Best, easiest,cheapest way to get rid of regen on a Radcity 4

[Bikeman]

Almost ready to get the radcity 4. Have had my heart set on radbike for a year, but the city has regen. I saw on videos where the wheel has a lot of drag when coasting. It may not matter to others, but for me that's ridiculous.

If I made a bike and someone wanted to make it so when you stopped peddling, the bike had lots of drag and came to a stop, I'd fire the guy on the spot. For me, that is so stupid. I have to say, this is pretty close to a deal breaker for me. This has made me look at another company.

Before I buy a different brand (after having my heart set on radpower bikes), I wanted to ask what would be the cheapest, easiest, best way to get rid of that set up on a radcity?

The hub looks bigger this year, can I just change the inside? Is the bigger looking hub the same inside or is that bigger one harder to replace? Do I need to get a whole new wheel? The other bike I'm looking at I got to test down the parking lot and back. It coasted like a regular bike. What all would be involved in getting a radcity 4 to coast like that?

 

[JRA]

Regen is a function of the controllers settings. Check and see if Bolton bikes has a replacement that is adjustable or can do without it.

Direct drive hubs like Rad uses always have a bit of drag however which can be over ridden by applying the slightest amount of power but that is a pain to keep track of.

 

[Bikeman]

Thank you for the reply,
I saw a video that the magnets are closer together on the direct drive so that's where the drag comes from. The controller won't effect how close the magnets are in the hub.

They even say that if you go down a long steep hill, you only put back 2% to the battery at most. That's almost nothing on the pros, and a big on the cons.
If I get a different bike, I have to wait until September. Just seeing how much it costs before I go in another direction.

 

[RangerDave]

From my experience with a 2019 City ST, the issue of drag due to the direct drive motor is negligible. Yes, there is a very small amount of drag when coasting, but how much time do you actually spend doing that? I find I only coast when I want to bleed off speed to come to a stop. The bonus regen function actually works in my favor as a fantastic aid to braking. I don’t think I will ever have to replace my brake pads because of this. If you ride primarily in flat terrain, the direct drive City is fine. If you have numerous hills to climb, I recommend going with a geared hub motor with more torque, perhaps the Runner or new Mission.

Have fun riding whatever you choose - RangerDave

 

[Gordon71]

Almost ready to get the radcity 4. Have had my heart set on radbike for a year, but the city has regen. I saw on videos where the wheel has a lot of drag when coasting. It may not matter to others, but for me that's ridiculous.

If I made a bike and someone wanted to make it so when you stopped peddling, the bike had lots of drag and came to a stop, I'd fire the guy on the spot. For me, that is so stupid. I have to say, this is pretty close to a deal breaker for me. This has made me look at another company.

Before I buy a different brand (after having my heart set on radpower bikes), I wanted to ask what would be the cheapest, easiest, best way to get rid of that set up on a radcity?

The hub looks bigger this year, can I just change the inside? Is the bigger looking hub the same inside or is that bigger one harder to replace? Do I need to get a whole new wheel? The other bike I'm looking at I got to test down the parking lot and back. It coasted like a regular bike. What all would be involved in getting a radcity 4 to coast like that?

Get the rover instead.

 

[AHicks]

The drag is a function of a direct drive motor. Those motors are turning if the bike is moving. Makes no difference who makes the bike or the motor. There's no way of avoiding it. Direct drive motors have drag when coasting, period.

Gear driven rear hubs (like the Rover) get around that with an internal clutch that allows the motor to stop when coasting. Same story with (most I understand) mid drives.

Put me in the school with those who believe the drag from a coasting direct drive is negligible. Not something 99% of the riders will ever notice. Spent quite a bit of time with the stock 'City hub, then replaced that OEM hub with a direct drive hub twice that size (1500w), before going to a geared hub that I have on it now (my very modified '17 Rad City)

Talking "regen" changes the story. If the bike's controller is set up for "regen" (not all are), that's a special circuit activated by either brake lever, that turns the motor into a generator, and uses that to charge the bikes battery for a place to dump the voltage - effectively creating a brake. Very noticeable over 15 mph or so, generally not activated long enough to put much charge back into the battery. It's WAY more about the braking power provided - and flat landers could care less. It's just the folks riding in the hills that care much about regen.

There's one exception to the regen comments above. That's the GMAC geared hub, but it's a whole different ball game that'll go way off topic here. Cutting edge stuff there, and expensive. Check into it if you'd like.

The direct drive hubs are WAY bigger than a geared hub for good reason. The larger they are, the more torque they are capable of. A larger diameter hub will have more power than a smaller hub - think leverage here. All else being equal, the larger diameter hub will have more leverage on the rim than a smaller diameter would.

Hope this helps. -Al

 

[JRA]

Good explanation by Al. Regen as the OP mentioned is different than magnet drag that all dd hubs exhibit.

I have found that an injection of Statorade does relieve the drag noticeably and my AnyAxle hub has hardly any drag at all. My 9c hub does have some but I have ridden it a lot unassisted also.

I find that it is primarily the overall weight of any eBike that can affect coasting far more, until you are going downhill and that’s when the regen does apply well.

 

[mrgold35]

I remember a few years ago when I was researching the Radcity on YouTube and the person was testing the regen feature. He had to do the regen test twice because he had it in PAS 0 and the regen engaged at a very low to almost unnoticeable minimal level (he accelerated down a hill when coasting). He did the test again in PAS 1 for regen to engage fully and regen cut his speed by 9-10 mph down the same hill.

I haven't tried this out on my Radcity Step-Thru. Regen isn't that intrusive and it doesn't bother my wife when we ride together (she just has to pedal downhill to keep up with me coasting on my Radrover).

 

[Bikeman]

Thank you for all the reply's.

Without knowing, I in my mind, I thought riding along at say, 15mph, if you stopped peddling, the bike would just slow down to a stop at say 15ft. That isn't the exact distance, just putting into words my imagination.

Glad it's not that bad.

 

[AHicks]

Bikeman, there's a lot of info written by folks that have never ridden a direct drive bike with regen. That info based on pure speculation or second/third hand info.

My bet is, if you do go with a new 'City, you'll be very pleasantly surprised when it comes to this direct drive drag issue..... If you're riding impression is anything like mine, it will be something like "what drag"?

 

[KenS]

Thank you for all the reply's.

Without knowing, I in my mind, I thought riding along at say, 15mph, if you stopped peddling, the bike would just slow down to a stop at say 15ft. That isn't the exact distance, just putting into words my imagination.

Glad it's not that bad.

No, it is not that bad.

I can detect the DD motor drag but it is not going to produce an effect like you fear. Routinely, I hit and maintain 25 MPH coasting down hill. A slight touch of the brakes (which activates the regen) adds little effect.

 

[Antia]

I am going to disagree with others here. I have an original radwagon (same direct drive motor as the rad city) and a rad rover (geared motor). I found the drag from the direct drive motor bothersome. I just did not like the way it altered the feeling of the bike when coasting to a stop. Now, this says nothing about functionality, direct drive motors are used because they are extremely tough and it is hard for anything to go wrong with them which is sensible on cargo bikes and commuters. The regen aspect makes a lot of sense in a cargo bike that might be heavily loaded down a hill, so I understand some of the reasons to choose that particular motor ... but personally, not my cup of tea. This might depend a lot on whether you primarily use the throttle or the PAS and how much assist you usually engage. I tend to run on PAS 1 or 2 and use the throttle for hills and to start from a full stop.

 

[Doowroh]

I have a Radcity StepThru(500W - Canada) and find the regen absurd. I have to pedal going downhill FFS. Whoever built this bike I don't think tested it going downhill because it is painfully slow. If I pedal it maxes out speed-wise(40km/h) super easy and then forces me slower until it goes below 36 or 37km/h and then I pedal again without fighting the motor. It is so F'ing frustrating.

 

[Gordon71]

I have a Radcity StepThru(500W - Canada) and find the regen absurd. I have to pedal going downhill FFS. Whoever built this bike I don't think tested it going downhill because it is painfully slow. If I pedal it maxes out speed-wise(40km/h) super easy and then forces me slower until it goes below 36 or 37km/h and then I pedal again without fighting the motor. It is so F'ing frustrating.

Yeah, I almost bought that one as I liked the style but then I learned about the difference between it's motor and the one they use in the Rover and quickly changed my mind.

 

[AHicks]

I have a Radcity StepThru(500W - Canada) and find the regen absurd. I have to pedal going downhill FFS. Whoever built this bike I don't think tested it going downhill because it is painfully slow. If I pedal it maxes out speed-wise(40km/h) super easy and then forces me slower until it goes below 36 or 37km/h and then I pedal again without fighting the motor. It is so F'ing frustrating.

That's something we hear about, but I'm not so sure it happens on all of them.

Have you tried contacting RAD?
Is it possible there's a setup issue?
Have you tried unplugging the brake switch/motor cut off wires (both of them)?

 

[RangerDave]

If I remember correctly, the motor cuts out at 20mph (32kph) under the stock setting. You can modify this via the lcd screen and mode + up/down arrows to around 25mph (40kph).

In the following hypothetical example:

If you are pedaling downhill and the motor is supplying 80% of the effort and you hit 20mph, the controller will stop supplying power to the motor. This means that you are now supplying 100% of the pedal effort, up from 20% while the motor was active. I believe that will seem like quite a bit of additional effort to pedal the bike. And these bikes typically weigh quite a bit more than a standard bike.

Could this be what people are experiencing when they are riding rapidly downhill? Or is pure coasting with no pedal movement also causing a slowdown when hitting 20mph? I live in flat terrain and have no large sustained hills to test this on with my 2019 City ST.

I would think this would be endemic to all class 2 bikes limited to 20mph, regardless of make or DD or geared motor.

RangerDave

 

[AHicks]

Nope, not endemic at all. I have a direct drive and a gear drive where things start getting worrisome when speeds get over 30 or so, and you're only half way down the hill. Worse is when there is a sharp curve or a stop sign at the bottom (hills are great!). The direct drive has a panic button (regen) that will hold the bike to 25 or so when used on all bet the steepest hills. This is just coasting.... big hills!

There's something going on with these City's. Likely a programming error, but you can't count out set up issues.

 

[RangerDave]

AHicks -

So you are saying you routinely purely coast >20mph downhill with no pedal movement on both DD and geared motor bikes? Coming to a stop is irrelevant to this discussion.

I get the notion from Doowroh’s post that he is pedaling downhill with motor assist and hits 20mph. The motor cuts out as it should and it requires more effort than he is used to to continue pedaling. He slows down to 15mph or so and then begins to pedal again with motor assist back up to 20mph.

It sounds to me like he is not purely coasting and would not coast >20mph on that hill if he was. He is using motor assisted pedal power to reach 20mph. If he wants to pedal faster than 20mph, he has to supply 100% of the effort because the motor assist cuts out >20mh.

Maybe I’m misunderstanding his comments. Again - I don’t have any large hills to test these types of conditions.

RangerDave

 

[KenS]

Hi RangerDave:

I hit 25+ mph on a down hill routinely, if I am purely coasting. If I pedal even slightly then something kicks in and I get a braking effect. It is a weird effect and I have learned not to pedal when I want to go fast down hill.

I suspect Doowroh is running into a software restriction related to it being a Class 2 bike. If that is the case then switching type of motor or brand of bike will not help.

 

[AHicks]

I would note 2 things. First, BOTH of my bikes are set to limit speed to 20 mph. That limit is in play only when under power. When that 20mph is exceeded, the power shuts down, that's it. There is no braking at that point. They'll coast MUCH faster than 20mph if allowed (I've seen 34mph while sitting upright). You'll need to trust me on that one. Further, there is (should be) nothing in the electronics, other than regen possibly, that might place a speed restriction on a bike coasting down hill by braking/applying regen.

Second, at the down hill speeds I'm talking about, ability to stop is definitely relevant. You'll need to trust me on that one too!

Asking questions/raising ideas, even without personal experience, is a learning/understanding process. Nothing wrong with that in my book.

I'd love a chance to ride a City with this issue for some first hand impressions. I doubt that's going to happen any time soon, that's why I think talking this over with RAD might be a good plan. Especially if you have the patience to get the issue elevated to a high enough tier of support to actually speak to somebody with a brain - no script.