

For poor SPD/platform duals like PD-M324 there is one drawback: the weight is rotationally symmetric so you never know which way the SPD side is and which way the platform side is. Thus, when starting riding the bike, it's possible you try to accidentally attach your SPD shoes to the platform side which obviously won't work. Then you need to remove your foot from the pedal for a half-rotation and try attaching again.

However, for good SPD/platform duals like PD-T8000, the pedals have very low-friction bearings and the weight is slightly asymmetric. For example in the case of PD-T8000, the SPD side points backwards and the platform side points forwards when at rest. Then when attaching your shoes, you choose the side using leg motion: move leg forwards and you get SPD side, move leg backwards and you get platform side. Easy and over 99% success rate.

It's very useful that you can use your pedals too without SPD shoes. I can think of at least two circumstances where it's useful:

  • Maybe you want to use your bike for few kilometer long shopping errands. Then having to use SPD shoes would be ridiculous
  • Maybe you want to occasionally ride in very cold weather, so cold that normal SPD shoes won't work (you would freeze to death) and your only option is very expensive shoes like 45nrth Wolvhammer or Wolfgar, or non-SPD-shoes which are available for very cold weather far cheaper. If you ride only occasionally in very cold weather, it isn't useful to buy the very expensive cold-weather SPD shoes, and thus, you want to use regular cold-weather shoes and you need platform sides on the pedals
4
  • 2
    The PD-M324 are not rotationally symmetric. The cage is higher on the rear side (when clipped in). It is quite visible on the side picture of the product page. bike.shimano.com/it-IT/product/component/deore-t6000/… In "calm condition", they reliably keep the same position.
    – Renaud
    Nov 23 at 16:57
  • 1
    Reflectors on the shoes are entirely sufficient. The view of the pedal is blocked by the shoe anyway. Those laws are hopelessly outdated and made for casual bikers with ordinary waling shoes. And written before reflecting elements on clothes and shoes became widespread. Also, it is always possible to temporarily exchange the pedals. Not for shopping, there is nothing ridiculous to shop in MTB shoes, but if one wanted to use some heavy winter boots for some time, why not. It takes a few minutes. Putting on many kinds of bike bags takes more time.
    – Vladimir F
    Nov 23 at 18:37
  • Re: "your only option is very expensive shoes like 45nrth ..." It appears that even 45nrth boots are inadequate. Here (youtu.be/gvQfTze-boo?t=538) he is wearing the 45nrth Ragnarok, and he still gives up and uses the chemical (and unfortunately disposable) solution. I'm sure you also have too many "winter cycling gloves" that are inadequate (and that can't be returned past one experiment). A collection of winter cycling boots that don't solve the problem becomes too much. The trouble may be that "winter" is a relative term.
    – Sam
    Nov 24 at 23:35
  • OK, I see that the 45nrth Wolvhammer (45nrth.com/products/wolvhammer-boa) and the 45nrth Wolfgar (45nrth.com/products/wolfgar) have lower temperature ratings than the 45nrth Ragnarok (45nrth.com/products/ragnarok-black). I wish they called themselves something higher than 45nrth. I'm north of the 49th.
    – Sam
    Nov 24 at 23:40
0

Why would anyone want to use SPD pedals... when SPD pedals with platforms (such as PD-M9120—right of the image) are available.

Another aspect to consider aside from the techinical aspects: vanity. I imagine a large number of people are put off because, although convenient, it's not a very "pro" look.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.