VK3CKC's eLecTricks Trike Design and Build.

Joined
Feb 20, 2013
Messages
354
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
So far, my testing is turning out OK except for the lack of low speed gearing which I will address shortly, and a propensity for dropping the rear chain when pushing backwards if necessary for a turn that can only be completed that way. Both fixes viewed as easy when I get the time.

Another successful experiment that I need to share:

Do any of you have any sick SLA batteries? I recently discovered that my two 12V, 9AH SLAs had become more than a little sick after sitting around for a while and were not appropriately responding to charging. They were also immediately dropping to 9-10V with only 150mA of discharge current. I recalled that I had been going to try something that I had seen in a YouTube video quite a while back. This is how it turned out:

1: Carefully remove the top panel from the battery with a knife or screwdriver to reveal the rubber caps on the cells.
2: Remove the rubber caps.
3: Top up each cell with water. Yes, that's right, the video mentioned water but I would use distilled water - if I had some.
4: Replace cell caps and top panel.
5: Charge.

I didn't have any distilled water left, so I used tap water after considering I really had nothing to lose. The charging process took longer than it had recently been taking, indicating that the process may have worked. The immediate voltage drop no longer occurred and now, all looks fine again.

I do have another battery that I labelled years ago as usable (barely), plus some I was given as no longer usable that I will also try to rejuvenate. It is worth a try.
 
Joined
Feb 20, 2013
Messages
354
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
Testing continues. I have now ridden about 50km with a few minor issues fixed. Had to add a little more length to the front chain, re-modelled the mid-drive gear selector lever to a T-bar, shifted it to a more visible place in front of the seat and later lengthened it (no longer a T-bar as I found it would encroach on the family jewels too much), lowered the height of the mid-drive derail wheel which also put it closer to the mid-drive sprockets and removed a chain rattling tendency with highest gear selected, fixed a rear tyre puncture, various odds and ends, etc. Placed some channel-type stuff on top of the 6 x 4 trailer, used the same stuff for front wheel ramps to make loading/unloading easier. It was more awkward than heavy due to the trailer height. Yes, I can still lift it all.

Will have a look at updating images in a day or two, including the trailer arrangement for those who have a cartage problem. Have another short ride to do tomorrow morning.
 
Joined
Feb 20, 2013
Messages
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Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
There was a post on AZ somewhere about how to transport a trike. This is what I fitted to my 6 x 4 trailer - three channels for three wheels. It didn't cost much but involved lifting the trike to position the front wheels into the rear of the channels and pushing it forward sufficiently far for the front wheels to sit between the horizontal bolts at the front end. That stops it rolling, tie it in place and you are ready to roll.

One problem, it was getting awkward to lift and place in position at it wanted to roll over as it rested only on the rear wheel until placed on the trailer. However, a solution was at hand.


Two x 2m lengths of channel were used to make two ramps.

It was easy to set the spacing for loading but as the trike was at the wrong end of the ramps when unloading, not so easy. Fixed it by making a spreader bar with 2 x 70mm lengths of the channeling. Just drop the ramps into the short lengths on the spreader and you are ready to offload.

Now that I have managed to post the images again, there will be more images to follow.
 
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An easier way would be to shift all three above channels to, say, the left side of the trailer rather than the centre, reverse the second trike, run its front right wheel in the same channel used by the right wheel of the first trike. This would only require two more channels, a full trailer length one for the rear wheel of the second trike and a shorter one for its left wheel. This makes the whole customisable as required. Same ramps could be used for either trike but might need adjustment for a different track width.

The channel only costs $AUD4.50/metre and is made to any length on the spot where I can get it now. The first lot on the trailer is of a lighter gauge and was left over from a shed installation.

See what you've done? Another project. It's now added to the list. I had fleetingly considered it earlier as I do have the occasional need to transport a second trike.
 
Joined
Feb 20, 2013
Messages
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Location
Axedale, Victoria, Australia
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axerail.coffeecup.com
Back to the eLecTricks build:

I managed to find a front disc braked wheel that could be used for the trike rear wheel that does not require a derailleur. Its matching mate had been disassembled some time back but it now provides a disc braked hub with an 8-speed cassette for the mid-drive. It didn't take long to locate it. This enabled me to start the design of the rear end, in concert with the front section as it has to match up where they are connected.

Dropouts at the rear end hold the rear wheel axle as would ordinarily be expected as, in this case, they are only required to hold the standard front bicycle wheel. Straight chainstays will be carried forward, with mounting for the rear or top end of the suspension shock. A gusset will be provided on both chainstays to provide strength for the shock mounting and general reinforcement of the rear end.

The suspension pivot is the mid-drive connection on the front section. The front end of the rear section connects at this point via two pillowblock bearings and spacers. The details of this connection will have to wait for the moment.

Rear wheel dropouts were cut from a length of flat steel and drilled for clearance holes for the rear wheel hub axle. A slot was then cut so that the axle would slide in an out of the dropouts. Suitable lengths of 20mm square tubing were then cut for the chainstays. One end of each was cut to allow one face (side) to wrap around at the rear end by 45 degrees, thereby saving welding separate end caps. The chainstays were then notched on the long side so that the dropouts could be inset flush with the chainstay inside face and they were then tack-welded in place. The chainstays were then put aside until the mid-drive was ready to fit to the front section.

This image shows one dropout tacked to a chainstay and one chainstay cut and ready for folding the end cap around to cover the open end.


Both chainstays completed with tack-welded dropouts.

I hope to get a couple of spacers machined for the mid-drive tomorrow. I will then be able to complete the rear section and attach it to the front section.
 
Joined
Feb 20, 2013
Messages
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Axedale, Victoria, Australia
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As users of the Bafang e-Assist conversion will know, the conversion comes with a single chainring, the size of which is chosen at the time of purchase. Mine is actually a 46t.

Consider what happens with such a chainring when the conversion is fitted in place of a 28t, 38t, 48t chainring set. It is obvious that the available gearing with the same rear cassette. Without putting too fine a point on it, the gearing range will be somewhere between that which was available via the 38t and 48t original chainrings. This means that the low gears that were available from the original 28t chainring will be missing, so will those of the 48t chainring. You may have trouble starting on up grades without the motor, and find that you will end up spinning if trying to ride at speed. There shouldn't be any surprises now that you know that it exists. Someone on the old forum mentioned that he had added another chainring but there was no detail of how it was done. I offer the following info for anyone contemplating a fix.

I have spent quite some time over the last week or so trying to retrieve some of that lost gearing by adding a smaller chainring to my Bafang system. My Hilgo transmission copy more than makes up for the loss of the high speed gearing and I have not yet managed to pedal at a cadence of 60 using the highest available gear.

The Bafang supplied chainring is mounted with five Allen head studs and is easily removed. The correct fitting of the chainring is such that the offset places the teeth closer to the motor than its centre. I managed to find a 28t chainring with five spokes, within a set of three that was rivetted together. Separating them was just a matter of drilling the rivets out. As fortune would have it, the stud holes were not on the same radius as the Bafang chainring. Also, as fortune would have it, the 28t ring had an offset centre, allowing the stud holes to fit neatly between the spokes of the Bafang ring.

I cut a steel disc from some 1mm plate, with a hole in the centre the same as the Bafang ring. I bolted the 28t ring to the disc and placed it against the Bafang so that the 28t offset was in the same direction. A 13mm spacer was cut from some aluminium. Five longer mounting studs were then placed through the Bafang ring, the disc with the 28t ring, the spacer, and into the original stud holes on the Bafang motor. Job done and I only have to fit a front derailleur.

Low gearing from the 28t chainring should now be speeds 0.6 of that available from the 46t alone. I haven't ridden it yet but that change, providing, if you like, a cruising range or a climbing range, with the Hilgo transmission, should do quite nicely, giving me high speed as well as the ability to climb up brick walls - if I can find tyres with sufficient grip.
 
Joined
Feb 20, 2013
Messages
354
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
A brief test ride on the Warrior with the lowest possible gear selected showed what I think will be more than enough low gear. Although, through necessity, the test was on level ground, I would expect that I will not be riding up any rise that is now too steep to ride. The front derailleur has not been fitted yet.

Unfortunately, I now have to make an adjustment to the front chain tensioner. One modification breeds another.
 
Joined
Feb 20, 2013
Messages
354
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
My Warrior test trike is now back in operation with dual chainrings on the Bafang motor.

The additions consist of the original chainring and an additional 5-spoke, 28t chainring bolted to a disc and held in place by 25mm x 5mm studs through the original chainring to the motor. An easy modification for those who want/need more low end gears with a Bafang drive. I still need to put a derailleur back on it.

By the way, Amazon have a range of Bafang components including a 4-spoke adaptor spider for those who want to use other brand chainrings.
 
Joined
Feb 20, 2013
Messages
354
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
I just had to try a steel wheel. Simplified construction: I drew up a design of a 16-spoke wheel centre to fit a 48-spoke rim. Then traced it onto a used sheet of <1mm steel, small drilled the centre and cut it out. Cut a length of steel flat that was 2 x the thickness of the sheet shorter than the inside diameter of the wheel rim to bend the ends of each spoke at right angles to make spoke-to-rim mounting tabs. The tabs are bent inwards to the rim so that the spokes will be splayed somewhat. Placed the spokes inside the rim, held each spoke carefully in place and drilled through the nipple holes. Placed appropriate sized small bolts through nipple holes and spokes, attached nuts and tightened. Impressed with how this "roughie" worked and it didn't seem significantly heavier than a standard wheel when I picked it up. Just realised that, in this image, there is no hub, so it will be, as expected, heavier. That doesn't worry me. It would look much better if painted.

Before I started, I reasoned that only one disc should be required with the spokes splayed to suit inside and outside nipple holes and a DIY hub could even be narrower.

It became obvious that the rim must be straight before starting as there is no adjustment available during construction.

Would I use it in a build? I think so but I need to mount it on a hub first.
 
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