@ Coops

 

I think we are still on a similar vein Coops. Although that Puma motor, although excellent, (this question might be stupid..) but wouldnt it be over the the 250W rule by basic design?

 

John

@ Ian and Flecc

 

What I was thinking was to have 20 x 11Ah tagged cells in series attached to a piece of ply, by cable ties or something in 2 rows of 10, 1 above the other with the wiring for power and for charging coming out of the waterproof bag which would be repeated on the other side of the bike. With straps they would tegether make a pannier that could be secured to the bottom of the side of the rack with velcro.

 

The power and charging cables would link in parrallel for connecting to the bike or the charger.

 

Possible or am I just showing my ignorance of the subject?

 

Thanks all

 

John

I was thinking the same Stuart, the threads do seem to overlap.

 

Ian, I wondered what John wanted with the D cell holders!

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Edited June 17, 200718 yr by flecc

That parallel arrangement is ok for usage, but not for charging John, packs should never be charged in parallel. You'd need to either charge one after the other or have two chargers.

 

Do you really need that sort of capacity though, it's a lot of weight to lug around?

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Flecc

 

Just thinking hypothetically at the mo. Each of those D cells weighs 166gms, so 20 would be 3.3Kg, 30 is 4.9Kg, 40 would be 6.6Kg, and 60 is a wopping 9.8Kg!!! (for ref, I carry the charger everywhere with me on my Twist, and I dont want to do that).

 

If I had a 36V motor like the puma (if theres a 250W version or one that can be adapted to 250W), then I would need at least 30 cells in series (or 60 in parrallel) and I would get power and range (esp from the 60).

John, your rows of 10 cells would be over 2' long and would be difficult to accommodate as panniers, 4 rows of 5 would be more practical. If connecting the two banks of cells in parallel it may be advisable to use blocking diodes in series with each bank to prevent cross currents flowing between them, Schottky barrier diodes are best as they have a low forward voltage drop.

As Flecc has said, charging the two banks in parallel is not a good idea as there is no way to ensure each bank is getting it's correct share of the current.

I thought perhaps that John meant side by side cell mounting, wiring top to bottom between each, as that would shorten the row to almost one half. That means link wires on tagged cells or rapid soldering onto normal cells of course.

 

If that's what you were thinking John, direct soldering onto the cells has to be done very quickly to avoid damage and I wouldn't normally recommend it even though I do it myself.

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Ian

 

I think I was thinking of connecting them the other way, which would make each bank of 5 roughly 6 inches wide? I suppose that ther are numerous ways of connecting them, but I think that the less wire the better..

 

EDIT Flecc beat me to it Yes that is what I was originally thinking, but I can see Ians point. Also I was only thinking of getting tagged cells.

 

John

That's fine John, but I don't know of tagged cells at that very good price of £8.50 for two. Those I've seen are usually about £10 each cell for 10 Ah, so would be very expensive. Battery holders like the ones Ian showed would be good normally, but the quality of those stocked by Maplin isn't good enough for high currents since the wire contacts are poorly made.

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Although that Puma motor' date=' although excellent, (this question might be stupid..) but wouldnt it be over the the 250W rule by basic design?[/quote']

 

A very sensible & law-abiding question John

 

The short answer, I think, is no, not illegal by basic design, but possibly illegal depending on implementation :

 

I hadn't thought much to be honest, since the 200W UK/250W EU "rule" is very hard to interpret and almost impossible to either calculate or enforce: an "average" 250W could be quite easily managed I think, and should (in theory) give a good torque for hills so long as the top speed is kept to the 15mph legal limit and the current limit can be set to say 13-15A @ 36V (that bit I'm not sure how to do - needs correct controller electronics) need to limit the peak power output to around 5-600W and bring the "average" in line with ~250W (with occasional pedalling/freewheeling downhill should do it) - that would be no more power or speed than other bikes such as the Sprint, and I think certainly within the spirit of the law, and if it could be calculated, most likely to the letter too. The image I've seen show its "stamped" as a "250W" (rated/continuous power) motor too.

 

Obviously you could run at higher voltage &/or current, which would give higher speed &/or torque, but would also be over the legal limit for speed and/or probably "average power" too! Maybe we could fit our own limiter, for off-road?

 

Stuart.

So as I understand it, a bank of 5 x 4 batteries ( as each battery is 33mm x 59mm) would be roughly 8" x 6" at a depth of 1 cell, and wieghs 3.3Kg. With wiring and connectors and shielding (and maybe diodes) should come in at 3.5Kg max.

 

PS - I just found some cheap A4 plastic box files from Tescos (3 for a pound) that would be quite sturdy, and easy to manipulate....

Sounds fine John, but allow a touch more on length for cell bindings to hold everything still, say half inch on a row in total. It's best not to have them rattling around.

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Flecc - is its really as easy as that? The magic is beginning to look like science

Coops - This project of yours is contagious...

 

Feedback please, what do you all think? (See what you've started flecc?! )

 

Stuart.

 

Yes, I thought the same, I really do seem to have kicked off a movement. Wouldn't it be good if an enterprising frame maker put on the market a frame with rear of seat tube space for a battery and a choice of forks, standard or wide in both rigid and sprung formats.

 

That would be the answer to constructors dreams, buck up sales of kit motors and maybe goad the e-bike suppliers into listening to customers more.

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Coops - This project of yours is contagious...

 

Hehehe! Its infectious, definitely! But its not mine, nor a project - yet - John! More just a "radical" Torq radical "idea"! And the idea/concept itself is flecc's: the "Torq radical principle" if you like :-) (correct that if its wrong flecc! :-))

 

Yes' date=' I thought the same, I really do seem to have kicked off a movement. Wouldn't it be good if an enterprising frame maker put on the market a frame with rear of seat tube space for a battery and a choice of forks, standard or wide in both rigid and sprung formats.[/quote']

 

Yes, it would be great for skilled workers and "tinkerers" alike - I had the same idea about the frames - I guess most companies would prefer to keep mods & improvements "in-house" if you like, but if the parts you describe were available separately, great! Pedelecs brand, what do you think, eh?!

 

I appreciate that it could be seen as an unnecessary extra expense just to modify an already "premium" price bike, shall we say, but for the cost of the mod, if I've got it right, you might have nearly all the parts to kit out another bike - except for a battery & fixture, but I've an idea for that too:

 

Personally, I'd quite like to build a sort of short-range "stealth" bike (call it an urban shopper ) which could, but not necessarily, combine aspects of both the Q & T mods i.e. find a suitable 20-24" bike to fit the replaced motor to, either in front forks (if they are wide & strong enough, and accepting the implications of front mounting - could use suspension, if wanted) or rear-mount like the T bike, and an "experimental" low weight, capacity & removeable lithium battery of, say, around 1kg for every ~100Wh or so, ~8miles at 15mph: handy for those short shopping trips you don't want to get the car (or the commuting bike ) out for, good low load carrying capacity for carrying it home & with mini battery removed while shopping, rather inconspicuous & "ordinary/boring" looking so good for security too :-).

 

EDIT: These are all just ideas, so feel free to add or criticise, since I don't have the knowhow to plan nor the skill to undertake any major project like this, so if it was ever going to happen, it could only be by a sort of collaboration I guess :-).

 

Good design principles should always be learned from & imitated, eh flecc?! I openly say all these ideas are inspired by & derived from your projects and your experiences so helpfully posted here - hope you don't mind; I just hope any projects which follow on from yours do them justice, and I'm definitely willing to improve or scrap any ideas for new ones, based on advice!

 

I'd have to rename the "urban shopper" though... any suggestions? Must be converse e.g. the "marathon racer" (clearly does neither, race nor marathon distances!)

 

P.S. Sorry John, your threads sort of mutating a bit! If the ideas seem feasible and are not inadvisable, then I could start a new thread on this new modding "movement", or at least the spin-off (i.e. the "marathon racer") :-).

 

Stuart.

Edited June 17, 200718 yr by coops

Ian

 

I think I was thinking of connecting them the other way, which would make each bank of 5 roughly 6 inches wide?

 

I've seen too many Ezee batteries in which the cells are end to end, I was forgeting there are other ways.

I'd have to rename the "urban shopper" though... any suggestions?

Ask Leonardo to come up with a snazzy Italian name

And the idea/concept itself is flecc's: but I've an idea for that too:

 

Personally, I'd quite like to build a sort of short-range "stealth" bike (call it an urban shopper ) which could, but not necessarily, combine aspects of both the Q & T mods i.e. find a suitable 20-24" bike to fit the replaced motor to,

 

Stuart.

 

At the time of conceiving the Q bike, I looked around for 22" rims, since there was the odd Chinese e-bike marketed with those, but none available, and tyres for that size were too restricted. It was possible to squeeze the 22" into the Quando II frame and that would have been a similar compromise, giving a touch more speed at the cost of a little of that immense hill climb capability. As it turned out I'm happy I didn't succeed, since the Quando spins up to 18 or more mph on a fully charged battery, plenty fast enough for an all purpose bike.

 

However, the Quando motor would be great in a 24" wheel, easily climbing as well as most mid power e-bikes and with 20 mph as well. Since most Quandos sold at around £745 at most and they've been out for well over three years, there are second hand ones about, and one member, Cocoabeans, bought one recently. Also, Team Hybrid had some Quando motors in stock a few months back and may still have some.

.

Ask Leonardo to come up with a snazzy Italian name

 

How about this Italian name for it: "Whatamistakatomaka"

 

(With apologies to the cast of 'allo 'allo) (and Stuart!)

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Edited June 17, 200718 yr by flecc

However' date=' the Quando motor would be great in a 24" wheel, easily climbing as well as most mid power e-bikes and with 20 mph as well. Since most Quandos sold at around £745 at most and they've been out for well over three years, there are second hand ones about[/quote']

 

I've asked the same question on the T-bike thread flecc, so please excuse the repetition, (and the engineering ignorance ) but which would you say is less technically difficult: adding a freewheel to the already rear-mounted Quando motor, or moving the Torq motor to the rear and adding a freewheel to that, and so which is easier to achieve in that respect: the Q freewheel motor, or rear-fitted freewheel T motor in, say, a suitable 20-24" frame?

 

How about this Italian name for it: "Whatamistakatomaka"

 

Hehehe! I like it! (I think I saw that, the other day!) (but what are you trying to say? I hope that's a (at least partially) "converse" name! )

 

P.S. Might have to lengthen the frame/downtube - just to fit the name on!

Edited June 17, 200718 yr by coops

bespoke frame builders

 

Just been doing a bit of surfing, and it seems that there are indeed a number of bespoke frame builders that will build it whatever way you want for reasonable prices too.

 

The first I saw was this and this

 

So if this 'project' for an efficient ebike, that is designed not to lose any rider input but remain relatively comfortable (sorry Coops those sus-forks have to go ) then one could design the frame based on expert advice perhaps?

 

John

sorry Coops those sus-forks have to go

 

That's ok John, that bit was just a suggested "leisure/comfort/utility" spin-off idea anyway... .

The Torq motor to the rear is more difficult in some ways, since it means turning a spigot with steps for the DMR hub end and the motor end plate to ensure absolute centering when attaching. Also grinding off the steel side plate end is a dangerous operation and must be accurately done so the motor bearing is brought into the motor just enough, a fraction too far and you'll need a new motor.

 

Using an angle grinder to that degree of accuracy is tricky, and I did it by using the Torq as a capstan lathe, the bike upside down with the motor running flat out while I ground against it with the angle grinder. It was the stuff of manufacturer's nightmares, but it gave me an accurately flat enough face to attach to. The DMR hub is a whopping £59 odd, and you need to be able to do tricky things with a lathe, both for adapting the hub and to make the support sleeve for the weak motor spindle. There's the short spindle problem too.

 

Using the Quando motor means getting someone to make the thread adaptor. I used Highpath Engineering as they are cycle stuff specialists. They have to buy a BMX hub as a template and work from that. Once made, you'll still need a lathe and have to do a delicate bit of paring 2 mm from the inner internal thread and 2 mm from the outer external thread for it all to assemble. The alloy thread adaptor is a job to "run in" on the steel hub thread as well, and you could get an irrevocable lock up part way on when assembling. The cost will be about £80 including the BMX hub charged to you. You still need to make the spindle support adaptor but at least the spindle is a bit longer on the Quando version.

 

As you will have gathered, neither is to be attempted lightheartedly, and if you don't have a lot of engineering experience of some relevance, probably not advisable. Definitely not for the average DIYer.

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Edited June 17, 200718 yr by flecc

I think I'd struggle to mod an existing bike, John is your idea to really design & build an ebike from start to finish? do you really think that's do-able?! (I'm open to persuasion, & no harm brainstorming )

 

Which type of motor do you think would be best/easiest/most economical i.e. best "bang for buck"? (hopefully no bangs though... )? I guess hub motors are simplest?

 

Stuart.