A New Cycling E-ra


Following a knee replacement in 2015 I have struggled to get back to my previous cycling mileage and certainly been unable to resume touring.  As a result after long consideration I have taken the plunge and converted my Trek 830 MTB to an electric bike.  Frankly I was not impressed by off-the-peg electric bikes which are very expensive and in my opinion, poorly specced compared to a good standard bike.  In general I was also put off by the retailers, who showed poor knowledge about bikes in general and were often clearly there only for the commercial E-bike ride that’s sweeping across Europe.  Hopefully this will change in time but for now it’s a case of buyer beware!

I had been toying with the idea of conversion for some time using a decent conventional bike and after 23 years I know the Trek 830 inside out, which despite its age is very well built.  After years of maintenance and previously converting the bike for touring it’s a bit like Trigger’s broom and I thought would make a strong base for converting.  I also hoped that by using a bike with which I was already familiar and happy, it would provide the same riding feel after conversion.

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Trek MTB 830: My new electrified steed!

In the end I chose the Cyclotricity 250W front wheel PAS system and after completing the conversion have just undertaken my first electric rides.  The kit seems good and I would describe the conversion as relatively easy, except for the very poor, unclear and often confusing instructions which have to be downloaded online.

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250W front wheel hub drive on a 26″ wheel. Axle nuts need to be very tight, with torque washers inserted into the drop-outs in order to stop spin-out when using power assistance.

Most conversions of this type use a PAS (Pedal Assistance Sensor) ring that goes over the bottom bracket spindle and is clamped either by a locking ring on the left side or by the bottom bracket collar on the right side.  However, as most modern bikes are now fitted with a cassette bottom bracket there is often no locking ring, as with my bike.  Alternatively the PAS ring can also fit on the right side but in my case, with a triple chainset the smallest inner chainring fouled the magnetic disc that operates the sensor when the pedals are turned.

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The PAS clip at the base of the seat tube is activated by a magnetic disc fitted on the bottom bracket spindle when the pedals are turned, thereby providing power assistance to the front hub motor via a control box located behind the rack mounted battery.

The answer was easy and should in my opinion be supplied as a standard fitting for these conversions i.e. a small clip-shaped sensor attached at the bottom of the seat tube on the left side with cable ties and a corresponding two-piece magnetic disc located between the crank arm and bottom bracket shell, which conveniently no longer requires dismantling the bottom bracket.  This had been omitted from my order and was not evident on the manufacture’s website either but after trying the first two methods, I obtained and successfully installed the alternative clip-type sensor from the retailer Electric Bike Conversions who had originally supplied the kit.

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The 17Ah battery is situated beneath the rack top and can be unlocked and slid out for charging or security – this is a very expensive battery! The PAS control box is placed inside an integrated box at the front of the battery and I’ve protected the lead connectors with a waterproof cover – though they are themselves rain proof.
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At the back the battery has an integrated rear light which works independently using x2 AA batteries; the instructions say nothing about this and I only found out how it works after much effort and eventually phoning the retailer – again!

Apart from the ‘on-demand’ assistance of the electric power, I was pleased to find that the bike otherwise rode generally as before, particularly with the power off.  The electric power is available in two modes: (i) through a thumb operated throttle, or (ii) using the PAS system, which only works when the pedals are turned and can be set at five increasing levels of power from a control unit mounted on the handlebars; I am yet to figure out the bewildering and unclear instructions for setting the LCD display!

LCD control panel + thumb throttle on the outer side of the brakes.  I was unable to fit the brake levers supplied which cut-off power under braking, as my brake levers are integrated with thumb operated gear shifters.  By using a PAS unit this this is not a problem as the power stops when pedalling stops. However, fitting all this across the handlebar space was tricky.

My other hang-up when considering an electric bike (like cars) is their limited range.  Manufacturers and retailers are careful how they word this but always include a caveat somewhere in small print that the advertised range will vary depending on the type of use.  It’s therefore my thinking that a given stated range of say 30-miles is almost certainly based on modest use of electric power, which with increased load or terrain is likely to fall considerably i.e. normal cycling.  I find this very unhelpful and somewhat disingenuous.  I have yet to determine the range of my set-up but using their new large capacity 17Ah pannier mounted battery, I was told the bike should have a range of up to 80 miles – which I very much doubt.  Notwithstanding, I have just completed two rides on the first full charge, deliberately seeking out hilly terrain on my first ride of 23-miles, with an apparent 50% of the battery power left at the end and <25% power after a second flatter 18-mile ride i.e. 41 miles in all with some power still remaining.

In general I have found the electric assistance to be highly beneficial on hills, as intended taking the pressure off my knees.  On the very steepest hill of almost 1-in-5 the hub motor strained somewhat but with a good charge coped with the incline, albeit at a very slow pace.  I am still learning how to best use power whilst at the same time optimizing the battery charge, generally turning the assistance to low or off when on the flat and only using the PAS on hilly sections; use of the thumb throttle for a quick squirt of power when pulling away or on short inclines can also be helpful and is becoming addictive! Bike handling is good but being front wheel hub drive, I suspect in wet conditions traction could become somewhat skittish, on occasion the extra weight is also quite noticeable.

At this early stage the jury is still out on my converted E-bike but so far it shows great promise and hopefully marks the beginning of a new personal cycling era.  Already it’s apparent that route planning needs to be different in order to ensure that there’s sufficient charge to complete the ride; in my case some hills along the final stretch home have always been the bane of local rides and I need to make sure I’ve still got some power assistance left at the end for this purpose.  I intend to continue riding locally with my other standard bikes and use the electric bike for longer local or day rides and centrally based touring trips.



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