Guest Bike Conversion

[Danidl]

I used maplin audio cable . The type intended for those incredibly loud subwoofer s in adolescents cars. These woofers are typically 3 ohm and the cable is intended to have a very low resistance perhaps 1 to 5%of 3 ohm. so very thick. Cannot remember the gauge, but you buy it by the yard

 

[Benjahmin]

That's great, thanks.

 

[malkie0831]

30A Powerpoles can take up to about 4mm cross section cable. For single wires look for tri-rated cable on 'the bay' or in your local electrical wholesalers, if they sell it by the metre.

 

[Benjahmin]

So, finally got the kit fired up today. Control led's lit up as did the pas led, but no motor. Then I remembered that, when putting the round motor plug together, some of the pins looked shorter than others. There are 3 larger diameter ones which are the longest. The others are a smaller diameter and shorter and two of these were shorter still. So I gave them a pull with the long nose pliers and felt them click into place. Hey presto, motor works.. Everything appears to be operating as it should.
Not road tested yet because I still need to fabricate the battery mounting. Battery terminals have been fitted to match the ones on my other bike, and I now know what I need to do to get this Insat battery to fit my Ezee.

This whole thing is taking far longer than I thought, but I'm just giving each obsticle it's time and enjoying finding my way around them.

 

[Benjahmin]

At last, 'tis done.
The battery fitted into the box with millimeters to spare. I've bedded it on a foam tray that came with one of the kits. I stiffened the box inside the front and bottom with 1/8th ply. The bottom piece is bolted through to the 3/4 ply that holds the bungee straps.
The power cables exit through a 20mm gland that seals around the cable. Just need some right sized heatshrink.

Box can be removed easily and fitted to the Carrera. Mission acomplished.

First shakedown run showed the motor to be, apparently, quite fast, hard to tell as no speedo fitted. However it has noticeably less torque than my Ezee, to be expected I suppose. Seems quiet when up to speed but doesn't like low revs, particularly hill starts. Then it is growly and puts a fair bit of vibration through the forks, until speed increases. The 3 assist levels seem to be giving speed control. Hope for a longer run tomorrow when battery is fully charged.
The HS11 is awesome. Light to the feel with nice progressive braking, this, combined with the longer blocks in the rear brake, should do the job on local hills.
The quill stem is on minimum height adjustment but is still giving a near upright ride position, as this bike is meant for guests( who maybe don't cycle much) I think that's fine.
The bike as a whole feels light and nimble, this is ironic as I used to ride this but swapped it for the Carrera, but then I needed front sus to deal with the local roads. The control box tends to get knocked as you step through, have to keep an eye on it.
Just needs some rudimentry lights and it's good to go.

I'll report back on the kit after a longer run.
Thanks for all the help and info.
Ben

 

[Benjahmin]

Managed to get out on a 14ml run today, but took the Carrera with the Insat battery on, because of fog and no lights yet on the fox.
Intended to 'work' the battery, so ran in a higher setting than normal. Battery voltage checked at 37.7 after settling. That's what I wanted as it may be a while before I can get to use it, so I'll store it at this.

 

[Benjahmin]

Got out on the fox today, it was very windy and I targetted a coupke of the steeper local climbs.
The Panda worked well but I think I've been spoiled as my first kit was an Ezee and, power wise, this just doesn't compare. On the flat I used setting 2/3 to get up to speed. Once there the bike hummed along with the mearest whine from the motor. Seems that power setting one wouldn't be much use except maybe a pedestrian precinct. The cut out at design speed was smooth and barely noticeable apart from the whine stopping. Drop back in was similarly smooth. It was when hitting the hills that the 'fun' started. First was a long incline varying from 1:20 to 1:12ish. Had to go to top setting here and was glad I'd left the front changer on the bike, onto the second ring in 2nd or 3rd gear. As the revs went down the motor noise increased, but it got there.
Now down into a steep valley and the longer mtb brake blocks on the rear and the Magura on the front worked the magic controllably and with no drama.
Now the steep climb out the other side, I'd say 1:8 to 1:6 with a killer switch back bend half way. Here I was quickly onto the granny ring and out of the saddle. The motor noise increased to a growl with detectable vibration coming through the bars, needless to say on top power setting. We got there but I had to work and came close to stalling the motor on the corner.
With my Ezee I would go up here in 2/5 and not in bottom gear.
I think if you have a commute to do that is mainly flat with only moderate hills, this kit is fine. It's a good kit and buzzes along nicely and is lighter than some. However if there's hills involved or you need serious power to get you home then I would look elsewhere.
For it's intended purpose of it being used by guests, probably not used to cycling generally let alone e-bikes, I think this will be OK, as the power comes in smoothly without that unsubtle kick that I'm used to. Just won't let them near the Ezee in case they realise what they're missing
This has been a bit of an eye opener for me, having previously only experienced the Ezee and the Big Bear. All motors are not created equal. Who'd a thunk

 

[Deleted member 4366]

little bit of solder on the shunt helps a lot with hill-climbing. The extra power helps you to go faster, so the motor is more efficient and makes more power because of that too. You therefore get a double win on the power.

 

[Benjahmin]

OK, so that bridges out a proportion of the windings of the shunt, so reducing the resistance, so must increase the max current - is that right? How would this affect the rest of the circuitry in the controller.
On a slightly different issue, there is a direct connection from the battery to the bikes cabling - no fuse or switch. This unsettles my electricians brain, should there be one?

 

[anotherkiwi]

On a slightly different issue, there is a direct connection from the battery to the bikes cabling - no fuse or switch. This unsettles my electricians brain, should there be one?

I have been living like that for quite a while. Only very occasionally do I see a tiny spark when plugging in the XT30. There are "no spark" XT plugs available too.

That said I am going to install a switch on the BFBattery box because my new lights are wired into the controller and a switch will allow me to turn the lights off without unplugging the battery each time.

 

[Benjahmin]

First big test passed with flying colours. The prodigal daughter's home for christmas and we went for a shortest day ride, dodging the rain drops. 17 miles and the lower powered motor prooved to be fine for the younger rider. She normally commutes around Cardif on an unpowered bike, so we took her up the hills for a blast and a big view.
Though I'd expressed doubts about this motor in comparison to my Ezee, it performs fine and the comparison is, perhaps, an unfair one, bearing in mind the cost of each. Maybe for the future, a sine wave controller might be on the cards so the motor runs quieter.

 

[Benjahmin]

So, on the christmas eve ride we got caught in some rain. Nothing too serious - by Welsh standards!
Anyway on our dry boxing day ride the bike developed an intermittant fault. (Aren't they the worst?). It's cutting out for a second or so, with no pattern. When it was playing up I got my daughter to use the throttle and that overode the fault. Also got her to use the brake whilst on throttle and that works as it should. So I'm thinking it's something on the pas circuit, wondering if some water's got in somewhere. I did notice a slight fogging in the led display so it's possible. Have to get the bike on the stand, maybe strip the connections out of the controller box. Really didn't want to have to go into that rats nest again!

 

[Deleted member 4366]

Are you sure it wasn't that she was touching the brakes? Some people ride like that - especially motorcyclists.

 

[Benjahmin]

That was my first thought too. But there's a switch only on the back brake and I explained that to her. Also it would have cut when using the throttle, if she was doing that.
I'll get it on the stand today and have a look see.

 

[Benjahmin]

Got the bike on the stand and, of course, it behaved impeccably. So went out for 14 miler with the daughter and, of course, it started playing up again, though not as bad as yesterday. I'm hoping it's one of those that will self clear, maybe as it dries out. (Well we can all dream).
Interesting observation. When out with the wife on her Big Bear, I'm normally in setting 2/5 and wait for her every mile or so. With the daughters younger legs to ride alongside, I'm in 3 to keep up and breathing heavy whilst she's apparently ambling along being all chatty. Ah the arrogance of youth

 

[Benjahmin]

Had the controller box apart today. No signs of condensation and all connections checked. Motor plug checked, pins look OK and seems fully inserted.
But the dam fault is still there. It seems that holding the throttle full open whilst still peddalling, defeats the fault. Hard to be certain though as it's so intermittant. It happens on rough or smooth road, uphill or flat. Led's don't go out, though fault duration maybe too short for this to show.
Took the bike out myself so I know that it's not the brake being touched or the throttle partially turned.
I'm stumped - any thoughts?

 

[Deleted member 4366]

If you don't get the problem with the throttle, there's nothing wrong with the battery, controller, motor, LCD or wiring. That only leaves the PAS or brakes. How's the gap between the magnet disc and the sensor? Is the magnet disc tight on the shaft? Does it touch the BB?

I just looked at your photo. I don't like that washer on the inside. There should be a gap there to stop the magnet disc from being stopped by the stationary BB.

 

[Benjahmin]

I just looked at your photo. I don't like that washer on the inside. There should be a gap there to stop the magnet disc from being stopped by the stationary BB.

That's a good point, I was a bit concerned about the rubbing potential there but hadn't thought about the disc stopping. The grip the disc has on the shaft isn't good and I did this to stop it wobbling. Next point of investigation - thanks.

 

[Deleted member 4366]

OK, so that bridges out a proportion of the windings of the shunt, so reducing the resistance, so must increase the max current - is that right? How would this affect the rest of the circuitry in the controller.
On a slightly different issue, there is a direct connection from the battery to the bikes cabling - no fuse or switch. This unsettles my electricians brain, should there be one?

Soldering 25% of the length of the shunt gives you approximately 25% more current, so 25% more torque. There's no detrimental effect on the rest of the controller because it's basically a software setting. naturally, you'll use up more battery when using the higher power, but for normal riding, you can turn the power down with the LCD power levels.

You don't need a fuse because your BMS has over-current protection already.

You don't need a switch because your controller and LCD more or less completely isolate the battery when switched off. If you were going to leave the bike unused for more than a month, it would probably be a good idea to disconnect the battery.

 

[Benjahmin]

I just looked at your photo. I don't like that washer on the inside. There should be a gap there to stop the magnet disc from being stopped by the stationary BB.[/QUOTE]
Well spotted D8veh.
The split magnet disc is great for not having to take the pedal off, but it's grip on the shaft is tenious. I've removed the washer and put a strip of rubber (roofing material) around the disc so that it covers the shaft hole and gorilla taped it in place. I put a knive through the rubber so it grips the shaft when slid on. This also prevents the disc wobbling on the shaft, which is why the washer was there in the first place.
Now out on a ride to try it.