Fitting an e-bike conversion kit in the UK costs roughly £50–£200+ in shop labour — or close to nothing if you fit it yourself. Add the kit and battery, and a finished conversion commonly lands between £350 and £2,000+. The biggest budget factor isn’t labour, though: it’s whether the kit fits your bike, and how much drivetrain, brake or wheel work the installation needs. This guide splits the decision into the two questions that decide the bill — DIY or shop, and will it fit — with real UK numbers for both.
A bike shop typically charges £50–£200+ to fit a conversion kit, depending on the kit and donor bike. A straightforward hub-motor install sits near the lower end; mid-drive, cargo, folding and custom-wheel work costs more. A complete project — kit, battery and fitting — usually lands between £350 and £2,000+. Get the fit right first and the cost tends to look after itself. The full conversion-kit range is grouped by wheel size and power to make matching easier.
- You already own a bike and want electric assist without buying a whole new e-bike
- You’re weighing a DIY fit against paying a shop, and want a realistic labour figure
- You need to know whether a hub or mid-drive kit will physically fit your frame, forks and wheels
- You want a full UK budget — kit, battery, fitting and the extras that catch people out — before you order
How Much Does Installation Cost in the UK?
| Route | Typical total (kit + battery + fitting) | Best when |
|---|---|---|
| Basic DIY front hub | £300–£550 | Sound bike, matched wheel/axle, you own tools |
| DIY rear hub | £400–£750 | You can transfer a cassette and true a wheel |
| Shop-fitted hub | £500–£900 | You want a clean fit with brake/gear setup |
| DIY mid-drive | £600–£1,100 | Confident with bottom-bracket tools |
| Shop-fitted mid-drive | £800–£1,400 | Steep routes, want chainline done right |
| Premium / specialist | £1,500–£2,100+ | Brompton, cargo, carbon or proprietary systems |
Planning bands, not fixed prices. Wheel size, battery capacity, bike condition and installer experience all move the quote. Treat the full project total as the real number — not the motor-only price on a listing.
DIY or bike shop: which is cheaper?
DIY has the lowest labour cost, but a shop can work out cheaper when the job needs specialist tools or several compatibility fixes:
DIY fitting
- No labour charge — often just £10–£40 in cable ties, wrap and connectors
- You learn the system and can service it later
- Front hub kits are genuinely beginner-friendly
- No booking wait — do it on your own schedule
Paying a shop
- £50–£200+ labour (more for mid-drive or specialist frames)
- £50–£200 in tools if you start with none
- One damaged thread or dropout can wipe out DIY savings
- Shop may keep the bike a day or more even for short jobs
Installation Cost by Kit Type
Motor position drives the labour. Front hub kits are simplest, rear hubs involve more drivetrain work, and mid-drives need the most component removal.
| Kit type | Shop labour (typical) | What drives the cost |
|---|---|---|
| Front hub | £50–£100 | Leaves the rear gears alone; may need a torque arm and rotor/tyre transfer |
| Rear hub | £70–£140 | Cassette/freewheel transfer, rotor fit, derailleur and axle spacing |
| Mid-drive | £100–£200+ | Cranks and bottom bracket removed; chainline and chain length corrected |
| Friction / removable | £0–£150 | Some fit at home; others need a dealer to fit permanent mounts first |
Hub motor vs mid-drive: the fit-and-cost trade-off
Hub motor (front or rear)
- Simpler, cheaper fit — the motor arrives inside a wheel
- Drives the wheel directly, so lighter drivetrain wear
- Great for flat and rolling commutes
- Rear wheel removal takes longer because of the motor cable
Mid-drive
- Higher fitting cost — the bottom bracket must come out
- Drives through the gears, so faster chain/cassette wear
- Stronger on steep climbs and loaded riding
- Needs a compatible bottom-bracket shell and clean chainline
If hills are the reason you’re converting, a torque-sensor mid-drive is worth the extra fitting cost. The Z16 48V 1000W Mid Motor Kit uses your bike’s own gears for climbing and reads how hard you pedal, so assist feels natural rather than switch-like — with app tuning and UK support behind it. Above 250W it is an off-road / private-land build.
What Professional Fitting Should Include
A good fit covers far more than bolting a motor on. Ask for a written list so a low quote can be judged fairly against a fuller one. It should cover: wheel or motor fitting, battery mounting, controller/display/sensor setup, cable routing and connector protection, brake and gear checks, a torque check on every critical fastener, and a test ride confirming assist starts and stops correctly.
On a road-use build the installer should also confirm the motor stops assisting at the legal limit and set the correct wheel size so the speed reading is accurate. A shop should never offer to disable the cut-off on a bike meant for public roads. Note: Halfords does not offer a general service to fit any third-party kit — its policy covers legal EAPCs bought from Halfords or a short list of supported systems, so ring the store with your exact bike and kit before buying.
Will Your Bike Take a Conversion Kit?
Compatibility is more specific than wheel diameter. Axle type, dropout width, brake system, bottom bracket, chainline and battery space all matter — and a mismatch in any one adds parts and labour. Check these before you order.
Frame and forks
Steel and aluminium frames usually accept a conversion; carbon needs caution because clamping and axle loads can damage material not designed for them. Front hub kits need strong, correctly shaped fork dropouts — suspension forks, carbon forks and thru-axles may need a different kit or rule one out. Inspect for cracks, dents and corrosion, and never hide a structural problem under a battery mount.
Wheel size, axle and dropout width
The motor wheel must match your diameter — 700C, 29″, 27.5″ or 26″ — and the dropout spacing has to line up. Front forks are commonly 100mm; rear dropouts are usually 135mm (quick-release) or 142mm (thru-axle). Also check whether the bike uses a quick-release skewer, solid axle or thru-axle — they aren’t interchangeable without the right hub. Unsure? The wheel and dropout size guide walks through how to measure both.
Brakes
Disc-brake bikes need the correct rotor standard and caliper clearance; rim-brake bikes need a motor rim with a proper braking surface. Some kits ship replacement brake levers with cut-off switches that may not suit hydraulic or drop-bar controls — separate brake sensors can solve that, but confirm they work with the controller first.
Bottom bracket (mid-drive only)
Mid-drives depend on shell width, diameter and clearance. Measure the shell rather than trusting the model name — makers change parts between years. Threaded shells are usually easier than press-fit; spacers that create clearance can worsen chainline, causing noise, dropped chains and quick wear.
Battery mounting space
Measure the battery and its rail, and leave room to slide the pack off its base. Small, step-through and full-suspension frames often lack triangle space. Rear racks work but shift weight backwards — and paired with a rear hub motor can feel tail-heavy. Never drill a frame to force a mount.
- Wheel size confirmed against the kit (700C / 29 / 27.5 / 26″)
- Dropout width: front ~100mm; rear 135mm QR or 142mm thru-axle — measured, not guessed
- Axle type identified: quick-release, solid axle or thru-axle
- Brakes: rotor standard and clearance checked, or a compatible rim braking surface
- Gears: freewheel vs cassette confirmed for a rear kit
- Bottom bracket: shell width and type measured (mid-drive only)
- Battery space: pack fits the frame triangle with room to remove it
- Frame condition: no cracks, deep corrosion or damaged threads
How KirbEbike Kits Change the Fit-and-Cost Maths
Two features help reduce the hidden costs above. Core-kit wheel variants come as a 7-speed threaded freewheel or an 8–11-speed cassette on supported sizes — so you match the hub to the drivetrain you already have. And the controllers are fully resin-potted for weather protection and heat management. Battery-inclusive configurations are available; confirm your selected variant includes both battery and charger.
The easiest fit in the range is the EZ Rider Kit — a 250W front-wheel system designed around EAPC limits. KirbEbike estimates about 20 minutes on a compatible bike and supplies the installation tools (actual time depends on tyre transfer, brake alignment and experience). It’s a complete, standalone system with a dual 36V battery and up to 60 miles of range.
| KirbEbike option | Where it fits | Install / fit notes | Price (from) |
|---|---|---|---|
| EZ Rider Kit (standalone) | Public-road commuting when the build meets EAPC rules | ~20-min fit on a compatible bike; battery included | £587.99–£707.99* |
| 500W / 750W MTX | Value upgrade, mixed terrain off-road | Check 7-speed freewheel or 8–11-speed cassette variant | £262 |
| Z16 48V 1000W Mid-Drive (standalone) | Hills & loaded climbs off-road | Mid-drive; needs BB check + chainline | £730 |
| 52V 2000W MTX | Performance sweet spot off-road | Hub fit; potted controller | £358 |
| 72V 4000W | Extreme / trail private land | Hub fit; 60A FOC, 110Nm | £670 |
*Complete-kit configurations. For the core 500W–4000W kits, the Taishan and HS-II packs (60A continuous BMS, 5A fast charging, 4–6h to full) and the Smart Controller & displays are shared across the range. The EZ Rider and Z16 are separate systems — don’t mix their parts with core-kit components.
Extra Costs That Inflate the Final Bill
The advertised kit price is one line of the budget. Inspect the bike before ordering — replacing worn parts at the same time is cheaper than pulling newly fitted components later.
| Extra | Typical add | When you’ll need it |
|---|---|---|
| Torque arm & mounting hardware | £20–£100 | Higher-torque hub motors; forks not built around a motor axle |
| Battery / charger upgrade | £100–£350+ | Longer commutes, hilly routes, or a kit sold without a battery |
| Brake pads / rotors / brakes | £40–£150 | Worn or weak brakes on a heavier, faster bike |
| Chain, cassette, chainring | £40–£150 | Common with mid-drives; a stretched chain slips under power |
| Wheel building / spoke work | £60–£150 | Motor hub supplied without a laced wheel, or a size mismatch |
Small parts are easy to overlook — the accessories range covers the mounting hardware most conversions need. On chargers: use only the one supplied or approved for the pack. A plug that fits is not the same as a matched charger.
Example UK Conversion Budgets
Whole-project examples compare better than headline kit prices. Each includes motor, battery, charger, fitting supplies, labour and likely bike upgrades.
Budget DIY hub — about £435
Front hub kit and wheel (£180), battery and charger (£180), torque arm and small parts (£35), basic tools or hire (£40). Works when the bike is already safe and the kit matches its standards. Leaves little room for new brakes or drivetrain parts.
Standard shop-fitted commuter — about £750
Better-quality hub kit with a branded battery (£550), professional fitting (£120), brake pads and service parts (£50), extra mounting hardware (£30). Cleaner and lower-risk than a bargain DIY build, with a clearer path to aftercare.
Premium mid-drive — about £1,430
250W-rated mid-drive configured to EAPC limits (£750), higher-capacity battery and charger (£350), professional fitting (£180), chain/cassette/chainring work (£150). Rises further on a non-standard bottom bracket — approaching the price of a mid-range complete e-bike.
Is Converting Cheaper Than Buying an E-Bike?
A conversion wins when you already own a suitable bike in good condition — you pay mainly for the electrical system instead of another frame and full component set. It’s especially strong on lightweight commuters, folders, tandems and cargo bikes, and it keeps a fit, saddle or gearing you like.
A complete e-bike often becomes better value once the conversion total passes roughly £1,000–£1,500, because factory models at that price bundle an integrated battery, matched brakes, reinforced wheels and one dealer warranty. Price the whole project first, then compare like with like.
UK Legal and Safety Checks Before You Fit
A conversion used on UK public roads must meet EAPC rules: a motor with a maximum continuous rating of 250W, working pedals, and assistance that stops at 15.5 mph (25 km/h). You can pedal faster; the motor just stops helping. If you only ride on the road, the road-legal kits are the simplest starting point.
Kits rated 500W, 1,000W, 3,000W or higher do not qualify as ordinary EAPCs — buying one online doesn’t make it road-legal. A non-compliant powered cycle can need registration, insurance, a licence and motorcycle-standard equipment.
KirbEbike’s Limit Mode switches between preset throttle, pedal-assist and speed settings on compatible app-programmable kits. These presets help control how the system behaves — but they do not change the motor’s rated power or guarantee road legality:
| Mode | Throttle | Pedal assist | Use case |
|---|---|---|---|
| Limit 1 | 250W / 25 km/h | 250W / 25 km/h | Reduced-output preset; does not reclassify a >250W motor |
| Limit 2 | Disabled | 250W / 25 km/h | Pedal-assist preset; classification depends on the completed bike |
| Limit 3 | 6 km/h walk-assist | 250W / 25 km/h | Walk-assist preset; check completed-bike classification |
| Unlimited | Unrestricted | Unrestricted | Private land / closed tracks only |
On batteries: a BMS monitors voltage, current and temperature, but can’t make poor cells or the wrong charger safe. Buy from a traceable supplier, charge on a hard surface away from your exit, and never use a swollen, crushed or water-damaged pack.
- Wheel nuts, thru-axle, cranks and pedals torqued to spec
- Torque arm fitted and tight on any hub-motor build
- Battery locks in, sits flush and can’t rattle loose over bumps
- Brakes bite cleanly; no rotor rub through a full wheel spin
- Gears shift across the full range with no chain-to-spoke contact
- Cables clear of the chain, tyre and steering through full lock
- Correct wheel size set so the speed reading and cut-off are accurate
- Road build confirmed to stop assisting at 15.5 mph
Find the Kit That Fits Your Bike
Battery-inclusive and kit-only configurations — check the selected variant for battery, charger, controller and display contents before comparing total cost.
Start with the main collection to match a kit to your wheel size and riding, or go straight to the EZ Rider Kit for the simplest road-legal fit.
FAQ
How much does it cost to put a conversion kit on a bike?
Can I fit a conversion kit myself?
Will a hub motor fit my bike?
Do Halfords do e-bike conversions?
Are e-bike conversion kits any good?
What are the disadvantages of conversion?
What is the cheapest e-bike conversion kit?
Is converting cheaper than buying an e-bike?
How fast can a 3000W conversion kit go?
Sources
- UK Government — Riding an electric bike: the rules. gov.uk/electric-bike-rules
- UK Government — EAPCs in Great Britain (information sheet). gov.uk
- UK Government — Battery safety for e-cycle users. gov.uk
- Halfords — E-Bike and E-Bike System Safety Policy. halfords.com
- London Fire Brigade — E-bike and e-scooter laws in the UK. london-fire.gov.uk
- Cyclescheme — A guide to e-bike conversion kits. cyclescheme.co.uk
