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bedstefan

Indentatii pe foaia mare, se pot poliza fara probleme?

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Pe foaia mare sunt niste indentatii, pot aceste indentatii fi polizate sau apar probleme? In acest moment agata lantul, datorita modului in care trebuie sa stea schimbatorul foi.

Am dat una din bicicletele mele unui prieten. Nu a vrut slickurile de la ea, a mers si si-a luat niste Schwalbe Table Top de 2.25. Toate bune si frumoarse, pana montam cauciucul pe spate si punem roata sus. Freca schimbatorul de foi. Sunam la magazin, nu au decat de 2.25, nimic mai mic. Pana la urma decide ca nu vrea foiaia mica musai, conform unui clasic in viata "foaia mica e pentru confortul psihologic nu ca sa o folosesti".

Am strans la maxim surubul de jos si am rotit patina un pic, astfel incat daca schimba din trigger pe foaia mica schimbatorul este la 1mm de roata (sa fie loc de noroi). Desigur, nu mai e paralel, dar oricum as incerca altfel risca sa atinga roata, si nu pot sa fiu sigur ca nu schimba pe foaia mica si se infige in anvelopa cu varful patinei. Am reglat cat de bine s-a putut limita de sus si tensiunea, si schimba pe cele doua foi (un pic mai lenes la urcare, destul de bine la coborare), insa pe al treilea cel mai mic pinion si foaia medie (evident si pe al doilea si pe primul, dar la 3 incepe) lantul se agata. Am crezut ca o fi foaia mare stramba, dinti loviti, ne-am invartit in jurul ei, pana la urma am constatat ca se agata in niste protuberante de pe foaia mare. Gen ca niste locasuri de suruburi, dar negaurite si nefiletate. Prietenul meu deja se intinsese spre polizorul cu baterii, dar zic sa intreb. Au un scop indentatiile alea sau sunt doar cosmetice, le putem poliza fara probleme?

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De la Sheldon Brown citire:

Pins & Ramps

Modern chainrings intended for derailer use commonly have special features on the sides to improve upshifting . These are pins, usually riveted to the sides of the larger chainrings, and ramps cut or stamped into the inboard sides of the chainrings.These pins and ramps help catch the chain to climb from a smaller to a larger chainring. The smallest chainring will usually not have these features, because you never upshift to the smallest ring.

The protruding rivets of older chains would catch in the space between chainwheel teeth. Modern chains for narrow sprocket spacing have rivets that do not protrude, and so the pins on the chainwheels take on the task of lifting the chain.

Steel pins are used in aluminum chainrings for improved wear resistance. The pins do the actual lifting of the chain, and take the most stress. The ramps just provide a smooth path for the chain to climb once it has been lifted by the pins.

Hyperglide-type rear sprockets have similar ramps, but don't need pins, because the sprockets are of hardened steel.

These features help improve shifting, and make rider skill less important in shifting, but none of these features is actually essential to the functioning of any system.

Imagine postată

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Lasa flexul si cumpara o anvelopa mai ingusta.

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I s-a pus pata pe alea, el si le-a luat si desi cei de la magazin au zis ca ok, sa le aduca si ii dau banii, le-a pastrat. Mai vede el.

Deci in principiu sa le lasam acolo ca dupa aia plangem. Merci de raspuns.

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