Quando queries

[BertYardbrush]

I've got a Quando 1. That's the one with rear suspension - not really designed for shorthouses like me (29 inside leg). The thing is, I can pedal away fine up to around 9mph above which speed my little legs can't keep up so the biking experience is not too brilliant. I don't have the ability to turn it into a Q bike but I feel that all it needs is one higher gear for pedalling at faster speed. Is there any way I could fit a double chainwheel and derailleur mechanism to get the extra gear and what size gearing of chainwheels would you suggest?
Also the switch between pedelec and electric modes does not work - it's always in electric, any suggestions?

 

[flecc]

I investigated the idea of a double chainwheel, but it's not really practical to fit a changer mechanism on the seat tube due to the battery closeness. The other problem is that a big step up is needed. Even a monster 60 tooth would leave it a bit lower geared than the Q bike, though you'd find it much better. However, that step up means a big change in chain length so you'd need a very long arm jockey wheel or better, a double arm derailleur rear mechanism locked into one side to side setting. That in turn means making a provision to mount the derailleur rear mechanism, so it all gets a bit complicated.

One possibility is the Schlumpf Speed Drive. This replaces the bottom bracket internals and if used with a 40 tooth chainring, down from the standard 48 tooth, it's 165% change would give you gears of 57" and 94". The 57" would help a lot with very steep hill climbing and the 94" is a bit higher than my Q bike top, so you'd be able to pedal at fair speeds.

This all sounds great, but there are downsides. It's tricky to fit, best done by someone who knows these drives. These drives are not very efficient, being epicyclic, so they add transmission drag, and they are very expensive.

However, have a look at the link below, second item down:

Schlumpf Speed Drive
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[JohnInStockie]

What an amazing device Flecc...

John

 

[flecc]

Yes, it is clever John, the brainchild on one Austrian man, Florian Schlumpf.

It's rather a pity that they are so expensive since they could have a much wider market, although the drag is noticeable. One sector that uses them is on recumbents, where a triple chainring is an awkward thing between the lower legs.
.

 

[BertYardbrush]

Thanks, Flecc, that's more than I would want to invest.
My other point was the switch from pedelec to electric mode doesn't work. It's always on electric. Any thoughts? Should I consult my local bike shop,(JE James)?

 

[JamesC]

Thanks, Flecc, that's more than I would want to invest.
My other point was the switch from pedelec to electric mode doesn't work. It's always on electric. Any thoughts? Should I consult my local bike shop,(JE James)?

If you speak to Lloyd at 50cycles - they might have an old ezee battery indicator / pedelec switch in their "bits and pieces".

Unfortunately it is not a "plugin" item, so there would be some soldering or cable joining to put it into the existing wiring.

James

 

[Mussels]

Yes, it is clever John, the brainchild on one Austrian man, Florian Schlumpf.

It's rather a pity that they are so expensive since they could have a much wider market, although the drag is noticeable. One sector that uses them is on recumbents, where a triple chainring is an awkward thing between the lower legs.
.

I'd have one if they were cheaper to improve the ratios available for hills, I guess the direct drive gear is almost 100% effcient.

 

[BertYardbrush]

If you speak to Lloyd at 50cycles - they might have an old ezee battery indicator / pedelec switch



James

Thanks for the suggestion James. It occurs to me that it might be the other end -the pedal sensor. Where exactly is the pedal sensor on a Quando? I can trace the cables to the motor, battery, brakes, pedelec switch but can't see anything down by the chain wheel. Maybe I've got an old machine that doesn't have the sensor. That's the problem with buying secondhand and having a manual thats somewhat opaque.
(Are these technical queries, am I in the right part of the forum?)

 

[flecc]

Thanks for the suggestion James. It occurs to me that it might be the other end -the pedal sensor. Where exactly is the pedal sensor on a Quando? I can trace the cables to the motor, battery, brakes, pedelec switch but can't see anything down by the chain wheel. Maybe I've got an old machine that doesn't have the sensor. That's the problem with buying secondhand and having a manual thats somewhat opaque.
(Are these technical queries, am I in the right part of the forum?)

No, this is the right forum, the technical one being for permanent items.

The Quando sensor assembly is a plastic disc with a ring of magnets inserted thats on the pedal shaft just behind the chainwheel. You'll see it from underneath the bottom bracket. Against the disc is a bracket with a tiny Hall sensor which just clears the disc, a lead from the sensor going up to the controller. Heres a picture of the sensor and magnet disc:

 

[BertYardbrush]

No, this is the right forum, the technical one being for permanent items.

The Quando sensor assembly is a plastic disc with a ring of magnets inserted thats on the pedal shaft just behind the chainwheel. You'll see it from underneath the bottom bracket. Against the disc is a bracket with a tiny Hall sensor which just clears the disc, a lead from the sensor going up to the controller. Heres a picture of the sensor and magnet disc:

View attachment 390

No there's nothing like that on my bike. Seems I've got a bike without pedelec.

 

[flecc]

No there's nothing like that on my bike. Seems I've got a bike without pedelec.

Either someone has removed the parts or it's a very early one. Can you tell me if the freewheel at the rear has 18 teeth or 14 teeth?
.

 

[BertYardbrush]

It's got 18 teeth

 

[flecc]

It's got 18 teeth

I thought so. That's the very earliest Quando which had an 18 tooth freewheel with the 48 tooth chainwheel, giving a 54" gear. That was very low geared, making it difficult to pedal with the motor except at very low speeds.

Later models were changed to have a 14 tooth BMX freewheel, raising the gear to nearly 70" and making it possible to pedal the bike to much higher speeds, though still not easy to spin to it's maximum motor driven speed.

I don't know if the early one also had a BMX freewheel thread, but if it does you could have yours changed to the 14 tooth. It's not an easy job though since it means disconnecting the 8 motor cables and rejoining them, few cycles dealers prepared to do that, though a few of the Powabyke approved service centre dealers might.
.

 

[BertYardbrush]

I thought so. That's the very earliest Quando which had an 18 tooth freewheel with the 48 tooth chainwheel, giving a 54" gear. That was very low geared, making it difficult to pedal with the motor except at very low speeds.

Later models were changed to have a 14 tooth BMX freewheel, raising the gear to nearly 70" and making it possible to pedal the bike to much higher speeds, though still not easy to spin to it's maximum motor driven speed.

I don't know if the early one also had a BMX freewheel thread, but if it does you could have yours changed to the 14 tooth. It's not an easy job though since it means disconnecting the 8 motor cables and rejoining them, few cycles dealers prepared to do that, though a few of the Powabyke approved service centre dealers might.
.

That's very helpful, I'm in North Derbyshire, so that's either Rotherham or Derby. I'll let you know how I get on.

 

[flecc]

Thanks, I'd be interested to find out if you have any luck with that.
.

 

[BertYardbrush]

I don't know if the early one also had a BMX freewheel thread, but if it does you could have yours changed to the 14 tooth. It's not an easy job though since it means disconnecting the 8 motor cables and rejoining them, few cycles dealers prepared to do that, though a few of the Powabyke approved service centre dealers might.
.

Flecc,
How about cutting the cable to the motor and rejoining it afterwards with push fit connectors into a block, then tape it all up with waterproof tape? It would then be relatively simple to change the freewheel. I've sent an email to ezee to see if they know the 18T thread type.

 

[flecc]

Flecc,
How about cutting the cable to the motor and rejoining it afterwards with push fit connectors into a block, then tape it all up with waterproof tape? It would then be relatively simple to change the freewheel. I've sent an email to ezee to see if they know the 18T thread type.

Later models have a five way plastic connector for the 5 Hall sensor leads, (a DIN inline plug and socket would be ok, but Maplins will have something), and three bullet connectors for the 3 power phase leads, and those are tucked away under the battery/bottom bracket/controller area with a heavy layer of insulation over them. With any luck yours will have the same, but you'll have to cut away the insulation to find out.

If it hasn't, cutting is fine if you use a five way light and reliable connector for those thin Hall wires, but for the three thick power wires, you need something that is up to handling current of up to 20 amps. Those car type bullet connectors are fine for the job, and you'll probably find some in car accessory shops that you can crimp or solder on.
.

 

[BertYardbrush]

Later models have a five way plastic connector for the 5 Hall sensor leads, ... and three bullet connectors for the 3 power phase leads, and those are tucked away under the battery/bottom bracket/controller area with a heavy layer of insulation over them.

It does have the connectors as you describe and is insulated with heatshrink. All has gone well apart from the fact that the thread on the old Quando is NOT BMX. (There are 2 sizes of BMX, the 14T being smaller than 16+, the old Quando is neither of these). It would seem that the best I can hope for is a 16T freewheel. Unfortunately I still do not know the thread size, does anyone have any enlightenment on what it might be? It is very close to a BMX, it will take it for half a turn before going tight.