YBB30, BBRight, BB86, BB90. Puas muaj dab tsi tshwm sim rau zoo qub BSA? Peb delve rau hauv lub ntiaj teb murky ntawm hauv qab brackets
Cov qauv tsis yog qhov lawv tau ua - qhov tseeb uas cov kab hauv qab muaj kev txhawj xeeb. Tau ntau xyoo muaj ib qho zoo nkauj heev: threaded. Hauv qab brackets screwed rau hauv qab bracket plhaub ntawm ib tug ncej, thiab nyob rau hauv lub ntsiab lub plhaub yog 68 hli dav, nyob rau hauv cov ntaub ntawv ntawm lus Askiv threaded, los yog 70 hli dav, nyob rau hauv cov ntaub ntawv ntawm Italian threaded. 'Kab hauv qab' yog ib lo lus yooj yim dua thiab. Los ntawm thaum ntxov 1990s cov no feem ntau yog ib-thooj units, muaj xws li ib tug qag - los yog spindle - mounted rau ob bearings. Niaj hnub no, tej yam nyuaj heev.
Rau ib qho, ib qho hauv qab tsis zoo ib yam. Hloov chaw, spindles yog ntsia ncaj qha rau cranks, thiab cov bearings tuaj yeem npaj-nias rau hauv cov khob sab nraud (xws li Hope unit pictured); nias rau ntawm spindles (xws li nrog Campagnolo lub cranks) uas ces nrhiav rau hauv threaded, sab nraud khob; nias ncaj qha rau hauv cov ncej xws li nrog BB30, BB90 lossis BBright hauv qab brackets; nias rau hauv cov khob hloov pauv tau nruab rau sab hauv hauv tus ncej (uas yog PF30, BB86 thiab 386 Evo), lossis txawm tias sib xyaw ntawm ob qho tib si, xws li Colnago's Threadfit 82.5, qhov twg cov khob sab hauv ntsia hlau rau hauv tus ncej ua ntej muaj cov kabmob nias
haum rau qhov chaw.
Ntawm qhov ntawd, lo lus 'hauv qab bracket' tau tsis meej pem. Qhov twg nws ib zaug xa mus rau ib chav tsev, tam sim no feem ntau siv los piav qhia tag nrho cov kab ke. BBright siv tib txoj kab uas hla (42mm) raws li BB30, thiab tseem txhawb nqa 30mm spindle. Txawm li cas los xij, tus qub haum rau 68mm BB plhaub, tom qab lub plhaub 79mm. Frankly, nws yog ib qho mob taub hau me ntsis rau cov neeg siv khoom, thiab raws li nws hloov tawm, rau qee tus neeg tsim khoom ib yam nkaus. Yog li vim li cas peb thiaj tsim tau ib lub minefield rau peb tus kheej? Thiab puas muaj ib qho 'tus qauv' tam sim no?
'Lub catalyst rau cov qauv tshiab no yog kev nrhiav cov bearings ruaj khov ua ke nrog stiffer crank spindles, 'hais tias Dan DePaemelaere, tus thawj tswj khoom ntawm Wheels Manufacturing, uas nws txoj hauj lwm nws yog ua rau hauv qab brackets uas sib haum xeeb loj array ntawm framesets nrog ntau hom chainsets. 'Cannondale pib pib nws tag nrho hauv 2000 nrog nws tus qauv BB30, tsawg kawg kom deb li deb li "nias haum" cov kabmob muaj kev txhawj xeeb.'
Raws li Cannondale pom nws, cov kev sib txuas tsis muaj zog nrog cov kab hauv qab yog qhov sib cuam tshuam ntawm crank thiab spindle txuas nrog spindle dav, thiab cov bearings me me siv nyob rau hauv cheeb tsam uas muaj kev ntxhov siab heev, rov ua dua. Ib qho lus Askiv threaded BB haum rau hauv 1.37-inch inch BB plhaub, uas txhais tau hais tias cov spindle dav ntawm cov units yog nyob ib ncig ntawm 17mm. Upping lub ante, Shimano tsim Octalink BBs thiab lwm yam kev lag luam ISIS Tsav, uas ob leeg muaj dav spindles ntawm ib ncig ntawm 20mm, tab sis tseem tej yam raug txwv los ntawm BB plhaub txoj kab uas hla. Raws li Cannondale pom nws, txoj kab uas hla dav dua, yog li nws tau teeb tsa txog kev tsim lub plhaub BB uas tuaj yeem txhawb nqa 30mm txoj kab uas hla crank spindle (kev koom ua ke rau hauv lub driveside crank). Nyob rau tib lub sijhawm, BB30 bearing txoj kab uas hla tau nce mus rau 42mm sab nraud / 30mm sab hauv kom muaj zog, raws li tam sim no muaj ntau cov kabmob, yog li hais, los daws qhov kev ntxhov siab BB mus dhau.
'Ib pliag tom qab Shimano thiab lwm tus tau pib nrog lub khob sab nraud BBs txhawb nqa 24 hli spindles, 'hais tias DePaemelaere. Tam sim no txoj kev lag luam muaj peb tus qauv: sab hauv threaded, BB30 thiab lwm threaded. BB plhaub dav tsis hloov pauv ntawm 68mm, txawm li cas los xij sab nraud threaded khob thaum ntsia tau thawb qhov kev ncua deb ntawm cov bearings mus txog 90mm, ntug mus rau ntug. Qhov no ua rau muaj zog torsional zog ntawm lub crank, raws li muab cov ntsiab lus txhawb nqa (cov bearings) dav sib nrug ua rau lub cev muaj zog dua. Qhov no ces txhawb cov neeg tsim qauv kom rov xav txog qhov dav ntawm lub plhaub hauv qab.
'Tib neeg tham txog crank stiffness thiab spindle stiffness, tab sis tom qab ib tug taw tes tus ncej yog lub limiting yam ntawm nruj nyob rau hauv lub system, 'hais tias Ben Coates, tus thawj tswj khoom ntawm Trek, uas qhia lub BB90 system nyob rau hauv 2007.' Qhov dav ntawm qhov system, qhov zoo dua. Yog tias koj muaj lub plhaub BB dav dua nrog txoj kab uas hla loj dua koj tuaj yeem tsim lub raj loj dua thiab dav dua offset chainstays rau nws thiab muaj lub kaum sab xis dav dua ntawm qhov nyob. Xav txog qhov no raws li koj txhais ko taw tso tseg kom ruaj khov dua.'
Trek thawb lub BB plhaub dav rau 90.5mm, tso ob lub xovxwm-haum 37mm txoj kab uas hla ntawm cov kabmob rau hauv tus ncej los txhawb nqa 24mm spindle. Qhov no tau muab thaj tsam ntau dua los txuas cov hlab dav dua, tawv dua thiab tso cai rau cov chainstays tau txais qhov dav dua, tawv dua.
Ntxhais hluas nraug
Txhua qhov kev tsim kho tshiab no tau ua rau muaj kev xaiv BB. DePaemeleare hais tias, 'Cov qauv sib txawv tam sim no yog BSA [English] threaded; BB30 (42mm dav bearings, 68mm plhaub, rau 30mm spindle); PF30 (46mm bearings, 68mm plhaub, 30mm spindle); BB86 (41mm bearings, 86.5mm plhaub, 24mm spindle); BB90 (Trek txheem nkaus xwb, 37mm bearings, 90.5mm plhaub, 24mm spindle); OSBB (Specialized's "tus qauv" uas tuaj yeem yog 42mm lossis 46mm bearings, txawm hais tias yog ib qho BB30 - Tshwj xeeb tsis xav siv tib lub npe Cannondale tau coined); 386 Evo (kev sib koom ua ke ntawm Wilier thiab FSA, 46mm bearings, 86.5mm plhaub, 30mm spindle) thiab BBright (Cervélo nkaus xwb! 46mm bearings, 79mm plhaub, 30mm spindle).
Lo lus nug yog, yog tias qhov loj dua txhais tau tias, vim li cas peb tsis siv 60mm bearings nrog 110mm shells thiab 45mm spindles? 'Cov neeg tsim khoom tsuas tuaj yeem thawb txhua yam dav dav yam tsis muaj kev cuam tshuam rau chainlines thiab Q-factors,' hais tias Cervélo tus thawj tswj haujlwm Graham Shrive.(Lub Q-factor yog qhov kev ncua deb ntawm lub pedals.) 'Muaj kev sib tham ntawm kev nthuav dav nrog kev txav mus rau 135mm spaced rear kawg [qhov dav ntawm lub rear dropouts, nce los ntawm 130mm kom haum rau disc hubs], tab sis tam sim no peb saib 90mm spindle ntev raws li qhov dav tshaj peb yuav mus. Peb tab tom ua haujlwm ze nrog cov tuam txhab tseem ceeb ntawm qhov teeb meem no.'
Yog li, yog tias tsis muaj kev npaj ua BBs dav dua, cov lus nug tom ntej yog, cov qoob loo tam sim no twg yog qhov zoo tshaj plaws?
Ib qhov loj haum txhua tus?
'Dab tsi yog qhov txawv txav? Wow, yog ib lo lus nug nyuaj los teb, 'hais tias DePaemelearee. 'Cov tuam txhab tau muddied cov dej raws li txhua tus sim ua kom pom lawv cov khoom qab zib, thov lawv tus qauv BB yog X% stiffer lossis Y% ntau dua li cov neeg sib tw. Cov neeg caij tsheb nruab nrab puas tuaj yeem pom tias lawv caij txhua hnub? Thiab tom qab ntawd txhua tus neeg muab khoom crank tau sib ntaus sib tua rau lawv daim ncuav qab zib ib yam nkaus! Kuv? Kuv yog ib tug neeg laus uas muaj sij hawm ntau ntawm lub tsheb kauj vab, tab sis BSA [English] threaded tseem yog kuv mus-rau tus qauv.
'BB30 yog ib qho kev sim zoo ntawm tus qauv tshiab, tab sis Cannondale ua rau nws nyuaj dhau rau cov hom sib txawv los tuav qhov nruj nruj rau cov bearings mus ncaj qha rau hauv BB plhaub. PF30 tau tsim - feem ntau los ntawm Sram - txhawm rau txo cov kev zam nruj no [los ntawm kev siv lub khob nylon sab hauv los nqa cov slack], tab sis lawv tsim cov creaking ntau tus neeg tam sim no ntxub. BB86, 386 Evo, BBright thiab OSBB tsuas yog siv tib tus qauv, PF30.' Nws yuav luag txaus kom koj nyob hmo ntuj, puas yog?
'Zoo tsis yog, tab sis nws mob taub hau,' Chris King hais. 'Kuv xav tias threaded BBs zoo li ua haujlwm zoo dua li cov khoom xovxwm. Qhov kev zoo nkauj yog koj tuaj yeem txiav cov xov rau hauv ib yam dab tsi thiab cov xov nws tus kheej tsis tas yuav ua kom zoo rau nws ua haujlwm zoo kawg nkaus. Thaum lub qhov dhuav [hauv ib lub thav duab] yuav tsum yog qhov loj, txwv tsis pub nws yuav tsis ua haujlwm zoo. Ua cov khoom uas yuav tsum tau mus rau hauv lub qhov? Qhov ntawd tsis yooj yim rau peb!' 'Kev lag luam tus qauv yog: tsis muaj tus qauv!' hais tias DePaemelearee. 'Tseem muaj ntau tus players uas xav muag lawv cov khoom.'
