My local ALDI recently had an offer for pushbikes with SRAM 7-speed gear hub and hub dynamo.

 

The price? A whopping £210 or probably half the price of the spares bought seperately.

Flecc

 

what would happen with the motor if you fit lower teeth on the rear? would it assist still at the higher speed. I'm assuming it would. Wonder what happens if you go even smaller that 18

 

Paul

 

Yes it will assist at higher speeds Paul, but eventually the motor power would be insufficient to cope at all, and the range would drop a lot since the bike would spend much of it's time in the highest power point of the software provision.

 

I've mentioned in here a few times the Lafree Twist Panasonic bikes that some have added the Xtracycle extension to, a couple with SRAM DualDrives. With that derailleur combination the smallest rear sprocket will be about 11 teeth, and the hub gear part of the DualDrive reduces that when in it's top gear to an effective 8 tooth.

 

On the new Panasonic units, in theory that would provide power assist at the maximum level up to about 27 mph, with the assist phasing down from there until ending at nearly 43 mph, but of course the power available could not do that on the flat, although one could have some wicked fun down quite gentle slopes and astonish anyone seeing it.

 

Realistically I think a 16 tooth would be about the limit, and you might find that gearing would leave the bike a bit weak into headwinds and on slight slopes in top gear, necessitating more gear changing than usual. Consumption would rise again too.

.

My local ALDI recently had an offer for pushbikes with SRAM 7-speed gear hub and hub dynamo.

 

The price? A whopping £210 or probably half the price of the spares bought seperately.

 

Isn't this so often the case Erik. The complete SRAM hub I bought for it's inner was on offer at much less that the normal price for the inner only. It's a mad world, but never boring.

.

Only until you change the rear sprocket though Hal. The 7 or 8 gears go so low that these bikes easily pull higher speeds while retaining low enough gearing for steep hills. That's especially true now with the high power mode availability.

 

An 18 tooth sprocket reduces the cadence to 53 at the legal speed, or conversely, at that moderate 65 cadence you'd get 19 mph, probably about ideal for most territories.

 

Bear in mind that I hit 27 mph on a slight downslope with the standard gearing for a short stretch, though my legs were probably invisible, and at the generally accepted physiological optimum of a 90 cadence, the standard gearing gives 21.4 mph.

 

Using an 18 tooth sprocket will increase the assist range as well of course, delaying the phase down of power. The latter is the biggest difference that you'll notice, the power assist declining with speed of pedalling.

.

 

I was hoping to get away without the gearing mod but I will just have to see how I get on. Even with the standard gearing I should still be able to go 17mph without legs whisking (as you were able to go 27mph). Having read your review again I think realistically 19/20 teeth will be the best compromise (I do want to do the majority of the work myself).

 

One question. At the moment I have a charger at work but I plan not to do the same with the agattu. I know that I should charge every time I use it but the charger is expensive and would go some way towards replacing the battery some time after year 2. I will go 20.24 miles a day - does this make economic sense? The arrival of the (cheaper?) portable charger may change this but it would be great not to have to carry the battery into work. It would certainly avoid having to explain what it is every five minutes!

 

All this talk and I will start getting excited about the delivery!

I wouldn't buy a second charger Hal, I'd just ride the 20 plus miles each day. The higher the quality of the battery and the better it's management, the less important the charge frequency becomes, the software protecting the battery well. Even at a high rate of drain on these bikes your journey is less than two thirds range, and on average nearer a half, so no problems with the 20 miles.

 

If you want to do much of the work yourself you may not need to change the sprocket at all, the bike very free running from 16 mph up, much more so then the Torq, so you'd enjoy the pedalling as much as I did. After a couple of hundred miles they become even more free running with everything bedded in, and that's when it's worth having no-power test rides on Torq and Kalkhoff. The difference from the hub-motor bike will surprise you.

.

Yes it will assist at higher speeds Paul, but eventually the motor power would be insufficient to cope at all, and the range would drop a lot since the bike would spend much of it's time in the highest power point of the software provision.

 

I've mentioned in here a few times the Lafree Twist Panasonic bikes that some have added the Xtracycle extension to, a couple with SRAM DualDrives. With that derailleur combination the smallest rear sprocket will be about 11 teeth, and the hub gear part of the DualDrive reduces that when in it's top gear to an effective 8 tooth.

 

On the new Panasonic units, in theory that would provide power assist at the maximum level up to about 27 mph, with the assist phasing down from there until ending at nearly 43 mph, but of course the power available could not do that on the flat, although one could have some wicked fun down quite gentle slopes and astonish anyone seeing it.

 

Realistically I think a 16 tooth would be about the limit, and you might find that gearing would leave the bike a bit weak into headwinds and on slight slopes in top gear, necessitating more gear changing than usual. Consumption would rise again too.

.

 

Thanks for that flecc its very interesting. My current fitness level means i am yet to get the top gear on the torq to any real sustained cadence unless going down hill. would 18 teeth give me a similar gear set up to the torq. Ideally i'd want something slightly lower but not too much

 

edit: forgot to ask - would you need to fit a shorter chain?

 

cheers

Paul

I wouldn't buy a second charger Hal, I'd just ride the 20 plus miles each day. The higher the quality of the battery and the better it's management, the less important the charge frequency becomes, the software protecting the battery well. Even at a high rate of drain on these bikes your journey is less than two thirds range, and on average nearer a half, so no problems with the 20 miles.

 

.

 

I am glad you agree with me about that as it is a total pain unplugging and carrying a battery together with pannier bags etc.

 

Yes I am looking forward to not having a hub motor causing all that drag. The Torq motor is very noticeable when you first ride it after a normal bicycle. The Tongxin motor is pretty good and probably the best on the market but for me the drag will always ruin what would be "perfection" in an electric bike. I seem to be a convert without ever riding a 'panasonic' pedelec. I still find riding the Torq a hoot so I will wait and see what I think about the agattu

 

Once again thanks for the advice.

 

Hal

Pleasure Hal. You'll like the Kalkhoff just as much but in a different way, as it's also enjoyable, but relaxing in the way a Torq isn't.

.

Not being very technical, I think cadence is like rpm. But from memory Flecc, I think you recommended a change from the 22 tooth to 19 as the best compromise for a bit more speed at slight reduction of range? I forgot to ask 50C to do this so they'll love that...

Now that we are on to the subject of defying Panasonics intentions with this motor, wouldn't it be possible to forge the signal of "rider input" to make the motor give more than 130% of rider input?

 

Sensor value manipulation is the way the cheaper tuning boxes for turbo diesel cars work.

Not being very technical, I think cadence is like rpm. But from memory Flecc, I think you recommended a change from the 22 tooth to 19 as the best compromise for a bit more speed at slight reduction of range? I forgot to ask 50C to do this so they'll love that...

 

Yes, cadence is just the name for pedalling rpm.

 

Either 18 or 19 tooth is ok for the Agattu rear sprocket, depending on territory, biased to hilly choose 19 tooth, or not too hilly the 18 tooth, but it's not critical.

 

I've no idea whether 50cycles will do this, since it alters the bike into the illegal area for assist speed. They wouldn't do it on the Torq for the same reason. It's an easy job though, or any cycle dealer can do it for you as the wheel is completely normal bike stuff.

.

Now that we are on to the subject of defying Panasonics intentions with this motor, wouldn't it be possible to forge the signal of "rider input" to make the motor give more than 130% of rider input?

 

Sensor value manipulation is the way the cheaper tuning boxes for turbo diesel cars work.

 

No.

 

It's integrated into the mainboard in computer fashion, using a dedicated processor chip, no adjustments. There is also a 150% version in a different unit:

 

http://myweb.tiscali.co.uk/flecc/images/maincircuit.jpg

Edited March 23, 200818 yr by flecc

[quote=flecc;22450

 

I've no idea whether 50cycles will do this, since it alters the bike into the illegal area for assist speed.

 

Interesting that they had one with a modded rear sprocket for Stokepa31 to try then;) . Thanks for the repeated advice though.

In that case fine Simon, I was just anticipating the possible objection. They'd possibly taken the cue from my review suggestion, but the bike that Paul tried might have been Scott's.

.

Would you need any specialist tools, ie beyond a set of spanners?

I think that given he new legislation, the main push now has to be on the weight and balance of a bike along with range at the legal limit. The one thing that also really appealed to me about the kalkoff's is that they would be easy to look after. No bike shop in coventry would touch my Torq and so the thought of being able to easily fix punctures, change spokes and other essential maintenance by just pooping off the wheel really appeals.

 

I guess what I am saying is tht in terms of being practical, the hub motor must surely die a death.

 

P

 

You can easily "poop" off the rear motor inserted wheel on the Wisper SE to fix a puncture Not all are the same.

Regards

Mandy

You can easily "poop" off the rear motor

------------------------------------------------------------------------

 

can you explain what "poop" or "pooping" off means in bike terms please as "poop" and "pooping" means something not to do with bikes round there ere parts...

Would you need any specialist tools, ie beyond a set of spanners?

 

No, just the spanners Simon, you'll instantly see how to do it when the wheel is out.

.

I dont think the bike I tried was for public consumption so to speak. I did ask Lloyd if 50c would be able to offer the mod and he said they were looking into it. Would you need to shorten the chain too???

I dont think the bike I tried was for public consumption so to speak. I did ask Lloyd if 50c would be able to offer the mod and he said they were looking into it. Would you need to shorten the chain too???

 

Hi stokepa31,

 

I removed a couple of links on my Agattu when I went to an 18T sprocket. Now my fitness is better and I have lost a few kilos I can average about 15.5 mph and have reached a top speed of 36.8mph (downhill of course). I have now done a little over 650 miles since I got it at the end of December, but now I am using it to commute to work I expect this to rise rapidly. I have been very impressed so far with my bike.

No.

 

It's integrated into the mainboard in computer fashion, using a dedicated processor chip, no adjustments. There is also a 150% version in a different unit:

 

http://myweb.tiscali.co.uk/flecc/images/maincircuit.jpg

 

http://myweb.tiscali.co.uk/flecc/images/pedelecdrumstrip.jpg

 

Amplifying the signal from the coil assembly would fool the controller to think one was pushing harder on the pedals.

 

That is what the do in the tuning boxes for cars. 10 cent tuning, a resistor replacing the fuel temperature sensor makes the ECU inject more fuel.

 

For common rail systems, the rail pressure sensor signal is forged lower and thereby raised. Harley Davidson and other motorcycles have ignition systems that retard the ignition at higher RPM's for noise reasons. Clever little add-on boxes give the advance back.

 

You also break into the chain speed hall sensor circuit and add an "electronic gearbox" that lowerered the sensed rotation speed.

 

Amplifying the signal from the coil assembly would fool the controller to think one was pushing harder on the pedals.

 

You also break into the chain speed hall sensor circuit and add an "electronic gearbox" that lowerered the sensed rotation speed.

 

That's not how it works Erik, it's a differential signal and not an amplitude signal that reads the pedal effort, hence the coil centre tap.

 

And there's no point in altering the Hall sensor circuit to read rotation speed differently when a simple change of rear sprocket on the bike or change of motor sprocket has the same effect.

 

Of course the differential signal from the pedelec sensor could be differentially amplified in theory, but in practice the signals are so minutely different and the reading so sensitive that such crude tactics would not produce a pleasant result, probably spoiling what was so good about these bikes.

 

Also relevant is how small and low powered the motor is, how it lacks cooling provision and is equipped with a temperature cut-out. Any extension of it's capability is severely limited.

 

I think a better approach is to scrap the present motor and mainboard, only reading rotation from the pedelec sensor and fitting a more powerful motor and conventional controller to the existing alloy crankcase. That would result in a better form of the Cyclone design.

.

By the way am I missing something - have Wisper started selling their 905SEs in the UK yet? So 50 cycles are not the only supplier struggling to get a popular product to the market place?

 

Hal, they've been on sale in the UK for about six months! Electric Bike Sales - Shop Online for Electric Bikes, Electric Vehicles and Cycle Accessories - 905se

Wisper sent half their first container to Germany and half to the UK. I tried one here back at the start of November, and would have bought one had the German ones not become available at a discount.

Regards,

Frank

Hal, they've been on sale in the UK for about six months! Electric Bike Sales - Shop Online for Electric Bikes, Electric Vehicles and Cycle Accessories - 905se

Wisper sent half their first container to Germany and half to the UK. I tried one here back at the start of November, and would have bought one had the German ones not become available at a discount.

Regards,

Frank

 

Frank

 

I thought Wisper had confirmed on here that it would be late April/early May before UK versions were in stock.

 

Paul

That's the 2008 version but, as David announced on the forum about 6 months ago, half of the first container of 2007 edition SE bikes went to Germany, half to the UK - see below for his clarification.

 

Hi Pedelecers all.

 

Regarding the confusion.

 

The situation is thus;

 

The first container of 905se went to Germany about 6 weeks ago in time for the FMA in Cologne. These bikes were essentially Sports. The Citys will be ready for next season. We have had half the German container shipped here to test the market, but are pretty sure they will be enthusiastically received.

 

Another batch went out to Australia where our Oz Partner achieved 80 kilometers in hilly terrain using assist mode on Sunday so the new 13.8a 36v battery seems to be doing it's job well.

 

The reason we have produced 4 models is for the world market, for instance our Canadian Partner wants a low entry model, so he is only stocking the basic 905, where as our Dutch Partners want a high end bike with full mudguards and rack hence the 905se City (now without those huge magnesium front forks Frank!) is their bike of choice. For the UK market we will be stocking the 905e and the 905se sport as we believe that they will be the best sellers although the 905 basic and the 905se City will be available to order.

 

The 705se City, which will have all the power of the 905se but no front suspension and will have caliper brakes instead of disk on the front wheel, will be available in January and will be the only 705 model stocked here in UK.

 

Prices will be; 905e £997.00 905se Sport £1195.00 and 705se City £1095.00 still wonderful value for money.

 

We do however have a few of the original 905e left at New Milton at £849.00

...

As always, very best regards David