Why male cyclists shave their legs

Al_38

kieronymous wrote:

@ AT: water is denser and more viscous than air, so small changes to the friction interface (e.g. your skin) will make a bigger difference.

'Course, it all gets a bit complicated when you start discussing the boundary layer. That's the reason you have dimples on skin suits, golf balls, speed skiing helmets, etc. The surface imperfections are there to encourage micro-eddies (vortices, whirlpools, call 'em what you want) to break away from the surface sooner, leaving behind pseudo-laminar flow conditions - until the next eddy builds up that is. The theory is that the imperfections allow pseudo-laminar conditions to exist for a greater percentage of the time, hence reducing drag.

...I think!

Any paddlers here? It's also the reason why artificial (smooth concrete) kayak courses eg Holme Pierrepoint exhibit much 'surgier' flow than natural (rocky) channels. Same principle, on a larger and slower scale. The smooth surface gives the eddies time to build up.

.. I think!

BTW I do have a degree in engineering and several years exp. in hydraulics so I sort of know what I'm talking about. Ish.

Hmmm, About right i think, the point of dimples / roughness on a bluff body is to trip the boundary layer to turbulence. This INCREASES skin friction drag but because of the greater momentum diffusion the boundary layer is more resistance to separation in an adverse pressure gradient. So you get a much smaller wake and so a much smaller form drag. (i.e. downstream of the body there is more laminar flow)
For every shape there is some optimum for what you can do to the surface to minimise the overall drag (the two above and wave drag).

I think the reason why holmepierre point is wavy normally is becasue it is very exposed to the wind and any waves formed in the water reflect off the smooth concrete sides and then recombine to form more extreme minima and maxima. Natural beds are much better at absorbing the waves

lost_in_thought

Al_38 wrote:

kieronymous wrote:

@ AT: water is denser and more viscous than air, so small changes to the friction interface (e.g. your skin) will make a bigger difference.

'Course, it all gets a bit complicated when you start discussing the boundary layer. That's the reason you have dimples on skin suits, golf balls, speed skiing helmets, etc. The surface imperfections are there to encourage micro-eddies (vortices, whirlpools, call 'em what you want) to break away from the surface sooner, leaving behind pseudo-laminar flow conditions - until the next eddy builds up that is. The theory is that the imperfections allow pseudo-laminar conditions to exist for a greater percentage of the time, hence reducing drag.

...I think!

Any paddlers here? It's also the reason why artificial (smooth concrete) kayak courses eg Holme Pierrepoint exhibit much 'surgier' flow than natural (rocky) channels. Same principle, on a larger and slower scale. The smooth surface gives the eddies time to build up.

.. I think!

BTW I do have a degree in engineering and several years exp. in hydraulics so I sort of know what I'm talking about. Ish.

Hmmm, About right i think, the point of dimples / roughness on a bluff body is to trip the boundary layer to turbulence. This INCREASES skin friction drag but because of the greater momentum diffusion the boundary layer is more resistance to separation in an adverse pressure gradient. So you get a much smaller wake and so a much smaller form drag. (i.e. downstream of the body there is more laminar flow)
For every shape there is some optimum for what you can do to the surface to minimise the overall drag (the two above and wave drag).

I think the reason why holmepierre point is wavy normally is becasue it is very exposed to the wind and any waves formed in the water reflect off the smooth concrete sides and then recombine to form more extreme minima and maxima. Natural beds are much better at absorbing the waves

Eh? Layman's terms please!

hisoka

Al_38 wrote:

kieronymous wrote:

@ AT: water is denser and more viscous than air, so small changes to the friction interface (e.g. your skin) will make a bigger difference.

'Course, it all gets a bit complicated when you start discussing the boundary layer. That's the reason you have dimples on skin suits, golf balls, speed skiing helmets, etc. The surface imperfections are there to encourage micro-eddies (vortices, whirlpools, call 'em what you want) to break away from the surface sooner, leaving behind pseudo-laminar flow conditions - until the next eddy builds up that is. The theory is that the imperfections allow pseudo-laminar conditions to exist for a greater percentage of the time, hence reducing drag.

...I think!

Any paddlers here? It's also the reason why artificial (smooth concrete) kayak courses eg Holme Pierrepoint exhibit much 'surgier' flow than natural (rocky) channels. Same principle, on a larger and slower scale. The smooth surface gives the eddies time to build up.

.. I think!

BTW I do have a degree in engineering and several years exp. in hydraulics so I sort of know what I'm talking about. Ish.

Hmmm, About right i think, the point of dimples / roughness on a bluff body is to trip the boundary layer to turbulence. This INCREASES skin friction drag but because of the greater momentum diffusion the boundary layer is more resistance to separation in an adverse pressure gradient. So you get a much smaller wake and so a much smaller form drag. (i.e. downstream of the body there is more laminar flow)
For every shape there is some optimum for what you can do to the surface to minimise the overall drag (the two above and wave drag).

I think the reason why holmepierre point is wavy normally is becasue it is very exposed to the wind and any waves formed in the water reflect off the smooth concrete sides and then recombine to form more extreme minima and maxima. Natural beds are much better at absorbing the waves

Worst thing is that this is reminding me of my uni days in Mathematics and fluid dynamics course I never sat the exams for (dropped out due to needing money badly). It makes sense to me but not the words, just the overall ideas.

always_tyred

lost_in_thought wrote:

Al_38 wrote:

kieronymous wrote:

@ AT: water is denser and more viscous than air, so small changes to the friction interface (e.g. your skin) will make a bigger difference.

'Course, it all gets a bit complicated when you start discussing the boundary layer. That's the reason you have dimples on skin suits, golf balls, speed skiing helmets, etc. The surface imperfections are there to encourage micro-eddies (vortices, whirlpools, call 'em what you want) to break away from the surface sooner, leaving behind pseudo-laminar flow conditions - until the next eddy builds up that is. The theory is that the imperfections allow pseudo-laminar conditions to exist for a greater percentage of the time, hence reducing drag.

...I think!

Any paddlers here? It's also the reason why artificial (smooth concrete) kayak courses eg Holme Pierrepoint exhibit much 'surgier' flow than natural (rocky) channels. Same principle, on a larger and slower scale. The smooth surface gives the eddies time to build up.

.. I think!

BTW I do have a degree in engineering and several years exp. in hydraulics so I sort of know what I'm talking about. Ish.

Hmmm, About right i think, the point of dimples / roughness on a bluff body is to trip the boundary layer to turbulence. This INCREASES skin friction drag but because of the greater momentum diffusion the boundary layer is more resistance to separation in an adverse pressure gradient. So you get a much smaller wake and so a much smaller form drag. (i.e. downstream of the body there is more laminar flow)
For every shape there is some optimum for what you can do to the surface to minimise the overall drag (the two above and wave drag).

I think the reason why holmepierre point is wavy normally is becasue it is very exposed to the wind and any waves formed in the water reflect off the smooth concrete sides and then recombine to form more extreme minima and maxima. Natural beds are much better at absorbing the waves

Eh? Layman's terms please!

I think it might be helpful if this were translated into Finnish:

vesi on tiheämpi ja sakea kuin ilmaa, niin pieniä muutoksia, kitka-liitäntä (esimerkiksi iho) tekee isompi ero.

"-Kurssi, se mikä saa hieman monimutkainen, kun aloittaa keskustelut rajakerroksessa. Se on syy olet dimples iholle puvut, golf-pallot, nopeus hiihto kypärät jne. pinnan epätasaisuuksien tarkoituksena on edistää mikro-sumun (vortices, whirlpools, soita 'em mitä haluat) katkaista pois pinnan nopeammin, joten takana pseudo-Laminar Flow edellytykset - siihen asti, kunnes seuraava pyörrevirtajarrujen kerääntyy, että on. Teoria on, että epätasaisuuksien sallia pseudo-Laminar edellytykset olemassa nykyistä suurempi osuus aikaa, siten vähentää vetämällä.

... Mielestäni!

Kaikki melojille täällä? Se on myös syy, miksi keinotekoinen (sileä betoni) kajakki kursseja esim. Holme Pierrepoint näytteille paljon "surgier" virtaus kuin luonnollisen (Rocky) kanavia. Sama periaate, jonka suurempi ja hitaampi mittakaavassa. Sujuvasti pinta antaa sumun aika rakentaa.

.. Uskon!

BTW minulla on suorittanut tekniikan ja useita vuosia exp. hydrauliikasta joten tavallaan tietää, mitä olen puhumme. Ish. [/ Lainaus]

Hmmm, Tietoa oikeus uskon, että kohta dimples / karkeus on bluffata elin on matkaa rajan kerros turbulenssi. Tämä lisää ihon kitka vedä vaan sitä enemmän vauhtia diffusion rajaolosuhteet kerros on enemmän vastustusta eri haitallisia paineita alamäessä. Niin saat paljon pienempiä vanavedessä ja niin paljon pienempi muodossa vetää. (eli alavirtaan elimistössä on enemmän laminaarivirtausympäristöissä)
Jokaisen muoto on olemassa optimaalinen siitä, mitä voit tehdä, jotta pinta minimoimiseksi koko vedä (kaksi edellä ja aalto vetää).

Uskon, että syy siihen, miksi holmepierre on aaltoileva yleensä siksi, että on hyvin alttiina tuulen ja kaikki aallot muodostunut vesi heijastaa pois sujuvaa konkreettisia puolin ja sitten rekombinaatiokyvyssä muodostaa rajuimmista minimit ja maksimit. Natural sängyt ovat paljon parempia imeytyy aallot

iain_j

Ah, thanks AT, it all makes sense now

carbonfiend

I shave my legs and started about 10yrs ago when I was doing triathlon and the odd road race, I did it because everybody else did and my best mate who I trained with is a roadie and he did, he started out riding MTBs in the 80's and when he crossed over to road racing he said roadies used to take the p**s out of him for not shaving his legs. In all the years of riding on the road I have had no reason to shave my legs though even when I had a serioud accident I didn't get any road rash. 3 yrs ago I took up MTB enduros and binned tri's and just train on the road but I still shaved my legs through habit, since riding off road I have had seriously more reason to shave my legs as I am constantly getting cuts and grazes which are far easier to clean etc when legs are shaved yet hardly any MTB riders shave

squired

I get seriously bad heat rash when I exercise, even in the winter, and I tend to find that trimming the hairs on my legs helps ease the rash (and itching). Having said that I also shave my armpits and other places too. Hairless legs do look better though, and tan better too in the summer.

DavidTQ

Im just one of those people for whom "because everyone else does" is a good reason not to But heck Im a commuter, not a triathlete and hairy legs are a FCN modifier

roger_merriman

i don't shave but then at heart i'm a MTB plus i'm very hairy so i would spend my life scraping hair off, i tan almost visably in sun so getting a tan never bothers me as i walk out side and tan.

lost_in_thought

AT, do you speak Finnish or was that a translation engine?

If you do speak Finnish where did you learn - I am keen to take my smattering of words and expand!

Also phrases like this make me chuckle:' joten takana pseudo-Laminar Flow edellytykset'

always_tyred

lost_in_thought wrote:

AT, do you speak Finnish or was that a translation engine?

If you do speak Finnish where did you learn - I am keen to take my smattering of words and expand!

Also phrases like this make me chuckle:' joten takana pseudo-Laminar Flow edellytykset'

Good god no. That was google translator. So many words come out as "EasyJet" don't they?

lost_in_thought

Always Tyred wrote:

lost_in_thought wrote:

AT, do you speak Finnish or was that a translation engine?

If you do speak Finnish where did you learn - I am keen to take my smattering of words and expand!

Also phrases like this make me chuckle:' joten takana pseudo-Laminar Flow edellytykset'

Good god no. That was google translator. So many words come out as "EasyJet" don't they?

Damn it, I got all excited there. I just enjoyed the mix of the english with the (mad) finnish words!

Teeheehee easyjet. I'm going to tell them that next time I'm there.

always_tyred

lost_in_thought wrote:

Always Tyred wrote:

lost_in_thought wrote:

AT, do you speak Finnish or was that a translation engine?

If you do speak Finnish where did you learn - I am keen to take my smattering of words and expand!

Also phrases like this make me chuckle:' joten takana pseudo-Laminar Flow edellytykset'

Good god no. That was google translator. So many words come out as "EasyJet" don't they?

Damn it, I got all excited there. I just enjoyed the mix of the english with the (mad) finnish words!

Teeheehee easyjet. I'm going to tell them that next time I'm there.

Be careful not to cause an international incident.

I once made the mistake of suggesting, that just because an airport took flights from Seattle and Vancouver, it should not be called an "International" airport.

Some locals took offence that I was belittling their little airport. I wasn't even being that loud.

I once also made the mistake of participating in a conversation with a bunch of highly educated Americans, which concluded that the president was a bit of a moron.

Even though I was one of about 6 people who came to this conclusion, I caused an international incident in the restaurant. We weren't even being that loud.

What has that do with anything, I hear you ask?

Mmmm. Not much.

ademort

lost_in_thought wrote:

AT, do you speak Finnish or was that a translation engine?

If you do speak Finnish where did you learn - I am keen to take my smattering of words and expand!

Also phrases like this make me chuckle:' joten takana pseudo-Laminar Flow edellytykset'

Ican translate into Dutch for you if it makes it any easier. Ademort

Littigator

For those that shave MTFU and use a depilator. Stings a bit but no stubble and it lasts a lot longer

lost_in_thought

Yaaaaaay Litts you're back!

Ignore him kids, depilators hurt.

jedster

Can I just point out that the two statements

1. it's mainly about aesthetics
2. you need to stop just above the bottom of your shorts sort of like hairy boxer shorts

Don't seem to me to be entirely consistent

Could I get opinions from the ladies - don't you reckon a bloke with smooth legs but hairy boxer shorts would look utterly ridiculous?

J

lost_in_thought

jedster wrote:

Could I get opinions from the ladies - don't you reckon a bloke with smooth legs but hairy boxer shorts would look utterly ridiculous?
J

Yes. But this is moving back into territory I don't really want to know about!

Littigator

lost_in_thought wrote:

Yaaaaaay Litts you're back!

Ignore him kids, depilators hurt.

I is back indeed! Bit of a not having lots of time at work (i.e. no work whatsoever) to post and having serious virus issues on home laptop conspired against me for the last couple of weeks.

I am now properly learning to chill wiv no job and lots of time...yeehah! But it's taken 3 weeks to start winding down.

ps...hurts!!! WTFU

caretaker42

cos it feels soooo Gooood lol :twisted:

always_tyred

lost_in_thought wrote:

jedster wrote:

Could I get opinions from the ladies - don't you reckon a bloke with smooth legs but hairy boxer shorts would look utterly ridiculous?
J

Yes. But this is moving back into territory I don't really want to know about!

Well you started it!!

lost_in_thought

Always Tyred wrote:

lost_in_thought wrote:

jedster wrote:

Could I get opinions from the ladies - don't you reckon a bloke with smooth legs but hairy boxer shorts would look utterly ridiculous?
J

Yes. But this is moving back into territory I don't really want to know about!

Well you started it!!

I said LEGS.

Rich158

They don't stop where the shorts begin, they normally go all the way up to the swonnicles. Well mine do - and for the record I don't shave them

roger_merriman

jedster wrote:

Can I just point out that the two statements

1. it's mainly about aesthetics
2. you need to stop just above the bottom of your shorts sort of like hairy boxer shorts

Don't seem to me to be entirely consistent

Could I get opinions from the ladies - don't you reckon a bloke with smooth legs but hairy boxer shorts would look utterly ridiculous?

J

well indeed though this would be no means a deal breaker for me, advantages of being hairy is one can wind ones wife up by arriving with new and intresting shapes on ones face, she loves it honest!

don_don

Leg shaving - other shaving - fluid dynamics - Finnish - back to leg shaving

Classic Commuting topic creep... well done folks!

That's why I love this forum so much

hisoka

don_don wrote:

Leg shaving - other shaving - fluid dynamics - Finnish - back to leg shaving

Classic Commuting topic creep... well done folks!

That's why I love this forum so much

I thought you loved it as you could trace IPs of someone on it to know what copse of trees to be in?

wait, that sounds even worse then I thought.

I just like the forum as it is random and about cycling

don_don

hisoka wrote:

I thought you loved it as you could trace IPs of someone on it to know what copse of trees to be in?

Well, yes that helps of course 8)

I still hate Marmite though...

BTW, forgot to say welcome back hisoka. I remember you from C+ days, seems like a long time ago

cjcp

lost_in_thought wrote:

Always Tyred wrote:

lost_in_thought wrote:

AT, do you speak Finnish or was that a translation engine?

If you do speak Finnish where did you learn - I am keen to take my smattering of words and expand!

Also phrases like this make me chuckle:' joten takana pseudo-Laminar Flow edellytykset'

Good god no. That was google translator. So many words come out as "EasyJet" don't they?

Damn it, I got all excited there. I just enjoyed the mix of the english with the (mad) finnish words!

Teeheehee easyjet. I'm going to tell them that next time I'm there.

My room mate (at work) is Finnish. What a crazy, crazy language. Her English is excellent, but, since sharing a room with me, she's found herself learning the more "colourful" side of our language. :oops:

hisoka

don_don wrote:

hisoka wrote:

I thought you loved it as you could trace IPs of someone on it to know what copse of trees to be in?

Well, yes that helps of course 8)

I still hate Marmite though...

BTW, forgot to say welcome back hisoka. I remember you from C+ days, seems like a long time ago

C+ Days? I don't remember being around in them. How long ago are we talking as I might have stolen someone else's ID? or I forgot being around and need memory jogging, I am known for my memory (mostly known for how bad it is)

lost_in_thought

cjcp wrote:

lost_in_thought wrote:

Always Tyred wrote:

lost_in_thought wrote:

AT, do you speak Finnish or was that a translation engine?

If you do speak Finnish where did you learn - I am keen to take my smattering of words and expand!

Also phrases like this make me chuckle:' joten takana pseudo-Laminar Flow edellytykset'

Good god no. That was google translator. So many words come out as "EasyJet" don't they?

Damn it, I got all excited there. I just enjoyed the mix of the english with the (mad) finnish words!

Teeheehee easyjet. I'm going to tell them that next time I'm there.

My room mate (at work) is Finnish. What a crazy, crazy language. Her English is excellent, but, since sharing a room with me, she's found herself learning the more "colourful" side of our language. :oops:

Finnish is completely insane. When I first started working in Finland I used video TV shows with my phone, because I knew people wouldn't believe how mad it is without proof...