[{"data":1,"prerenderedAt":387},["ShallowReactive",2],{"article-en-coaster-brake":3,"articles-en":290},{"id":4,"title":5,"applies_to":6,"author":8,"body":9,"confidence":266,"description":267,"extension":268,"faq":269,"meta":276,"navigation":277,"path":278,"seo":279,"sources":280,"stem":285,"test_bike":286,"topic":287,"updated":288,"__hash__":289},"content_en\u002Fen\u002Fwissen\u002Fcoaster-brake.md","Coaster Brake and E-Bike Conversion: What Works",[7],"all","fabio-gentsch",{"type":10,"value":11,"toc":255},"minimark",[12,16,21,24,27,44,48,125,128,132,148,151,155,191,195,201,209,213,239,242,246,249],[13,14,15],"p",{},"A coaster brake is the most common reason a conversion does not work. The simplest solution is a front motor, because the rear wheel with coaster brake then stays untouched. Rear motors generally rule themselves out, and with mid-drives the coaster brake is often lost unless a suitable variant exists.",[17,18,20],"h2",{"id":19},"why-the-coaster-brake-gets-in-the-way","Why the coaster brake gets in the way",[13,22,23],{},"The coaster brake sits in the rear hub, usually together with hub gears. You brake by pedalling backwards. That only works if crank, chain and hub have a continuous connection.",[13,25,26],{},"In an e-bike conversion this interferes in two ways:",[28,29,30,38],"ul",{},[31,32,33,37],"li",{},[34,35,36],"strong",{},"Rear motor:"," The motor replaces the rear hub. Then there is no coaster brake any more, and the hub gears go too. Hub gears and a coaster brake rule out most rear motors.",[31,39,40,43],{},[34,41,42],{},"Mid-drive:"," The motor sits at the bottom bracket and has a freewheel. Back-pedalling often no longer brakes, because the force does not travel back to the hub.",[17,45,47],{"id":46},"what-works-what-does-not","What works, what does not",[49,50,51,67],"table",{},[52,53,54],"thead",{},[55,56,57,61,64],"tr",{},[58,59,60],"th",{},"Option",[58,62,63],{},"Rear coaster brake",[58,65,66],{},"Note",[68,69,70,82,93,104,115],"tbody",{},[55,71,72,76,79],{},[73,74,75],"td",{},"Front motor",[73,77,78],{},"stays",[73,80,81],{},"simplest solution, check fork and front brake",[55,83,84,87,90],{},[73,85,86],{},"Rear motor",[73,88,89],{},"gone",[73,91,92],{},"hub gears too, derailleur needed",[55,94,95,98,101],{},[73,96,97],{},"Mid-drive",[73,99,100],{},"mostly ineffective",[73,102,103],{},"freewheel in the motor",[55,105,106,109,112],{},[73,107,108],{},"Mid-drive with coaster variant",[73,110,111],{},"works",[73,113,114],{},"few models",[55,116,117,120,122],{},[73,118,119],{},"Friction roller",[73,121,78],{},[73,123,124],{},"only an add-on drive at the tyre",[13,126,127],{},"Coaster-brake variants exist for individual mid-drives, for example for the TSDZ2, and Pendix advertises compatibility. That is an assumption Fabio is still checking. Ask before buying whether your model can be combined with your bike.",[17,129,131],{"id":130},"the-brakes-have-to-be-enough-anyway","The brakes have to be enough anyway",[13,133,134,135,142,143,147],{},"An e-bike is heavier and faster than your old bike. If you rely on the coaster brake alone, braking power is often too weak, and you need extra brakes front and rear. Rim brakes reach their limits with extra weight and speed, and hydraulic disc brakes are best (",[136,137,141],"a",{"href":138,"rel":139},"https:\u002F\u002Fwww.giga.de\u002Ftech\u002Fwer-billig-kauft-kauft-zweimal-diese-fehler-solltet-ihr-vermeiden-wenn-ihr-eurer-fahrrad-zum-e-bike-umbaut--01K0YYJEVGW05AE9TTBCPW0DAM",[140],"nofollow","GIGA","). More under ",[136,144,146],{"href":145},"\u002Fen\u002Fknowledge\u002Fbrakes","brakes",".",[13,149,150],{},"With a coaster brake at the rear and a new brake at the front you combine two systems. That can work, but test it on every ride.",[17,152,154],{"id":153},"options-if-you-have-a-coaster-brake-bike","Options if you have a coaster-brake bike",[156,157,158,168,179,185],"ol",{},[31,159,160,163,164,147],{},[34,161,162],{},"Front motor."," The coaster brake stays. In return the weight sits at the front, more in ",[136,165,167],{"href":166},"\u002Fen\u002Fknowledge\u002Fmotor-types","motor types compared",[31,169,170,173,174,178],{},[34,171,172],{},"Mid-drive with coaster variant."," Only if your bottom bracket fits (",[136,175,177],{"href":176},"\u002Fen\u002Fknowledge\u002Fmeasure-bottom-bracket","measure your bottom bracket",").",[31,180,181,184],{},[34,182,183],{},"Modify the bike."," Fit a rear wheel with derailleur gears and hand brakes. That is a lot of work and often costs more than a used e-bike.",[31,186,187,190],{},[34,188,189],{},"Leave it."," If no solution is economical, buy used instead.",[17,192,194],{"id":193},"safety-in-daily-use","Safety in daily use",[13,196,197,198,200],{},"On an e-bike the motor must switch off when you brake. Without cut-off the motor can keep pushing while you brake. That is why you need brake levers with cut-off or sensors, see ",[136,199,146],{"href":145},". With a coaster brake you do not have that lever, so the cut-off has to work through the pedalling motion. Ask the dealer how the kit handles this.",[13,202,203,204,178],{},"That a conversion counts as tampering and some workshops refuse it hits coaster-brake bikes especially hard (",[136,205,208],{"href":206,"rel":207},"https:\u002F\u002Ffahrrad-xxl.at\u002Fblog\u002Fe-bike-umbausatz",[140],"Fahrrad XXL",[17,210,212],{"id":211},"checking-your-bike","Checking your bike",[156,214,215,221,227,233],{},[31,216,217,220],{},[34,218,219],{},"Look at the rear wheel."," Does the hub have a brake rotor or is there a brake lever on the rear triangle? Then it is not a coaster brake.",[31,222,223,226],{},[34,224,225],{},"Pedal backwards."," If the bike brakes, it is a coaster brake.",[31,228,229,232],{},[34,230,231],{},"Clarify the gearing."," If the gears sit in the hub, it is a hub gear. That rules out many rear motors.",[31,234,235,238],{},[34,236,237],{},"Ask the dealer."," Send bike, hub model and the motor you want. An honest dealer will tell you whether it works.",[13,240,241],{},"The configurator takes some of these questions off you. If in doubt, still talk to a workshop before you order.",[17,243,245],{"id":244},"how-reliable-is-this","How reliable is this?",[13,247,248],{},"The general statement that hub gears and coaster brakes rule out most rear motors, and that a freewheel in the mid-drive often disables the coaster brake, is an assumption Fabio is still checking. The statement on braking power comes from the source named.",[13,250,251],{},[136,252,254],{"href":253},"\u002Fen\u002Fconfigurator","Does a conversion fit your bike?",{"title":256,"searchDepth":257,"depth":257,"links":258},"",2,[259,260,261,262,263,264,265],{"id":19,"depth":257,"text":20},{"id":46,"depth":257,"text":47},{"id":130,"depth":257,"text":131},{"id":153,"depth":257,"text":154},{"id":193,"depth":257,"text":194},{"id":211,"depth":257,"text":212},{"id":244,"depth":257,"text":245},"assumption","A coaster brake is the most common deal-breaker. Which motors work, where coaster-brake variants exist and when to leave it.","md",[270,273],{"q":271,"a":272},"Can I convert a bike with a coaster brake?","Yes, but with limits. A front motor leaves the rear coaster brake alone. Rear motors mostly rule themselves out, and with mid-drives it depends on the model.",{"q":274,"a":275},"Why does a mid-drive cause trouble with a coaster brake?","The motor usually contains a freewheel that does not pass backward force on to the coaster brake, so the function is often lost.",{},true,"\u002Fen\u002Fwissen\u002Fcoaster-brake",{"title":5,"description":267},[281,283],{"title":282,"url":206},"Fahrrad XXL: e-bike conversion kit (German)",{"title":284,"url":138},"GIGA: mistakes when converting to an e-bike (German)","en\u002Fwissen\u002Fcoaster-brake",null,"ruecktrittbremse","2026-11-09","Hrz0ajyZ4PkzFp_ekTPT9tbZZy4QV6kSSFxCZDNSaqw",[291,297,303,305,311,317,323,329,335,343,350,356,362,369,375,381],{"path":292,"title":293,"description":294,"topic":295,"applies_to":296,"confidence":266,"updated":288,"author":8},"\u002Fen\u002Fwissen\u002Fbattery","E-Bike Battery for a Conversion: Position, Space, Range","Where the battery fits on a converted bike, how to measure the space, what branded cells bring, real-world range and how to dispose of it.","akku",[7],{"path":298,"title":299,"description":300,"topic":301,"applies_to":302,"confidence":266,"updated":288,"author":8},"\u002Fen\u002Fwissen\u002Fbrakes","Brakes for an E-Bike Conversion: What You Need","Rim or disc, cut-off levers and sensors: which brakes are enough for a 250 W pedelec and when an upgrade is needed.","bremsen",[7],{"path":278,"title":5,"description":267,"topic":287,"applies_to":304,"confidence":266,"updated":288,"author":8},[7],{"path":306,"title":307,"description":308,"topic":309,"applies_to":310,"confidence":266,"updated":288,"author":8},"\u002Fen\u002Fwissen\u002Fcommon-problems","Common Problems After an E-Bike Conversion","Axle spinning, broken spokes, motor cutting out, jerky starts, fast chain wear: causes and fixes from everyday conversions.","haeufige-probleme",[7],{"path":312,"title":313,"description":314,"topic":315,"applies_to":316,"confidence":266,"updated":288,"author":8},"\u002Fen\u002Fwissen\u002Fconvert-bike-to-ebike","Convert a Bike to an E-Bike: Overview and Steps","What a conversion costs, which motor fits, what the law says and when you should buy a used e-bike instead. An honest overview from the workshop.","fahrrad-zum-e-bike-umbauen",[7],{"path":318,"title":319,"description":320,"topic":321,"applies_to":322,"confidence":266,"updated":288,"author":8},"\u002Fen\u002Fwissen\u002Fcosts","What Does an E-Bike Conversion Really Cost?","Cost items at a glance: kit EUR 400 to 1,700, brakes, tools, small parts. Plus the comparison with used and new (about EUR 2,500) and the cost calculator.","kosten",[7],{"path":324,"title":325,"description":326,"topic":327,"applies_to":328,"confidence":266,"updated":288,"author":8},"\u002Fen\u002Fwissen\u002Fframe-and-weight","Frame and Weight: Which Bike Suits a Conversion","Steel and aluminium are usually fine, carbon is not. Plus the magnet test, total weight, warranty and the wear parts to replace before converting.","rahmen-und-gewicht",[7],{"path":330,"title":331,"description":332,"topic":333,"applies_to":334,"confidence":266,"updated":288,"author":8},"\u002Fen\u002Fwissen\u002Fglossary","E-Bike Conversion Glossary: Terms Explained","Rated power, volts, watt-hours, newton metres, PAS, torque sensor, Higo and Julet, controller and display: the glossary for e-bike conversions.","begriffe",[7],{"path":336,"title":337,"description":338,"topic":339,"applies_to":340,"confidence":266,"updated":288,"author":8},"\u002Fen\u002Fwissen\u002Fhub-spacing","Hub Spacing and Axles for an E-Bike Conversion","How to measure hub spacing, quick release versus thru-axle, spreading 130 to 135 mm on steel frames and what to watch with dropouts.","einbaubreite",[341,342],"front","rear",{"path":344,"title":345,"description":346,"topic":347,"applies_to":348,"confidence":266,"updated":288,"author":8},"\u002Fen\u002Fwissen\u002Fmeasure-bottom-bracket","Measure Your Bottom Bracket for a Mid-Drive","How to measure shell width and bore of your bottom bracket and tell BSA 68\u002F73, Pressfit and BB30 apart. Step by step for a mid-drive motor.","tretlager-messen",[349],"mid",{"path":351,"title":352,"description":353,"topic":354,"applies_to":355,"confidence":266,"updated":288,"author":8},"\u002Fen\u002Fwissen\u002Fmid-drive-vs-hub-motor","Mid-Drive or Hub Motor: What Suits You?","Ride feel, hills, gears, installation and cost compared, with a clear guide to when a mid-drive and when a front or rear hub motor makes sense.","mittelmotor-oder-nabenmotor",[349,341,342],{"path":357,"title":358,"description":359,"topic":360,"applies_to":361,"confidence":266,"updated":288,"author":8},"\u002Fen\u002Fwissen\u002Fmotor-types","E-Bike Conversion Motor Types Compared","Front, rear and mid-drive motors, friction rollers and seat-tube motors compared: feel, installation, cost and which bikes suit which.","motorarten",[7],{"path":363,"title":364,"description":365,"topic":366,"applies_to":367,"confidence":368,"updated":288,"author":8},"\u002Fen\u002Fwissen\u002Fpedelec-law","Pedelec Law: 250 W, 25 km\u002Fh and Walking Assist","What a conversion may do legally: 250 W rated power, assist only while pedalling up to 25 km\u002Fh, walking assist up to 6 km\u002Fh and what lies beyond.","pedelec-recht",[7],"source",{"path":370,"title":371,"description":372,"topic":373,"applies_to":374,"confidence":266,"updated":288,"author":8},"\u002Fen\u002Fwissen\u002Ftools","Tools for an E-Bike Conversion: The List","Which tools you need for front, rear and mid-drive conversions and what kits usually lack, above all the lockring tool.","werkzeug",[7],{"path":376,"title":377,"description":378,"topic":379,"applies_to":380,"confidence":266,"updated":288,"author":8},"\u002Fen\u002Fwissen\u002Ftorque-arm","Torque Arm: When You Need One","Why the axle of a hub motor turns in the dropout, when you need a torque arm and how to fit it.","drehmomentstuetze",[341,342],{"path":382,"title":383,"description":384,"topic":385,"applies_to":386,"confidence":266,"updated":288,"author":8},"\u002Fen\u002Fwissen\u002Fwheel-sizes","Wheel Sizes and ETRTO for E-Bike Conversions","Inches are unreliable, ETRTO is not: how to read wheel size off the tyre and avoid the 635\u002F622 and 406\u002F451 traps.","laufradgroessen",[341,342],1794247507501]