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
.

[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]

Originally Posted by 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)?

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]

Originally Posted by 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.
.

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]

Originally Posted by JamesC

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]

Originally Posted by BertYardbrush

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:

sensor.jpg

[BertYardbrush]

Originally Posted by flecc

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:

Attachment 390

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