Bafang (common on many brands)

• **Error 21 / 22** — throttle or speed sensor fault. Check the connectors first.
• **Error 30** — communication error between controller and display. Usually a damaged cable.
• **Error 25 / 26** — brake or motor phase issue. Stop riding and inspect.

Rad Power Bikes

• **Error 21** — throttle stuck or shorted
• **Error 30** — controller-to-display communication lost
• **Error 06** — low voltage protection. Charge the battery.

Aventon

• **Error 04** — throttle not in zero position at startup. Don't touch it during boot.
• **Error 06** — low voltage. Time to charge.
• **Error 08** — motor sensor issue.

Super 73

• Most "E" codes trace to motor phase connector or display cable issues. Disconnect and inspect.

When to call a mechanic

If a code returns after a basic connector check, or you see anything pointing to motor or controller faults, get it diagnosed before riding hard. We carry diagnostic tools for every major brand and can usually fix the underlying issue in one visit.

Time

An eBike averages 18–22 mph; a fit rider on a regular bike averages 12–15 mph. On a 6-mile commute, that's 10+ minutes saved each way.

Sweat

eBikes let you arrive at work in normal clothes. Regular bikes require a change and (often) a shower. This is the #1 reason eBike commuters stick with it.

Hills

La Costa Avenue, Birmingham, Manchester — North County is hillier than people think. eBikes flatten them. Regular bikes don't.

Cost

• Regular bike: $500–$2,000 upfront, ~$50/year maintenance
• eBike: $1,500–$5,000 upfront, ~$200/year maintenance, plus battery replacement every 4–6 years

Still cheaper than a car by an order of magnitude.

Reliability

Regular bikes have fewer failure points. eBikes have more — but with regular service, they're highly reliable. We see well-maintained eBikes go 5+ years without major issues.

The verdict

If your commute is over 3 miles or has hills, eBike wins for almost everyone. If it's flat and short, a regular bike is simpler and cheaper.

1. Use proper tire pressure

Underinflated tires pinch flat against the rim. Check pressure weekly — eBike tires lose air faster than you'd think.

2. Upgrade to puncture-resistant tires

Schwalbe Marathon Plus, Continental Contact Plus, and similar tires have a thick puncture belt. They're worth every dollar for daily riders.

3. Add a tire liner

Mr. Tuffy or similar liners sit between the tube and tire. Cheap insurance against thorns and glass — common on Coast Highway shoulders.

4. Use sealant in tubes (or go tubeless)

Slime or Stan's sealant in your tubes seals small punctures instantly. Tubeless setups are even better but require compatible rims.

5. Inspect your tires monthly

Pick out embedded glass, thorns, and metal shards before they work through to the tube. A 2-minute inspection saves a roadside flat.

Already getting a flat a month?

We do flat-prevention upgrades during any mobile visit — new tires, liners, and sealant in one stop.

Battery

• Charge to 60–80% before storage
• Remove from the bike and store indoors at room temperature
• Top off every 4–6 weeks if storing longer than a month

Drivetrain

• Clean and re-lube the chain
• Shift to the smallest cog to relieve derailleur tension

Tires

• Inflate to max recommended pressure (they'll lose air slowly)
• If possible, hang the bike or rotate tires every few weeks to prevent flat spots

Electronics and frame

• Wipe down the frame, especially around the motor and battery contacts
• Cover with a breathable cover — never plastic, which traps moisture
• Store indoors or in a dry garage, away from coastal salt air

Bringing it back

Before the first ride, check tire pressure, brake function, and battery voltage. Or book a spring tune-up and we'll handle it.

Wet lube

Stays on through rain and humidity. Best for coastal commuters in Cardiff or Encinitas. Downside: attracts dirt.

Dry lube

Cleaner, but washes off in fog and rain. Skip it if you ride near the coast.

Wax-based lube

The longest-lasting and cleanest, but requires a clean chain to start. Best long-term option for serious riders.

Common mistakes

• Using WD-40 — it's a solvent, not a lubricant. It strips your chain dry.
• Over-lubing — extra lube just collects grit and grinds your chain
• Lubing a dirty chain — wipe it down first, always

How often

Every 100–150 miles, or after any wet ride. Wipe excess off after 5 minutes.

A worn chain ruins everything

A stretched chain destroys your cassette and chainring — turning a $25 chain replacement into a $200 drivetrain swap. We check chain stretch on every tune-up.

What Carlsbad riding demands

• Real torque for La Costa and Aviara hills
• Corrosion resistance against coastal salt air
• Range for Coast Highway commutes
• Brakes that handle a heavy bike at 20+ mph downhill

Bikes that hold up well

• **Specialized Turbo Vado / Como** — sealed components, excellent service support
• **Trek Allant+** — strong motors, great brakes, built for hills
• **Aventon Level / Aventure** — great value, solid for the price
• **Rad Power RadCity / RadRover** — workhorse, easy to service

Bikes we see in the shop a lot

• Cheap Amazon eBikes — controllers and batteries fail fast in salt air
• Some Super 73 models — fun, but pads, throttles, and connectors need regular attention
• Direct-to-consumer bikes with no local parts support

Our advice

Pick a bike with parts you can actually get, brakes rated for the bike's weight, and a sealed battery. Then service it twice a year. Need a pre-purchase inspection? We do those too.

Clicking under load

Often a loose torque arm or axle nut. Stop riding and check torque before the dropout damages itself.

Grinding or crunching

Bad bearings inside a hub motor, or a failing freewheel. This gets expensive if ignored — bearings can be replaced cheaply, but a destroyed motor case can't.

High-pitched whine

Normal at high speed for many geared hub motors. If it's new and constant, suspect a worn planetary gear set.

Buzzing or stuttering

Usually a hall sensor issue or a damaged phase wire. The motor pulses instead of running smoothly. Don't ride it hard until it's diagnosed.

Clunk on throttle engagement

Loose freewheel or a damaged sprag clutch. Common on older Bafang and generic hub motors.

Get it diagnosed early

We bring a motor analyzer to every visit and can usually pinpoint the noise in 10 minutes. Catching motor issues early is the difference between a $50 fix and a $400 replacement.

1. Controller errors (E-codes)

Most Super 73 error codes trace back to a loose motor phase connector or a damaged display cable. Disconnect, inspect for corrosion, reconnect firmly.

2. Throttle stops working

Usually a connector issue under the controller cover, not a dead throttle. Check the 5-pin throttle plug first.

3. Brake fade on downhills

Stock pads on the heavier S2 and RX models glaze quickly. Upgrade to sintered pads and bed them in properly.

4. Battery won't charge to 100%

Often a BMS protection trip. Let it sit for an hour, try a slow charge, and if it still won't top off, get a battery health test.

5. Squeaky chain and worn sprockets

The single-speed drivetrain takes abuse. Lube the chain every 100 miles and replace the chain before the rear sprocket wears.

Need a hand?

We carry Super 73 pads, throttles, controllers, and chains. Most fixes happen same-day in your driveway in Carlsbad, Encinitas, or anywhere else in North County.

The checklist

• Tire pressure and sidewall inspection
• Brake pad thickness and rotor trueness
• Brake lever pull and bleed check (hydraulic)
• Drivetrain wear (chain stretch with a gauge, cassette, chainring)
• Shifting adjustment (limit screws, indexing, hanger alignment)
• Wheel truing and spoke tension
• Headset, bottom bracket, and hub bearing check
• Bolt torque audit (stem, seatpost, motor mount, racks)
• Battery contact cleaning and voltage test
• Motor connector inspection and torque arm check
• Display firmware and error code review
• Test ride with PAS and throttle verification

What gets skipped

Most quick tune-ups skip the torque audit, motor connector check, and battery diagnostic — exactly the things that prevent expensive failures.

How often

Every 6 months for daily riders, once a year for weekend riders. Coastal salt air in Carlsbad and Encinitas accelerates corrosion, so don't stretch it longer.

Book a mobile tune-up and we'll run the full 12-point check in your driveway.

Signs your pads are worn

• Squealing or grinding when you brake
• Lever pulls closer to the bar than it used to
• Visible pad material under 1.5mm thick
• Reduced stopping power, especially downhill

Why eBike pads matter more

On a 30 lb road bike, worn pads are annoying. On a 70 lb eBike going downhill in Encinitas or Carlsbad, worn pads are dangerous. Stopping distances grow quickly with worn pads and added mass.

What to replace them with

• **Resin (organic) pads** — quieter, better feel, wear faster. Good for dry riders.
• **Sintered (metallic) pads** — last 2–3x longer, handle heat better. Best for heavy eBikes and coastal hills.
• **Semi-metallic** — a balanced middle ground.

For most North County eBike riders, we recommend sintered pads.

Get it done right

Bedding in new pads correctly is critical — skip it and you'll get glazed pads that never stop well. We handle the full swap and bed-in during a mobile visit.

The case for mobile repair

• No loading a 60–80 lb bike into a car
• Most repairs done in your driveway in 30–90 minutes
• Transparent pricing — you watch the work happen
• Same-day or next-day availability
• Better for: flats, brakes, gear adjustments, tune-ups, battery diagnostics

The case for a shop

• Heavy frame work (welds, bent forks)
• Wheel building from scratch
• Specialized motor rebuilds that need a press
• Warranty work on certain brands

What about cost?

Mobile service typically adds a small trip fee ($25 in our base radius), but you save the time and gas of driving — and most shops charge a similar bench fee. Net cost is usually a wash, with mobile saving you the bigger cost: your time.

Bottom line

For 90% of eBike issues — flats, brakes, drivetrain, electrical diagnostics, tune-ups — mobile is faster, easier, and the same price. For deep frame or warranty work, a shop is the right call.

If you're in North County San Diego and want to skip the hassle, book a mobile visit with Coastline Fix.

1. Don't store it at 100%

Lithium batteries hate being stored full. If you're not riding for more than a few days, charge to ~60–80% and unplug.

2. Never store it empty

The opposite is also true. Storing a battery below 20% for weeks can cause permanent capacity loss. Top it up before storage.

3. Charge in moderate temperatures

Charging in a hot garage (>95°F) or a freezing one (<40°F) damages the cells. Bring the battery inside.

4. Use the original charger

Aftermarket chargers can deliver the wrong voltage or current. Stick with the OEM charger that came with your bike.

5. Don't leave it on the charger for days

Modern chargers shut off, but heat from being plugged in continuously still degrades cells over time. Unplug when full.

6. Clean the contacts

Salty coastal air corrodes battery contacts. Wipe them down monthly with a dry cloth — never water.

7. Get a yearly battery health check

We offer a battery diagnostic that tests actual capacity vs. rated capacity. If it's drifting, you'll know before you get stranded.

Need a battery diagnostic in North County San Diego? Book a mobile visit and we'll come to you.

What you'll need

• Tire levers (plastic, never metal on Rad rims)
• A new tube (Rad uses Schrader valves, 26x2.3 or 20x3.3 depending on model)
• A 15mm wrench or socket
• Patience — the rear wheel takes a few minutes

Front tire flat

Front flats are easy. Pop the quick release, remove the wheel, swap the tube, and reinstall. Just make sure the wheel is fully seated before tightening.

Rear tire flat (the tricky one)

The rear wheel houses the hub motor and the motor cable. Do NOT just yank the wheel off — you can damage the motor connector.

Steps

• Shift to the smallest rear cog before you start
• Disconnect the motor cable at the connector near the dropout — never pull the cable itself
• Loosen both axle nuts with a 15mm wrench
• Remove the torque arm (note its orientation — it must go back the same way)
• Slide the wheel out, swap the tube, and reverse the process
• Make sure the torque arm is correctly seated before you torque the axle nuts to spec (~35 Nm)

When to call us instead

If you're unsure about the motor cable, the torque arm, or you've had repeat flats, book a mobile visit. We carry tubes, tires, and tire liners for every Rad model — and we'll be in and out in under 30 minutes.