Power Assist - What Am I Doing Wrong?

[newbert]

I have a new Rad Mini StepThru 2 which I'm still getting used to. During the last few rides, I'm having difficulty in switching to a lower PAS level from a higher one while I'm still moving. Specifically from 3 down to 2. When the bike is stopped, switching down from 3 to 2, or whatever, works fine.

Depending on conditions, I usually ride at PAS 2. But when going uphill, I switch up to PAS 3 and when things level back off I switch back to PAS 2 - at least that's what I try to do. The trouble is that the PAS level often won't switch down. I end up hitting it a couple of times trying to get it to work, and it either doesn't switch at all or suddenly goes to 0 (after hitting the down button a few times).

Is there something I'm doing wrong (which is quite possible) or is there a problem with the computer?

Any thoughts on this would be appreciated.


P.S: ...And is it just me, or is there quite a large increase in power between PAS 2 and 3, Compared to between PAS 1 and 2?

Thanks!

 

[Gordon71]

I had a similar problem in the beginning with my new rad rover step through. I found that I needed to hit the button nearer the top of the up button and nearer the bottom of the down button. Wearing gloves made it a bit more difficult. In any case once I got the feel for it I had no further issues.

 

[Browneye]

The pas-setting is a speed target for the motor. If you're going to ride faster up the hill, and pedal to maintain it, level 3 might make sense. OTOH, if you're bumping up the speed and actually going slower due to the grade, you are over working and overheating your drive motor.

Get yourself a gauge for what speed each pas level performs at on level ground, then match that when pedaling up a hill. I'm relatively sure this is how wifey burned out her hub drive climbing hills. I was working hard in a low gear and she was wondering why I had slowed down - BIG hill. When hers quit I want back and she had it on pas 3 which is nearly 20mph, and in top gear, trying to maintain 10mph. Yep, burned it out.

If your bike slows way down going up a hill, increasing the pas is a really bad idea because your motor is then trying to gain up to that speed level. I just browsed the owners manual and was surprised there is no mention of this.

EDIT: RadPower used a controller that adds additional amperage at each pas level.

Not sure why it's not switching down when you select 2 from 3.

 

[AHicks]

Several in the past have complained of this issue, though it hasn't been a huge issue. I think the consensus was found to be a combination of switch quality and cold weather (use with gloves).

Also, the PAS level is NOT related to speed. On RAD controllers, PAS number function is to control the amount of power to the motor. As the PAS level is increased, more power is allowed to the motor. Speed has nothing to do with it. PAS 1 will allow the same amount of power to the motor regardless of speed, be it 5 mph or 15 mph

Some less expensive/desirable controller types types monitor the speed, which changes with each PAS level. These are NOT desirable, and generate a lot of complaints (PAS 1 too fast for instance).

 

[Browneye]

So pas 1 will go 28mph?
I did not know that.

 

[newbert]

Interesting discussion - Now I'm confused. I'll try to keep this simple and to the point. Assume that I'm already in 6th or 7th (top) gear for each of these. Please correct me if I'm wrong regarding these scenarios:

1. Level Ground - If I want to ride at a faster speed, but do not want to or cannot pedal faster, I've been increasing the PAS level. Is that, or is that not, recommended? If not, what should I be doing?

2. Riding uphill - If I simply want to maintain my effort, which I assume is reflected by my cadence, (not trying to increase my speed), I've been increasing the PAS level. Recommended or not? If not, what should I be doing?

3. Riding up a steeper hill - In addition to doing #2 above, I give it some throttle as needed. Recommended or not? If not, what should I be doing?

This is all new to me, so please bear with me.

Thanks for your patience.

Bert

 

[Gordon71]

So pas 1 will go 28mph?
I did not know that.

The Rad line are class 2 so top out at 20 mph. I see no reason why you can't reach that in PAS1 and 7th gear on a straight. I'll test that out tomorrow if I can find a straight stretch that's long enough. I generally ride my Rover in PAS 2 or 3 and use 4 when I need to on hills. I almost never use 1 or 5.

 

[Gordon71]

Interesting discussion - Now I'm confused. I'll try to keep this simple and to the point. Assume that I'm already in 6th or 7th (top) gear for each of these. Please correct me if I'm wrong regarding these scenarios:

1. Level Ground - If I want to ride at a faster speed, but do not want to or cannot pedal faster, I've been increasing the PAS level. Is that, or is that not, recommended? If not, what should I be doing?

2. Riding uphill - If I simply want to maintain my effort, which I assume is reflected by my cadence, (not trying to increase my speed), I've been increasing the PAS level. Recommended or not? If not, what should I be doing?

3. Riding up a steeper hill - In addition to doing #2 above, I give it some throttle as needed. Recommended or not? If not, what should I be doing?

This is all new to me, so please bear with me.

Thanks for your patience.

Bert

That's the way I ride mine more or less. I start out in 2. When I reach a point where the peddling is getting too hard and I'm in a lower gear then I go up to a higher pas. Most of the time I'm in pas 2 or 3. I'll use 4 and rarely 5 on steeper hills. I've used the throttle but I've never needed the throttle. There are some bike trails near where I live where class 2&3 are prohibited so I unplug my throttle. Since I ride on them quite a bit I often don't bother to plug it back in.

 

[RangerDave]

I have a 2019 City StepThru. I have found that you need to stop pedaling so the display reads zero watts when lowering the PAS setting. Otherwise, it seems the controller will still allow the higher amount of watts to the motor. You can increase the PAS level while pedaling and it will take effect immediately.

On my City, PAS-1 is about 60 watts and PAS-2 is about 175 watts. If I start pedaling in PAS-2, I get about 175 watts on the display. If I set it to PAS-1 while still pedaling, it will continue feeding 175 watts to the motor. I have to stop pedaling for a couple of seconds so it reads zero watts, then start pedaling again in PAS-1 before the wattage goes down and it will read about 60 watts again. Either that method or stop pedaling in PAS-2 and confirm zero watts is displayed, lower the PAS level, then start pedaling again.

On my City with the DD motor, I get the approximate watt usage on the display while pedaling on level terrain:

PAS 1 = 60 watts
PAS 2 = 175 watts
PAS 3 = 375 watts
PAS 4 = 550 watts
PAS 5 = 750 watts

I have no experience with the geared hub motor to know if a similar wattage applies to each level. You can conduct your own test on the Mini to see what pedaling on level terrain in each setting is and post a reply for us here.

On the City with the DD motor, you can see you get an approximate 120 watt boost from PAS-1 to 2 and a 200 watt boost from PAS-2 to 3. Your top speed on level terrain would be considerably faster as the motor is getting quite a bit more power.

Yes - PAS-1 will do 28 mph....if you want to supply the additional pedal power to get up to that speed! Ghost pedaling on my City in PAS-1 gets me about 10mph with no real assistance from me.

As usual, YMMV! - RangerDave

 

[newbert]

Thanks for relating your experiences, Dave. I'll try it next time by stopping pedaling when "down - powering". As you say, PAS can increase while pedaling, but I guess the opposite isn't true.

Thanks.

 

[AHicks]

Interesting discussion - Now I'm confused. I'll try to keep this simple and to the point. Assume that I'm already in 6th or 7th (top) gear for each of these. Please correct me if I'm wrong regarding these scenarios:

1. Level Ground - If I want to ride at a faster speed, but do not want to or cannot pedal faster, I've been increasing the PAS level. Is that, or is that not, recommended? If not, what should I be doing?

Let's put some numbers on that. Lets say you're on level ground, in PAS 2, top (7th) gear, doing 15 mph. You want to go faster, without putting more effort into your pedaling. Switching to PAS 3 will reduce the amount of effort to maintain that 15mph, but to go faster, you HAVE to peddle faster! Your SPEED (cadence and ground speed) will be established by what gear you are in. How much effort it takes to maintain that cadence level or mph, is controlled by your PAS level (how much assistance the motor is going to provide).

So bottom line, more assitance makes it easier to pedal, but does not by itself make you go faster.

2. Riding uphill - If I simply want to maintain my effort, which I assume is reflected by my cadence, (not trying to increase my speed), I've been increasing the PAS level. Recommended or not? If not, what should I be doing?

Exactly. Increase PAS level to reduce effort, without gaining speed.

3. Riding up a steeper hill - In addition to doing #2 above, I give it some throttle as needed. Recommended or not? If not, what should I be doing?

On a steeper hill, in addition to Increasing the PAS level, you would gear down (to maybe 4th or 5th, whatever it takes). You can keep increasing the PAS level until you get to 5 to maintain the original amount of effort (maybe, depending on how steep the hill is) - OR - you can use a combination of increased PAS level and a reduction in gearing. No right or wrong here. It about how much energy you want to use, and how big a hurry you're in.


This is all new to me, so please bear with me.

Thanks for your patience.

Bert

I would add that in the beginning, it's not at all unusual to be a little lost figuring out how to coordinate the throttle, the PAS level, the gear you're in, with how much effort you want to contribute, AND your ground speed!

I remember that clearly. I was lost! It took me quite a while to get used to it all, and start making mileage numbers that weren't embarrassing.

Today, it's all done without a second thought. I ENJOY making every effort as efficient as possible. -Al

 

[Browneye]

Well, if pas level is watts/amps feed to the motor, then put it at 5 and let it work. That's what I do with my mid-drives. And they're only 250watt.

 

[legsofbeer]

1. Level Ground - If I want to ride at a faster speed, but do not want to or cannot pedal faster, I've been increasing the PAS level. Is that, or is that not, recommended? If not, what should I be doing?

2. Riding uphill - If I simply want to maintain my effort, which I assume is reflected by my cadence, (not trying to increase my speed), I've been increasing the PAS level. Recommended or not? If not, what should I be doing?

3. Riding up a steeper hill - In addition to doing #2 above, I give it some throttle as needed. Recommended or not? If not, what should I be doing?

Replying from 2019 radrover perspective, but it appears to have the same drivetrain except different wheel diameters and maybe different cogs.

1. Yup, more PAS for more go is fine there. You can also (not in canada, or in US on MTB trails) change your controller's 20mph power cutout to 25mph.
2. Hitting the hill is just like an acoustic bike. You should be in the gear for good climbing cadence before you hit the ascent, and if you think you'll need more PAS then do that before you're putting out the effort.
3. Twisting the throttle to pull out of a bonk puts a smile on my face. But...I'm pretty sure using the full 750 watts for X seconds drains the battery more than using 375 for 2X seconds. And better to be in the right gear at the beginning so the bonk doesn't happen.

The drivetrain doesn't care what gear you're in. If it detects pedals turning it's going to put out the PAS wattage you asked for. If you have to climb from a stop in a high-numbered gear it might take a long while to make that first revolution that kicks in the motor.

To answer your original question about hitting the up/down arrow buttons, yeah, it takes a month or two before it becomes natural and reliable. That and the two-button press turning on the front light, which had me swearing the first month. Biking with fat goretex gloves I've twice accidentally turned off the bike.

One more note on hills: getting into granny gear may take a bit of anticipation: on my bike I find shifting from 3 to 1 often results in hunting between 1 and 2. If I put the chain on 2 for a few revolutions before shifting to 1 this does not happen. There's a huge size gap between 1 and 2 on the cassette.

 

[legsofbeer]

And is it just me, or is there quite a large increase in power between PAS 2 and 3, Compared to between PAS 1 and 2?

On my bike, PAS 1: 1/20th full power; PAS2 1/6th; PAS3 1/2; PAS 4 2/3; PAS5 full power. I wish I could reprogram PAS 1 and 2 into something more range-extendingly useful. As it is on long rides I have to grind the flats in PAS2 (1/6th) and use PAS3 (1/2) on the hills. I think there's a good role for 1/4 and 1/3 power there.

 

[Wolf66]

Also, the PAS level is NOT related to speed. On RAD controllers, PAS number function is to control the amount of power to the motor. As the PAS level is increased, more power is allowed to the motor. Speed has nothing to do with it. PAS 1 will allow the same amount of power to the motor regardless of speed, be it 5 mph or 15 mph

Some less expensive/desirable controller types types monitor the speed, which changes with each PAS level. These are NOT desirable, and generate a lot of complaints (PAS 1 too fast for instance).

Hey Ahicks,

I have been looking for information regarding the type of pedal assists out there between speed based PAS and motor watts output PAS like you described and which some people seem to be confused including myself.

Some answers i got is that the speed based PAS are ebikes with Cadence sensors... while the motor watts output PAS like in the Rads bikes have Torque sensors, and they say it is this Torque sensor which allows the motor to provide power based on how hard we pedal...

But i feel this is not about sensors right? I think this has more to do with the controller and how it is set up to control the motor watts output at any pedal assist level.
Do you know if this is actually from torque sensors, the controller, or both?

Im also considering to get a Bafang bbsxx diy kit, and im trying to find out if these kits behave exactly like the Rads, Bosch on pedal assist and so far it looks like they are based on speed levels from some answers which is not ideal for range saving using efficient pedal assist ..

 

[byunbee]

Interesting discussion - Now I'm confused. I'll try to keep this simple and to the point. Assume that I'm already in 6th or 7th (top) gear for each of these. Please correct me if I'm wrong regarding these scenarios:

1. Level Ground - If I want to ride at a faster speed, but do not want to or cannot pedal faster, I've been increasing the PAS level. Is that, or is that not, recommended? If not, what should I be doing?

2. Riding uphill - If I simply want to maintain my effort, which I assume is reflected by my cadence, (not trying to increase my speed), I've been increasing the PAS level. Recommended or not? If not, what should I be doing?

3. Riding up a steeper hill - In addition to doing #2 above, I give it some throttle as needed. Recommended or not? If not, what should I be doing?

This is all new to me, so please bear with me.

Thanks for your patience.

Bert

#1 is fine.
#2 & 3 you can lower your gears rather than increasing PAS level. You will slow down, but the effort should remain similar.

 

[AHicks]

Hey Ahicks,

I have been looking for information regarding the type of pedal assists out there between speed based PAS and motor watts output PAS like you described and which some people seem to be confused including myself.

Some answers i got is that the speed based PAS are ebikes with Cadence sensors... while the motor watts output PAS like in the Rads bikes have Torque sensors, and they say it is this Torque sensor which allows the motor to provide power based on how hard we pedal...

But i feel this is not about sensors right? I think this has more to do with the controller and how it is set up to control the motor watts output at any pedal assist level.
Do you know if this is actually from torque sensors, the controller, or both?

Im also considering to get a Bafang bbsxx diy kit, and im trying to find out if these kits behave exactly like the Rads, Bosch on pedal assist and so far it looks like they are based on speed levels from some answers which is not ideal for range saving using efficient pedal assist ..

No, not true. Rad bikes use cadence sensors. There's no torque sensor involved - they not equipped with one.

Unfortunately this is about the software used in the controller/display combo. My expereince has been that the cheaper bikes tend to use speed based PAS levels, while others use the amount of wattage available to the motor, which is far more controllable in my experience.

On top of that, there's MUCH more that CAN be done with the software (PAS levels switchable between speed and wattage for instance). The delay, the time required for the controller to start feeding power to the motor is another parameter that's nice to have some control over. When I tell my bike to GO for instance, I want it to GO - get me across this busy road right now! Others, they don't like all that power coming on all at once. They prefer what I call a "soft start".

Because I have learned what CAN be done, what is available with a better, aftermarket conroller/display combo that is not locked down by the manf. , I'm completely spoiled. Rad is one company where a fellow by the name of Bolton, has a plug and play "kit" with customer configurable parameters. Pretty popular for those that have purchased them.

Bottom line, there a ton of stuff going on with the programming of e-bikes.

The issue with the mid drives is that the controller is often built in to the drive. Some are user configurable, while others are not - even within the Bafang lineup. It's something I would want to know more about prior to buying one. There's also the throttle issue. I'm not even going to touch that, other than to say I wouldn't have a bike without one. -Al

 

[Wolf66]

No, not true. Rad bikes use cadence sensors. There's no torque sensor involved - they not equipped with one.

Unfortunately this is about the software used in the controller/display combo. My expereince has been that the cheaper bikes tend to use speed based PAS levels, while others use the amount of wattage available to the motor, which is far more controllable in my experience.

On top of that, there's MUCH more that CAN be done with the software (PAS levels switchable between speed and wattage for instance). The delay, the time required for the controller to start feeding power to the motor is another parameter that's nice to have some control over. When I tell my bike to GO for instance, I want it to GO - get me across this busy road right now! Others, they don't like all that power coming on all at once. They prefer what I call a "soft start".

Because I have learned what CAN be done, what is available with a better, aftermarket conroller/display combo that is not locked down by the manf. , I'm completely spoiled. Rad is one company where a fellow by the name of Bolton, has a plug and play "kit" with customer configurable parameters. Pretty popular for those that have purchased them.

Bottom line, there a ton of stuff going on with the programming of e-bikes.

The issue with the mid drives is that the controller is often built in to the drive. Some are user configurable, while others are not - even within the Bafang lineup. It's something I would want to know more about prior to buying one. There's also the throttle issue. I'm not even going to touch that, other than to say I wouldn't have a bike without one. -Al

I see, its just what i been suspecting. I have myself a cheap chinese bike and the pedal assist is definitely based on speed, so as soon as i touch the pedal it launches like a rocket lol, its just dangerous in a very crowded city, well right now everything is empty but thinking ahead. So i only use throttle and yea i am one of those that want a soft start but only because of the crowded situations.

Then all this means is i may not be able to have that pedal assist experience on a Bafang kit like in a Bosch or Rad bike. It looks like Bafang stock pedal assist control is definitely based on speed. I wonder if someone was able to play with that controller and change it for these settings we are talking bout.


Also i just looked for Bolton and Rad kits, i think its Boltonbikes, so do they offer a complete kit like Bafang or is that just an upgrade kit for current Rad bikes? It would be awesome to have a Rad kit for DIY ebike considering it has all i want: throttle, and their pedal assist system with their controller just like we want it, configurable.

 

[AHicks]

To my knowledge, the Bolton kits are currently available for the RAD's and one other line of bikes - both rear hub drives. Not for mid drives. As mentioned, I believe there are guys messing with the mid drive controllers. I read some of the more advanced are taking the internal controller right out, and replacing it with an external unit. Not for just access to the programming, but for greatly increased amperage capacity. Lot's to read up on for sure! Due diligence for DIY'ers required for sure..... -Al

 

[Gordon71]

"Unfortunately this is about the software used in the controller/display combo. My expereince has been that the cheaper bikes tend to use speed based PAS levels, while others use the amount of wattage available to the motor, which is far more controllable in my experience."

That's the way my Rad Rover works. It doesn't seem to have anything to do with speed.