Single Speed Conversion Kit for E-Bikes: Step‑by‑Step Installation
Converting your e‑bike to a single‑speed drivetrain removes the derailleur, shifter, cassette, and shift cables. The result is a simpler, lower‑maintenance setup with fewer parts that can jam or fail. This guide walks you through installation of a single‑speed conversion kit for a typical hub‑motor or mid‑drive e‑bike.
Important applicability boundary: This conversion works best on e‑bikes with horizontal or semi‑horizontal rear dropouts (where the wheel slides back to tension the chain). If your e‑bike has vertical dropouts, you’ll need a spring‑loaded chain tensioner or an eccentric bottom bracket. Measure your dropout type before buying any parts – kits that assume horizontal dropouts will not tension properly on vertical dropouts without extra hardware.
Before You Start: Tools, Parts, and Safety Checks
Work through this checklist before touching any bolts. Mistakes here cause extra trips for hardware.
Shut down and isolate the battery
Turn the battery off, remove it from the frame, and wait two minutes for the controller capacitors to discharge. On bikes with a fixed internal battery, disconnect the main harness at the controller.
Tools you’ll need
- Chain breaker (for shortening the chain)
- Cassette lockring tool and chain whip (if removing the rear cassette)
- 10–15 mm wrenches or Allen keys (axle nuts/bolts, derailleur hanger)
- Torque wrench (recommended for motor axle nuts – see your e‑bike manual for spec; typical hub‑motor nuts: 25–35 Nm / 18–26 ft‑lb)
- Pliers (for pulling chain pin or master link)
- Flathead screwdriver or cable cutters (to remove shift cables)
Parts in a typical conversion kit
- Single‑speed chain (or chainring if your kit includes one)
- Chain tensioner (either a simple spring‑loaded arm or a half‑link system)
- Spacers and lockring for the rear cog (often a BMX or track cog)
- Optional: narrow‑wide chainring for the front (prevents chain drops)
Check your dropout spacing
Most e‑bike rear dropouts are 135 mm or 142 mm. Measure the inside distance between the frame ends with a ruler or caliper. Write it down – your conversion kit’s axle spacer set must match. If your spacing is 150 mm (common on fat‑tire e‑bikes), verify the kit includes the correct spacers.
Fit verification step: Before ordering, hold the single‑speed cog up to the motor axle or freewheel threads. Hub‑motor cogs use a specific right‑hand thread and a stepped washer that prevents the cog from spinning loose under torque. A standard track cog without that washer can unscrew under motor power – check that your kit includes the motor‑specific lockring or adapter.
Step 1: Remove the Original Derailleur and Shifter
1. Shift the chain to the smallest rear cog and smallest front ring to relieve tension.
2. Disconnect the shift cable from the derailleur and pull it out of the cable housing. Remove the housing entirely or tape it out of the way.
3. Unscrew the derailleur hanger bolt (usually a 5 mm Allen) and remove the derailleur and hanger together.
4. If you have a cassette, use the chain whip and lockring tool to remove the lockring, then slide off the cassette. Replace it with the single‑speed cog and spacers, torquing the lockring to manufacturer spec. On a freewheel hub, unscrew the freewheel with a freewheel remover and install the single‑speed freewheel the same way.
Step 2: Clean and Shorten the Chain
1. Wipe the old chain clean with a degreaser. If the chain is worn or stretched (check with a chain wear indicator), replace it with the new single‑speed chain from the kit.
2. Wrap the chain around the front chainring and rear single‑speed cog. Pull the chain until it has about ½ inch of slack at the mid‑point between the rings – no more.
3. Mark the extra links, then break the chain at that point using a chain breaker tool. Rejoin with a master link or a pushed pin (follow chain manufacturer instructions).
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Step 3: Install the Chain Tensioner (If Needed)
Horizontal dropouts let you slide the rear wheel back to tension the chain. No tensioner required – skip to Step 4.
If your e‑bike has vertical dropouts, a spring‑loaded chain tensioner is mandatory.
1. Bolt the tensioner to the derailleur hanger mount or to a dedicated axle‑mount tab.
2. Route the chain over the tensioner pulley so the pulley arm points rearward and downward.
3. Adjust the tensioner’s spring preload so the pulley keeps moderate pressure on the chain without pulling it taut.
Realistic mismatch/trade‑off: If your e‑bike has a vertical dropout and you try to run without a tensioner, the chain will go slack as the wheel shifts forward under pedal torque. This causes chain slap and eventual derailment. A tensioner adds one more moving part, but it’s still far simpler than a full derailleur system. Some riders prefer an eccentric bottom bracket for a cleaner look – that requires a frame designed to accept one and costs more.
Step 4: Reinstall the Rear Wheel and Set Chain Tension
1. Clean the axle threads and apply a small amount of anti‑seize compound (especially on aluminum frames with steel bolts).
2. Place the wheel into the dropouts. For horizontal dropouts, push the wheel fully back to take up chain slack, then pull it forward 1–2 mm to allow a tiny bit of play.
3. Tighten the axle nuts alternately to the torque spec in your owner’s manual. On e‑bikes with a hub motor, overtightening can warp the motor casing – stick to 25–35 Nm (18–26 ft‑lb).
4. Spin the pedals forward. The chain should run smoothly without noise. Check for tight spots (a stiff link) and slight vertical play (about ½ inch at the chain’s lowest point).
Common Pitfalls to Avoid
- Chain too tight. E‑bikes generate higher torque than acoustic bikes. A tight chain adds drag and can wear the motor bearings. Always allow ½ inch of vertical play.
- Forgetting the chain guard or guide. Single‑speed e‑bikes dropped chains are common without a narrow‑wide front ring or a chain keeper. If your kit doesn’t include one, install a simple guide.
- Wrong cog for the motor. Hub‑motor cogs are right‑hand threaded and use a specific lockring washer. Using a standard bicycle cog without the motor‑specific spacer can let it spin loose under power – this can damage the motor wires and leave you stranded.
- Cable housing left loose. Unused shift housing can rattle and get caught in the chain. Either remove it entirely or zip‑tie it securely to the frame.
Success Check: What a Good Conversion Should Feel Like
- Pedal the bike forward with the motor off. The chain runs silently – no ticking or rubbing.
- Lift the rear wheel and spin it by hand. No drag from the drivetrain beyond normal bearing resistance.
- Ride a short loop at low power. The chain stays on the rings through bumps and turns. If the chain falls off, adjust tension or add a chain guide.
- Re‑torque the axle nuts after 10 miles of riding – motor torque can settle them slightly.
A proper single‑speed conversion reduces drivetrain maintenance to occasional chain lube and tension checks. You lose the gears, but you gain reliability and simplicity on your daily commute.
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Ryan Williams has spent over 8 years testing, repairing, and writing about electric bikes. He has personally ridden and reviewed 150+ e-bike models from brands like Lectric, Aventon, Rad Power, Super73, and dozens more.
Before founding EBIKE Delight, Ryan worked as a bicycle mechanic for 5 years at independent bike shops across California, where he specialized in e-bike conversions and electrical system diagnostics. He holds a Certificate in Electric Vehicle Technology from the Light Electric Vehicle Association (LEVA).
Ryan’s work has been cited by Electric Bike Report, Electrek, and BikeRumor. When he is not testing the latest e-bike on California backroads, he is in his workshop tearing down batteries and controllers to understand what makes them tick — and what makes them fail.
Areas of Expertise
E-bike performance testing and real-world range verificationBattery diagnostics, charging best practices, and safetyBrand comparisons: Lectric, Aventon, Rad Power, Super73, and moreError code troubleshooting across major e-bike systemsE-bike laws, registration, and compliance by state
Ryan believes every rider deserves honest, hands-on information — not marketing hype.