Our original bike conversions were a DIY project, back in 2018. Whilst they have served us well, the front hub drives have their limitations. They lack the power / torque, balance and grip offered by the mid-drive eBikes. They are also very heavy to lift on top of the Sorento and we hoped the new conversions would be a little easier to handle.

Regarding torque, the modern mid-drive motors have around twice the torque of the front wheel hub drives.

We wanted to upgrade both of our bikes to mid-drive motors and essentially I’d decided to go street legal again, this time with the Bafang BBS01b 250w mid-drive motor.

We wanted to preserve the battery system as my Dillenger battery pack is still in first rate condition and came with high quality Samsung cells. Moe’s battery pack had only just been replaced a year ago.

I’ll come on to the kit’s we ordered but for my bike, I needed to buy a new bottle battery holder. That’s because on the hub conversion, the controller electronics are part of the battery holder and the mid-drive motors require simply a battery with all the electronics encased in the main motor unit. I was able to source a new battery holder relatively easy at a cost of around £30 or £40.

For Moe, we wanted to replace the rear rack (which houses the battery unit) with a lightweight aluminium version. The original steel version makes her bike incredibly heavy and cumbersome – her bike was an absolute monster to lift on top of the car. This was more of a challenge but eventually I found something on eBay which looked compatible, of very light aluminium construction but with a price tag just shy of £60.

The kits were ordered from an Internet company called Custom Built eBikes. I was originally planning on fitting these myself but I noticed a special offer on their website of £129 for installation of their kit. I though that was good value and whilst researching a bit more, realised the company is a short distance from us near to Exeter airport.

Their normal business model is to collect your bike, convert and then re-deliver but not surprisingly, this incurs some fairly heft delivery charges.

In this instance we were able to deliver and collect the bikes ourselves. No special tools to buy, plus they had some difficulties removing the bottom bracket which would have presented me with a challenge. On one of the installs the motor was dead so they had replaced that before we collected.

Here are some after pictures of our two bikes.

The Conversion – Custom Built E-Bikes, Exeter

What about the conversion company? They were excellent. We wanted a quick turnaround which was a little beyond what they would normally commit to but they delivered both bikes on a tight timeframe. Despite one of the motors failing during installation.

One of our chains was stretched so they replaced this, again at a reasonable cost.

Communication was brilliant and all-in-all great value.

Weight

Moe’s bike is so much lighter and better balanced. It’s now the easy-one to lift on top of the car. The weight of mine is similar but much better balanced.

Power / Torque

Just a different world. Because the motor is driving the front chain cog, the speed and torque is reflected through the rear gears. It takes a bit of getting used to compared to the basic hub drive but the results are superb.

Other

What you do lose with a mid-drive motor is the high range of gearing. This is particularly noticeable on my 2009 Cross Trail because as an older bike, it only has 9 gears at the rear. The front chain reels previously had 28 – 38 – 48 teeth on each cog. The Bafang chain reel we chose has 44 teeth. This is fine when cycling normal hills with electricity but without electric, the really low gears just aren’t available any more and this is less than ideal.

There is a special Leckie ring which will take the front cog down to 40 teeth but this is expensive and requires a modified Bafang motor case cover.

There is also the option of fitting a 10 or 11 cog cassette to the rear but this will also require a new derailleur and shifter. I might just push the button on this change…