Conversion kit vs a new electric bike: the savings, pros and cons

A top-of-the-range ebike can cost up to £10,000 so electric bike conversion kits have several advantages over buying a brand new one - a key plus is that you are upgrading your existing model. You keep the bike you know and enjoy but add more range and comfort.

The main pros of electric bike conversion kits:

  • Lower cost
  • Less weight
  • UK built and supported (with Boost)
  • Save 100kg of CO2 by upgrading a bike versus buying a new one in terms of embedded carbon.
  • Reduce landfill - you’re not contributing to the 15 million bikes thrown away each year.

The two main personal advantages, cost and weight, are explained below.

Costs: Kits vs buying new 

The exact cost of a Boost kit depends on the options you choose - but the base kit is just £649.  

Boost kit - no wheel (self fit)£522£20
Boost kit - with wheel (self fit, existing cassette)£649£20
Boost kit - with wheel (self fit, new cassette)£649 + £15.83 to 29.17£20
Boost kit - with wheel (shop fit, existing cassette)£695n/a

Buying a new electric bike, however, is likely to cost a lot more. The cheapest decent ebike is around £1,700. Although you can get budget models for less over the internet, there are often dropshipped from China with no ongoing support and compromises in frame quality, parts, battery longevity and even electrical safety. 

This table has some example costs with specs for popular UK models - in comparison, the Boost kit has a typical range of around 50km and a maximum of 80km and offers three levels of assistance. The brakes and gears will be those of your current bike (obviously).  

Halfords own brand Carrera impel im-2.1 hybridNine-speed, three levels of assistance, mechanical disc brakes, average range 35km£1,299
Estarli e28 classicEight speed, five levels of assistance, 60-90km range, disc brakes£1,625
Techtron Ultra 8000Twelve speed, 150km range, hydraulic disc brake£2,399
Cyrusher TraxNine gears, fat tyres, 56 miles range, not road legal£2,799
Temple classicNine speed, five levels of assistance, 60-120km range, hydraulic brakes£3,395

Weight comparison: Kits vs new

A typical hybrid road bike will weigh about 12kg, and the Boost kit adds under 4kg to the weight - so let’s say 16kg in total. If your bike has premium parts or carbon fibre elements, it could easily weigh less. 

We checked a typical electric bike retailer and here is the range of weights we found:

Weight rangeNumber of models
Under 18kg22 (15%)
19-24kg63 (42%)
25-30kg27 (18%)
30kg+38 (25%)
Survey: Ebike weight ranges

As you can see, most ebikes are much heavier than typical bikes, with 20+kg models the most common. Here are the weights of the specific bikes above, and how much extra they weight compared to a 16kg Boost-upgraded bike. 

BikeWeight (kg)Vs upgraded (%)
Halfords own brand Carrera impel im-2.1 hybrid19.6kg+22.5%
Estarli e28 classic16.5kg+3.1%
Techtron Ultra 800025kg+56.3%
Cyrusher Trax41kg+156.3%
Temple classic18.9kg+18.1%

A 4kg difference in weight is like cycling with 10 tins of beans on the back. A 20kg difference is equivalent to 50 tins. Good luck with the hills! Bear in mind that a heavier bike isn’t just about riding - you also may need to lift it into a bike shed or your home or raise it up to lock it to something.