The original bottom bracket began to make grinding noises so I intented to strip and regrease it however it was beyond service.

A new old stock Shimano BB-UN26 was found and fitted into the cleaned up frame.

The original cantilevers would have been sufficient if they were not broken. The plastic collars hold adjusters which soon crack when exposed to the elements.

I looked for a modern alternative but after learning about brake pull ratios I decided the new levers would work better with Shimano ‘V-brakes’.

These were fitted without issue and provide significantly better brake feel.

Whilst the frame has mudguard eyelets, the rear ones are taken up with the torque arm so I looked for an alternative that still offered near full wheel coverage.

I selected a set of Zefal Classic MTB plastic guards that mount on the brake bridges.

The supplied mounting bolts are rather long so I shall replace them in time with a shorter pair.

With all the recent rain they have gotten a good workout and have significantly reduced the road spray.

The first road test was a success with nothing getting caught up or falling off. Next task is to fine tune the brakes and saddle height etc then take it for a longer ride.

Weights:
Orginal Bike = 14 kg
Electrified Bike = 23.7 kg
Electric Rear Wheel (inc tyre etc) = 7.8 kg
Original Rear Wheel (inc tyre etc) = 2.5 kg
Battery (inc mount) = 3.9 kg
Controller = <500g

A typical conversion kit comes with meters of cable for the various sensors and a frame bag to store the motor controller within.

I’ve done a quick cable tie job to keep everything out of way but in time I shall cut down the cables and use waterproof quick release connectors.

A quick tip for when fitting the rear wheel is to make sure that the cable is not facing upwards like this.

If I leave it in this configuration it will provide a nice channel for water to run in into the motor so I shall flip it next time the wheel is removed.

The conversion kit came with new brake levers that contain microswitches for cutting out the motor when you brake. The original brake levers were the one-peice type that is integrated with the gear shifters so I had to buy separate shifters to use the new levers.

Basic Shimano triple levers with rapidfire triggers.

The rear wheel was test fitted and luckily only required a slight springing of the dropouts.

At a quick glance the controller uses 12 MOSFET’s with 4 per motor phase. This and the various signals from the throttle etc are controlled using a Sinowealth SH79F1611U microcontroller.

https://datasheet.lcsc.com/szlcsc/1809140319_Sinowealth-SH79F1611U_C182003.pdf

Later on I shall give a more detailed analysis of the controller.

I purchased a 36V kit from eBay which includes a 26″ rear wheel with hub motor, motor controller, switched brake levers, throttle and pedal assist sensors.

The battery is a 36V 15Ah unit with a downtube/bottle cage mount.