Electric Bike Conversions

Welcome to Electric bike conversions South West. I specialise in road legal and high performance mid-drive electric bike builds and conversions.  I can also supply the full range of Bafang and Tongsheng mid-drive electric bike kits, plus a huge range of lithium battery packs.

Table of Contents:

  1. Products and Services
  2. Is your bike suitable for conversion?
  3. Gallery
  4. Customer bikes
  5. Important considerations
  6. Self-build electric bike kits
  7. Common Problems
  8. Legal Information
  9. Contact me

Short promotional video demonstrating the benefits of electric bikes

New Electric Bikes

Electric bike conversions South West now offer a range of cheap electric bikes for UK customers. These bikes can be delivered direct to your door or they can be delivered to me where they will be fully assembled for collection in person from my business address in Cornwall.

I passionately believe in electric bikes. They are great for personal mobility and good for the environment. They have helped so many people get back in to the saddle and enjoy a healthier lifestyle.

The services I offer include converting regular bikes to electric assist, building custom high performance electric mountain bikes, maintenance and repairs. I also provide a free custom programming service for all my mid-drive installations.

For all enquiries relating to my services, please use the contact form at the bottom of this page.

an inside view of my workshop where the electric bike conversions take place
My Workshop in South East Cornwall

I can convert most types of bicycle to electric assist, and have converted commuter bikes, hybrid bikes, fat bikes, mountain bikes and road bikes.

I have converted countless bikes over the last two-and-a-half years, and through trial and error have learnt what does and does not work

Electrically assisted bicycles are one of the most liberating technological innovations to emerge in the last few years.

A certain degree of fitness is required to ride a conventional bicycle for long distances, particularly if the rider lives in a hilly area. Electric bikes have revolutionised personal transport and have enabled so many people to get back on two wheels regardless of their physical abilities.

My Products and Services

Cheap Electric Bikes

I can supply a range of affordable electric bikes to customers throughout the UK, Ireland and Europe. I can also offer a collection-in-person service, whereby a customer can order a bike and collect it from me fully assembled and ready-to-ride.

Electric Bike conversion kits and Lithium Batteries: I can supply a full range of electric bike conversion kits, ranging from a basic hub motor kit through to Tongsheng and Bafang mid-drive motors. I also supply a variety of electric bike batteries and electric bike parts.

Installation service: I can fit electric bike kits for UK based customers, if you can get the bike down to me in Cornwall.

Electric Bike Conversion Service

I have converted countless bikes over the last two-and-a-half years, and through trial and error have learnt what does and does not work. Some bikes are simply not suitable for a mid-drive electric conversion. Please read my list below:

Is your bike suitable for conversion?

Most bicycles at the cheaper end of the scale (under £1000) can be converted to electric assist. Older bikes in particular are usually very straightforward to convert.

a hybrid bike converted to electric using a bafang bbs02 mid drive kit with 48v battery

Bottom bracket compatibility (for mid-drive installations only). Most bicycles under a £1000 will have a BSA threaded bottom bracket which is 68-73mm wide and should be compatible with a mid-drive installation.

Pressed-fit bottom bracket: If your bike has one of these bottom brackets, then it will not be suitable for a mid-drive conversion. Generally speaking, PF bottom brackets are fitted to higher end mountain bikes and road bikes. It is unusual to find them on commuter bikes, cheaper mountain bikes, hybrid bikes and road bikes.

Hardtail mountain bikes account for a large percentage of bicycles I convert along with hybrid and commuter bikes. I can also convert certain folding bikes.

Full Suspension mountain bikes can sometimes prove problematic to convert due to the following things:

  • Limitations for battery placement
  • Bottom bracket (BB) compatibility. A lot of modern full suspension mountain bikes use a pressed-fit bottom bracket. This means that the BB shell (the place where the mid-motor would be installed) is too big in diameter and width to accommodate the electric motor.
  • Thru-Axles (relevant for hub motors only). Higher priced hardtail and full-suspension mountain bikes often have thru-axles, making it impossible to fit a hub motor.

 

full suspension mountain bike fitted with a bafang BBSHD mid drive electric motor kit

Tandems by design are unsuitable for mid-drive conversions.  There are two main reasons: 1. Tandems usually use an eccentric bottom bracket (for chain tension adjustment) and 2. The front crankset is usually on the left-hand-side. They are suitable for small hub motor conversions though, and I can supply and fit these if required.

Gallery

Below is a selection of some of the new bikes I have supplied and converted over the last couple of years. All of the electric bikes that I supply are custom-built to order, and are available with a choice of motor and battery configurations.

b twin rock rider 540 powered by a bafang bbshd mid drive electric motor
B’TWIN Rockrider 540 powered by a Bafang BBSHD with a 52v14ah battery
cube aim pro fitted with a bafang 750w mid drive electric motor kit
Cube Aim Pro (2017 model) powered by a Bafang BBS02 750w and 52v13ah Battery
carrera vulcan mountain bike fitted with a bafang 750w mid drive motor kit
Carrera Vulcan powered by a Bafang BBS02 750w and 48v11.6ah Battery
b twin rockrider 540s full suspension e bike built by fast electric bikes uk
B’TWIN Rockrider 540s powered by a Bafang BBSHD and 52v14ah battery

The mid-drive electric motors I use in my conversions are from Bafang and Tongsheng – the most popular brands on the market at the moment. They also represent excellent value for money and offer the performance for the money

Electric fat bike built by electric bike conversions south west
Voodoo Wazoo Fat Bike powered by a Bafang BBSHD and 52v14ah Battery
muddyfox electric mountain bike fitted with a bafang 750w mid drive motor kit and 48 volt battery
Muddy Fox mountain bike powered by a Bafang BBS02 750w and 48v17.5ah Battery
giant electric hybrid bike built by electric bike conversions south west
Giant Roam 0 hybrid bike powered by a Bafang BBSHD and 52v17.5ah Battery
voodoo electric mountain bike fitted with a bafang bbs02 750w mid drive electric motor kit
Voodoo Bantu powered by a Bafang BBS02 750w and 52v13ah Battery
b twin rock rider 540 s powered by a bafang 750w mid drive electric motor and 52 volt battery
B’TWIN Rockrider 520s powered by a Bafang BBS02 750w and 52v13ah Battery

A powerful electric bike ridden sensibly, is unlikely attract unwanted attention.  The flip side to that is, if you ride it everywhere in full-power mode and treat it like an electric motorcycle you will draw attention to yourself.

carrera vulcan fitted with a bafang bbs02 500w mid drive electric motor kit and 48 volt rack battery
Carrera Vulcan powered by a Bafang BBS02 48v500w and 48v14.5ah Rack Battery

 

Customer bikes

Below are some examples of used bikes that I have converted for customers.

orbea ladies electric mountain bike built by electric bike conversions south west
Ladies Orbea mountain bike powered by a Bafang BBS01B 250w and 36v13ah battery
specialized rock hopper fitted with a bafang bbs01 250w mid drive motor kit and 36 volt battery
Specialized Rockhopper powered by a Bafang BBS01B 250w and 36v13ah battery
scott aspect mountain bike converted by fast electric bikes uk
Scott Aspect mountain bike powered by a Bafang BBSHD and 52v14ah Battery
carrera kraken electric mountain bike fitted with a bafang bbs02 750w mid drive electric bike motor kit and 52 volt battery
Carrera Kraken powered by a Bafang BBS02 750w and 52v17.5ah

 

Important things to consider

Most of the conversion kits I install provide my customers with many miles of trouble-free riding, however due to the nature of retro-fitting a kit to a bicycle, problems sometimes occur.

Hub motors are generally incredibly reliable and the only issues I sometimes have relate to the pedal sensor.

Mid-drive motors on the other hand are more complex, and thus susceptible to more potential long-term issues.

There are many factors that can contribute to issues with the mid-drive motors, the main one being the way the bike is ridden. I find the bike’s that are ridden sensibly tend to rarely get problems.

The minor issues can be having to periodically tighten the motor in the bottom bracket or accidentally knocking the speed sensor out of alignment.

The bigger problems are mainly the motor controller, pedal assist circuit, motor hall sensor and the nylon primary gear wearing over time.

The motor controller’s can be replaced in a matter of minutes, but getting a replacement sent over from China can take a few weeks, I certainly recommend purchasing a spare just in case – ‘it’s better to have it and not need it than need it and not have it!’

Gear selection is crucial for optimum motor efficiency and performance. Let the motor labour in a high gear on a hill climb and you run a real risk of frying the controller

Taking the above in consideration, these motors are only really suitable for DIY enthusiasts and tinkerers. If you want a nice reliable e-bike with a two year parts and labour warranty please go to Tredz, or one of the other big retailers. If you are in my area go to Certini in Saltash for a great range of electric bikes.

You can also check out my page featuring a price comparison table of some of the best electric bikes for sale on Amazon. I have personally hand picked these bike and spent hours researching them. There is something there to suit all budgets from £400 all the way up to £7000. This is a great selection of electric bikes and covers everything from low-step commuter bikes all the way up to cargo e-bikes.

Legal information

If you decide on purchasing a custom-built electric bike from me, any bicycle I convert, that produces more than 250w of continuous power would be classified, under current law as a motorised vehicle and not an electric bicycle. It would be subject to restrictions of use in public places. This includes the public highway, cycle paths, trails or any other area that the general public have free access to. This means that the only legal place you can technically use these bikes without fear of prosecution is on your own land or private land that you have permission to use. If you are not familiar with UK electric bike law please click here for further information.

If you do choose to use a high powered electric bike on UK roads, make yourself aware of the potential legal ramifications. It would also be prudent to use your power wisely.  A powerful electric bike ridden sensibly, is unlikely attract unwanted attention.  The flip side to that is, if you ride it everywhere in full-power mode and treat it like an electric motorcycle you will draw attention to yourself.

Can you have the best of both worlds?

Customers have often asked me in the past about having the ‘best of both worlds’. In essence an e-bike that can be used legally on the road (restricted to 250w and 15mph) and then unrestricted to full power and speed for off-road use.

The answer to this question is not clear, as there is a certain ambiguity within the legal small print. Both the Bafang and Tongsheng systems have a speed limiting feature built into their displays. Unfortunately just by restricting your assisted speed to the legal 15 mph (25 km/h), there is nothing to stop you pulling over and altering the speed settings at the side of the road. So from a legal stand point it is unlikely this feature alone would satisfy a court.

The other issue would be, even if you could permanently restrict the speed to 15 mph, the motor power output would still exceed the legal limit of 250w continuous power. Road legal electric bikes can and do produce more than 250w when under load, climbing a steep hill etc. I have it on good authority that the Bosch units used on a lot of factory produced e-bikes will peak at over 400w! This buffer zone is allowed under law, as once the motor is no longer under load or the pedalling torque decreases, then the power would settle back to 250w.

All of the Bafang motors can be reprogrammed using a USB programming lead and software. I have successfully restricted a 750w BBS02 to 250w maximum and set the speed limit at the controller. Why not just buy a 250w motor I here you say! 

With the programming lead and software, you could have two different sets of programming parameters saved on your computer. One would be the 250w settings, for using the bike for commuting etc. The other could be the full power setting for when you are blasting around on private land.

The fact is, if the firmware is set at 250w and 15mph maximum and there is no way this can be changed at the roadside or with the flick of a switch, then technically the output of the bike.would be within the legal parameters.

Even with everything above taken in to account, you would still have the 750w or 1000w stamped on to the underside of the motor, and that in itself maybe enough to secure a conviction in the unlikely event you were collared.

programming a bbs02 for lower power
Screen shot from my BBS02 reprogramming

Personally, I would stick with the 36v 250w motors. They are far more reliable, and you can still reprogram them up to about 640w without compromising reliability.

Problems with the motor

The electric motors I use in my conversions are the most popular brands on the market at the moment. They also represent excellent value for money and offer the ‘best bang for your buck’. Unfortunately as with all things electric, problems do arise from time to time.

It is unfortunate, but the warranties that come with these particular motors falls way short of what the average consumer would expect in the UK. For example, a blown controller can be easily posted back to China, but it could take over a month for the replacement to arrive. Out of all the installations I have done, there is a fairly consistent failure rate of 10% within the first three months of use. Most of my suppliers will only replace a controller once.

Most of the controller failures are with the 750w motor using a 52v battery (note: I have not had a controller failure with a 48v battery fitted). Basically the motor’s controller will handle peak voltage of 60v, a 52v battery fully charged is around 58.8v – this leaves a very narrow margin. I recommend all my customers now have a 48v battery fitted. The performance gain with a 52v is so marginal it is not worth the risk.

There are other factors that cause premature controller failure. One of the main issues is improper use of the bike’s gearing. Look at it this way. If you rode a motorcycle, you wouldn’t pull away on a hill in sixth gear?

Because these motors work through the drive-train of the bike, gear selection is crucial for optimum motor efficiency and performance. Let the motor labour in a high gear on a hill climb and you run a real risk of frying the controller. The same applies to excessive use of the throttle. These motors are primarily designed as pedal assist. The throttle is a kind of afterthought, and works more like an on/off switch. There is no smooth, linear delivery of power, it is either all or nothing. If your are a big chap like me and you have that little motor hauling you up a steep hill, and you’re not making any effort to pedal, then sooner or later the controller is going to go pop!

Self build option

If you fancy having a go at converting a bike yourself, the good news is there are plenty of places you can purchase one of these kits online. I have compiled a price comparison table for some of the best electric bike kits available at the moment on Amazon. If your budget doesn’t stretch to a mid-drive kit, that is not a problem as there are loads of cheap electric bike kits available. These are hub motors ranging from 250w all the way up to 3000w.

I purchase all of my kits and batteries direct from suppliers in China, and have been doing so for nearly three years. The only issue with this is if you do have a problem with your motor, you usually have to foot the bill of return postage to China which can be quite pricey. There is a product table of mid-drive kits below available from trusted suppliers I use regularly.

Bafang BBS01B 250w mid-drive kit with choice of 36v batteries - International Shipping
==>>SHOP NOW
Bafang BBS02B 36v 500w mid-drive kit - International Shipping
==>>SHOP NOW
Bafang BBS02B 750w mid-drive kit with choice of 48v or 52v batteries - International Shipping
==>>SHOP NOW
Bafang BBSHD 1000w mid-drive kit with choice of 48v or 52v batteries - International Shipping
==>>SHOP NOW
Tongsheng TSDZ2 250w / 350w / 500w 36v or 48v - International Shipping
==>>SHOP NOW
GP-LB01 mid-drive motor 250w / 350w / 500w 36v or 48v - International Shipping
==>>SHOP NOW
Electric Bike Batteries - 36v / 48v / 52v / 72v - International Shipping
==>>SHOP NOW
All the suppliers that are linked to in this table are trusted sources that I use regularly. They provide excellent customer service, and communication is always good.

 

Battery selection is a very important factor in your electric bike build, and to help you decide, I have compiled a price comparison table for electric bike batteries.

The great thing about the Bafang motor is it has been around for a few years now and there is a lot of help and advice available on forums such as Endless-Sphere. There are also countless videos on YouTube.

If you decide to do down the self-build route, you can be safe in the knowledge that there is always a plentiful supply of electric bike parts available.

Delivery

I always recommend my electric bikes are collected in person. That way I can personally run through everything with the customer face to face.

I will not entertain delivery through any of the big parcel companies. Parcelforce won’t touch e-bikes, and DPD have damaged several of my bikes in the past, despite me spending hours painstakingly packaging the bikes up in the hope they won’t get dropped or thrown off the back of a lorry!

I do know a couple of trustworthy independent local couriers who go to London and the Midlands regularly, they have delivered bikes for me in the past and offer a door to door service.

Contact

Please use the contact form below for all enquiries. I aim to respond to all messages within 24 hrs.

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