The effects of shoe weight

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pwa
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The effects of shoe weight

Postby pwa » 22 Aug 2020, 2:40pm

I have just been out testing the cleat positioning on some new shoes (all good) and I have come back with the definite impression that the lightness compared to the tatty shoes they replace makes spinning the pedals a bit easier. The old shoes, with cleats and screws, weigh 515g each. The new shoes, again with cleats fitted, weigh 425g. 90g less on each foot, 180g less at the end of the cranks to rotate. I have long suspected that shoe weight affects pedalling and now I'm pretty much convinced.

fastpedaller
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Re: The effects of shoe weight

Postby fastpedaller » 22 Aug 2020, 4:02pm

I'm going to amputate my toes - much weight saving as the shoes will also be smaller :lol:

LuckyLuke
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Re: The effects of shoe weight

Postby LuckyLuke » 22 Aug 2020, 4:07pm

Start with the toenails Fastpeddler!
My Fu Manchu tree climbers are overdue a trim. Thanks for the incentive pwa :D

pwa
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Re: The effects of shoe weight

Postby pwa » 22 Aug 2020, 4:37pm

Fastpedaller's drastic pedicure doesn't appeal to me, but maybe I'm just too fussy. I'll probably stick to doing what I do when I buy hiking shoes: pick them up off the display shelf and feel the relative weights and then try on the lighter offerings.

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foxyrider
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Re: The effects of shoe weight

Postby foxyrider » 22 Aug 2020, 9:25pm

My summer road shoes are about half the weight of my touring/winter footwear which feel like deep sea divers boots on the end of my legs! A few grams might not make a difference but when you are talking over 200g, well the attritional effect of that extra weight is very noticeable over a days ride.
Convention? what's that then?
Airnimal Chameleon touring, Orbit Pro hack, Orbit Photon audax, Focus Mares AX tour, Peugeot Carbon sportive, Owen Blower vintage race - all running Tulio's finest!

cyclop
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Re: The effects of shoe weight

Postby cyclop » 23 Aug 2020, 7:08am

Wouldn,t the extra weight help on the downstroke thus cancelling out the upstroke(in theory)?

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fausto99
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Re: The effects of shoe weight

Postby fausto99 » 23 Aug 2020, 8:05am

cyclop wrote:Wouldn,t the extra weight help on the downstroke thus cancelling out the upstroke(in theory)?

Indeed, but the extra weight will still count against you when climbing. Also acceleration will be reduced due to an increase in rotational moment of inertia.

Jdsk
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Re: The effects of shoe weight

Postby Jdsk » 23 Aug 2020, 8:15am

fausto99 wrote:
cyclop wrote:Wouldn,t the extra weight help on the downstroke thus cancelling out the upstroke(in theory)?

Indeed, but the extra weight will still count against you when climbing. Also acceleration will be reduced due to an increase in rotational moment of inertia.

Yes.

But the question also reminds us why it is worth drawing the distinction between mass and weight, even in ordinary discourse.

The shoes differ in mass, the greater weight will be harder to lift up hills, the paired weights will cancel out the effort of lifting one in the stroke (but there will be slightly more load on the bearings and slightly more power needed), and the greater inertia will make the more massive pair harder to accelerate both in any direction and in rotation and whether that's faster or slower.

Jonathan

PS: It came up very recently in another thread.... there probably is a Nobel Prize waiting for someone who can explain the equivalence of of gravitational and inertial mass.

Jdsk
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Re: The effects of shoe weight

Postby Jdsk » 23 Aug 2020, 8:28am

But the experiment that I'd really like to see revolves around (!) measuring the threshold for detecting any difference. Not hard to do with a combination of lead sheet and ingenuity, but would need to be blinded...

Jonathan

Brucey
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Re: The effects of shoe weight

Postby Brucey » 23 Aug 2020, 8:38am

I think that having relatively heavy shoes may be a good training aid, and that it isn't especially harmful in efficiency terms.

Most cycling shoes are very toe-heavy; their weight might as well be pedal weight. This just twirls around the BB in a way that conserves angular momentum, much as a flywheel does.

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PDQ Mobile
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Re: The effects of shoe weight

Postby PDQ Mobile » 23 Aug 2020, 9:19am

And.....
heavier may well be more strongly constucted and therefore more durable.
Saving money and materials in the longer term.

And perhaps better for walking in?

fastpedaller
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Re: The effects of shoe weight

Postby fastpedaller » 23 Aug 2020, 11:25am

Heavier may be less flexible and therefore transmit more power to the pedals?

pwa
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Re: The effects of shoe weight

Postby pwa » 23 Aug 2020, 3:32pm

The lighter shoes were bought as a direct replacement for the heavier ones, the weight saving being an accidental bonus. They are about the same stiffness and the sole looks as durable, but the uppers are lighter. The pedalling is definitely a bit easier. I wasn't anticipating being able to feel it and I wasn't looking for it, my attention being purely on ensuring the cleats were positioned right. Okay, if you imagine the cranks going round to be like a flywheel with the advantages of momentum you could think the extra mass would not matter, but my cycling isn't as clockwork as a time trial rider on a flat road. I pedal a bit, pause for a corner, pedal a bit more, pause for a cat in the road, and so on. Anyone in any doubt about the disadvantages of weight in that area could try attaching a brick's worth of extra mass, possibly in the form of lead, to each pedal, and I think you would find your pedalling impeded on anything but a time trial flat straight road. I could certainly feel the lack of 80g on each foot as I rode around our twisty lanes, and it felt nice.

Jdsk
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Re: The effects of shoe weight

Postby Jdsk » 23 Aug 2020, 3:46pm

pwa wrote:Anyone in any doubt about the disadvantages of weight in that area could try attaching a brick's worth of extra mass, possibly in the form of lead, to each pedal, and I think you would find your pedalling impeded on anything but a time trial flat straight road. I could certainly feel the lack of 80g on each foot as I rode around our twisty lanes, and it felt nice.

Your shoes are 90g less massive per shoe, a typical brick has a mass of around 2,000g.

It would be great if someone did the experiment, but it needs to be blinded.

Jonathan

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Syd
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Re: The effects of shoe weight

Postby Syd » 23 Aug 2020, 3:52pm

pwa wrote:The lighter shoes were bought as a direct replacement for the heavier ones, the weight saving being an accidental bonus. They are about the same stiffness and the sole looks as durable, but the uppers are lighter. The pedalling is definitely a bit easier. I wasn't anticipating being able to feel it and I wasn't looking for it, my attention being purely on ensuring the cleats were positioned right. Okay, if you imagine the cranks going round to be like a flywheel with the advantages of momentum you could think the extra mass would not matter, but my cycling isn't as clockwork as a time trial rider on a flat road. I pedal a bit, pause for a corner, pedal a bit more, pause for a cat in the road, and so on. Anyone in any doubt about the disadvantages of weight in that area could try attaching a brick's worth of extra mass, possibly in the form of lead, to each pedal, and I think you would find your pedalling impeded on anything but a time trial flat straight road. I could certainly feel the lack of 80g on each foot as I rode around our twisty lanes, and it felt nice.

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