Noob - Creo question

[etgo]

Hi guys, I have some question in mind about creo. Hope some guru here can help..

1) Will the odometer be counting even the TCU is off? or it will only count when you use the assist mode?

2) When is the best time to charge the bike unit battery?
In my normal day use, I used 15% of the batt every other day. Should I charge it right away even its still in 85%? or there is a certain % then charge the batt.

3) Anyone have tried changing the chainring with oval/elliptical type? and how many teeth?


Regards to all..

 

[Stefan Mikes]

1) Will the odometer be counting even the TCU is off? or it will only count when you use the assist mode?

The TCU needs to be ON. You can set the assistance OFF by a long press on the "S" button (the one surrounded by LEDs).

2) When is the best time to charge the bike unit battery?
In my normal day use, I used 15% of the batt every other day. Should I charge it right away even its still in 85%? or there is a certain % then charge the batt.

If you use the battery so little, just don't let it go down below 20%, and possibly re-charge up to 80%. That will ensure the best longevity for the battery.
(People like me recharge the battery to 100% after each ride, and I often ride the battery down to 10% because I need to ride, not to take care about the battery lifetime).

3) Anyone have tried changing the chainring with oval/elliptical type? and how many teeth?

What would you gain by doing that? (I am afraid the oval chainring would confuse the assistance sensors). Not all inventions made for traditional bikes are practical for e-bikes.
To better explain it: The oval chainring concept assumes the crank is directly connected to the chainring. In a mid-drive motor e-bike, the chainring is disconnected from the crank, and you pedal through the motor's gears. So again, what would you gain by using the oval chainring on your Creo?

 

[etgo]

Thanks Mikes..

For #1.
Its the odometer that I'm wondering.
Will the odometer of the motor will count even the TCU is off?

For #2.
Me too. I like to full charge the batt every after ride. Then store a day or 2.
Then I realized that I only used 15%, should I charge it? or wait for below 40% then charge?

For #3.
Just wondering about this oval chainring..

 

[Stefan Mikes]

For #1.
Its the odometer that I'm wondering.
Will the odometer of the motor will count even the TCU is off?

The odometer only works when the TCU is ON. It is because the odometer takes read-outs from the Creo sensors, and the TCU as the controller has to be powered to do so. To keep the TCU on but the assistance off, you can disable the assistance but keep the TCU alive as I described before.

For #2.
Me too. I like to full charge the batt every after ride. Then store a day or 2.
Then I realized that I only used 15%, should I charge it? or wait for below 40% then charge?

The best strategy is to keep the battery charge between 20-80% if one can afford doing so. It is the fundamental rule for Li-Ion battery longevity.

For #3.
Just wondering about this oval chainring..

I have elaborated more above. Not practical!

 

[etgo]

got it.. many thanks Mikes

 

[Stefan Mikes]

Many people swear by them for comfort, knee issues, and power. Install one if you want to. There is no downside if you find them useful.

How many people use them on e-bikes?
Think of variable torque.
I repeat: These make sense when the crank is connected to the chainring. Not on e-bike.

 

[mschwett]

Waiting is the best strategy for battery longevity.

Many people swear by them for comfort, knee issues, and power. Install one if you want to. There is no downside if you find them useful.

to restate what @Stefan Mikes said a different way, the elliptical chainring only works if there's a fixed and consistent relationship between the oval and the pedal position. when you're pushing down hard on the pedal, the leverage is related to the fatter part of the oval. when you're on the return stroke, that foot is moving around the smaller part of the oval while the other foot in the power stroke is above to drive the other big quadrant of the oval.

you cannot turn the pedals and the crank independently on a standard bike, so this relationship is forever fixed.

on a specialized mid-drive e-bike, you can hold the chainring in place and turn the crank backwards! the relative position of the crank and pedals is completely variable, because some of the motor's gears essentially sit "in between" them.

elliptical chainring is a no go on a mid drive ebike. it would serve no purpose, and you'd randomly be pedaling through the big part and the small part.

 

[kahn]

to restate what @Stefan Mikes said a different way, the elliptical chainring only works if there's a fixed and consistent relationship between the oval and the pedal position. when you're pushing down hard on the pedal, the leverage is related to the fatter part of the oval. when you're on the return stroke, that foot is moving around the smaller part of the oval while the other foot in the power stroke is above to drive the other big quadrant of the oval.

you cannot turn the pedals and the crank independently on a standard bike, so this relationship is forever fixed.

on a specialized mid-drive e-bike, you can hold the chainring in place and turn the crank backwards! the relative position of the crank and pedals is completely variable, because some of the motor's gears essentially sit "in between" them.

elliptical chainring is a no go on a mid drive ebike. it would serve no purpose, and you'd randomly be pedaling through the big part and the small part.

Does this "NON-connection" explain why the bike shop was able to re-install my cranks backward or left crank on right side and visa versa. Which as a thread I posted a while ago explains how my pedals, and therefore, SPD cleats were backwards, making getting out of the damn things near impossible.

I will admit, I'm pretty uninformed about the mechanics of my Creo and have not explored the crank-chainring movements.

 

[mschwett]

Does this "NON-connection" explain why the bike shop was able to re-install my cranks backward or left crank on right side and visa versa. Which as a thread I posted a while ago explains how my pedals, and therefore, SPD cleats were backwards, making getting out of the damn things near impossible.

I will admit, I'm pretty uninformed about the mechanics of my Creo and have not explored the crank-chainring movements.

not sure about that!! i don’t have too much experience wrenching on regular bikes, the two cranks of a creo are definitely identical *looking* except for the threading! many modern cranks for non electric bikes are integrated with the spider, so the left and the right look totally different, not remotely possible to mix them up.

 

[BioWheel]

OK - my thought on oblong chain rings has to do with the position of the leg in relation to the pedals. At certain points of the rotation, we're able to transfer power more efficiently. The oval shape 'smooths' this power transfer out making the distribution of power more efficient/equal throughout the whole of the travel. So, if more power is transferred to the cranks then really doesn't matter if you're connected to an ebike or a spool of thread. A more efficient transfer of power will save energy and there's an advantage to using it.

 

[mschwett]

OK - my thought on oblong chain rings has to do with the position of the leg in relation to the pedals. At certain points of the rotation, we're able to transfer power more efficiently. The oval shape 'smooths' this power transfer out making the distribution of power more efficient/equal throughout the whole of the travel. So, if more power is transferred to the cranks then really doesn't matter if you're connected to an ebike or a spool of thread. A more efficient transfer of power will save energy and there's an advantage to using it.

yes, that’s the theory, and it would apply just fine to an ebike IF the ellipse stayed fixed relative to your leg’s rotation. on a mid-drive ebike, it won’t.

 

[Stefan Mikes]

Yes, exactly. That's how it works. You are correct BioWheel. That's also why it's great for people with knee issues.

I totally disagree. The oval chainring only works as intended when the spider is the part of the drive-side crank so the pedal position remains fixed relative to the ring:

In a mid-drive motor e-bike, the spider is connected to the motor, and the crank moves independently of the pedal position, as @mschwett said. It is clear to anyone who has changed the chainring on their mid-drive e-bike at least once.

 

[BioWheel]

I totally disagree. The oval chainring only works as intended when the spider is the part of the drive-side crank so the pedal position remains fixed relative to the ring:
View attachment 116075

In a mid-drive motor e-bike, the spider is connected to the motor, and the crank moves independently of the pedal position, as @mschwett said. It is clear to anyone who has changed the chainring on their mid-drive e-bike at least once.

Here's another way to think about it. Let's say I have a standard bike with a round chainring. And, on that bike, it takes me 100 pedal strokes to go from point A to B. OK - now I switch to an oval chainring, and thanks to the greater efficiency, it now only takes 99 pedal stokes to go from A to B. You can see that I would be using less energy to go the same distance.

Ok - now for the same experiment on my VadoSL. And according to some, no matter the configuration of the chainring, I'd be back to pedaling 100 strokes to get from A to B. So, somewhere I'm losing energy now. Would be interesting to know where the energy is lost.

Finally, let's say there's a new chainring design that can increase pedaling efficiency by 50%. That way, it would only take 50 pedal strokes to go the same distance that used to take 100. I'm in the group of folks that would buy it for my SL even though it doesn't do anything.

 

[Stefan Mikes]

I'm in the group of folks that would buy it for my SL even though it doesn't do anything.

Ya, you want to spare the motor its knee joint problems

 

[Allan47.7339]

As explained by Stefan, the reason an oval chain ring won't provide any potential benefit IN THIS CASE is because the chain ring is not indexed at all to the crank arm. They can move separately due to the mid-motor clutch. You can see on this wolftooth product page it shows where the power stroke and recovery stroke are supposed to align.

https://www.wolftoothcomponents.com/collections/powertrac-elliptical

If the oval is out of sync it will be like when you are walking and you don't see a step up and then the next step it will be like when you don't see a step down. It will produce a very uneven effort.

 

[Dazmanturbo]

I have Absolute Black oval rings on my Roubaix and they are very good. However, as pointed out, they have to be in the correct position to support the dead spot, which is not possible on the Creo due to the crank and the spider moving independently. Round rings only on the Creo I am afraid.

 

[BioWheel]

I'm just glad Einstein never watched Youtube. Then it might be E=MC without the little 2.

Great discussion btw. And remember - if the forecast says there's a 60% for rain that actually means 60% of the area has 100% of getting wet.

 

[kahn]

I'm just glad Einstein never watched Youtube. Then it might be E=MC without the little 2.

Great discussion btw. And remember - if the forecast says there's a 60% for rain that actually means 60% of the area has 100% of getting wet.

But if that were the case, we might not be staring at 6,000 nuclear bombs!

 

[Stefan Mikes]

But if that were the case, we might not be staring at 6,000 nuclear bombs!

Kahn! Politics, politics. Risking the ban, I need to ask the question whether the last name of Angela M. is Merkel. (If I disappear, don't worry for me)

 

[Stefan Mikes]

It wouldn’t be the first time you’ve been totally wrong either.

Some people say it is practical to pull their underpants on through their head. Let them try. It is not my underpants