Interim update.......
I still plan to do a complete thread on the installation of the XF07 hub motor and battery sourced from Woosh Bikes onto the Kettwiesel Evo, but the development of Plan A, issue 3 is still incomplete, meaning the project is still "work-in-progress" although there might be
some news of interest...
Delivery
The kit was delivered, by DPD who I would recommend to no-one. Two delivery times were missed, and to thwart them missing a third, we had the kit delivered to another address. Andy at Woosh was as underimpressed as we were, and it wasn't like he didn't try to get the kit delivered either. Seems DPDs delivery performance is dependant on your location, and the original delivery address wasn't one of the good ones....
Fitting
The 20" hub motor is fitted (unsurprisingly) to 20" forks. As it turns out (because I hadn't realised) they are 20"
air forks. Why are these two particulars of any importance? Firstly, there is possible more 'spring' in 26" forks, more in 27.5" and more in 28" forks, meaning the dropouts in either might be persuaded to open an extra millimeter or so if required. The shape of the air forks, meant fitting the hub motor was almost impossible, because there just wasn't room for the hub and spacers to keep moving parts away from the fork. I've actually crimped the left-hand fork tube, getting the hub to fit. I have priced up a suitable non-suspension fork at £44, that doesn't have the fork struts encroaching on the dropout gap. Put another way, the installation of XF07 hub wouldn't normally be possible with the
Grind branded 20"
air forks.
On longer forks, it would have
probably been possible to add washers to provide the necessary clearance, but not with these forks. I accidentally crimped the bottom of the left fork leg using a car jack to try to open the legs. I only needed a couple of millimeters to get the hub in after all..... Fortunately, the air shock still works as it should, although an air fork at the front of this style seem a bit redundant to me.
Right side of fork, indicating clearance.
Left side, showing clearance.
It took some considerable time to get the wheel mounted. I am not looking forward to remove it, and reinstall it the other side of a puncture repair (for example). When time allows, I will be trying to use some thinner washers to see if there's enough space to get the hub on without having to (literally) lever it into place. I also had to remove some paint from the dropouts to get the hub axles inserted.
You can see from the images, it's the fork tubes that are encroaching on the hub. This isn't a problem with a regular wheel because the hub/spoke arrangement is narrower.
The battery was then (literally) lashed to the boom of the trike .....
To test whether the hub and battery combination was capable of carrying me and the trike up that hill. The controller was sat on my lap for the test.
Performance.
With assistance set to Max, I was able to get up that hill so quickly, I overtook several pedestrians walking uphill in the same direction. Previously, when pedalling under my own steam, I was going so slowly, they would have overtaken me..... I was very impressed with the ride and went back down the hill and came up a second time because it was such a pleasant experience. Yay!
With the test passed as it were, we could be sure there was no need for a respoked BPM motor and could keep the kit we had been supplied.
It has taken some time since, for me to design and source the means of securely fitting the battery where it needs to go. I want it slung under the boom, but since the battery holder and mounting system is plastic, it would need to sit on a tray, and the mountings would need to be offset because of the steering arm (once again) which moves under the boom on hard left and hard right turns. The whole idea of having the battery at the front of course, is to add weight (and thus grip) to the front wheel. The underslung solution provided so many demands on a design, it has been temporarily shelved, and an over-boom method was put together, as a proving concept, rather like ensuring the battery and hub would get up
that hill.
As with the whole project, costs had to be minimised because mistakes would be part of the project. £40 wasted, would be better than £200 wasted. We got some mountings made, that were very reasonably priced, although I would slightly change the design for a second issue.
The platform the battery is currently fixed to is made of wood, because shaping that is easier than metal, and a mistake can easily/cheaply be resolved. When the final shape is confirmed, there is an expectation the platform will be replaced with aluminium plate.
For the record, the current battery mounting, is very
very stable.
The next problem, and hopefully the last problem with fitting the kit, is placing the controller somewhere. Typically these fit to handlebars..... As of yesterday, I think I've come up with a solution, and once that is tested, the owner does not need to have the cable and controller sat in her lap while riding.
There might be an extra picture to add over the weekend.
I do have one query, which is regarding how the system works. While the system is switched to Max assist, almost any movement of the cranks has the expected result. (And as I wrote above, a very pleasant experience it is too.) When I move the assistance level to Min, there doesn't seem to be much difference in the actual assistance provided? The sensor for this kit is on the pedal spindle, so 'cadence' sensor not torque sensor?? Does this mean, it's impossible for the controller to know how much assistance I actually need? ie More assistance climbing a hill? If this is the case, I can understand that. The sensor doesn't recognise resistance.
So, (and this is the question I would like answered please), what is the actual difference between Min and Max on the controller? What is effected by changing this on the controller?