ponedeljek, 23. april 2018

Namig no. 11








Nov teden in nov namig, tako da pozdravljeni dragi bralci in bralke. Namigi kar dežujejo z izjemo velikonočnega ponedeljka. Danes se obračamo na cesto, na kolo ali pa tudi na avte. A ker je to blog, ki se vrti na bolj kot ne telesni pogon, se bom dotaknil cestnih koles. Gorskih koles tukaj ni omenjati, morda kar se tiče teže. Danes bo govora o večni tekmi med aerodinamiko proti teži.

Preden so cestna kolesa postala popularna so bili le najbolj zanesenjaki mahnjeni na jeklena kolesa, ki so bila težka in okorna. V devetdesetih letih prejšnjega stoletja še ni bilo veliko govora o karbonu in aerodinamiki. No, v tekmovalnem kolesarstvu da, a za navadne smrtnike pač ne. Kdo je hotel imeti lažje kolo, je preprosto zvrtal luknje v okvir ali komponente. To se seveda ne dela več.

Vrnimo se v preteklost, v leto 1989, ko je Greg LeMond s svojim, za takrat vesoljskim aerodinamičnim kolesom pometel s konkurenco v kronometru in seveda zmagal na Tour de France. Od takrat naprej se inženirji trudijo v tej smeri.

Ne pozabimo pa seveda omejitev, ki jih je UCI uvedel glede teže koles leta 2000. Najlažje kolo sme biti težko 6.8 kg. Če je kolo lažje od tega, mora biti kolo obteženo z utežmi. To velja za tekmovalno kolesarstvo. Inženirji različnih proizvajalcev se neumorno trudijo narediti kolesa čim lažja, a ponavadi na ceno materiala in na žalost varnosti. Po pravici povedano, se ne upam usesti na kolo lažje od 4 kg in se peljati po naših cestah.

Sem že izgubil rdečo nit. Skoraj da. Najprej sem hotel samo navesti nekaj dejstev in morda razsvetliti nepoznavalce.

Skratka, sedaj smo v telu 2018, ki je v ozadju tehnologija še kako velika. Če damo tekmovalno kolesarstvo na stran, saj pač je tekmovalcev veliko manj kot rekreativcev. Prvo vprašanje je; kako narediti kolo lažje? Preprost odgovor je; debelina denarnice. Lažji materiali kot so karbon in titan pač niso poceni. Drugo vprašanje; kako narediti kolo bolj aerodinamično? Odgovor je; z aerodinamičnimi komponentami. Dodajanje aerodinamičnih komponent je malce ceneje kot zamenjevati z lažjimi. Dodatki kot so triatlonski nastavek krmila, aerodinamični obroči ali nastavki za okvir so cenejši.

Lightweight kolo. Eno najlažjih na svetu.



Ampak, če bom lažji bom šel hitreje v hrib. Seveda, da boš šel. Najprej se vprašaj, po kakšnem terenu kolesariš; ali je bolj hribovito ali bolj ravno. Morda si že kdaj opazil, da do hitrosti cca. 25 km/h ni težko priti. Naprej pa malo težje. Za vse to je kriv nevidni sovražnik, ki se mu reče zračni upor. Prokleti k****. Ko kolesarimo hitreje od 25 km/h, porabimo približno 90 % energije, samo da se prebijemo skozi tega nevidnega sovražnika. Se je za vprašati, koliko watov obračajo profesionalni kolesarji na kronometru. Še to, v 5 % klanec je še zmeraj boljše aerodinamično kolo kakor lažje, saj v tak klanec še zmeraj premagujemo zračni upor kot pa gravitacijo.

Aerodinamično kolo. Ni kronometrska specilaka.


Lažje kolo bo šlo hitreje v klanec. No, kolo samo ne. Tudi kolesar pač ne sem izgledati kot reklama za michelin pnevmatike. Najprej je treba kakšno kilo na sebi izgubiti. Kar se pa samega kolesa tiče, pa je pomembna tudi razporeditev teže. Če imamo dva para platišč, oba težka 1,5 kg na par. Ene so z lahkimi karbonskimi naperami, keramičnimi ležaji in jeklenimi obroči, druge pa so z aluminijastimi naperami, jeklenimi ležaji in karbonskim obročem. Prve so težje na obodu, druga pa na sredini. Se pozna vse to, ko je treba poganjati v klanec. Pri vseh ostalih komponentah se pa to na srečo ne pozna. A vsak lažji del je seveda dražji. Vijaki in matice iz titana, karbonska krmila in držala nanesejo ceno.

Aerodinamično kolo bo šlo hitreje po ravnini. Ne pravim, da je potrebno imeti kronometrsko "kozo", pač pa če imamo triatlonske nastavke za krmilo, obroče z višjim robom ter oprijeta oblačila, se bo zmanjšal zračni upor in bo za isto hitrost porabljeno manj moči. Vsi nastavki, za povečanje aerodinamičnosti so malce cenejši, ker tu teža ne igra prevelike vloge. Tudi sama teža kolesarja igra manjšo vlogo kot za v klanec. Ko pogledamo profesionalne kolesarje, ko imajo zadnji obroč poln, jim to pomaga ustvariti vrtilni moment.

Sedaj pa odgovor na vprašanje: ali aerodinamično ali lažje kolo? Ne vem odgovora, saj je to odvisno od vsakega posameznika.

To je to, za današnji namig. Če se odločaš med temi dvema vrstama, upam, da sem ti malo pomagal. Na kon

Do naslednjič.


.....................

New week and new clue, so hello dears readers. On the exception of easter monday the clues just keep coming in. Today we keep focus on the road, on the bikes and also on the cars. But this is a blog for physically activity, i'll be focusing on road bikes. MTB bikes will not be mentioned here. Today i'll discus the ongoing battle between aerodynamics versus lightweight.

Before the road bikes become popular, there were just a few enthusiast open for steel bikes which was heavy and cumbersome. In the 90's in the past century there wasn't much to talk about carbon fibers and aerodynamics. Well, maybe in profesional cycling, but not among the amaters. Wjo wants to had a lighter bike, he simply drilled a holes in the frame or components. This is not a practice enymore.

Lets go back in to the past, in the year 1989 when Greg LeMond, on his futuristic looking bike won the time trial and won the Tour de France. Engeneers have their effort in that direction.

Don't forget about UCI regulations from the year 2000 fo the minimal weight of the bike. The lightes bike in PRO Tour can be 6,8 kg. If the bike is lighter, a special weight are putted on. That regulations are for profesional cycling. Engeneers of diferent manufacturers are trying their best, to make a lightest bike possible, usualy on the price of material and saddly the safety. To tell you the truth, i will be scared to sit on a 4 kg bike and ride on our roads.

Did i loose the focus? Almost. I just want to let you know some facts and brighten those who don't know it.

Today, we are in year of 2018, where technology behind all that is great. If we put proffesionall cycling aside, because the proffesionall cyclist are less in number then amaters. First question: how to make a bike lighter? Simple answer is: the thickness of your wallet. Zhe lighter the material, like carbon fibers and titan don't come cheep. Second question: how to make a bike more aerodynamicall? Answer is: with a aerodynamicall components. Adding aerodynamicall components is easier and cheaper then light weight materials. Accessories like clip on handlebar, aero wheels or accessories fro the frame are cheaper.

Lightweight bike. One of the lightest in the world


But if i'm lighter, i'll be going much faster uphill. Of course you will go. But ask yourself, on what kind of terrain are you cycling: is more hillier or flat. Maybe you alredy notice that to speed about 25 km/h is not a problem to come. But faster is a little bit harder. The main reason for that is an invissible enemy called air resistance. Dam you. When we cycle faster than 25 km/h we spend about 90 % of our energy just to move this invisible enemy. I'm wondering, how many watts are rolling among the proffesionall cyclist in time trail. And one more thing, in 5 % grade uphill, the aerodynamical bike is faster than lightweight, because in that kind of hill, we still move air resistance than gravity.

Aerodynamicall bike. Not a time trial bike.


The lighter the bike, the faster it will go uphill. Well, just a bike alone it woudn't. The biker itself can't look like figure for michelin tires. First loose a pound or two. What is for the bike, the weight distribution is important. If we have a two sets of wheel, both weight a 1,5 kg per set. First one has a light carbon spokes, ceramical bearings, and steel ring, second has a aluminium spokes, steel bearings and karbon ring. First one are heavier on the outside, second in the center. A the other components the weight distriburion is not that issue. But every lighter part is more expensive. Nuts and blots from titanium, carbon handlebars and stems add up the price

Aerodynamicall bike will go faster on the flat terrain. I don't say that you need a time trail bike, but if you put on clip on bar, wheels with a higher edge and fitted chlotes, the drag will be reduced and for the same speed, you will use less amount of energy. All components for aerodynamicall efficiency are cheaper, because the weight is not that kind of issue here. Aslo the weight of a rider is less important that for uphill. When we look the proffesionall cyclist that they have disc back wheel, that gives them angular momentum.

And now the answer for the question: or aerodynamicall or lightweight? I don't know the answer. That is up to you.

This is it for todays clue. If you are tilting between this two options, i hope that i was helpfull.

'till next time.


ponedeljek, 16. april 2018

Namig no. 10







Pozdravljeni v novem namigu tedna. Današnji namig vam razkriva kakšne vrste tekača oziroma športnika si. Na različnih prireditvah najdemo različne vrste udeležencev. Razlika je v hitrosti in odnosu. Preberi in morda se najdeš notri.

Elite – kot že samo ime pove, to so elitni tekači, ki ponavadi zasedajo stopničke na različnih prireditvah. Ponavadi so sponzorirani iz strani klubov ali izdelovalcev športne opreme, saj jim to prinaša ali dobiček ali opremo za tekmovanja in treninge. Imajo za seboj karavano ljudi, ki jim svetujejo in jih vodijo v njihovih športnih poteh. Elitnih tekačev je najmanj in zaradi tega so smetana na vrhu torte. Oni so tudi razlog, da ostali kupujejo izdelke, ki jih uporabljajo.

Egotripi – večina teh tekačev je kar dobro pripravljenih in tudi zasedajo stopničke na tekmah. A so malce slabši kot elitni tekači. Imajo pa še eno slabo lastnost; to je njihov ego. Ko zmagujejo, jim zrastejo krila in se počutijo nadljudje, a ko pa so malce slabši, pa se izgovarjajo na sto in en problem. Prepoznamo jih po tem, da so oblečeni v najnovejša oblačila in imajo najboljšo opremo. So dobri na tekmah, a jim je na poti njihov ego, ki jih tudi omejuje. Pred startom se prerivajo v ospredje, po poku startne pištole pa se zaženejo, kot da bi bilo tekme konec čez 200 m. In ne sprašujte jih o kakem nasvetu o čemerkoli. Ne bodo povedali, saj so to njihove skrivnosti.

Rakete – ti tekači spadajo v širšo skupino navadnih rekreativcev, a so malce boljši. Na vaških tekmah zasedajo stopničke, a na bolj uveljavljenih prireditvah pa morda pridejo med prvo deseterico. V nasprotju z egotripi, njihove skrivnosti radi delijo in tudi pomagajo slabšim. Te je težko prepoznati pred tekmo, saj se zlijejo med množico, imajo navadno opremo in oblačila, a po startu se poženejo naprej, začnejo po pameti in stopnjujejo tempo.

Rekreativci – to je najširša skupina ljudi. Cela množica jih je na vseh prireditvah. O teh ni kaj dosti povedati, saj sem spadajo (spadamo) večina vsi. Uporabljajo različne kose oblačil in opreme od različnih proizvajalcev. Pred startom skačejo, se raztegujejo, se fotkajo, smejijo, so zaskrbljeni in še kaj bi se našlo. Vsi bi bili radi rakete ali eltini tekači, a obenem vemo, da do tega ne bo prišlo.

Old skul fotri – posebna kategorija rekreativcev so stari fotri oziroma jih imenujejo tudi korenine. Njihova leta so šteta v več desetletjih, njihove izkušnje pa tudi v stoletjih. Nekateri med njimi so tekmovali na vseh mogočih prireditvah, ko smo mi še veselo plavali v jajčkih. Nekateri iz med njih uporabljajo opremo in oblačila še iz prejšnjega tisočletja, nekateri pa so že posodobljeni, a skupno jim je, da so prekleto dobri in da jim tudi mladi zavidajo njihovo vzdržljivost.


Polžki – počasi se premikamo proti koncu karavane. Medtem, ko so elitni tekači že dolgo naprej, ko so rakete še malce za njimi in ko navadni rekreativci veselo skakljajo naprej, se polžki premaknejo mimo startne črte. Nočejo, ne zmorejo ali ne znajo iti hitro, polžki vsako ravnino rahlo tečejo, za gor ali dol pa hodijo. Časovni limiti so njihova stalna spremljevalka. Če ne drugega, delajo najboljše fotografije, saj zaradi njihove hitrosti vidijo največ okolice in razgledov.

To je to za namig tega tedna. Upam, da ti je bilo všeč branje. Se vidimo naslednji teden v naslednjem namigu.


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Hello in this weeks clue. This week i'll let you know, what kind of racer or a runner are you. There are many different types of racers that you come across different events. Difference is in speed of movement and their attitude.

Elite racers - like the names tells you, those are elite racers, that usually takes places at the top of the race. Normally they are sponsored by equipment manufacturers or clubs. Well that gives them or money or equipment  for races and training. They have a crew behind them which they give them guidance and plans in their paths. Elite racer are the lowest in races and they are creme de la creme. They are also the reason that rest of the world buys the equipment and use it.

Duche bags - most of them are good racers and also are at the top of the race. But they are little worse then elite. But they have another bad character - that is their ego. When trey are winning, they are above all and are some kind of superhumans, but when they loose, they have complains for a reason or two. They are recognized by the appearance to have the newest chlotes and equipment. They are good on races, but their ego is in the way, which is a huge limitation. They intrude in the front before the beginning and after the bang from the starter pistol, they are off. Don't ask them for an advice. They won't tell, because that are their secrets.

Rockets - those kind of racers are among the big bunch of normal recreational racers, but they are a bit better. On non known races are at the top, but on the well known races are among the top ten. In despite the duche bags, their secrets are for the people and tend to help the slower then them. They are hard to recognize them before the start, because they blend in the crowd, have normal equipment, but at the bang of the pistol, they are off, starts slow and then progressing faster.

Recreational - this is the far majority crowd on the races. It isn't to tell much about them, because here are the most of us. They use different peaces of chlotes and equipment from different manufacturers. Before the start, the run around, takes selfies and pictures, laughing, they are worried and some more of that. All of them wont to be an elite or rocket, but we know that isn't possible.


Old skull - this special group of peoples are old fathers. Their ages are counted in decades, but their experience in millennium. Some of them were on the all sort of races, while we all swim in our fathers eggs. Some of them still uses the same equipment from the last millennium and some of them are more new. What they have in common is that they are still fast and most of the young racers are jealous of them.


Snails - slowly we move to the back of the pack. While the elite are long gone and the rockets are a few steps behind them, when the recreationals are moving along, the slowly snails are crossing the starting line. They won't, can't or the couldn't the snails don't run fast. Every plains they run slowly, uphill and downhill they walk. Time limits are their constant companion. But they do the best looking pictures, because the of their velocity they see the more of the landscape and views.

That is all for this week. Hope that you like it. We will be back together next week in next clue.
x

ponedeljek, 09. april 2018

Namig no. 9








Pa naj bo luč“ je nekdo na začetku zakričal. Sicer ta luč sveti podnevi, ponoči pa je potrebno imeti kakšno svetilno napravo. Iz časa sveč, lantern in karbidnih svetil, smo prešli na baterijske oziroma električne svetilke, največji razlog pa je seveda naš slab dar za nočni vid. Žal se moramo s tem sprijaznit in pustiti tekanje po naravi prvotnim prebivalcem – živalim. Spodaj preberi kaj je na voljo in kaj bi ti najbolje odgovarjalo.

Začel bom z malo teorije, ker vem, da je na trgu ogromno različnih produktov in zaradi tega nastane zmeda, kaj vzeti, kaj je uporabno in kaj priporočljivo.

Najprej merske enote. Sigurno ne gre mimo tega, da ti vsak pove, da vzemi svetilko, ki ima največ lumnov. Lumen je samo eden izmed treh parametrov oziroma sveilinih metrov, iz katerih vemo, kako bo svetilka močna, razdalja svetenja in čas svetenja. Poznamo watt, lux in lumen.

Watt – merska enota watt nam pove kako je svetilno telo močno. To seveda ne pomeni, da večji kot je watt, bolj bo svetila. Pomeni samo, da porabi več energije, proizvede več toplote in manj časa sveti. Ker si nobeden ne želi, da ima pri sebi namesto svetilnega telesa, grelno, je bolje, da ima manj vatov. Sodobne LED svetilke imajo mnogo manj vatov kot navaden halogenske, a svetijo isto ali celo močneje.

Lumen – merska enota, ki pove kolikšno svetlobo odda svetilno telo. Problem nastane, ker nekatere svetilke obljubljajo veliko število lumnov, a tega ne izpolnijo. Zakaj? Hudič je v detajlih. Ne povedo, kje so bili ti lumni merjeni. Namreč maksimalno število lumnov pove, njegovo svetilnost na tisti razdalji. Lumni merjeni na razdalji 2 m, bodo na razdalji 10 m manjši.

Lux – tretja merska enota, ki pove svetilnost na površini. Po domače povedano, kako svetla bo površina na katero posvetimo. Seveda spet detajl. Lux je merjen samo na eno enoto površine. Kaj!? Če je merjen s 100 lux na en kvadratni meter iz določene razdalje in če se premaknemo nazaj, da posvetimo 4 kvadratne metre, bo moč lux-a samo še 25.

Sonce, ki sredi dneva najbolje sveti proizvede na zemlji približno le 1 lumen, a sveti z cca. 15000 – 25000 lux, polna luna v jasnem nebu pa sveti le z cca 1 – 5 lux in nekaj malega 0,001 lumnov.

Do naslednjič.



Let there be light“ said someone at the beginning. Well, that light is wisible by day, but by night we need some kind of light device. Time of candles and carbide lanterns are over and we got to the electrical lights, and the main reason is our bad gift of night vision. Sadly we have to deal with that and let the night running to the original habitants – animals. Read below what is available and what is best for you.

I'll let you know some theory because we all know, that on the market there is a lot of products and the confusion is, what to get and what is recomended.

First, the unit of measurment. We can get trough, that everybody says „take the light with most lumens“ Lumen is just one of three units of measurment from wich we can know the brightnes, distance and time of illumination. We know the watt, lumen and lux.

Watt – unit of measurment that that says, how powerfull the lightning body is. That doesn't mean, the more wats, the more will shine. That means, consume more energy, produce more heat and shine less time. Nobody wants to have insted illumination body, heated body, is better to have less watts. Modern LED lights have less watts than regular halogen, but shines the same or more.

Lumens – unit of measurment tell how the bright the bulb is. The problem is that most of the light promises many of lumens, but doesn't fulfill that. Why? The devil is in the details. It doens't says, where was the lumens mesured. Well, the maximall number of lumens says its maximal brightnes at that distance. Lumens mesured at 2 meters will be less brigth mesured at 10 meters.

Lux – the third unit of mesurment that says the brightnes on the surface. To say it easy, how bright will be thr surface wich is illuminated. And of course, a detail. What? If we light a surface with 100 lux on 1 square meter from a certain distance and then we move back to illuminate 4 square meters, the power of lux will be just a 25.

The sun that shines on the bright day, it produce just a 1 lumen on the surface, but it shines with a 15000 – 25000 lux. A full moon on a clear sky shines with a 1 – 5 lux, and produce sometnihg between 0,001 lumens.

Untill next time.