Roads.. where we are going we don’t need… roads

Reviewing the last 12 months it is sad to see that I have not done a great deal on the bike at the weekends, mostly because I am knackered by then having cycled 100 miles during the week.   I pondered about catching the train a bit more, but I don’t like having to fit around timetables, I like being on a bike, plus trains were becoming rare on Southern.   I did look at electric bikes but dismissed them as they were too expensive, and actually I liked the bike I had.

Over Christmas I happened to come across ebike kits where you just strap on a battery and a motor, and off you go.   The prices looked pretty decent and you didn’t have to make permanent changes to your bike should you wish to return it back to non electric.   A kept an eye on forums for a while, saw what was available (and legal) and how people got on with it all.    It seemed like the future…

The first choice was a motor on the front wheel, rear wheel, or within the bottom bracket.  I dismissed the bottom bracket option as it changed the bike way too much, too many special tools and doing things to a bike that it just didn’t seem ready for.   My initial interest was in a front wheel motor with the battery build into the rear rack.  This solution seemed the simplest as all you had to do would be to replace the front wheel with the new motor one, fit the new rear rack, plug it all in and off you go.

I started to learn about passive assistance (PAS) which gives you power as you pedal instead of using a throttle on the handlebars.  That seemed an good way to go, but it meant fitting a sensor to the bottom bracket requiring the cranks to come off.   While I had the tools to do this, I also had the experiences of trying to get cranks off of bikes and I didn’t know if my swearing quota for the month would survive.

With the online community I was able to ask around and learn of my naive learner mistakes.  While front wheel drive is cheap and easy, it can make steering a bit unpredictable at times – which makes sense.  Having the battery high up on the rear rack affects the point of gravity for the bike, affecting the ride – it made sense again.   The advice was rear wheel with a battery where the water bottle would go.    Price wise, there wasn’t much difference, so I carried on with my research.

Battery size and motor size was the next choice.   Motor was easy, to be street legal you have to keep to 250 watts and limit the speed to 15mph.   The other options of 500, 1000, 1500 watts all give you extra speed but extra weight too.  The size increases from a hub looking similar size as a dynamo or Rohloff geared wheel hub, to something that takes up most of the wheel.    I opted to keep it small and light at 250 watts, who really wants to do 30mph on a push bike each day?!

The battery I wanted to keep light, but I also wanted to make sure I would always have enough power to do 20 miles a day plus a bit more (always be prepared).  I was aware that over time the capacity will drop, so something that just does it now will soon start not doing it.

The appearance was important, I didn’t want my bike to look like an over weight electric bike done on a DIY budget, I didn’t want wires all over the place.   I am pretty sure I am a “naturally neat person” and this is reflected on my bikes, seeing them dirty or untidy brings me out in a bit of a rash.  I had great worry that I would turn my nice looking bike into some homemade monstrosity.   One of the things I noticed is that all kits must have a control unit that brings the battery, motor, sensors, and throttle bits all together so that when you press a button or move the pedals, the motor knows what to do and how much to do it.   A number of kits (in fact most of them) had this as a little box that you have to fit to the bike somewhere and then plumb in all the wiring.   I was happy to see that some options had the controller built into the battery block, in doing so cutting down on clutter and wires.

Through advice I narrowed everything down to two online suppliers, both around the same price and spec.  A lot of kits did not support many gears on the rear wheel, and almost all of them only supported freewheel hubs and not cassettes.  Not wanting to change the spec of what is a quite well spec’ed bike, I found the only two suppliers that offered a cassette hub.   I still have the worries of getting the pedal crank off so that I could fit a PAS sensor, which didn’t fill me with joy.   Through another project I had recently been trying to get a pedal crank off the old Highway bike (that’s another story).  Having got hold of the right tools and pullers, I am still no closer to getting the crank off (and so then onto the bottom bracket) as it is totally welded to the axle.  Even the local bike shop gave up after a week of having it.    The thought of having to go through the same again on this bike did not fill me with joy, and yet the idea of the PAS seemed to good.   One of the two kits came with a PAS that came in two pieces allowing it to fit over the bottom bracket axle before being clipped into place.  This meant no crank removal, which meant I placed my order.




In what seemed like seconds, a huge parcel arrived at home straight after I put my order in.  Being mid-week and horrid wet weather, the bike was not in a fit state to do any work on it in the evenings and so all I could do was to look at the parts.   I had 101 queries going round in my head.  I knew the clearance of the rear forks was 5mm too narrow and I had doubts that the drop outs where wide enough.  I knew I was only talking about millimeters for everything, but I just wanted to get things done.

I bought a week train ticket which meant the next evening I was able to bring the bike inside.  It was still very wet outside, but the bike was dry having spent the day undercover.   I was able to wipe off the worst of the crud that had collected on the bike having spent days on wet commutes.   I was yet to get hold of a cassette removal tool and whip but I was able to spend the evening making sure everything would fit.   A little bit of pushing here and there and without too much trouble I managed to make the extra millimeters fit (they were only millimeters after all).   I had chance to fit everything apart from the rear wheel.

The frame has always been a bit of a bugger, even fitting mudguards had been a bit of an effort.  Everything about it seems just slightly different, things fit but not ever without a fight.   So my worries about the critical things fitting, like the new wheel, were all valid.   The battery holder where the water bottle is meant to go only just fit, lots of mucking about to get it in.    The various bits for the handle bar, the throttle and the screen, had me playing about for hours.  The control screen would not fit across the stem where it should be, the bars just way to wide, not the first time I had come across this…  The throttle would not fit if I were to also have clearance for the gear trigger shifters.  I was able to overcome some of these problems by being able to pull out the hand grips out a bit (they are made of hard rubber instead of soft) and in doing so make the handlebars wider with more room.   I got everything on, with suitable clearance, but I was worried that I now had some seriously wide handlebars should I need to get through any small spaces!  Amazingly, although maybe not so with this bike, the simpler things had turned out to be the real complicated bits.

Still catching the train on the next day I was able to keep the half completed bike out of the wet while during the day I shopped for tools required for the rear cassette.   I had a tool to remove a freewheel but not a cassette, I had a chain whip fresh from Amazon.  While purchasing the correct tool, I also bought a replacement 9 speed cassette just in case I could not get my one off of the existing wheel, I could always return it if it was not needed.

Not needed indeed, with just a little bit of effort the cassette came off the old wheel and I was able to fit it on the new motorised wheel.   I swapped over the inner tube and tire and soon had the new wheel in the bike, a quick test showed the motor turning at a sleep 5mph.  Such throttles are only really meant for when you “walk the bike”, so I was happy to see it working as expected.

The last bit would be fitting the PAS, just a case of quickly fitting the two parts over the bottom axle and putting the sensor reader near by it.  The idea of the PAS is that it is a large wheel dotted with little magnets, as the bottom bracket axle turns with the pedals a reader picks up the magnets and how quickly they are passing and in doing so able to give a suitable amount of power to the motor to give you the assistance.

I looked at the space between the frame and the pedal crank and though it looked all a bit thin to get the big plastic PAS wheel in place.  I wasn’t surprised when I found out it did not fit.  This would mean replacing the bottom bracket with one with a slightly longer axle, not something I wanted to be doing.   The good news was that the local bike shop would have no trouble (I hope!) doing such a job and so with the PAS yet to be fitted I biked over to the the shop.   I had managed to get the throttle to go from 5mph to 8mph in its power having read that actually I should be able to use it on the throttle on its own.  I was a bit puzzled why I could only get 8mph though, so the ride to the bike shop was manual all the way.  Nicely the extra weight of the motor and battery was not noticeable.

It would be a week until I next would have chance to work on the bike and so in the meantime I asked questions on just how the throttle should work.   It turned out that the controller comes restricted so that the throttle keeps at a walking pace and so that the PAS does not do more than 15mph.  However, it you are to put in certain settings you can get the throttle unrestricted and the PAS up to higher speeds.  This was starting to answer some of my questions, I don’t want to do super fast but something more than 8mph!  It was also soon apparent that the kits are meant to be PAS and running the motor with no pedal assitance would not only flatten the battery quicker but would wear out the motor over a long period of time.  It was suggested that if you are on the flat then you could in theory not peddle as long as you kept an eye on the power gauge (a bit like a rev counter) to determine how hard the motor was having to work.

The next weekend I picked the bike up and the shop had even fitted the PAS leaving me with just the reader to fit when I got home.  With my new knowledge I was able to bike home this time taking full advantage of the unrestricted throttle where I was able to cruise along at 18mph with no peddling and little stress on the motor due to no hills.

As soon as I got home I started to fit the reader, having first moved the front mechs up a bit in order to give myself a bit more room for it to fit.   Within minutes I had it in place and was able to test it by picking up the rear wheel and starting to pedal by hand.  Within seconds the sound of the motor cutting in was hard, I stopped moving the pedals and it stopped.  It seemed it was time for a test ride.

A quick chain change (previously I had tested the chain it is over the 1mm stretch limit and so I had bought a new one) and then a whizz around the block.   As soon as I started to pedal off the bike zoomed off with me holding on!  As soon as I stopped pedalling, calm was restored.   I came up to my first junction and stopped pedalling, the now familiar motor noise stopped and I drifted to the junction.  A random casual turn of the pedals (like you do sometimes) and I shot off again by suprise before I grabbed the brakes!   Actions such as casual turning of the pedals I would have to get used to, and stop doing (or do it backwards instead!).

The next day I planned a 10 mile round route (thanks to the new Garman Tour GPS planning it all for me).  I got up early and the weather was both windy and rainy, and cold with it, a perfect test for a typical commute into work.    For the way out the wind was behind me and so I soon reached the 18mph limit of the motor as I kept pedalling on, although I soon learnt that if I didn’t put much effort into pedalling then I would go back down to the limit and be going at an acceptable speed with no effort at all.  I had to turn the power down a bit as I came to busy section.   Most of the time, apart from when setting off, the motor was having to put hardly any effort in at all with the power gauge showing not much going on, and yet I was coasting along with ease.     I changed direction and started to make my way back, this time against the wind.  The freezing rain hit my face as the motor’s effort increased but the speed did not.  I turned it all off to see the difference, going from 18mph with no effort to 10mph with lots of effort.  While the bike was now heavier than before, it didn’t feel that much difference to when I have my laptop with me.  Good to know it would be easy to pedal unassisted in the worst case of it failing at any time.

The 10 mile ride was cold,  with me putting hardly any effort into pedalling had meant I had not warmed up, which was good in a way.  Hopefully no more turning up at work looking like I have biked for 10 miles and taking a while to recover!  The battery was down from 40 volts to 38 which showed it had more than enough range for the day, both now and in months to come.    At times it felt like I wanted to go faster until I remembered I was in top gear doing 18mph without any effort at all, which would do for me.

Cost wise, compared to the train it will all take around 5 months to pay off and the battery will probably start to show signs of old age after a couple of years.   With the controller built into the battery housing it could be a problem in the future if the battery is no longer available, but there will always be other controllers and batteries if it came to it.

The real test will be later on this week when I am due to be biking to and from work again.  The nice thing is that it is hard to see that it is a now an ebike unless you spot the battery and the motor.  It’s not a snobbish thing (ebikes aren’t for real cyclists sort of thing)  but instead means it still looks relevantly neat and tidy.   The option to return it to a normal bike is always there and simple to do – but for now why would you want to?

Role on warmer weather and touring weekends….



A bit of trouble getting it all to fit
A bit of trouble getting it all to fit


Doesn't look like a bit enough gap...
Doesn’t look like a bit enough gap…


It does now, PAS fitted


Ready and waiting for daily commuting

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