Recumbent electric trike

[CheKmx]

Hello,

I am intending on building an electric trike and I'd be very interested in any feedback you have.

I'm planning to get a KMX Cobra and add a Bionx electric drive although I haven't decided which unit to get or infact finalized on the bionics.

The main purpose of my bike will be to provide me with a commuting/city run around but I would also like to do some off road as well. I live in Zurich so the area is quite hilly and I'm quite heavy (95-kg) so I want to make sure I get a unit that will give me plenty of assistance up hills.

The options on the electric engine system I must use are

1) Bionx PL 250 HT: I think this High Torque system will guarantee me good hill climbing capability and I like the idea of the bionx system.

2) Bionx PL 500 HS: I'm also quite tempted by this for the same reason as above but it gives speads >45 km/h and is street legal in Switzerland if I get a moped plate. My main concern is that the hill climbing ability will be compromised but never having had an electric assist I'm not sure quite what that means. Roads here don't tend to be too steep more usually you get long gradual gradients.

3) The third option is to get one from here. This is a local company and they work with the supplier of the KMX so I could get the whole thing from one place pre installed but I'm not really sure how there systems compare to the Bionx.

Any way that's as far as I have got.

 

[Beeping-Sleauty]

pedalling whilst reclining

Hello,

I am intending on building an electric trike and I'd be very interested in any feedback you have.

I'm planning to get a KMX Cobra and add a Bionx electric drive although I haven't decided which unit to get or infact finalized on the bionics.

The main purpose of my bike will be to provide me with a commuting/city run around but I would also like to do some off road as well. I live in Zurich so the area is quite hilly and I'm quite heavy (95-kg) so I want to make sure I get a unit that will give me plenty of assistance up hills.

The options on the electric engine system I must use are

1) Bionx PL 250 HT: I think this High Torque system will guarantee me good hill climbing capability and I like the idea of the bionx system.

2) Bionx PL 500 HS: I'm also quite tempted by this for the same reason as above but it gives speads >45 km/h and is street legal in Switzerland if I get a moped plate. My main concern is that the hill climbing ability will be compromised but never having had an electric assist I'm not sure quite what that means. Roads here don't tend to be too steep more usually you get long gradual gradients.

3) The third option is to get one from here. This is a local company and they work with the supplier of the KMX so I could get the whole thing from one place pre installed but I'm not really sure how there systems compare to the Bionx.

Any way that's as far as I have got.

Hi ChekMx,

sounds like a great idea, i'd be inclined to go with option 3,

liked the look of this e-trike,

let us know how you get on,
beeps

 

[flecc]

I'd be inclined to go with option 3 as well. Driving through the gears means that hill climbing will virtually have no limits, and it's a neat fit on the KMX, just so long as you don't apply the front brakes too hard, doing a "stoppie" and crashing the motor into the ground.

Some have observed that the BionX 250 isn't particularly powerful with hill climbing, and with the recumbent's extra weight it could be a bit inadequate.

Amongst the legal hub motors, the Heinzmann is quite good on hills and has been used many times in recumbent trike rear wheels.
.

 

[Miles]

Another possibility: EcoSpeed, Worlds Best Electric Assist

Bit expensive though......

 

[CheKmx]

Thanks for the advice. I suppose the only things that bother me a bout option 3 is

a) I've read stories about Lipo batteries exploding but I suppose they still do Nimh.

b) I liked the idea that with the Bionx I could take off the battery and swap the wheel without to much bother if and when I wnated to use a normal trike but if im honest with myself I very much doubt once I've got the motor on I'll want to go out without it.

I'll keep you posted as to how I get on.

 

[CheKmx]

Well the bikes under construction so I should recieve it next week

 

[CheKmx]

It's arrived.

Well the bikes arrived and I've had my first real taste of riding a recumbent trike and using an electric bike. I'm happy too say that both are great and when time permits I'll write a little review of my experience so far. I'll try and sort out some photos as well

 

[andyh2]

CheKMX,

Was it option 3 you went for in the end. Looking forward to seeing your report and photos.

 

[CheKmx]

Yes i decided on option 3 with a hell power 25.9V 10Ah battery.

When I went to pick it up we found a few issues including that the motor was stopping the deralier(?) from pushing the chain on to the top ring. They had to remount the motor on the bottom of the boom so I had to be patient and go home and wait whilst they did it. Then for the second test ride. Again I was very disappointed I could only seem to pedal the bike with the motor running and not very quickly, I realize now that I had left the parking break on, doh! Finally after Markus( the man at Noco Sports where I bought my bike) had checked out the problem and couldn't find anything we realized the battery was out of juice so my first ride home would be unassisted...

 

[CheKmx]

Photo

Here's a photo of my bike

 

[CheKmx]

Ride 1. 12-km unassisted

So with out any juice in the motor but desperate to try my new toy out I decided to cycle home under my own steam. Although the bike is quite heavy, about 23-kg including motor and battery I found it very nice to pedal and the laid back riding position gave me good all round visibility. I found getting the hang of the twist grips a bit of a pain and still find it very easy to change gear by accident specially on the throttle handle.

Speed on the flat was good if not blindingly fast and I was pleased by how much force you could apply by pushing back into the saddle when going up hill.

I was very pleased to observe that what I have read on the web regarding trikes and recumbents seems to be true in that motorists seem to give you a wide birth or actually que behind you although I found that I felt the need to pedal harder when this happened to try to allow them to pass.

 

[CheKmx]

REroblems

I have been having a few teething problems with my bike. First off they'd stuck the battery permanently to my bike. Fortunately I was able to remove it without damaging the paint work. I now have the battery installed in a backpack that fits neatly on the back of my seat.

The second problem was that on the fourth or fifth ride the pedal and crank fell off.

And finally I have been having some issues with the battery. Initially every time I rode up even the slightest gradient the battery cut out, it would return if you turn the power on and off but after the first cut out the system shuts down intermittently even on the flat. When the battery was plugged back into the charger sometimes it would even say that the battery was full.

The shop has been very good even coming to my house to pick up the bike and the have made some improvement in the performance, which they did by reducing the size of one of the cogs on the motor. I managed to get to work (8 km) without any cut outs. On the way back from work, with the battery fully recharged, the battery cut out at the top of the longest hill on my route and again after this the system would shut off often yet still come back after a reset.

It seems to me that even though I am quite heavy, Bike and rider altogether must weigh approximately 120 kg, I would expect better performance than this given the 50 km range posted for this battery. I do use it as a pedal assist so the battery isn't doing all the work but even if it was I would have expected it to get me 8 km

I have contacted the shop and we will see what they suggest but I wonder if anyone had any suggestions what might cause this kind of behaviour?

 

[flecc]

The two most common things that cause this are a poor connection limiting current delivery, or a battery with an inadequate discharge characteristic. This last is something that some of the most powerful bikes like the eZee range suffered until recently, but the latest generation batteries are overcoming it now.

Which one of the three batteries have you got? Judging by the look and size of that motor and the weight of the recumbent, the NiMh and smaller Lipo batteries could be inadequate for the job. This is a problem that the more powerful Cyclone motors suffer also, and they refuse to sell the smaller battery sizes with those.
.

 

[CheKmx]

I have the hellpower 260Wh 25.9V 10Ah. I have seen reports on there site of people using this with a rider and bike of 100 kg doing far in excess of the rides that I have done so far. They are bringing a replacement battery for me whilst they look into the problem so that's good news anyway.

 

[flecc]

That's good news.

The range isn't necessarily a reflection on the maximum current capability of lithium batteries though, some cells holding plenty but unwilling to give it up above certain rates. When delivery is below those current rates, the range can be very good. When taken above those rates, chemical exhaustion sets in and the cells waste content, so range reduces.

Resting after a safety cutout operates recovers some of the lost charge as the chemistry recovers, but not all of it, and it's dependent on how long the rest is.
.

 

[CheKmx]

Thanks

Thanks for the advice flecc.

Spoke with the producer of the systems yesterday as he came round to deliver a spare battery and charger (the Nimh model) and he said that the safety electronics in the hellpower battery were kicking in too early a 20A when it should be 40A , well something along those lines.

Pretty impressed with the service as he popped round on his moped on Saturday lunch time.

 

[flecc]

Full marks for that service, I hope your replacement battery is up to the job now. What the supplier said makes sense, it being critical that the cutout voltage and current settings aren't set too low. All that matters after that is that the cell chemistry can deliver up to the correct cutout rating.
.

 

[CheKmx]

First week of electric trike commuting

Well the temporary replacement battery might be bulkier and heavier but it certainly supplies an improvement of the first battery. It's now an absolute joy to get up in the morning and go to work, and even more so coming home. Just a pity the weather's been a little bit pants or I'd have given the bike a bit more of a run out. I even find I'm enjoying going up hill and looking for some climbs to do which I is a definite first for me.

Just like to say thanks for the advice, it is greatly appreciated.

 

[flecc]

Good to hear CheKmx, glad that you're able to fully enjoy it now. Hopefully we'll get some better weather soon.
.

 

[CheKmx]

Nutter

By the way I was on the way to work on my flying deck chair this morning and as I passed a post van who was waiting at a junction and I did the usual of trying to get eye contact he stuck his finger to the side of his head and made a twisting motion, I think he may have been questioning my sanity. I was too busy pedalling and grinning but had I been going a bit slower I would have given him a wave.