Fitting Alien 36v legal kit to Giant Sedona with alloy forks

[Val]

Alien Ocean 36v Road Legal kit

Part one.

I purchased this kit to fit to my wife's 2007 Giant Sedona DX Comfort Bike. Having already got a reasonable quality bike, it seemed to make no sense to buy an e-bike so I trawled the forums to help select a suitable kit.

We use our bikes for leisure but my wife surrers from asthma and finds hills very difficult.
The most important criteria for us was:
Hill climbing ability (with light pedal assistance).
Low weight (we have a motorhome and carry the bikes on a rack mounted on the back).
Reliability.
Availability of spare/replacement parts.

I fairly quickly discounted chain drive kits running through the bikes existing gears as I felt they were rather 'heath robinson', ugly and potentially un-reliable.
Of hub motors, it became clear that geared motors are generally far better at hill climbing than non geared motors.
Out of the generally available hub motors, the best hill climber is the Heinzmann, but with kits running at around £1,300 they do seem excessively expensive and are reputed to be quite noisey. This left the Suzhou Bafang hub which is widely used and seems to be very well respected as a quality 'all round' hub motor. I considered front or rear hub, and could really see no benifit in fitting a rear hub where as the front hub gives 'two wheel drive' and is easier to fit.

Having started my search with a recommendation to look at Alien kits, after many days of researching the various internet forums I found myself coming full circle back to the kits offered by Alien!

I selected the 36v Road Legal kit.

The kit arrived 'Next Day', very well packed. On unpacking, everything was present appart from NO fitting instructions. There was a wiring diagramme, but nothing else. However, there are more than enough guides on the internet, so I was not too worried.

Fitting:
The first job was to swop the tyre and tube from the original wheel to the new one, no problems there.
Next was to fit the new wheel and hub motor to the bike. I knew this would be the hard part as the Sedona has cast alloy forks with very deep 'Lawyers Lips'.

I needed to increase the depth of the 'U' with a file to allow the motor shaft to sit fully into the fork and for the center of the shaft to sit perfectly in the centre of the 'Lawyers Lips'.

Before:

 

[Val]

Part two.


After:

and the other side

 

[Val]

Part three.

I modified a stainless steel washer that had the correct o/d to fit perfectly into the lips. I used a Dremmel to shape the inside of the washer to fit the motor shaft.

Next was to make a pair of 'Torque Bars'. I used a 10mm spanner that I first increased the depth of the 'U' so that the head would fit over the motor shaft and cut back the web at the shaft so the head of the spanner fitted snugly into the lip.

I then cut the shaft of the spanner turning it through 135 degrees so that it would run up to the mudguard fixing hole and tack welded it in place.

 

[Val]

Part four.

Once removed from the bike, I welded it fully, drilled the fixing hole, cleaned it up with the grinder and painted it.

Then repeat for the other side!

That sorted the motor fitting, the rest was quite simple. The forward stays for the rear rack were too short to reach the seat post, so I bought some 6mm aluminium rod at B&Q for £5 and made a couple of longer stays.

I did not fit the brake levers or pedelec, relying only on the twist throttle. It seems totally natural to use and I don't really see the point of the other bits, other than to make the bike 'legal'.

On first pulling away you get a real sense of how powerful this motor is. On full throttle from a standing start it feels like it could pull the bike clean out from under you if you weren't ready for it! I'll write a full review of how the kit performs on the road in a week or two when we have got over the initial buzz, but indications are that it will do everything we need.

The reason for making the torque bars was because I had read many times that fitting a hub motor to alloy forks was not recommended and that strong torque bars were a necessity. Whilst I think that fitting torque bars is a very good idea, the following research would appear to show that the SunTour Cast Alloy forks, as fitted to the Sedona, can be as strong or even stronger , in terms of motor shaft turnout, than standard steel forks! Not a difinative study, but I think it clearley shows that the most important thing is tight axle nuts and that torque bars are a very valuable safety device for all bikes.
Test of spin-out on aluminium forks: Endless-sphere.com • View topic - Dropout Failure Experiements, and a call for Fork Donations

Val

 

[Val]

Part five.

The finished bike:

 

[NRG]

A neat installation Val, well done, and as you point out those torque arms x2 are maybe a little OTT one would have probably been enough...

 

[Old Timer]

Part five.

The finished bike:

I went to the links re torque arms, I`m amazed just how easily those fork ends cracked up. I fitted an alien kit to my 20 year old Evans MTB with the standard steel front forks, the flats on the spindle were a perfect tight fit in the fork ends (although i had to file them deeper) Looking at my set up I didn`t give it a second thought that the spindle might break out. I`ll check my fork ends but so far around 200 miles using lots of power they seem fine. I had to take the front wheel out last week to fit some slime inserts after a puncture and all seemed fine. you have me wondering now

 

[Val]

The neat installation is really down to Alien (other than the torque arms). The kit is very neat, especially with the integrated box for the controller built in to the battery slide. The rear rack is also very well made and the battery is a nice snug fit.

I decided to fit two torque arms as I already had the grinder and welder out so it was just another 15 minutes and a second £5 Halfords spanner! I'm more used to cars than bikes, and the rule on cars is always to fit parts in pairs, just makes for a better job I am amazed that there is nobody in the UK selling torque arms. It would cost pence to make them with a water cutter and they sell for good money. I would have certainly bought them if they were offered as an add-on to the kit.

Val

 

[Old Timer]

The neat installation is really down to Alien (other than the torque arms). The kit is very neat, especially with the integrated box for the controller built in to the battery slide. The rear rack is also very well made and the battery is a nice snug fit.

I decided to fit two torque arms as I already had the grinder and welder out so it was just another 15 minutes and a second £5 Halfords spanner! I'm more used to cars than bikes, and the rule on cars is always to fit parts in pairs, just makes for a better job I am amazed that there is nobody in the UK selling torque arms. It would cost pence to make them with a water cutter and they sell for good money. I would have certainly bought them if they were offered as an add-on to the kit.

Val

Val

I`ve been searching the country for a Halfords that have a 10mm spanner in stock. They tell me that someone created a rush on them
Good idea