Kev nruj (raws li qhov tsis zoo ntawm lub zog) ntawm txhua lub tsheb kauj vab yog qhov tseem ceeb rau pedaling efficiency, tshwj xeeb tshaj yog thaum nce toj lossis sim ua ntej. Nws tuaj yeem txhais tau los ntawm qhov kawg ntawm deformation lossis flex ntawm tag nrho lub tsheb los ntawm cov rog siv rau cov pedals thaum lub log tsheb yog qhov tseeb thiab tam sim ntawd "tso" rau txoj kev. Lub finite deformation los yog flex ntawm tag nrho lub tsheb kauj vab suav nrog: log tsheb, lawv tus ntoo khaub lig- ntu thiab siab, rims, diav rawg, cranks, handlebar system thiab seatpost, thiab lwm yam, tab sis tseem ceeb tshaj plaws yog tus ncej nws tus kheej! Lub zog uas ua rau cov deformations yog qhov tseem ceeb irretrievably poob los ntawm lub hom phiaj tseem ceeb ntawm propulsion. Monotube folding thav duab flex ntau dua nyob rau hauv kev thauj khoom dua li cov kab hauv ntej daim duab peb sab ncej - tsis xav tsis thoob!
Yuav ua li cas los txhais thiab ntsuas qhov nruj ntawm tus ncej tsis yog ib qho teeb meem yooj yim. Ntau tus neeg tau sim. Ua ntej, peb yuav tsum paub ntau npaum li cas "frame deflection", uas tau muab faib ua ntau lub raj thiab khaws lub zog. Hmoov zoo, feem ntau ntawm cov hlab no txuas ncaj qha lossis tsis ncaj rau BB hlab. Txij li cov khoom BB tube yog qhov chaw siv dag zog, peb tuaj yeem yooj yim saib nws qhov kev hloov pauv. Hauv peb cov qauv, peb npaj siab los ntsuas qhov pom kev hloov pauv ntawm BB raws li lub ntsiab lus ntawm tag nrho cov nyiaj deformation zog - uas yuav raug sim sim.
Zoo li txhua qhov chaw hauv physics, BB muaj 6 qhov kev ywj pheej ntawm kev ywj pheej, feem ntau orthogonal X, Y, Z (linear) thiab A, B, C (angular), raws li pom hauv daim duab 3. Pom tseeb, vim tias tsis muaj kev quab yuam- siv cov khoom siv hauv kev sim, qhov kev hloov pauv hauv Z kev taw qhia yog negligible; C yog xoom vim BB tus kabmob. Yog li, muaj 4 qhov sib txawv deformation qhov ntev thiab raug kaw los ntawm lub zog siv rau lub pedal. Thawj khub ntawm deformations yog ib ntus X thiab Y hloov chaw txog qhov nruab nrab ntawm lub ntiajteb txawj nqus ntawm BB raj; ob khub yog kev sib hloov ntawm BB raj, sawv cev los ntawm cov ces kaum A thiab B ntawm Z pem hauv ntej -rov qab axis thiab Y ntsug axis. Cov plaub deformation qhov ntev no yog "linear" (feem ntau rau cov ntawv thov quab yuam, rov qab mus rau qhov qub chaw tom qab lub zog thov raug tshem tawm yam tsis muaj deformation mus tas li) los ntawm kev txhais hauv classical physics. Cov qib kev ywj pheej thiab deformations no feem ntau yog ywj siab thiab yuav tsum tau txiav txim siab sib cais, thiab raws li classical physics, lawv lub zog khaws cia yog ntxiv. Rau lub hom phiaj ntawm txoj kev tshawb no, tej zaum yuav muaj cov ntsiab lus me me, tab sis cov no tsis quav ntsej.
Tianjin Panda Groupyuav txuas ntxiv txhim kho kev tshawb fawb ntawm cov tsheb kauj vab thiab tsim cov tsheb kauj vab roob ntau dua uas ua tau raws li cov kev xav tau ntawm cov neeg caij tsheb kauj vab.
