Sector

I've only just noticed this thread, or otherwise I could have jumped in earlier. My Quando sounded like it was firing on three cylinders, particulalry at low speed. While looking for the fault I removed the handlebar unit with the three LEDs (the voltage indicator). When I did this I permanently linked the two wires that previously went to the "Pedelec" switch. so that it would always be in twistgrip mode. I also removed the installed lighting, because I prefer wiring simplicity, and anyway I like to use modern battery lights. I disconnected the wires going to the crank speed sensor and removed the speed sensor. The bike still ran, but with the same fault. From this I concluded that a good Ezee controller should work without the voltage indicator, and without the speed sensor, provided you are happy with twistgrip control. I never found out because the cost of a replacment ezee controller seemed rather high. I bougyht an Ecrayzyman controller and substituted it in place of the Ezee controller and the bike now works fine. I still don't have a voltage indicator, pedelec sensor, pedelec switch, or installed lights, but I prefer it that way.

20 inch wheels I bought a Brompton and loved the Swiss watch engineering and innovative folding method. I did a few hundred miles on it, but after the novelty wore off it was pushed to the back of the garage and never used. I never enjoyed the ride, and I think the small wheels were mostly to blame. Bromptons are a wonderful compromise between portability and rideability for those that need it, but with 16 inch wheels the ride is definately compromised. By contrast, I've done thousands of miles of happy cycling on 20 inch wheels. I currently have both 20 and 26 in wheeled E-bikes and at the present I'm tending to favour the smaller wheels. I've never used a 20 inch push-bike, but there seems to be a following for 20 inch Raleigh folding bikes. I'm currently looking for a cheap one to see if a relatively large man can actually pedal one of those and get some fun out of it.

Potholes Yes, some of the roads I use in Leicester are getting to be very pitted recently. Where the roads have been patched the surface still has ridges and hollows. A supspension seatpost takes out some of the shocks but it can be very unpleasant if you don't examine every metre of road in front of you and take avoiding action when necessary. I've been considering a Thudbuster recently, but they seem to be very expensive for what appears to be quite a simple linkage with a lump of elastomer to absorb the shocks.

It has always been a problem with folding bikes that the wheels cannot be folded. Here is an interesting proposal to get over this difficulty. duncfitz- Crossbreed folding wheel The tyres remain inflated when the wheel is folded. Lets hope that this leads the design of folding bikes away from those incredibly small wheels, which must make the bikes twitchy to ride and disater prone with even the smallest potholes.

Sprint motor Flecc, Yes that big heavy steel item would be relatively expensive. It seems to have no other support apart from the sprag clutch/bearing unit, which also has to be big, heavy and expensive. The SB arrangment probably saves weight and has cost benefits at the expense of a little more drag.

Sprint motor Flecc, No, have a look at the picture below. [ATTACH]694.vB[/ATTACH] The orbital gears engage in the black coloured ring gear. What isn't obvious from photos is that the ring gear is not fixed inside the hub. It can rotate relative to the wheel (in one direction at least). The black coloured ring gear forms the side of a shallow steel cup. You are looking into the cup in the photo. All of the black colour is this heavy steel item. The bottom of the cup is pierced at the centre and the outside race of the sprag clutch is interference fitted into this bore. There is a peg between the bore of the cup and the outside race to transfer the torque. The inside race of the sprag clutch is interference fitted onto a thin-walled steel sleeve, visible in the photo. The sleeve extends out of the far side of the sprag clutch and is rigidly attached to the wheel. There is another bearing inside the steel sleeve. The stationary axle passes through the bore of this bearing so the wheel and sleeve and inner race of the sprag clutch can turn freely on the axle. So, in the particular motor I've taken apart, the sprag clutch is between the orbital gears and the wheel. I've just checked and I believe it is possible to feel more drag on the Quando than the Chopper just by turning the wheels by hand. I've tried spinning the wheels by hand and recording the time to stop. Not a very exact measure of drag I suppose, but the best I could get from the Quando with a firm push on the spokes was 19 seconds, whereas the Chopper's Sprint motor manged 59 seconds. Peter

Sprint motor Flecc, For interest, when I stripped down the "Sprint" motor on my Chopper I noticed that the freewheel was between the gears and the wheel. I must try to do some freewheel comparisons between the Chopper and the Bafang-motored Quando. Peter

Good idea This is an initiative of which I definately approve. I will try to support with suitable photos.

Antique radio gear Mussels I now have a picture in my mind of you carrying a load of battleship-grade radio equipment and several big black Avos. Mussels or Muscles? Torrent99 Is Birketts really still operating? It's worth a trip to Lincoln to have a dose of nostalgia. The near-equivalent in Leicester was called Eley Electronics and closed years ago. Marvellous shop in its heyday, and a nice distance for a bike ride. I can't remember ever seeing another Avometer 2001 like mine. I've just had a look around the web for Avometers and found a site where they are listed like museum exhibits. Maybe it will be worth something one day. Pete

Early test results I'm still short of time to do some proper testing, but I managed to lash together a 20 ohm load from wirewound resistors and the results are as follows. This is using a NiMh 36 volt battery as the power source. Maplin Meter/ Old digital Avo Reading 39.6v / 39.9v 1.91A / 2.0A (+/- 0.1) 76w 71va pf 1 0.00 kWh (I didn't run it long enough to get a reading) When I pressed the Hz button it displayed "dC" These tests wer hampered by the fact that the Avo would only work on the 10 amp range for current so the Avo current reading could be out by 5%. Also the Avo voltage and current readings couldn't be taken at the same time. Note that the "live" must be used as the postive connection, otherwise the voltage readings are about 3 volts lower than they should be. This is evidence of diodes in circuit I suppose. I think the Maplins meter should be adequate for the first job I have in mind: comparative testing of my Ezee batteries to find out which has most capacity left. Yes, Rog, I agree that there is no reason at all why the L61AQ 250vAC power monitoring device should work on DC. I feel a little screwy using it like this but the guy who first tried out the mod was in a different league for lateral thinking. Now I've just got to think of an automatic way to disconnect the battery when the voltage gets low (31.5v?), then I can start battery testing. Any ideas anyone? Pete

I'm with experimentalists Well, I've bought a Maplins meter and done the conversion. I've not had time to test it on current yet, but I can confirm that it does say DC when you put a DC voltage across the wires. I understand that its not for everyone, but I love this kind of project. Personally I'd rather have this to play with than half a tank of petrol for the car, which is what the money might otherwise buy. Thirty years ago I used to be a radio ham, which when I think about it was quite expensive and totally without practical benefit. Great fun at the time though. The best part was buying real ex-services gear and making it work. Beautiful silver plated coils, glass encased vacuum variable capacitors, and big transmitting valves. Marvellous. Pete

Maplins Meter Torrent99, Thanks for letting me know about the posibilities with the Maplin power meter. Are you referring to the Maplin L61AQ item? Plug-In Mains Power and Energy Monitor > Maplin I might just have to point the bike towards Maplins tomorrow. Looks like its going to be a nice day for a ride. I managed to find the following on Endless Sphere: Endless-sphere.com • View topic - Dewalt 36V (inside the charger) Are there any other pages I ought to look at before I start modding? Pete

Re-celling Bert, As far as I'm aware it is not really possible to re-cell a Lithium Ion battery. Each cell has an electronic circuit called a battery managment system connected to it, actually inside the battery casing. The whole thing is just too complex to replace as a do-it-yourself project. In contrast the older NiMh batteries are electrically very simple. The battery box just contains a lot of individual NiMh cells, with one thermistor that is used to monitor temperature during charging. NiMh cells call still be bought, although it might be difficult to obtain cells suitable for the high rate of discharge. The cells should have connecting tags already attached if possible, otherwise there will be the job of soldering connections to each cell, which might destroy some cells. Anyway there are accounts on the web of successful re-celling of NiMh batteries. The risks to life and limb come from the huge electrical current that these cells can deliver if you get the connections wrong. It might be possible to use an Ezee Lithium Ion battery case to house NiMh cells, but I've not heard of this being done. There would be the problem that the Lithium Ion charger would not be suitable for charging the NiMh battery, so an expensive new charger would also be needed. I've not really looked into the economics of re-celling, but I suspect that it would not save much money. It used to look attractive for Ezee batteries when new Phylion Lithium Ion batteries were failing prematurely, and new NiMh batteries were almost impossible to obtain. My vague interest now in re-celling would really be to obtain something that can't be bought off the shelf. It would, for example, be good to have a lightweight get-you-home battery, and various attempts have been made at this idea. Alternatively there is a new type of cell that first appeared in DeWalt power tools that seems to offer possibilites. Try Googleing "A123 battery" if you have half an hour to spare. What we really need now is for car manufacturers to really have a go at developing electric cars. Having lived with electric bikes for a few years I suspect that current ideas for cars are badly flawed and doomed to failure in current circumstances. However there should at least be rapid development of cell technology and that would be useful for electric bikes. Pete

Risks I've been thinking through the risks associated with taking up to 20 amps out through the fuseholder. It seems to me that the biggest risk I'm running is that there will be a bad connection where I've shown the red spark in the picture. [ATTACH]673.vB[/ATTACH] There is a risk that a spark at this point would melt the solder, and the wire might solder itself to the fixed contact in the fuseholder. I've got an idea to improve the situation but in the meantime I've only using the adapter with my oldest battery. That battery is on its last legs anyway. I'm considering re-celling it, and it would be no bother to replace the fuseholder at the same time.

Flecc Flecc, Thanks for the offer. I'll send a PM. Sector (Pete)