Hub & Mid-Drive Motor Service
Motor service covers diagnosis and repair of hub and mid-drive e-bike motors — hall sensors, phase wiring, bearings, nylon planetary gears, and clutch assemblies — including full motor removal and replacement without you loading the bike into a car.
- Starting at
- $145
- Typical time
- 1 hr–3 hr
- Warranty
- 90 days on labor
Motor removal & reinstall from $145. Rebuilds and replacements quoted after diagnosis.
Hub motors and mid-drives fail differently. A geared hub motor usually announces itself with a click or a freewheeling sensation — that's stripped nylon planetary gears, and it's a rebuild, not a replacement, on most Bafang and generic hubs. A grinding whine under load is bearings. A stutter or a dead spot at low speed is almost always a hall sensor or a phase wire that chafed through at the axle exit.
Mid-drives — Bosch, Shimano STEPS, Brose, Bafang M-series, Yamaha — carry far more torque through the chainline, so they show up as drivetrain symptoms first: premature chain stretch, chainring wear, and bottom bracket play. Diagnosing a mid-drive without checking chain wear is how people end up replacing expensive motors that were fine.
The genuinely hard part of mobile motor work is the rear wheel. Pulling a motor wheel means dealing with torque arms, a motor cable that runs through the axle, and disc brake alignment on reassembly — done wrong it's a warranty-voiding mess. It's done to the manufacturer's torque specs, with the torque arms and cable routing put back exactly as designed.
One honest limit: on Bosch and some Shimano systems, firmware and certain diagnostics are dealer-locked. I can do every mechanical and electrical repair on those bikes, and I'll tell you upfront the rare occasions when something genuinely has to go through an authorized dealer.

Trip fee for this visit
- Zone 1 — San Clemente +FREE
- Zone 2 — Ladera Ranch +$35
- Zone 3 — Irvine +$65
Symptom → cause
What the bike is doing, and what it usually means
| What you notice | What it usually is |
|---|---|
| Clicking, then no drive | Stripped nylon planetary gears in a geared hub |
| Grinding or rumble that changes with speed | Hub motor bearings |
| Stutter or dead spot from a standstill | Hall sensor or chafed phase wire |
| Motor cuts out then recovers | Thermal cutback, or an intermittent connection at the axle exit |
| Mid-drive eating chains | Chain wear tolerance — mid-drives need replacement earlier than analog bikes |
| Burning smell after a climb | STOP RIDING — windings or controller. Call before riding again. |
Prices
Electrical Repairs
Labor shown. Parts at cost plus 15%, quoted before I order anything.
| Charge port repair or replacement | $125–$195 |
|---|---|
| Battery mount contact service | $75 |
| BMS replacement+ part | $145 |
| Battery pack cell-level repairBench work — pickup and return included | from $225 |
| Battery replacement install+ pack; OEM or UL-certified only | $65 |
| Controller replacement+ part | $95 |
| Display replacement+ part | $75 |
| Throttle replacement+ part | $55 |
| PAS / cadence sensor + magnet ring+ part | $75 |
| Torque sensor service & calibration+ part if needed | $125 |
| Speed sensor + magnet alignment | $45 |
| Brake cut-off switch repair+ part | $55 |
| Connector rebuild (crimp, shrink, seal)Per connector, $95 for a full harness pass | $45 |
| Wiring harness repair | $95–$185 |
| Hub motor remove & reinstall | $145 |
| Mid-drive remove & reinstall | $185 |
| Geared hub motor rebuild+ gear set | from $185 |
| Hub motor replacement+ motor | $195 labor |
Book service
Need motor service?
Takes a minute. You'll hear back within 30 minutes during business hours — and if it's faster to just call, call.
- Free quote before any work starts
- No trip fee in San Clemente, Dana Point or San Juan Cap
- 90 days on all labor
- Nothing gets added to the bill without a call first
FAQ
Before you book
Do you actually work on batteries, motors, and controllers — or just the mechanical stuff?
All of it. This is the main reason to call me instead of a general mobile bike mechanic. Most mobile bike services in Orange County explicitly decline battery, motor, throttle, and controller work, which means a bike with an electrical fault has nowhere local to go. I diagnose and repair charge ports, battery management systems, controllers, displays, throttles, cadence and torque sensors, brake cut-off switches, wiring harnesses, and hub and mid-drive motors — plus everything mechanical.
What brands do you work on?
Every brand. That includes direct-to-consumer bikes with no local dealer — Rad Power, Aventon, Lectric, Ride1Up, Velotric, Heybike, Himiway, Juiced, Super73, Segway — and dealer brands like Specialized Turbo, Trek, Giant, Cannondale, Electra, Gazelle, Tern, Pedego, Blix, Magnum, and Riese & Müller. On the motor side I work on Bosch, Shimano STEPS, Brose, Yamaha, Bafang, Fazua, Mahle, and generic hub systems. One honest caveat: Bosch and some Shimano systems lock firmware and certain diagnostics to authorized dealers. I can do every mechanical and electrical repair on those bikes and I'll tell you upfront on the rare occasion something has to go through a dealer.
My range dropped a lot. Do I need a new battery?
Probably not, and this is the most expensive assumption in e-bike ownership. Lost range has at least five common causes and only one of them is a worn battery: low tire pressure, a dragging brake rotor, a worn or dry chain, colder weather, corroded battery mount contacts, and actual capacity fade all produce the identical symptom. A $59 battery health test measures capacity against the pack's rated watt-hours and checks balance across cell groups, which tells you definitively which it is. That fee is waived if you have me do the repair. A new pack is $400 to $1,200 — it's worth $59 to find out whether you need one.
Is there a warranty on the work?
90 days on all labor. If something I worked on isn't right afterward, I come back and fix it — no trip fee, no argument, in any zone. Parts carry whatever warranty the manufacturer provides and I'll handle the claim paperwork with the brand for you.
What can't you do at my house?
Three things go to the bench rather than the driveway: cell-level battery pack repair (opening a lithium pack in a customer's garage isn't something a careful technician does), full wheel rebuilds and rim replacement, and internal motor rebuilds that need a press. For all three I pick the part or the bike up and bring it back, usually within two to four days. Everything else — including motor removal and reinstall, controller and display replacement, harness repair, brake bleeds, and full tune-ups — happens where your bike is.
Do you need power or water at my house?
No. The van carries its own power, lighting, compressed air, and water. All I need is a flat spot roughly the size of a parking space, within reason of where the bike is. Driveway, street, garage, courtyard, parking lot, or a turnout on a Laguna hillside all work fine.
Do I need to be home the whole time?
Only at the start and the end. I need five minutes with you at the beginning to understand what the bike is doing and to confirm the quote, and five minutes at the end to hand it back and show you what changed. In between you can go to work, take a call, or leave entirely.
My display is showing an error code. What does it mean?
It depends on the system, because every maker numbers its own faults: 21 is a speed sensor fault on a Bafang display but abnormal current on a Rad, and Shimano's codes start with W or E. The free error code lookup has the makers' own tables for Bafang, Bosch, Shimano STEPS, Rad Power Bikes, KT and Segway-Ninebot, with the maker's first step for each. If a code points at the battery or charger, stop charging and riding until it's checked.
Something not answered here? Just ask — I’d rather talk it through than have you guess.