Drive Through Gears on E-bikes

[Geebee]

They are brilliant especially the full sus and e-assist in that weight range. My light weight "racing" recumbent trike is only a kilo lighter and it is strictly human powered.

I have seen some of his work before but not that one.
I notice a lot more through crank drives using the standard front rings? I find that I need and use all of the chain rings, at the very least it keeps power consumption down on steep hills.

Flecc I wasn't aware of the pulsed drive of the panasonic, does that still apply if you spin smooth circles?
I was seriously looking for one of these drives to fit but when I saw the cadence of operation (thanks to this site) I lost interest as I am a high speed spinner.
Good maintainence of the chain and reducing power on shift are essential, but IMHO are for normal riding anyway.

Cheers

 

[kraeuterbutter]

hey..
for the chain and maintainence:
on the flyers/kalkhoffs (Panasonic-drive) there is a very small pinion used, which
a) makes more noise
b) does more wear to the chain and itself

on the tongxin-drives the pinion can be bigger, for example 15 on the motor-pinion, 30 on the crank

because the chaine is short, it is more often cycled compared to the rear-chain of the bike..
for that more wear
on the other hand: no shifting, no skew (no inclined running) of the chain = less wear compared to the rear one

for the cadenz: on the tongxin no problem...
if you want, you can also set it up for 120rpm cadence

for the gears: yes.. some possibilities:
1.) vautech uses the Rohloff Speedhub on some of his bikes - 14 gears with ~540%

2.) vautech planes to use the much cheaper Shimano alfine 11gears-hub (coming this year) for one of his bikes -> 409% of gear-coverage

3.) you can mount the motor a little bit more front and out of the middel and use 4 chain rings on the crank..
"linzlover" has done this to his bike,
look this video where he explains it (German, but a lot of pictures so you can see)

YouTube - Projekt Pedelec 1 - der Umbau


but even when you sacrifice the first, small 22tooth chainring to replace it with 30tooth chainring to power it by the motor:

with 32tooth chainring in front and 34 chainring on the rear-wheel you still have a gearing less than 1:1
thats still more than mountianbikes had 20 years ago
(my old mountainbike for example has 28:28 for smallest gearing)

here another bike, just for looks:
also using the light, quiet spinning, small tongxin (nano)

the battery is a 37V and 10,5Ah battery, weighting only 2kg
in a trinking-bottle
it was meanwhile poder-coated (painted) with the same color than the bike to match perfectly

he has also opend the motor and added 3 tempsensors to it, so he can see on the display what the motortemps of housing, windings are
(thats why you see so many wires coming out of the motor on the first pic)

also very cool bike in my eyes

the crank is here too a modified crank, which uses a high quality freewheel

 

[kraeuterbutter]

some other tongxin-versions:

Naders Version
motor inside the frame, mounted with an child-seat-mounting-post

Ingolfs Version of a modern, light fully:

schwarzwaldächzers version:

 

[kraeuterbutter]

here the version of grosserschnurz:

a cannondale superV:

i have a superV too, and also plan to convert ist:

have already motor, controller, CycleAnaylst here, pinion-holder for the motor is coming..

the plan is:

something like that (here the motor has still the ring for the spokeholes)

here where i want to place the small battery (37V 3,9Ah)
for more distance, i plan to use
a) a light bottle-battery in front
b) a battery-rucksack on my back

(the bike looks here a little bit odd (the wheels are not round) because of the wide angle objektiv of the camera)

 

[kraeuterbutter]

first thing i have done to the motor:

used a very old bike for mounting the motor and removing the spokes-ring with an angle grinder


Original:

cooling, some already removed:

finished

 

[kraeuterbutter]

just to compare:

a SRam Sparc
(also one of the lightest motors of its kind... only 3,2kg
considering that there is a 5gear-hub included, the motor itself without the 5-gear-hub also weights only around 2,3kg !)

the little tongxin is nearly as heavy (~2kg)

but much much more compact
and about same power

so.. i hope i have not overloaded the server with pics now
sorry for that

i will report, when i have finished my bike (hope until summer... in the moment some stress (exames at the university))

 

[kraeuterbutter]

just to compare:

a SRam Sparc
(also one of the lightest motors of its kind... only 3,2kg
considering that there is a 5gear-hub included, the motor itself without the 5-gear-hub also weights only around 2,3kg !)

the little tongxin is nearly as heavy (~2kg)

but much much more compact
and about same power

 

[NRG]

Excellent pictures very interesting!

 

[flecc]

Flecc I wasn't aware of the pulsed drive of the panasonic, does that still apply if you spin smooth circles?

It wouldn't make any difference unless toeclips were used and pedal power was pushed through the top and
bottom of the arcs.

The Panasonic system is truly bionic, mimicking the leg muscle actions. There's no power until the magnetic
flux torque sensor receives input from the rider, and the power from the motor is directly proportional to the
rider input in any setting, one to one in standard mode.

Therefore the motor operates in servo mode, the power rising from the top of the stroke, at it's peak with the
crank horizontal with maximum leverage adbvatage, and then dying away again as the leverage advantage of
the crank reduces near the bottom. There is a degree of lag in the system that allows some power to continue,
but it still rises and falls at every stroke. This of course is another reason why the lower cadences are used for
full power application.

If you ever get a chance to try one momentarily, switch on, sit on board and give one thrust down on a pedal
to take off. You'll feel a huge surge of rising and then falling power, unmistakeable.

Apart from the cadence issue, this mimicking of the rider muscle action makes it arguable that these are the
only true electric-assist bicycles, the rest are just under-powered light motorcycles with pedal assistance.
.

 

[Geebee]

Sounds ideal except for the cadence issue as I use clipless and spin circles, but my cruise rpm's are over 100 and I sprint at 180.

Mine is setup to max assist at 80 rpm and taper to nothing at 90, so at my normal cadence there is no assist, same idea different rpm range.

 

[Boby]

I finally came to the conclusion that perfect ebike is the one designed by the rider. Now I am talking to the frame manufacturer. Any input of experienced ebikers would be warmly welcomed.



IDEA

It was flecc to say that drive through gears systems can have some advantages and perform better than hub motors in off road high speed rides (here).

In fact this is my goal. I am looking for a standard pedelec with an off road high speed mode. Off road mode should enable the bike to go ~40kph (assisted) on (empty) road.

This bike should be a simple and universal commuting machine.


EXISTING SYSTEMS

Cyclone Australia distributor shows that 200W motor can help to maintain a speed of 40kph (here). This video confirms what flecc was saying about chain drive systems. No 200W hub motor would assist the biker at this speed. One would need at least 500W and much heavier battery.

kraeuterbutter presents some projects with motor installed in the front of the crank. This system has many advantages, mainly gear range (in absence of Rohloff). Because of simplicity I will use older idea promoted by Cyclone – one chain drive system (here). I will wait for Shimano 11 speed hub (400% range) and try to survive till Sept using Shimano 8 gears.

Other systems are on the horizon. pashiran (South Korea) uses a Cyclone motor in an easily detachable way (here). Unfortunately the inventor says that power transfer still was not smooth. However the idea is great.


FRAME/WHEEL SIZE

The frame will be made of aluminum. It does not have to be reasonable but is very popular.

Standard XC frame seems to be very nervous. This is probably due to typical for XCs head angle. I am looking for something more stable at 20-30kph. More stable than XC but still maneuverable. Should it be a geometry adapted from roadster or city bike (here, here)?

DH frames and DH bikes can offer suitable geometry. I was also considering Cycletool Attack (here). This bike will need the motor in front of the crank like in bikes presented by kaeuterbutter or in bike finished this winter by a colleague in Russia (here).

Motor will be placed between the crank and the rear wheel (with Schwalbe Big Apple tire). No space in a typical mountain bike. Cyclone kit has small chainring (strange and unexplainable). Planned bike may have chainring 48T large (to be reconsidered – optimal cadence! I computed it long time ago and cannot find the file).

I think that 24 in large wheel is a good compromise between portability and stability (gyroscopic effect).

The handlebar height should be regulated to various riding styles (English roadster vs. European city bike).

I believe that in terms of portability the master is Flyer i:SY (here). The problem is the wheel size. At 25-30kph 24 in should be a better idea.


QUESTIONS

Is the concept above reasonable? Any mistakes? What should I improve or take under consideration?

I do not know whether front suspension would be needed. Bikers using Cyclone and Cyclone-like stuff recommend full suspension bikes. I want hardtail but did not decide whether the front wheel would be suspended.

Isn’t Schwalbe Big Apple in front wheel good enough in terms of shock absorptive power?

Kraeuterbutter – this Akkuflasche is a great idea. I will need 24V ~20Ah, can be in two separate bottles. Do you have any guidelines where to buy batteries and other stuff?

 

[Geebee]

I finally came to the conclusion that perfect ebike is the one designed by the rider. Now I am talking to the frame manufacturer. Any input of experienced ebikers would be warmly welcomed.



IDEA

It was flecc to say that drive through gears systems can have some advantages and perform better than hub motors in off road high speed rides (here).

In fact this is my goal. I am looking for a standard pedelec with an off road high speed mode. Off road mode should enable the bike to go ~40kph (assisted) on (empty) road.

This bike should be a simple and universal commuting machine.


EXISTING SYSTEMS

Cyclone Australia distributor shows that 200W motor can help to maintain a speed of 40kph (here). This video confirms what flecc was saying about chain drive systems. No 200W hub motor would assist the biker at this speed. One would need at least 500W and much heavier battery.

kraeuterbutter presents some projects with motor installed in the front of the crank. This system has many advantages, mainly gear range (in absence of Rohloff). Because of simplicity I will use older idea promoted by Cyclone – one chain drive system (here). I will wait for Shimano 11 speed hub (400% range) and try to survive till Sept using Shimano 8 gears.

Other systems are on the horizon. pashiran (South Korea) uses a Cyclone motor in an easily detachable way (here). Unfortunately the inventor says that power transfer still was not smooth. However the idea is great.


FRAME/WHEEL SIZE

The frame will be made of aluminum. It does not have to be reasonable but is very popular.

Standard XC frame seems to be very nervous. This is probably due to typical for XCs head angle. I am looking for something more stable at 20-30kph. More stable than XC but still maneuverable. Should it be a geometry adapted from roadster or city bike (here, here)?

DH frames and DH bikes can offer suitable geometry. I was also considering Cycletool Attack (here). This bike will need the motor in front of the crank like in bikes presented by kaeuterbutter or in bike finished this winter by a colleague in Russia (here).

Motor will be placed between the crank and the rear wheel (with Schwalbe Big Apple tire). No space in a typical mountain bike. Cyclone kit has small chainring (strange and unexplainable). Planned bike may have chainring 48T large (to be reconsidered – optimal cadence! I computed it long time ago and cannot find the file).

I think that 24 in large wheel is a good compromise between portability and stability (gyroscopic effect).

The handlebar height should be regulated to various riding styles (English roadster vs. European city bike).

I believe that in terms of portability the master is Flyer i:SY (here). The problem is the wheel size. At 25-30kph 24 in should be a better idea.


QUESTIONS

Is the concept above reasonable? Any mistakes? What should I improve or take under consideration?

I do not know whether front suspension would be needed. Bikers using Cyclone and Cyclone-like stuff recommend full suspension bikes. I want hardtail but did not decide whether the front wheel would be suspended.

Isn’t Schwalbe Big Apple in front wheel good enough in terms of shock absorptive power?

Kraeuterbutter – this Akkuflasche is a great idea. I will need 24V ~20Ah, can be in two separate bottles. Do you have any guidelines where to buy batteries and other stuff?

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

Noise maybe an issue depending on your tolerance level, a thread form endless sphere with a video showing the noise level of a high powered one http://endless-sphere.com/forums/vie...16750&start=15


And a more worrying thread re longevity http://endless-sphere.com/forums/vie...10349&start=30


Here is a source of cheap and well tested batteries and chargers, they also sell low voltage alarms etc as they have no on board bms. they also have a cheap and effective version of the Watts up for around $25 usd HobbyKing Online R/C Hobby Store : Turnigy 5000mAh 5S 20C Lipo Pack $42.25

Two other points, there are a lot more choices in tyres in the 26" size and I hate the large bend in the chain with this setup it has to hurt pedalling when un-assisted if that is a concern.

 

[Gepida uk]

Hi Flecc,

Once again very useful information

 

[flecc]

Thanks Aiden. The article does tend to bias in favour of hub motors, but it was intended to correct some
misunderstandings about them. However, where the really steep hills are concerned the drive through gears
systems come into their own and I post accordingly as you know.

Over much of Britain though, personal preference on the rideability is also important and can be more so than the
performance variations between the systems. The way the Yamaha/Panasonic systems work with the rider makes
them more bicycle like in their characteristics, and that's important to many.

I really must make the effort to get down to you at some convenient time to try one of the Yamaha powered bikes,
so that I can better appreciate the differences between that and the Panasonic system.
.

 

[Gepida uk]

Hi Flecc,

Are you going to Tour De Presteigne? If so you’re more than welcome to test ride one then

 

[flecc]

No Aiden, I tend to avoid the longer drives these days so Presteigne isn't planned. Not to worry, no rush, I'll fit in sometime when it's convenient with you or one of your dealers.
.