Maelochs

Actually, @seamuis pretty much translated my post.

I am not a mathematician. I do understand that aero drag increases at a rate in multiples of speed, not directly, so that id you go twice as fast, the drag quadruples ... or some such. I thought it went by the square of the irate of increase ... but the basic principle is the same. if you go slowly, drag is relatively low. If you go a little faster, drag increases even more quickly. if you go way faster, drag balloons and gets to be huge.

Therefore ... if you are riding at 15 mph, the aero drag isn't huge, but if you are riding at 25 it is. if you are trying to get from 30 to 32 mph, the wattage increase is proportional to the increase in drag, which is Way more than the increase in drag going from 15 to 16 mph. (And yes, I see where @asgelle claims it takes the same watt increase to go from 15-16 as from 30-32---but since the aero resistance is about three times as great or more, i don't see how that makes sense since you need power to overcome resistance and the resistance is not growing in a linear fashion... why would required wattage? Whatever.)

So, while anyone Can wear a skinsuit, it might not make much of a difference---spend the money on hiring a coach or something. or buy a skinsuit and wear it proudly--I don't care.

I have seen a couple different charts showing how much each alteration translates into a time advantage---but those all presuppose a person riding flat-out over a 40-k TT or some such.(I notice they all claim radically different numbers, which makes me totally doubt their accuracy. Science is performing the same experiment and getting approximately the same result. if one gets a number twice what the other got, someone is doing it wrong--maybe both.)

Also, this chart lists aero bars and an aero position ... but how can one achieve an full aero position without aero bars? Hmmmm .....

In any case ... even a hardcore pro TT expert isn't going to gain much from wearing a skinsuit when he is riding around the block with his kids on their bikes with training wheels. So, pretty much, at speeds below what the really fast riders ride, that skin suit is likely not the most effective investment.

Still might be the right purchase. That is a personal thing. I never see sea lions while out riding.

Nermal

Yes, oil definitely reduces friction.

seamuis

jefnvk

Sure, but when looking at performance "upgrades" in any speed sport, aero is the thing that bumps you from 99.5% to 99.9%, it is something that can bump up speed a bit when much larger contributions are running consistently as fast as they can. It is absolutely critical at top competition, because everyone else has the body tuned out, it can provide the marginal gains you need to win.

Yes, someone averaging 15mph can go marginally faster with a suit, but they aren't consistent to the point where you can actually look at the suit and notice it making any difference. They may well beat their suit time in jean shorts and a cotton tshirt the next day, simply because that day they got into a better rhythm.

cyclist2000

Tattooed

asgelle

OBoile

It's been said many times on this forum, the absolute time differences are actually greater at slower speeds.
How much that matters to someone is personal preference, but it doesn't change the fact that it will make a difference.

OBoile

He didn't say this.

asgelle

jon c. 

htfu

jefnvk

Not quite sure I'm following you here. Are you saying if you put a rider that could average 13mph and one that could ride 25mph on the same course, the presence or lack of a suit would affect the 13mph rider more?

bruce19

I'm an ex-college football player. If I get a skin suit it's going to say GOODYEAR on it.

Maelochs

if for no other reason than because he will be on the course longer and enjoying the benefit for longer.

As i tried to say earlier ... as far as I have heard, aero advantages are greater proportionately for slow riders .... but that means you are going from 15.75 to 15.85 mph----and smaller proportionately but greater overall for fast riders. if a skin suit saves 5 watts and you are only putting out 100, it is a five percent gain. if you are putting out 400 watts, 5 watts is almost negligible ... but it might be the difference of beating the guy who didn't wear the skinsuit.

For someone who is riding at 40 percent output ... and not even timing his ride ... what metric matters? Wear a skinsuit if you like it.

For someone pushing for maximum performance in a race, the metric which matters is shortest time from start to finish ... and skinsuit will save a couple seconds.

Maelochs

I guess you don’t see that your reply completely validated my post … but thanks. The numbers quoted are not absolutes, as you say … they are specific to a single experiment or set of experiments.

So any one quoting thos e figures and applying them to any other rider in any other situation (“A skin suit will save you X, acas this chart shows”) is wrong. All it show s ihtat there is some saving to be had under certain conditions. And as I pointed out, we don’t even know how they did their experiments---how did they evaluate the benefit of a ‘wind-tunnel-refined aero riding position” which had to have been done with aero bars … and then determine a different value for the riding position and the aero bars? Can’t have one without the other. So … as I stated those are not scientifically derived and verified values …. And in themselves, all they say is that there seems to be some advantage to certain gear and practices. Glad we agree.

asgelle

Speak for yourself. If you looked up the articles from which the figure was taken, Buying Time: Costs and Benefits of Time Trial Equipment - The Buzz https://www.aerosportsresearch.com/pdf/buying-time.pdf all the details are described. I'd say the fault is with Elvo for presenting the figure out of context and any reader who thinks that one figure is the sum total and definitive word on the subject.

OBoile

Depending on your perspective, yes.

As I understand it, the 13 mph rider will actually save more total time over a given distance. But, the percentage of time saved will be lower. So for example (I'm just making these numbers up) lets assume a 13 mph rider and a 26 mph rider. For a 13 mile course, the 13 mph rider might save 1 minute over an hour of riding. The 26 mph rider may save 40 seconds over half an hour of riding. Something like that.

But all this is just going by what I've read here.

Ultimately, it will make both riders slightly faster. It's up to you if that is worth the cost/expense of a speed suit. I don't own one, so it clearly isn't worth it to me.

seamuis

OBoile

Hence my statement above. Others may feel differently. It's entirely a matter of personal preference.

grayEZrider

As a (Passive, Retired, Old (68) rider I agree. The only time I hit 30mph is bombing down the mountain, and then I'm dragging the brakes and promising myself disc brakes on the next bike. And I am certain the "slick" advantage (to me) of a skin suit is lost by the extra weight and resistance of additional water bottles needed to get there in twice the time. I think skin suits are really effective for only two types of riders. Pure racers and Egos with money to burn.

seamuis

asgelle

Again with the special physics just for cycling. Skin suits lower drag and hence are effective for all riders at all cycling speeds. whether the cost is worth the gain is up to each rider to decide for themself. Don't impose you values on others. And what do you mean by a pure racer? What separates the pure from the impure?

One thing to mention regarding greater time saved for slower riders, if you look at results for a time trial, the absolute time gaps between riders is about the same for the slower groups as it is for the faster ones. That means a slower rider is likely to move up more places by optimizing equipment than a faster one.

grayEZrider

I agree that the gear does work and to a larger (percentage wise?) for slower riders, as I can feel and measure the difference between my bulky winter riding gear as opposed to light, tighter summer riding gear. As for a definition of "Pure racer"? I think a pure racer is anyone who actually enters and races at any level. Its a question of determination.
First race, once a year, Pro, whatever. It is the dedication to the task that defines "racer".
Or maybe that is just my age giving into the new age "participation trophy" thinking?

Maelochs

Well .... evolution is proven. This is what grew out of the "Does weight matter" debates.

Doge

Body position generally matters most. When you got that, then work on bike and kit. It all adds up from bike parts, to placement (cables) etc. Shaving legs and arms helps. A speed suit (like a Castelli body paint) is noticeable when riding for time. Booties - vs most shoes, help. Vs some shoes, not as much. Silicone spray bike, oil body, don't turn head - or get a different helmet. Aero water bottle. If you are really into it you need to get a rule book and see what you can get away with. The really fast stuff is not allowed.
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But naked would be pretty fast, just that hard to pedal in bare feet, also most would fidget vs a good set of shorts with correct pad. The compression on the kits (technically UCI illegal, they just ignore speed suits) is likely better than being naked.
So my guess is a naked person would put in a slower speed than one in a speed suit.

jefnvk

OK, fair enough @Maelochs and @OBoile, that makes sense what you are saying now. Yeah you are probably always going to be faster with it on than off in that exact situation.

I always thought the shaving was more to aid in medical attention to road rash, than actual aero affects?